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  • 1.
    Andersson Escher, Stefan
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson-Lestander, Å
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    The Drosophila glucose transporter gene: cDNA sequence, phylogenetic comparisons, analysis of functional sites and secondary structures.1999Ingår i: Hereditas, ISSN 0018-0661, Vol. 130, nr 2, s. 95-103Artikel i tidskrift (Refereegranskat)
  • 2.
    Birve, Anna
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Sengupta, A K
    Beuchle, D
    Larsson, Jan
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Kennison, J A
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Müller, J
    Su(z)12, a novel Drosophila Polycomb group gene that is conserved in vertebrates and plants.2001Ingår i: Development, ISSN 0950-1991, Vol. 128, nr 17, s. 3371-9Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    In both Drosophila and vertebrates, spatially restricted expression of HOX genes is controlled by the Polycomb group (PcG) repressors. Here we characterize a novel Drosophila PcG gene, Suppressor of zeste 12 (Su(z)12). Su(z)12 mutants exhibit very strong homeotic transformations and Su(z)12 function is required throughout development to maintain the repressed state of HOX genes. Unlike most other PcG mutations, Su(z)12 mutations are strong suppressors of position-effect variegation (PEV), suggesting that Su(z)12 also functions in heterochromatin-mediated repression. Furthermore, Su(z)12 function is required for germ cell development. The Su(z)12 protein is highly conserved in vertebrates and is related to the Arabidopsis proteins EMF2, FIS2 and VRN2. Notably, EMF2 is a repressor of floral homeotic genes. These results suggest that at least some of the regulatory machinery that controls homeotic gene expression is conserved between animals and plants.

  • 3.
    Chen, Sa
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Birve, Anna
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    In vivo analysis of Drosophila SU(Z)12 function2007Ingår i: Molecular Genetics and Genomics, ISSN 1617-4615, E-ISSN 1617-4623, Vol. 279, nr 2, s. 159-170Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polycomb group (PcG) proteins are required to maintain a stable repression of the homeotic genes during Drosophila development. Mutants in the PcG gene Supressor of zeste 12 (Su(z)12) exhibit strong homeotic transformations caused by widespread misexpression of several homeotic genes in embryos and larvae. Su(z)12 has also been suggested to be involved in position effect variegation and in regulation of the white gene expression in combination with zeste. To elucidate whether SU(Z)12 has any such direct functions we investigated the binding pattern to polytene chromosomes and compared the localization to other proteins. We found that SU(Z)12 binds to about 90 specific eukaryotic sites, however, not the white locus. We also find staining at the chromocenter and the nucleolus. The binding along chromosome arms is mostly in interbands and these sites correlate precisely with those of Enhancer-of-zeste and other components of the PRC2 silencing complex. This implies that SU(Z)12 mainly exists in complex with PRC2. Comparisons with other PcG protein-binding patterns reveal extensive overlap. However, SU(Z)12 binding sites and histone 3 trimethylated lysine 27 residues (3meK27 H3) do not correlate that well. Still, we show that Su(z)12 is essential for tri-methylation of the lysine 27 residue of histone H3 in vivo, and that overexpression of SU(Z)12 in somatic clones results in higher levels of histone methylation, indicating that SU(Z)12 is rate limiting for the enzymatic activity of PRC2. In addition, we analyzed the binding pattern of Heterochromatin Protein 1 (HP1) and found that SU(Z)12 and HP1 do not co-localize.

  • 4.
    Chen, Sa
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Larsson, Anna L.
    Umeå universitet, Medicinska fakulteten, Institutionen för molekylärbiologi (Medicinska fakulteten).
    Tegeling, Erik
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Birve, Anna
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap.
    Rasmuson Lestander, Asa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    In vivo analysis of Suppressor of zeste 12´s different isoformsManuskript (Övrigt vetenskapligt)
    Abstract [en]

    Polycomb Group (PcG) genes are known to encode a large chromatin-associated family of proteins which are involved in genomic regulation of many cellular processes. Su(z)12 is a key component in PcG silencing. It is needed for three levels of methylation of histone 3 lysine 27 in vivo in Drosophila. Here, we report that Su(z)12 may exist in different isoforms and that these isoforms are spatially and temporally regulated. The biological function of the Su(z)12-A and -B isoforms seems to be very different. For instance the transgenic Su(z)12-B and the human homolog SUZ12, but not Su(z)12-A, rescue Su(z)12 mutants. Furthermore, transgenic flies over-expressing Su(z)12-B show typical homeotic transformation phenotypes, while over-expression of Su(z)12-A does not. However, the two isoforms appears to be able to substitute for each other in some aspects. During larval and pupal stages, Su(z)12-A seems to play the main role. 

