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Selstam, Gunnar
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Publications (10 of 16) Show all publications
Jiguet, F., Burgess, M., Thorup, K., Conway, G., Arroyo Matos, J. L., Barber, L., . . . Hewson, C. (2019). Desert crossing strategies of migrant songbirds vary between and within species. Scientific Reports, 9, Article ID 20248.
Open this publication in new window or tab >>Desert crossing strategies of migrant songbirds vary between and within species
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2019 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 20248Article in journal (Refereed) Published
Abstract [en]

Each year, billions of songbirds cross large ecological barriers during their migration. Understanding how they perform this incredible task is crucial to predict how global change may threaten the safety of such journeys. Earlier studies based on radar suggested that most songbirds cross deserts in intermittent flights at high altitude, stopping in the desert during the day, while recent tracking with light loggers suggested diurnal prolongation of nocturnal flights and common non-stop flights for some species. We analyzed light intensity and temperature data obtained from geolocation loggers deployed on 130 individuals of ten migratory songbird species, and show that a large variety of strategies for crossing deserts exists between, but also sometimes within species. Diurnal stopover in the desert is a common strategy in autumn, while most species prolonged some nocturnal flights into the day. Nonstop flights over the desert occurred more frequently in spring than in autumn, and more frequently in foliage gleaners. Temperature recordings suggest that songbirds crossed deserts with flight bouts performed at various altitudes according to species and season, along a gradient ranging from low above ground in autumn to probably >2000 m above ground level, and possibly at higher altitude in spring. High-altitude flights are therefore not the general rule for crossing deserts in migrant songbirds. We conclude that a diversity of migration strategies exists for desert crossing among songbirds, with variations between but also within species.

Place, publisher, year, edition, pages
Nature Publishing Group, 2019
National Category
Evolutionary Biology
Identifiers
urn:nbn:se:umu:diva-168241 (URN)10.1038/s41598-019-56677-4 (DOI)000509351600010 ()31882957 (PubMedID)
Available from: 2020-02-18 Created: 2020-02-18 Last updated: 2020-02-18Bibliographically approved
Jiguet, F., Robert, A., Lorrilliere, R., Hobson, K. A., Kardynal, K. J., Arlettaz, R., . . . Moussy, C. (2019). Unravelling migration connectivity reveals unsustainable hunting of the declining ortolan bunting. Science Advances, 5(5), Article ID eaau2642.
Open this publication in new window or tab >>Unravelling migration connectivity reveals unsustainable hunting of the declining ortolan bunting
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2019 (English)In: Science Advances, E-ISSN 2375-2548, Vol. 5, no 5, article id eaau2642Article in journal (Refereed) Published
Abstract [en]

In France, illegal hunting of the endangered ortolan bunting Emberiza hortulana has been defended for the sake of tradition and gastronomy. Hunters argued that ortolan buntings trapped in southwest France originate from large and stable populations across the whole of Europe. Yet, the European Commission referred France to the Court of Justice of the European Union (EU) in December 2016 for infringements to legislation (IP/16/4213). To better assess the impact of hunting in France, we combined Pan-European data from archival light loggers, stable isotopes, and genetics to determine the migration strategy of the species across continents. Ortolan buntings migrating through France come from northern and western populations, which are small, fragmented and declining. Population viability modeling further revealed that harvesting in southwest France is far from sustainable and increases extinction risk. These results provide the sufficient scientific evidence for justifying the ban on ortolan harvesting in France.

Place, publisher, year, edition, pages
American Association for the Advancement of Science, 2019
National Category
Zoology
Identifiers
urn:nbn:se:umu:diva-160618 (URN)10.1126/sciadv.aau2642 (DOI)000470125000009 ()31131318 (PubMedID)
Available from: 2019-06-24 Created: 2019-06-24 Last updated: 2019-06-24Bibliographically approved
Jiguet, F., Arlettaz, R., Bauer, H.-G., Belik, V., Copete, J. L., Couzi, L., . . . Sokolov, A. (2016). An update of the European breeding population sizes and trends of the Ortolan Bunting (Emberiza hortulana). Ornis Fennica, 93(3), 186-196
Open this publication in new window or tab >>An update of the European breeding population sizes and trends of the Ortolan Bunting (Emberiza hortulana)
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2016 (English)In: Ornis Fennica, ISSN 0030-5685, Vol. 93, no 3, p. 186-196Article, review/survey (Refereed) Published
Abstract [en]

