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Publikationer (10 of 17) Visa alla publikationer
Lehrstrand, J., Davies, W. I. L., Hahn, M., Korsgren, O., Alanentalo, T. & Ahlgren, U. (2024). Illuminating the complete ß-cell mass of the human pancreas - signifying a new view on the islets of Langerhans. Nature Communications, 15(1), Article ID 3318.
Öppna denna publikation i ny flik eller fönster >>Illuminating the complete ß-cell mass of the human pancreas - signifying a new view on the islets of Langerhans
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2024 (Engelska)Ingår i: Nature Communications, E-ISSN 2041-1723, Vol. 15, nr 1, artikel-id 3318Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Pancreatic islets of Langerhans play a pivotal role in regulating blood glucose homeostasis, but critical information regarding their mass, distribution and composition is lacking within a whole organ context. Here, we apply a 3D imaging pipeline to generate a complete account of the insulin-producing islets throughout the human pancreas at a microscopic resolution and within a maintained spatial 3D context. These data show that human islets are far more heterogenous than previously accounted for with regards to their size distribution and cellular make up. By deep tissue 3D imaging, this in-depth study demonstrates that 50% of the human insulin-expressing islets are virtually devoid of glucagon-producing α-cells, an observation with significant implications for both experimental and clinical research.

Ort, förlag, år, upplaga, sidor
Springer Nature, 2024
Nationell ämneskategori
Endokrinologi och diabetes Cell- och molekylärbiologi
Identifikatorer
urn:nbn:se:umu:diva-223844 (URN)10.1038/s41467-024-47686-7 (DOI)001204844700001 ()38632302 (PubMedID)2-s2.0-85190704494 (Scopus ID)
Forskningsfinansiär
Kempestiftelserna, SMK-1455Vetenskapsrådet, 2017- 01307Vetenskapsrådet, 2023-02221BarndiabetesfondenNovo Nordisk fonden, NNF21OC0069771Novo Nordisk fonden, NNF21OC0084520Novo Nordisk fonden, NNF20OC0063600Insamlingsstiftelsen Diabetes Wellness, PG21-6566Stiftelsen familjen Ernfors fond, 2023Diabetesfonden, DIA2021-59
Tillgänglig från: 2024-04-29 Skapad: 2024-04-29 Senast uppdaterad: 2024-04-29Bibliografiskt granskad
Karthikeyan, R., Davies, W. I. L. & Gunhaga, L. (2023). Non-image-forming functional roles of OPN3, OPN4 and OPN5 photopigments. Journal of Photochemistry and Photobiology, 15, Article ID 100177.
Öppna denna publikation i ny flik eller fönster >>Non-image-forming functional roles of OPN3, OPN4 and OPN5 photopigments
2023 (Engelska)Ingår i: Journal of Photochemistry and Photobiology, E-ISSN 2666-4690, Vol. 15, artikel-id 100177Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Detecting different wavelengths and intensities of environmental light is crucial for the survival of many animals. In response, a multiplicity of opsins (a special group of photosensitive G protein-coupled receptors), when combined with a retinal chromophore, is able to directly detect light and initiate different downstream phototransduction signaling cascades. Although avian studies from the 1930s suggested the presence of deep brain photoreceptors that could respond to seasonal changes in the light/dark cycle, it was only a few decades ago that photopigments other than those found in the visual system (i.e. rods and cones) were identified as functional photoreceptors. It is now established that several classes of non-visual photoreceptors and the photopigments they express, in lower vertebrates to higher mammals alike, can regulate a plethora of mechanisms that function outside of vision. These include the synchronization of light/dark cycles with biological/cellular rhythms of the body (i.e. photoentrainment); melanogenesis in dermal tissues; thermoregulation in adipose tissue; embryonic eye development; smooth muscle relaxation; and the development of certain cancers. These and other mechanisms have been shown, in part at least, to be controlled by the expression of three important non-visual opsin genes, namely OPN3, OPN4 and OPN5, although other vertebrate opsin classes exist, many with unknown or unclear functional roles assigned to them presently. Specifically, these three opsins have been shown to be expressed during early embryogenesis and throughout adulthood, which will be discussed here. Moreover, this review highlights recent studies that focus on several key non-image-forming functional roles of OPN3, OPN4 and OPN5, and in particular those that impact photoreception in developing structures and pathways, as well as in adulthood.