  • 5.
    Chen, Sa
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Regulation of the Drosophila engrailed gene by Polycomb repressor complex 22009Ingår i: Mechanisms of Development, ISSN 0925-4773, E-ISSN 1872-6356, Vol. 126, nr 5-6, s. 443-448Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Suppressor-of-zeste-12 (Su(z)12) is a core component of the Polycomb repressive complex 2 (PRC2), which has a methyltransferase activity directed towards lysine residues of histone 3. Mutations in Polycomb group (PcG) genes cause de-repression of homeotic genes and subsequent homeotic transformations. Another target for Polycomb silencing is the engrailed gene, which encodes a key regulator of segmentation in the early Drosophila embryo. In close proximity to the en gene is a Polycomb Response Element, but whether en is regulated by Su(z)12 is not known. In this report, we show that en is not de-repressed in Su(z)12 or Enhancer-of-zeste mutant clones in the anterior compartment of wing discs. Instead, we find that en expression is down-regulated in the posterior portion of wing discs, indicating that the PRC2 complex acts as an activator of en. Our results indicate that this is due to secondary effects, probably caused by ectopic expression of Ubx and Abd-B.

  • 6.
    Jacobsson, Linn
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Kronhamn, Jesper
    Umeå universitet, Medicinska fakulteten, Institutionen för molekylärbiologi (Medicinska fakulteten).
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    The Drosophila Pax6 paralogs have different functions in head development but can partially substitute for each other2009Ingår i: Molecular Genetics and Genomics, ISSN 1617-4615, E-ISSN 1617-4623, Vol. 282, nr 3, s. 217-231Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There are two Pax6 genes in Drosophila melanogaster; eyeless (ey) and twin-of-eyeless (toy), due to a duplication, which most likely occurred in the insect lineage. They encode transcription factors important for head development. Misexpression of either toy or ey can induce formation of ectopic compound eyes. Toy regulates the ey gene by binding to an eye-specific enhancer in its second intron. However, Toy can induce ectopic eyes also in an ey( - ) background, which indicates a redundancy between the two Pax6 copies in eye formation. To elucidate to what extent these two genes are interchangeable, we first generated toy-Gal4 constructs capable of driving the Pax6 genes in a toy-specific manner. Genetic dissection of the promoter proximal region of toy identified a 1,300-bp region around the canonical transcription start that is sufficient to drive toy expression in embryonic brain and eye primorida and in larval eye-antennal discs. We find that exogenous expression of toy can partially rescue the lethality and eye phenotype caused by lethal mutations in ey and vice versa. We therefore conclude that Toy and Ey, to some extent, can substitute for each other. Nevertheless, the phenotypes of the rescued flies indicate that the two Pax6 genes are specialized to regulate defined structures of the fly head.

  • 7.
    Jacobsson, Linn
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Identification of regulatory regions within the intron sequence of the toy geneManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    In Drosophila there are two paralougus Pax-6 genes, twin of eyeless (toy) and eyeless (ey) Both genes have an extensive elaborate expression pattern in the brain and ventral nerve cord but are not activated at the same time in these regions. Since both genes are expressed in several tissues during different time points in development, one might expect that more than one regulatory enhancer controls them. It is known, that eyeless is directly regulated by toy at the beginning of eye development and it has been shown that there are binding sites for regulatory proteins within the introns of the eyeless gene and in vertebrate Pax-6 genes. We investigate the transcriptional activation of toy within the intron sequences of the gene and show that there is a presumptive regulatory element in intron 2, controlling toy expression in the ventral nerve cord of embryos.

  • 8.
    Jacobsson, Linn
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Skottheim Honn, John
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Ekström, Karin
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Empty spiracles represses twin-of-eyeless in the Drosophila embryonic headManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    The specification of the eye-antennal disc primordium in the Drosophila embryo requires the expression of two paralogous Pax6 genes: twin of eyeless (toy) and eyeless (ey). toy is considered to be the first eye specification gene expressed in the regulatory network that governs eye formation and the gene that, in turn, activates eyeless. What regulates toy expression is, however, still unclear. We show, by misexpression and mutant analysis, that the head-specific gene empty spiracles alters the expression pattern of Toy in the head region around the visual primordia.