Following recent updates proposed by BirdLife International and further updates across Europe gathered in the context of a continent-wide study of the migration strategy of the species, we propose here an update of national population sizes and associated recent trends of the Ortolan Bunting (Emberiza hortulana). Previous estimates for the period 1999-2002 reported 5,200,000 to 16,000,000 breeding pairs, for an area extending east to European Russia, and south to the Caucasus and Turkey. The countries holding the largest populations were Turkey (3-10 million pairs) and Russia (1.5-5.0 million pairs). The updated results give approximately 3,319,000 to 7,057,000 pairs in Europe (for the period 2012-2014), representing a c. 50% decrease in numbers over the last decade. This decrease is partly due to overestimates proposed in previous reports for the key country, Turkey, which is now considered to support only 500,000 to 1,000,000 pairs. Russia still holds 2.0-4.3 million pairs, although with an estimated decline of c.15-30% since 2000. Overall, within the 39 European countries assessed here, recent decadal trends (on average 2000-2012) in population size are reported as unknown in 15 countries, increasing in 2 countries (Germany and Serbia), stable or fluctuating in 6 countries, and decreasing in 16 countries including recent extinctions in Belgium, Hungary, Slovakia and the Netherlands. Overall, declining populations are mostly located in northern Europe, and fourteen of the 15 northern European countries with a known national trend have declining breeding populations, suggesting that northern breeders are of particular conservation concern.

Place, publisher, year, edition, pages
Birdlife Finland, 2016
National Category
Zoology
Identifiers
urn:nbn:se:umu:diva-127260 (URN)000384961100005 ()
Available from: 2016-11-09 Created: 2016-11-03 Last updated: 2018-06-09Bibliographically approved
Suutre, S., Toom, A., Arend, A. & Selstam, G. (2010). Involvement of BMP-2, TGF-beta 2 and TGF-beta 3 signaling in initial and early stages of heterotopic ossification in a rat experimental model. Scandinavian Journal of Laboratory Animal Science, 37(1), 31-40
Open this publication in new window or tab >>Involvement of BMP-2, TGF-beta 2 and TGF-beta 3 signaling in initial and early stages of heterotopic ossification in a rat experimental model
2010 (English)In: Scandinavian Journal of Laboratory Animal Science, ISSN 0901-3393, Vol. 37, no 1, p. 31-40Article in journal (Refereed) Published
Abstract [en]

This study focused on the localization and expression of bone morphogenetic protein 2 (BMP-2) and different isoforms of transforming growth factor beta (TGF-beta(1), TGF-beta(2) and TGF-beta(3)) in the initial and early stages of heterotopic ossification (HO) employing an animal model mimicking the situation after total hip arthroplasty (THA). Bone growth was induced in rats using beta-tricalcium phosphate implants immersed either in osteoinductive rhBMP-2 solution or in saline and implanted at the site where the HO is usually expected to develop after THA. Implants were removed at 3 or 21 days after the operation and handled according to stereology principles. mRNA expression and protein staining of growth factors in different types of tissues was determined by in situ hybridization and immunohistochemistry, respectively. After three days, TGF-beta(3) content in the undifferentiated mesenchymal-like cells in the rhBMP-2 treated implants was, as assessed by immunohistochemistry, 49.6% higher compared to the saline treated group (p=0.024). This was also supported by in situ hybridization of mRNA of TGF-beta(3), which showed stronger expression in rhBMP-2 treated group. Immunohistochemical investigation showed that after 21 days the connective tissue in the rhBMP-2 treated implants contained more TGF-beta(1),TGF-beta(2) and TGF-beta(3), compared to BMP-2 and osteoblasts contained significantly (27.2%) more TGF-beta(3) compared to TGF-beta(1) (p=0.045). In the formed HO the proportion of the TGF-beta(2) and TGF-beta(3), producing bone tissue was increased by 32.1% and 47.8% respectively, compared to the TGF-beta(1) producing bone tissue (p=0.007 and p=0.006) and although this difference was not so clear at mRNA level, this suggests that TGF-beta(2) and TGF-beta(3) signaling seem to play an important role during initial and early stages of HO formation.