Ort, förlag, år, upplaga, sidor
Elsevier, 2023
Nyckelord
Encephalopsin, Melanopsin, Neuropsin, OPN3, OPN4, OPN5
Nationell ämneskategori
Zoologi
Identifikatorer
urn:nbn:se:umu:diva-206767 (URN)10.1016/j.jpap.2023.100177 (DOI)2-s2.0-85151749996 (Scopus ID)
Forskningsfinansiär
Vetenskapsrådet, 2017-01430Kempestiftelserna, JCK22-0014Kempestiftelserna, SMK-1763Energimyndigheten, P2022-00284Kronprinsessan Margaretas Minnesfond
Tillgänglig från: 2023-04-27 Skapad: 2023-04-27 Senast uppdaterad: 2023-04-27Bibliografiskt granskad
Eilertsen, M., Davies, W. I., Patel, D., Barnes, J. E., Karlsen, R., Mountford, J. K., . . . Helvik, J. V. (2022). An EvoDevo Study of Salmonid Visual Opsin Dynamics and Photopigment Spectral Sensitivity. Frontiers in Neuroanatomy, 16, Article ID 945344.
Öppna denna publikation i ny flik eller fönster >>An EvoDevo Study of Salmonid Visual Opsin Dynamics and Photopigment Spectral Sensitivity
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2022 (Engelska)Ingår i: Frontiers in Neuroanatomy, E-ISSN 1662-5129, Vol. 16, artikel-id 945344Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Salmonids are ideal models as many species follow a distinct developmental program from demersal eggs and a large yolk sac to hatching at an advanced developmental stage. Further, these economically important teleosts inhabit both marine- and freshwaters and experience diverse light environments during their life histories. At a genome level, salmonids have undergone a salmonid-specific fourth whole genome duplication event (Ss4R) compared to other teleosts that are already more genetically diverse compared to many non-teleost vertebrates. Thus, salmonids display phenotypically plastic visual systems that appear to be closely related to their anadromous migration patterns. This is most likely due to a complex interplay between their larger, more gene-rich genomes and broad spectrally enriched habitats; however, the molecular basis and functional consequences for such diversity is not fully understood. This study used advances in genome sequencing to identify the repertoire and genome organization of visual opsin genes (those primarily expressed in retinal photoreceptors) from six different salmonids [Atlantic salmon (Salmo salar), brown trout (Salmo trutta), Chinook salmon (Oncorhynchus tshawytcha), coho salmon (Oncorhynchus kisutch), rainbow trout (Oncorhynchus mykiss), and sockeye salmon (Oncorhynchus nerka)] compared to the northern pike (Esox lucius), a closely related non-salmonid species. Results identified multiple orthologues for all five visual opsin classes, except for presence of a single short-wavelength-sensitive-2 opsin gene. Several visual opsin genes were not retained after the Ss4R duplication event, which is consistent with the concept of salmonid rediploidization. Developmentally, transcriptomic analyzes of Atlantic salmon revealed differential expression within each opsin class, with two of the long-wavelength-sensitive opsins not being expressed before first feeding. Also, early opsin expression in the retina was located centrally, expanding dorsally and ventrally as eye development progressed, with rod opsin being the dominant visual opsin post-hatching. Modeling by spectral tuning analysis and atomistic molecular simulation, predicted the greatest variation in the spectral peak of absorbance to be within the Rh2 class, with a ∼40 nm difference in λmax values between the four medium-wavelength-sensitive photopigments. Overall, it appears that opsin duplication and expression, and their respective spectral tuning profiles, evolved to maximize specialist color vision throughout an anadromous lifecycle, with some visual opsin genes being lost to tailor marine-based vision.

Ort, förlag, år, upplaga, sidor
Frontiers Media S.A., 2022
Nyckelord
atomistic molecular simulation, eye, photoreception, RNA in situ hybridization, RNA sequencing, salmonid, visual opsin
Nationell ämneskategori
Zoologi Evolutionsbiologi
Identifikatorer
urn:nbn:se:umu:diva-198333 (URN)10.3389/fnana.2022.945344 (DOI)000832800900001 ()2-s2.0-85134699424 (Scopus ID)
Forskningsfinansiär
Norges forskningsråd, 254894Norges forskningsråd, 315106NIH (National Institutes of Health), P30 GM103324
Tillgänglig från: 2022-08-02 Skapad: 2022-08-02 Senast uppdaterad: 2024-01-15Bibliografiskt granskad
Nagloo, N., Mountford, J. K., Gundry, B. J., Hart, N. S., Davies, W. I. L., Collin, S. P. & Hemmi, J. M. (2022). Enhanced short-wavelength sensitivity in the blue-tongued skink Tiliqua rugosa. Journal of Experimental Biology, 225(11), Article ID jeb244317.
Öppna denna publikation i ny flik eller fönster >>Enhanced short-wavelength sensitivity in the blue-tongued skink Tiliqua rugosa
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2022 (Engelska)Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 225, nr 11, artikel-id jeb244317Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Despite lizards using a wide range of colour signals, the limited variation in photoreceptor spectral sensitivities across lizards suggests only weak selection for species-specific, spectral tuning of photoreceptors. Some species, however, have enhanced short-wavelength sensitivity, which probably helps with the detection of signals rich in ultraviolet and short wavelengths. In this study, we examined the visual system of Tiliqua rugosa, which has an ultraviolet/blue tongue, to gain insight into this species' visual ecology. We used electroretinograms, opsin sequencing and immunohistochemical labelling to characterize whole-eye spectral sensitivity and the elements that shape it. Our findings reveal that T. rugosa expresses all five opsins typically found in lizards (SWS1, SWS2, RH1, RH2 and LWS) but possesses greatly enhanced short-wavelength sensitivity compared with other diurnal lizards. This enhanced short-wavelength sensitivity is characterized by a broadening of the spectral sensitivity curve of the eye towards shorter wavelengths while the peak sensitivity of the eye at longer wavelengths (560 nm) remains similar to that of other diurnal lizards. While an increased abundance of SWS1 photoreceptors is thought to mediate elevated ultraviolet sensitivity in a couple of other lizard species, SWS1 photoreceptor abundance remains low in this species. Instead, our findings suggest that short-wavelength sensitivity is driven by multiple factors which include a potentially red-shifted SWS1 photoreceptor and the absence of short-wavelength-absorbing oil droplets. Examining the coincidence of enhanced short-wavelength sensitivity with blue tongues among lizards of this genus will provide further insight into the co-evolution of conspecific signals and whole-eye spectral sensitivity.