  • 9.
    Kronhamn, Jesper
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Frei, Erich
    Daube, Michael
    Jiao, Renjie
    Shi, Yandong
    Noll, Markus
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Headless flies produced by mutations in the paralogous Pax6 genes eyeless and twin of eyeless.2002Ingår i: Development, ISSN 0950-1991, E-ISSN 1477-9129, Vol. 129, nr 4, s. 1015-1026Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The two Pax6 gene homologs eyeless and twin of eyeless play decisive early roles in Drosophila eye development. Strong mutants of twin of eyeless or of eyeless are headless, which suggests that they are required for the development of all structures derived from eye-antennal discs. The activity of these genes is crucial at the very beginning of eye-antennal development in the primordia of eye-antennal discs when eyeless is first activated by the twin of eyeless gene product. This activation does not strictly depend on the Twin of eyeless protein, but is temperature-dependent in its absence. Twin of eyeless acts also in parallel to the eyeless gene and exerts functions that are partially redundant with those of Eyeless, while Eyeless is mainly required to prevent early cell death and promote eye development in eye-antennal discs.

  • 10.
    Kronhamn, Jesper
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Genetic organization of the ci-M-pan region on chromosome IV in Drosophila melanogaster.1999Ingår i: Genome, ISSN 0831-2796, E-ISSN 1480-3321, Vol. 42, nr 6, s. 1144-1149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The genes cubitus interruptus (ci), ribosomal protein S3A (RpS3A), and pangolin (pan) are localized within 73 kb in the cytological region 101F-102A on chromosome IV in Drosophila melanogaster. A region of 13 kb harbours the regulatory regions of both ci and pan, transcribed in opposite directions, and a 1.1-kb gene encoding RpS3A. This dense clustering gives rise to very complicated complementation patterns between different alleles in these loci. We investigated this region genetically and molecularly by use of an enhancer trap line (IA5), where the P-element was found to be inserted into the first intron of pan. Screens for imprecise excisions of the P-element were performed, and complementations between new and old established mutant lines were investigated. We found that when mutated or deleted the RpS3A gene gives rise to a Minute phenotype, and we conclude that M(4)101 encodes the ribosomal protein S3A.

  • 11.
    Larsson, Anna
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Keller, U
    Nilsson, J A
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    The c-Myc toAurora B kinase axis is conserved down to Drosophila melanogasterManuskript (preprint) (Övrigt vetenskapligt)
  • 12.
    Larsson, Anna
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Tegeling, Erik
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Chen, Sa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Lu, C-M
    Stief, A
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Investigation of the two isoforms of SU(Z)12 shows difference in expressionand interaction in vitro with the core components of PRC2Manuskript (preprint) (Övrigt vetenskapligt)
  • 13.
    Larsson, Jan
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Chen, J D
    Rasheva, Vanya
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Pirrotta, V
    Painting of fourth, a chromosome-specific protein in Drosophila.2001Ingår i: Proc Natl Acad Sci U S A, ISSN 0027-8424, Vol. 98, nr 11, s. 6273-8Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Chromosome-specific gene regulation is known thus far only as a mechanism to equalize the transcriptional activity of the single male X chromosome with that of the two female X chromosomes. In Drosophila melanogaster, a complex including the five Male-Specific Lethal (MSL) proteins, "paints" the male X chromosome, mediating its hypertranscription. Here, with the molecular cloning of Painting of fourth (Pof), we describe a previously uncharacterized gene encoding a chromosome-specific protein in Drosophila. Unlike the MSL proteins, POF paints an autosome, the fourth chromosome of Drosophila melanogaster. Chromosome translocation analysis shows that the binding depends on an initiation site in the proximal region of chromosome 4 and spreads in cis to involve the entire chromosome. The spreading depends on sequences or structures specific to chromosome 4 and cannot extend to parts of other chromosomes translocated to the fourth. Spreading can also occur in trans to a paired homologue that lacks the initiation region. In the related species Drosophila busckii, POF paints the entire X chromosome exclusively in males, suggesting relationships between the fourth chromosome and the X and between POF complexes and dosage-compensation complexes.