Keywords
growth-factor-beta, bone morphogenetic protein, s mesenchymal stem-cells, human osteogenic protein-1, total hip-arthroplasty, messenger-rna, increased expression, differentiation, marrow, gene
National Category
Veterinary Science
Identifiers
urn:nbn:se:umu:diva-43200 (URN)000280949300004 ()
Available from: 2011-04-22 Created: 2011-04-22 Last updated: 2018-06-08Bibliographically approved
Suutre, S., Toom, A., Arend, A. & Selstam, G. (2009). Bone tissue content of TGF-2 changes with time in human heterotopic ossification after total hip arthroplasty. Growth Factors, 27(2), 114-120
Open this publication in new window or tab >>Bone tissue content of TGF-2 changes with time in human heterotopic ossification after total hip arthroplasty
2009 (English)In: Growth Factors, ISSN 0897-7194, E-ISSN 1029-2292, Vol. 27, no 2, p. 114-120Article in journal (Refereed) Published
Abstract [en]

Transforming growth factor beta isoforms (TGF-1, TGF-2, and TGF-3) most likely play a role in bone physiology, but little is known about their relative importance in normal as well as in heterotopic bone. This study focused on possible differences in the localization and relative content of different TGF beta isoforms in heterotopic ossifications (HO) by comparing HOs, which have developed less than 17 months (immature HOs) with those developed 3-9 years (mature HOs). The HOs were harvested after total hip arthroplasty (THA) during revision surgery. The HO samples were decalcified, embedded in paraffin and sectioned. Azan staining was used to evaluate histological structure of the ossifications and immunohistochemical analysis was performed to estimate the localization of three TGF beta isoforms in the HOs. Comparison of different TGF beta isoforms in the immature and the mature ossifications showed that the content of TGF-2 was decreased by almost three times in the mature HO as compared to the immature HO (p=0.0064). The proportions of other isoforms in HOs did not differ significantly. This study shows that the relative importance of TGF betas change with HO development.