  • 14.
    Larsson, Jan
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Cloning, mapping and mutational analysis of the S-adenosylmethionine decarboxylase gene in Drosophila melanogaster.1997Ingår i: Mol Gen Genet, ISSN 0026-8925, Vol. 256, nr 6, s. 652-60Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    S-adenosylmethionine decarboxylase is a key enzyme in the synthesis of polyamines. These small cationic molecules are required for growth and development in all organisms. A wealth of biological processes, including synthesis of DNA and protein and condensation of chromatin, involve polyamines. Inhibition of polyamine synthesis has been proposed for treatment of cancer but this requires more knowledge about the in vivo function of polyamines. We report here the cloning of the S-adenosylmethionine decarboxylase gene from Drosophila melanogaster and the analysis of corresponding mutants. The mutant phenotypes are similar to those previously described for ribosomal protein genes (Minutes) and rRNA genes (bobbed). This work elucidates the in vivo consequences of impaired polyamine synthesis with respect to the development of a whole animal.

  • 15.
    Larsson, Jan
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Molecular cloning of the S-adenosylmethionine synthetase gene in Drosophila melanogaster.1994Ingår i: FEBS Lett, ISSN 0014-5793, Vol. 342, nr 3, s. 329-33Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    We have isolated and sequenced cDNA clones encoding the Drosophila melanogaster S-adenosylmethionine synthetase. The deduced amino acid sequence contains 405 amino acid residues and shows high homology to rat, yeast, Arabidopsis and Escherichia coli counterparts. The gene is transcribed throughout Drosophila development but its main activity is seen in adult males and females. The highest transcription activity is seen in female ovaries. The transcript has an unusually long 5'-untranslated region, which might be of importance for translational regulation

  • 16.
    Larsson, Jan
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Somatic and germline clone analysis in mutants of the S-adenosylmethionine synthetase encoding gene in Drosophila melanogaster.1998Ingår i: FEBS Lett, ISSN 0014-5793, Vol. 427, nr 1, s. 119-23Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    We have analysed the phenotypic consequences of homozygous mutant clones in the S-adenosylmethionine synthetase encoding gene in Drosophila melanogaster. The results suggest that SamS function is required for cell proliferation/growth in embryonic/early larval cells and during development of imaginal disc cells. Homozygous SamS germline clones can, however, develop and give rise to viable heterozygous offspring. This offspring expresses a Minute-like phenotype. We suggest that this phenotype is caused by an obstruction of the polyamine biosynthesis

  • 17.
    Larsson, Jan
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Zhang, Jingpu
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Mutations in the Drosophila melanogaster gene encoding S-adenosylmethionine synthetase [corrected] suppress position-effect variegation.1996Ingår i: Genetics, ISSN 0016-6731, Vol. 143, nr 2, s. 887-96Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    In Drosophila melanogaster, the study of trans-acting modifier mutations of position-effect variegation and Polycomb group (Pc-G) genes have been useful tools to investigate genes involved in chromatin structure. We have cloned a modifier gene, Suppressor of zeste 5 (Su(z)5), which encodes S-adenosylmethionine synthetase, and we present here molecular results and data concerning its expression in mutants and genetic interactions. The mutant alleles Su(z)5, l(2)R23 and l(2)M6 show suppression of wm4 and also of two white mutants induced by roo element insertions in the regulatory region i.e., wis (in combination with z1) and wsp1. Two of the Su(z)5 alleles, as well as a deletion of the gene, also act as enhancers of Polycomb by increasing the size of sex combs on midleg. The results suggest that Su(z)5 is connected with regulation of chromatin structure. The enzyme S-adenosylmethionine synthetase is involved in the synthesis of S-adenosylmethionine, a methyl group donor and also, after decarboxylation, a propylamino group donor in the bio-synthesis of polyamines. Our results from HPLC analysis show that in ovaries from heterozygous Su(z)5 mutants the content of spermine is significantly reduced. Results presented here suggest that polyamines are an important molecule class in the regulation of chromatin structure.

  • 18.
    Rasmuson, Åsa
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Larsson, Jan
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Somatic and germline mutagenesis assayed by the unstable zeste-white test in Drosophila melanogaster.1992Ingår i: Mutagenesis, ISSN 0267-8357, Vol. 7, nr 3, s. 219-23Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    This investigation is an attempt to compare mutation rates in germinal and somatic cells by the use of the unstable zeste-white assay in Drosophila melanogaster. In this system it is possible to use the same genetic end point to measure both somatic mutations (aberrantly pigmented spots in the eyes of adult flies) and germinal mutations (males with aberrantly pigmented eyes). We used two mutagens, formaldehyde and methylmethane sulphonate (MMS), to induce mutations and two different routes of mutagen administration, larval feeding and adult feeding, and scored mutations in somatic as well as germinal cells. Both types of tissues were susceptible to MMS mutagenesis, showing elevated frequencies of both germline mutations and eye spots. Formaldehyde, however, gave no increase in the germinal mutation rate but caused somatic mutations. These were found after larval exposure, but also among the offspring of exposed males, as formation of delayed somatic mutations. The results show that somatic cells are much more sensitive in monitoring induced mutations than germinal cells in this system. We also found that spontaneous mutation rate among germinal cells is 200 times higher than that in somatic cells, which presumably is due to the involvement of a mobile element

  • 19.
    Rasmuson-Lestander, Å
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    The Drosophila Stock Centers and their implications for developmental biology.1995Ingår i: Int J Dev Biol, ISSN 0214-6282, Vol. 39, nr 5, s. 765-8Artikel i tidskrift (Övrigt vetenskapligt)
  • 20.
    Rasmuson-Lestander, Å
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Ekström, K
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Genetic and molecular analysis of a set of unstable white mutants in Drosophila melanogaster.1996Ingår i: Genetica, ISSN 0016-6707, Vol. 98, nr 2, s. 179-92Artikel i tidskrift (Refereegranskat)
  • 21.
    Rasmuson-Lestander, Åsa
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Larsson, Jan
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson, Bertil
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Position-effect variegation and z1 mediated white repression in the In(1)wis system in Drosophila melanogaster.1993Ingår i: Hereditas, ISSN 0018-0661, Vol. 119, nr 3, s. 209-18Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    We have characterized a new X-chromosomal inversion in Drosophila melanogaster, extending from just distal of white to just proximal of the bb locus. The inversion places the w-isoxanthopterinless (wis) allele close to heterochromatin and under the influence of position-effect variegation (PEV). The wis gene activity is also regulated by chromosome pairing-dependent z1-mediated repression. By changing the environment, using specific second site modifiers, altering the amount of heterochromatin, and disturbing the chromosome pairing, we have been able to separately affect the two regulatory phenomena and analyse their respective impact on the wis regulation. We provide evidence that under normal conditions PEV and z1 mediated white repression are additive. However, at extreme levels of wis repression by PEV, changes in the z1-mediated interactions are not observable. This indicates that PEV is epistatic to z1-mediated regulation of wis. We also show that deficiencies in the short arm of Y act as suppressors of the z1-mediated white repression. This suppression does not influence PEV and is thus not due to the lower amount of heterochromatin. We propose that nonhomologous chromosome pairing between X and Y is important for the synapsis-dependent z1-mediated repression of white transcription activity in this system

  • 22. Ryder, Edward
    et al.
    Ashburner, Michael
    Bautista-Llacer, Rosa
    Drummond, Jenny
    Webster, Jane
    Johnson, Glynnis
    Morley, Terri
    Chan, Yuk Sang
    Blows, Fiona
    Coulson, Darin
    Reuter, Gunter
    Baisch, Heiko
    Apelt, Christian
    Kauk, Andreas
    Rudolph, Thomas
    Kube, Maria
    Klimm, Melanie
    Nickel, Claudia
    Szidonya, Janos
    Maróy, Peter
    Pal, Margit
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Ekström, Karin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Stocker, Hugo
    Hugentobler, Christoph
    Hafen, Ernst
    Gubb, David
    Pflugfelder, Gert
    Dorner, Christian
    Mechler, Bernard
    Schenkel, Heide
    Marhold, Joachim
    Serras, Florenci
    Corominas, Montserrat
    Punset, Adrià
    Roote, John
    Russell, Steven
    The DrosDel deletion collection: A Drosophila genomewide chromosomal deficiency resource2007Ingår i: Genetics, ISSN 0016-6731, E-ISSN 1943-2631, Vol. 177, nr 1, s. 615-629Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We describe a second-generation deficiency kit for Drosophila melanogaster composed of molecularly mapped deletions on an isogenic background, covering 77% of the Release 5.1 genome. Using a previously reported collection of FRT-bearing P-element insertions, we have generated 655 new deletions and verified a set of 209 deletion-bearing fly stocks. In addition to deletions, we demonstrate how the P elements may also be used to generate a set of custom inversions and duplications, particularly useful for balancing difficult regions of the genome carrying haplo-insufficient loci. We describe a simple computational resource that facilitatesselection of appropriate elements for generating custom deletions. Finally, we provide a computational resource that facilitates selection of other mapped FRT-bearing elements that, when combined with the DrosDel collection, can theoretically generate over half a million precisely mapped deletions.