Place, publisher, year, edition, pages
Taylor & Francis, 2009
Keywords
TGF-β, heterotopic ossification, immunohistochemistry, human
National Category
Cell and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-116045 (URN)10.1080/08977190802703976 (DOI)000264098800005 ()19180355 (PubMedID)
Available from: 2016-02-15 Created: 2016-02-08 Last updated: 2018-06-07Bibliographically approved
Gunnarsson, D., Selstam, G., Ridderstråle, Y., Holm, L., Ekstedt, E. & Madej, A. (2009). Effects of dietary phytoestrogens on plasma testosterone and triiodothyronine (T3) levels in male goat kids. Acta Veterinaria Scandinavica, 51
Open this publication in new window or tab >>Effects of dietary phytoestrogens on plasma testosterone and triiodothyronine (T3) levels in male goat kids
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2009 (English)In: Acta Veterinaria Scandinavica, ISSN 1751-0147, E-ISSN 1751-0147, Vol. 51Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Exposure to xenoestrogens in humans and animals has gained increasing attention due to the effects of these compounds on reproduction. The present study was undertaken to investigate the influence of low-dose dietary phytoestrogen exposure, i.e. a mixture of genistein, daidzein, biochanin A and formononetin, on the establishment of testosterone production during puberty in male goat kids. METHODS: Goat kids at the age of 3 months received either a standard diet or a diet supplemented with phytoestrogens (3-4 mg/kg/day) for approximately 3 months. Plasma testosterone and total and free triiodothyronine (T3) concentrations were determined weekly. Testicular levels of testosterone and cAMP were measured at the end of the experiment. Repeated measurement analysis of variance using the MIXED procedure on the generated averages, according to the Statistical Analysis System program package (Release 6.12, 1996, SAS Institute Inc., Cary, NC, USA) was carried out. RESULTS: No significant difference in plasma testosterone concentration between the groups was detected during the first 7 weeks. However, at the age of 5 months (i.e. October 1, week 8) phytoestrogen-treated animals showed significantly higher testosterone concentrations than control animals (37.5 nmol/l vs 19.1 nmol/l). This elevation was preceded by a rise in plasma total T3 that occurred on September 17 (week 6). A slightly higher concentration of free T3 was detected in the phytoestrogen group at the same time point, but it was not until October 8 and 15 (week 9 and 10) that a significant difference was found between the groups. At the termination of the experiment, testicular cAMP levels were significantly lower in goats fed a phytoestrogen-supplemented diet. Phytoestrogen-fed animals also had lower plasma and testicular testosterone concentrations, but these differences were not statistically significant. CONCLUSION: Our findings suggest that phytoestrogens can stimulate testosterone synthesis during puberty in male goats by increasing the secretion of T3; a hormone known to stimulate Leydig cell steroidogenesis. It is possible that feedback signalling underlies the tendency towards decreased steroid production at the end of the experiment.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:umu:diva-32860 (URN)10.1186/1751-0147-51-51 (DOI)20003293 (PubMedID)
Available from: 2010-03-29 Created: 2010-03-29 Last updated: 2018-06-08Bibliographically approved
Gunnarsson, D., Leffler, P., Ekwurtzel, E., Martinsson, G., Liu, K. & Selstam, G. (2008). Mono-(2-ethylhexyl) phthalate stimulates basal steroidogenesis by a cAMP-independent mechanism in mouse gonadal cells of both sexes. Reproduction, 135(5), 693-703
Open this publication in new window or tab >>Mono-(2-ethylhexyl) phthalate stimulates basal steroidogenesis by a cAMP-independent mechanism in mouse gonadal cells of both sexes
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2008 (English)In: Reproduction, ISSN 1470-1626, E-ISSN 1476-3990, Vol. 135, no 5, p. 693-703Article in journal (Refereed) Published
Abstract [en]

Phthalates are widely used as plasticizers in a number of daily-life products. In this study, we investigated the influence of mono-(2-ethylhexyl) phthalate (MEHP), the active metabolite of the frequently used plasticizer di-(2-ethylhexyl) phthalate (DEHP), on gonadal steroidogenesis in vitro. MEHP (25–100 µM) stimulated basal steroid synthesis in a concentration-dependent manner in immortalized mouse Leydig tumor cells (MLTC-1). The stimulatory effect was also detected in KK-1 granulosa tumor cells. MEHP exposure did not influence cAMP or StAR protein levels and induced a gene expression profile of key steroidogenic proteins different from the one induced by human chorionic gonadotropin (hCG). Simultaneous treatment with MEHP and a p450scc inhibitor (aminoglutethimide) indicated that MEHP exerts its main stimulatory effect prior to pregnenolone formation. MEHP (10–100 µM) up-regulated hormone-sensitive lipase and 3-hydroxy-3-methylglutaryl coenzyme A reductase, suggesting that MEHP increases the amount of cholesterol available for steroidogenesis. Our data suggest that MEHP, besides its known inhibitory effect on hCG action, can directly stimulate gonadal steroidogenesis in both sexes through a cAMP- and StAR-independent mechanism. The anti-steroidogenic effect of DEHP has been proposed to cause developmental disorders such as hypospadias and cryptorchidism, whereas a stimulation of steroid synthesis may prematurely initiate the onset of puberty and theoretically affect the hypothalamic–pituitary–gonadal axis.