  • 23. Ryder, Edward
    et al.
    Blows, Fiona
    Ashburner, Michael
    Bautista-Llacer, Rosa
    Coulson, Darin
    Drummond, Jenny
    Webster, Jane
    Gubb, David
    Gunton, Nicola
    Johnson, Glynnis
    O'Kane, Cahir J
    Huen, David
    Sharma, Punita
    Asztalos, Zoltan
    Baisch, Heiko
    Schulze, Janet
    Kube, Maria
    Kittlaus, Kathrin
    Reuter, Gunter
    Maroy, Peter
    Szidonya, Janos
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Ekström, Karin
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Dickson, Barry
    Hugentobler, Christoph
    Stocker, Hugo
    Hafen, Ernst
    Lepesant, Jean Antoine
    Pflugfelder, Gert
    Heisenberg, Martin
    Mechler, Bernard
    Serras, Florenci
    Corominas, Montserrat
    Schneuwly, Stephan
    Preat, Thomas
    Roote, John
    Russell, Steven
    The DrosDel collection: a set of P-element insertions for generating custom chromosomal aberrations in Drosophila melanogaster.2004Ingår i: Genetics, ISSN 0016-6731, Vol. 167, nr 2, s. 797-813Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We describe a collection of P-element insertions that have considerable utility for generating custom chromosomal aberrations in Drosophila melanogaster. We have mobilized a pair of engineered P elements, p[RS3] and p[RS5], to collect 3243 lines unambiguously mapped to the Drosophila genome sequence. The collection contains, on average, an element every 35 kb. We demonstrate the utility of the collection for generating custom chromosomal deletions that have their end points mapped, with base-pair resolution, to the genome sequence. The collection was generated in an isogenic strain, thus affording a uniform background for screens where sensitivity to genetic background is high. The entire collection, along with a computational and genetic toolbox for designing and generating custom deletions, is publicly available. Using the collection it is theoretically possible to generate >12,000 deletions between 1 bp and 1 Mb in size by simple eye color selection. In addition, a further 37,000 deletions, selectable by molecular screening, may be generated. We are now using the collection to generate a second-generation deficiency kit that is precisely mapped to the genome sequence.

  • 24.
    Skottheim Honn, John
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Johansson, Linn
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson Lestander, Asa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Regulation of twin of eyeless during Drosophila development2016Ingår i: Gene Expression Patterns, ISSN 1567-133X, E-ISSN 1872-7298, Vol. 20, nr 2, s. 120-129Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Pax-6 protein is vital for eye development in all seeing animals, from sea urchins to humans. Either of the Pax6 genes in Drosophila (twin of eyeless and eyeless) can induce a gene cascade leading to formation of entire eyes when expressed ectopically. The twin of eyeless (toy) gene in Drosophila is expressed in the anterior region of the early fly embryo. At later stages it is expressed in the brain, ventral nerve cord and (eventually) the visual primordium that gives rise to the eye-antennal imaginal discs of the larvae. These discs subsequently form the major part of the adult head, including compound eyes. We have searched for genes that are required for normal toy expression in the early embryo to elucidate initiating events of eye organogenesis. Candidate genes identified by mutation analyses were subjected to further knock-out and miss-expression tests to investigate their interactions with toy. Our results indicate that the head-specific gap gene empty spiracles can act as a repressor of Toy, while ocelliless (oc) and spalt major (salm) appear to act as positive regulators of toy gene expression. (C) 2016 Elsevier B.V. All rights reserved.

  • 25. Tie, F.
    et al.
    Prasad-Sinha, J.
    Birve, Anna
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Harte, P.J.
    A 1 MDa ESC/E(Z) complex from Drosophila that contains Polycomblike and RPD32003Ingår i: Molecular and Cellular Biology, ISSN 0270-7306, E-ISSN 1098-5549, Vol. 23, nr 9, s. 3352-3362Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polycomb group (PcG) proteins are required to maintain stable repression of the homeotic genes and others throughout development. The PcG proteins ESC and E(Z) are present in a prominent 600-kDa complex as well as in a number of higher-molecular-mass complexes. Here we identify and characterize a 1-MDa ESC/E(Z) complex that is distinguished from the 600-kDa complex by the presence of the PcG protein Polycomblike (PCL) and the histone deacetylase RPD3. In addition, the 1-MDa complex shares with the 600-kDa complex the histone binding protein p55 and the PcG protein SU(Z)12. Coimmunoprecipitation assays performed on embryo extracts and gel filtration column fractions indicate that, during embryogenesis E(Z), SU(Z)12, and p55 are present in all ESC complexes, while PCL and RPD3 are associated with ESC, E(Z), SU(Z)12, and p55 only in the 1-MDa complex. Glutathione transferase pulldown assays demonstrate that RPD3 binds directly to PCL via the conserved PHD fingers of PCL and the N terminus of RPD3. PCL and E(Z) colocalize virtually completely on polytene chromosomes and are associated with a subset of RPD3 sites. As previously shown for E(Z) and RPD3, PCL and SU(Z)12 are also recruited to the insertion site of a minimal Ubx Polycomb response element transgene in vivo. Consistent with these biochemical and cytological results, Rpd3 mutations enhance the phenotypes of Pcl mutants, further indicating that RPD3 is required for PcG silencing and possibly for PCL function. These results suggest that there may be multiple ESC/E(Z) complexes with distinct functions in vivo.

  • 26. Tie, Feng
    et al.
    Prasad-Sinha, Jayashree
    Birve, Anna
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Harte, Peter J
    A 1-megadalton ESC/E(Z) complex from Drosophila that contains polycomblike and RPD3.2003Ingår i: Mol Cell Biol, ISSN 0270-7306, Vol. 23, nr 9, s. 3352-62Artikel i tidskrift (Refereegranskat)
  • 27.
    Zeng, Qing-Yin
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Wang, Xiao-Ru
    Extensive set of mitochondrial LSU rDNA-based oligonucleotide probes for the detection of common airborne fungi.2004Ingår i: FEMS Microbiology Letters, ISSN 0378-1097, E-ISSN 1574-6968, Vol. 237, nr 1, s. 79-87Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Fungi exist in every indoor and outdoor environment. Many fungi are toxigenic or pathogens that may cause various public health concerns. Rapid and accurate detection and identification of fungi require specific markers. In this study, partial mitochondrial large subunit rDNA was amplified and sequenced from 32 fungal strains representing 31 species from 14 genera. Based on the sequence variation pattern, 26 oligonucleotide probes were designed for their discrimination. The specificity of the probes was evaluated through homology search against GenBank database and hybridization examination on 38 fungal strains. The 26 probes were verified as highly specific to 20 fungal species. A two-step detection procedure through PCR followed by probe hybridization gave ten-fold increase in detection sensitivity than single-step PCR assay and would be a practical approach for environmental sample screening. The probes developed in this study can be applied in clinical diagnosis and environmental monitoring of fungal agents.

  • 28.
    Zeng, Qing-Yin
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Westermark, Sven-Olof
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Wang, Xiao-Ru
    Detection and quantification of Cladosporium in aerosols by real-time PCR2006Ingår i: Journal of Environmental Monitoring, ISSN 1464-0325, E-ISSN 1464-0333, Vol. 8, nr 1, s. 153-160Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cladosporium is one of the most common airborne molds found in indoor and outdoor environments. Cladosporium spores are important aeroallergens, and prolonged exposure to elevated spore concentrations can provoke chronic allergy and asthma. To accurately quantify the levels of Cladosporium in indoor and outdoor environments, two real-time PCR systems were developed in this study. The two real-time PCR systems are highly specific and sensitive for Cladosporium detection even in a high background of other fungal DNAs. These methods were employed to quantify Cladosporium in aerosols of five different indoor environments. The investigation revealed a high spore concentration of Cladosporium (10(7) m(-3)) in a cow barn that accounted for 28-44% of the airborne fungal propagules. In a countryside house that uses firewood for heating and in a paper and pulp factory, Cladosporium was detected at 10(4) spores m(-3), which accounted for 2-6% of the fungal propagules in the aerosols. The concentrations of Cladosporium in these three indoor environments far exceeded the medical borderline level (3000 spores m(-3)). In a power station and a fruit and vegetable storage, Cladosporium was found to be a minor component in the aerosols, accounted for 0.01-0.1% of the total fungal propagules. These results showed that monitoring Cladosporium in indoor environments is more important than in outdoor environments from the public health point of view. Cladosporium may not be the dominant fungi in some indoor environments, but its concentration could still be exceeding the threshold value for clinical significance. The methods developed in this study could facilitate accurate detection and quantification of Cladosporium for public health related risk assessment.