Identifiers
urn:nbn:se:umu:diva-3527 (URN)10.1530/REP-07-0460 (DOI)
Available from: 2008-10-09 Created: 2008-10-09 Last updated: 2018-06-09Bibliographically approved
Toom, A., Arend, A., Gunnarsson, D., Ulfsparre, R., Suutre, S., Haviko, T. & Selstam, G. (2007). Bone formation zones in heterotopic ossifications: histologic findings and increased expression of bone morphogenetic protein 2 and transforming growth factors beta2 and beta3. Cell Calcium, 80(4), 259-67
Open this publication in new window or tab >>Bone formation zones in heterotopic ossifications: histologic findings and increased expression of bone morphogenetic protein 2 and transforming growth factors beta2 and beta3
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2007 (English)In: Cell Calcium, ISSN 0143-4160, E-ISSN 1532-1991, Vol. 80, no 4, p. 259-67Article in journal (Refereed) Published
Abstract [en]

Heterotopic ossifications (HOs) formed after total endoprosthetic replacement of the hip joint were collected during revision surgery (n = 7). Tissues collected during regular hip arthroplasty (n = 12) were used as reference. Histomorphometric analysis was performed for assessment of bone formation activity in HOs and reference bone. HOs were dissected with histological guidance into three zones: formed bone, zone of active bone formation, and zone with fibrous connective and fibrocartilagineous tissue. Relative expression of the mRNA for bone morphogenetic protein 2 (BMP-2), transforming growth factor beta2 (TGF-beta2), and TGF-beta3 was determined by reverse-transcription polymerase chain reaction relative to beta-actin. Expression of all three growth factors was higher than in orthotopic bone. Similarly, the osteoid surface density was increased in HOs. The levels of all growth factors were higher in the zone of active bone formation or remodeling than in the zone of formed bone. In matured HOs, the osteoid surface density as well as mRNA levels were lower, although still significantly raised, indicating that bone formation slows down after 2 years. Immunohistochemical analysis demonstrated the presence of TGF-beta1, TGF-beta2, TGF-beta3, and BMP-2 proteins in the zone of bone formation. We conclude that bone formation after heterotopic bone induction is initially intense, slows down within 2 years, and thereupon continues as active remodeling mainly on the border of HO. Our data indicate that BMP-2, TGF-beta2, and TGF-beta3 are involved in bone formation in HO.

Keywords
Bone Morphogenetic Proteins/*genetics/metabolism, Case-Control Studies, Female, Gene Expression Regulation, Humans, Immunohistochemistry, Male, Middle Aged, Ossification; Heterotopic/*genetics/metabolism/*pathology, Osteogenesis/genetics/*physiology, RNA; Messenger/metabolism, Transforming Growth Factor beta/*genetics/metabolism, Transforming Growth Factor beta2/*genetics/metabolism, Transforming Growth Factor beta3/*genetics/metabolism
National Category
Cell and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-16506 (URN)17401695 (PubMedID)
Available from: 2007-10-04 Created: 2007-10-04 Last updated: 2019-01-10Bibliographically approved
Gunnarsson, D., Nordberg, G. & Selstam, G. (2007). Differential effects of cadmium on the gene expression of seven-transmembrane-spanning receptors and GAPDH in the rat testis.. Toxicology Letters, 168(1), 51-7
Open this publication in new window or tab >>Differential effects of cadmium on the gene expression of seven-transmembrane-spanning receptors and GAPDH in the rat testis.
2007 (English)In: Toxicology Letters, ISSN 0378-4274, E-ISSN 1879-3169, Vol. 168, no 1, p. 51-7Article in journal (Refereed) Published
Abstract [en]

Cadmium (Cd) is a widely spread toxicant with endocrine disrupting properties. Under experimental conditions it suppresses sex steroid synthesis in the male as well as the female. Testicular steroidogenesis is primarily regulated by gonadotropins, but is also influenced by catecholamines. We have previously shown that Cd exposure affects rat testosterone synthesis by down-regulating luteinizing hormone (LH) receptor mRNA expression. In this study, rats were given 10 micromol/kg Cd subcutaneously and sacrificed 0.48-144 h later. We investigated the effects of Cd on testicular gene expression of two adrenergic receptors. In addition, mRNA levels of the androgen-regulated house keeping gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were measured. In contrast to the suppressive influence on LH receptor expression Cd lacked effect on the expression of alpha(1A)- and beta(2)-adrenergic receptors. GAPDH gene expression, on the other hand, was up-regulated 1.6-fold after exposure to 10 micromol/kg Cd. These data suggest that the influence of Cd on testicular gene expression involves a specific effect on the LH receptor and not a general effect on seven-transmembrane-spanning receptors. Also, data indicate that the increased expression of GAPDH may be secondary to Cd-induced testosterone deprivation, suggesting future studies of androgen-regulated genes in the toxicity of Cd.

Keywords
Animals, Cadmium/*toxicity, Gene Expression/*drug effects, Glyceraldehyde-3-Phosphate Dehydrogenases/*genetics, Male, RNA; Messenger/metabolism, Rats, Rats; Sprague-Dawley, Receptors; Adrenergic; alpha-1/genetics, Receptors; Adrenergic; beta-2/genetics, Testis/*drug effects/metabolism
Identifiers
urn:nbn:se:umu:diva-16509 (URN)10.1016/j.toxlet.2006.10.015 (DOI)17123754 (PubMedID)
Available from: 2007-10-04 Created: 2007-10-04 Last updated: 2018-06-09Bibliographically approved
Liu, L., Rajareddy, S., Reddy, P., Jagarlamudi, K., Du, C., Shen, Y., . . . Liu, K. (2007). Phosphorylation and inactivation of glycogen synthase kinase-3 by soluble kit ligand in mouse oocytes during early follicular development.. Journal of Molecular Endocrinology, 38(1-2), 137-146
Open this publication in new window or tab >>Phosphorylation and inactivation of glycogen synthase kinase-3 by soluble kit ligand in mouse oocytes during early follicular development.
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2007 (English)In: Journal of Molecular Endocrinology, ISSN 0952-5041, E-ISSN 1479-6813, Vol. 38, no 1-2, p. 137-146Article in journal (Refereed) Published
Abstract [en]

Communication between mammalian oocytes and their surrounding granulosa cells through the Kit-Kit ligand (KL, or stem cell factor, SCF) system has been shown to be crucial for follicular development. Our previous studies (Reddy et al. 2005, Liu et al. 2006) have indicated that the intra-oocyte KL-Kit-PI3 kinase (PI3K)-Akt-Foxo3a cascade may play an important role in follicular activation and early development. In the present study, using in situ hybridization and in vitro culture of growing oocytes from 8-day-old postnatal mice, we have demonstrated that another Akt substrate, glycogen synthase kinase-3 (GSK-3), is expressed in growing oocytes. Also, treatment of cultured mouse oocytes with soluble KL not only leads to increased Akt kinase activity in the oocytes, which can phosphorylate recombinant GSK-3 in vitro, but also leads to phosphorylation of oocyte GSK-3alpha and GSK-3beta, which can result in the inactivation of GSK-3 function in oocytes. In addition, we have shown that the regulation of GSK-3alpha and GSK-3beta in cultured oocytes by soluble KL is accomplished through PI3K, since the PI3K-specific inhibitor LY294002 completely abolished the KL-induced phosphorylation of GSK-3alpha and GSK-3beta. Moreover, blockage of the Kit signaling pathway by a Kit function-blocking antibody, ACK2, resulted in reduced phosphorylation of GSK-3. Taken together, our data suggest that the cascade from granulosa cell-derived KL to Kit-PI3K-Akt-GSK-3 in oocytes may take part in regulation of oocyte growth and early ovarian follicular development.

Keywords
Animals, Female, Glycogen Synthase Kinase 3/*antagonists & inhibitors/metabolism, Mice, Mice; Inbred C57BL, Oocytes/*enzymology, Ovarian Follicle/*enzymology, Phosphorylation, Proto-Oncogene Proteins c-akt/physiology, Stem Cell Factor/*physiology
Identifiers
urn:nbn:se:umu:diva-16507 (URN)10.1677/jme.1.02027 (DOI)17242176 (PubMedID)
Available from: 2008-01-11 Created: 2008-01-11 Last updated: 2018-06-09Bibliographically approved
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