  • 29.
    Zeng, Qing-Yin
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet). National Institute for Working Life.
    Westermark, Sven-Olof
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Wang, Xiao-Ru
    Detection and quantification of Wallemia sebi in aerosols by real-time PCR, conventional PCR, and cultivation2004Ingår i: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 70, nr 12, s. 7295-7302Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Wallemia sebi is a deuteromycete fungus commonly found in agricultural environments in many parts of the world and is suspected to be a causative agent of farmer's lung disease. The fungus grows slowly on commonly used culture media and is often obscured by the fast-growing fungi. Thus, its occurrence in different environments has often been underestimated. In this study, we developed two sets of PCR primers specific to W. sebi that can be applied in either conventional PCR or real-time PCR for rapid detection and quantification of the fungus in environmental samples. Both PCR systems proved to be highly specific and sensitive for W. sebi detection even in a high background of other fungal DNAs. These methods were employed to investigate the presence of W. sebi in the aerosols of a farm. The results revealed a high concentration of W. sebi spores, 10(7) m(-3) by real-time PCR and 10(6) m(-3) by cultivation, which indicates the prevalence of W. sebi in farms handling hay and grain and in cow barns. The methods developed in this study could serve as rapid, specific, and sensitive means of detecting W. sebi in aerosol and surface samples and could thus facilitate investigations of its distribution, ecology, clinical diagnosis, and exposure risk assessment.

  • 30.
    Zhang, Jingpu
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Larsson, Jan
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Expression preference of the S-adenosylmethionine synthetase (SamS) gene in Drosophila melanogaster1997Ingår i: Dev Rep Biol, Vol. 6, s. 7-17Artikel i tidskrift (Övrig (populärvetenskap, debatt, mm))
  • 31. Zhou, Guang-Qian
    et al.
    Zhang, Youyi
    Ferguson, David J P
    Chen, Sa
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Rasmuson-Lestander, Åsa
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Campbell, Frederick C
    Watt, Suzanne M
    The Drosophila ortholog of the endolysosomal membrane protein, endolyn, regulates cell proliferation.2006Ingår i: J Cell Biochem, ISSN 0730-2312, Vol. 99, nr 5, s. 1380-96Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Endolyn (CD164) is a sialomucin that regulates the proliferation, adhesion, and migration of human haematopoietic stem and progenitor cells. This molecule is predominately localized in endocytotic compartments, where it may contribute to endolysosomal biogenesis and trafficking. In order to more closely define the function of endolyn from an evolutionary view-point, we first analyzed endolyn orthologs in species ranging from insects, fish, and birds to mammals. The predicted molecular structures of the endolyn orthologs from these species are well conserved, particularly with respect to significant O-linked glycosylation of the extracellular domain, and the high degree of amino acid similarities within their transmembrane and cytoplasmic domains, with the latter possessing the lysosomal target signal, YXXphi. Focusing on Drosophila, our studies showed that the subcellular distribution of endolyn in non-polarized Drosophila S2 cells resembles that of its human counterpart in hematopoietic cells, with its predominant localization being within intracellular vesicles, while a small fraction occurs on the cell surface. Both Y --> A and L --> A mutations in the YHTL motif perturbed the normal subcellular distribution of Drosophila endolyn. Interestingly, embryonic and early larval development was often arrested in endolyn-deficient Drosophila mutants. This may partly be due to the role of endolyn in regulating cell proliferation, since knock-down of endolyn expression in S2 cells resulted in up to 50% inhibition of cell growth, with a proportion of cells undergoing apoptosis. Taken together, these results demonstrate that endolyn is an evolutionarily conserved sialomucin fundamentally involved in cell proliferation in both the human and Drosophila melanogaster. 2006 Wiley-Liss, Inc.

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