Ort, förlag, år, upplaga, sidor
The Company of Biologists, 2022
Nyckelord
Electroretinography, Opsins, Photoreceptors, Scincidae, Spectral sensitivity
Nationell ämneskategori
Zoologi Evolutionsbiologi
Identifikatorer
urn:nbn:se:umu:diva-198002 (URN)10.1242/JEB.244317 (DOI)000811278900021 ()35582824 (PubMedID)2-s2.0-85131903228 (Scopus ID)
Tillgänglig från: 2022-07-11 Skapad: 2022-07-11 Senast uppdaterad: 2022-07-11Bibliografiskt granskad
Eilertsen, M., Dolan, D. W. .., Bolton, C. M., Karlsen, R., Davies, W. I. L., Edvardsen, R. B., . . . Helvik, J. V. (2022). Photoreception and transcriptomic response to light during early development of a teleost with a life cycle tightly controlled by seasonal changes in photoperiod. PLOS Genetics, 18(12), Article ID e1010529.
Öppna denna publikation i ny flik eller fönster >>Photoreception and transcriptomic response to light during early development of a teleost with a life cycle tightly controlled by seasonal changes in photoperiod
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2022 (Engelska)Ingår i: PLOS Genetics, ISSN 1553-7390, E-ISSN 1553-7404, Vol. 18, nr 12, artikel-id e1010529Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Light cues vary along the axis of periodicity, intensity and spectrum and perception of light is dependent on the photoreceptive capacity encoded within the genome and the opsins expressed. A global approach was taken to analyze the photoreceptive capacity and the effect of differing light conditions on a developing teleost prior to first feeding. The transcriptomes of embryos and alevins of Atlantic salmon (Salmo salar) exposed to different light conditions were analyzed, including a developmental series and a circadian profile. The results showed that genes mediating nonvisual photoreception are present prior to hatching when the retina is poorly differentiated. The clock genes were expressed early, but the circadian profile showed that only two clock genes were significantly cycling before first feeding. Few genes were differentially expressed between day and night within a light condition; however, many genes were significantly different between light conditions, indicating that light environment has an impact on the transcriptome during early development. Comparing the transcriptome data from constant conditions to periodicity of white light or different colors revealed overrepresentation of genes related to photoreception, eye development, muscle contraction, degradation of metabolites and cell cycle among others, and in constant light, several clock genes were upregulated. In constant white light and periodicity of green light, genes associated with DNA replication, chromatin remodeling, cell division and DNA repair were downregulated. The study implies a direct influence of light conditions on the transcriptome profile at early developmental stages, by a complex photoreceptive system where few clock genes are cycling.

Ort, förlag, år, upplaga, sidor
Public Library of Science, 2022
Nationell ämneskategori
Zoologi Genetik
Identifikatorer
urn:nbn:se:umu:diva-202065 (URN)10.1371/journal.pgen.1010529 (DOI)000924505200019 ()36508414 (PubMedID)2-s2.0-85144584295 (Scopus ID)
Forskningsfinansiär
Norges forskningsråd, 254894
Tillgänglig från: 2023-01-03 Skapad: 2023-01-03 Senast uppdaterad: 2023-09-05Bibliografiskt granskad
Dakhel, S., Davies, W. I. L., Joseph, J. V., Tomar, T., Remeseiro, S. & Gunhaga, L. (2021). Chick fetal organ spheroids as a model to study development and disease. BMC Molecular and Cell Biology, 22(1), Article ID 37.
Öppna denna publikation i ny flik eller fönster >>Chick fetal organ spheroids as a model to study development and disease
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2021 (Engelska)Ingår i: BMC Molecular and Cell Biology, E-ISSN 2661-8850, Vol. 22, nr 1, artikel-id 37Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

BACKGROUND: Organ culture models have been used over the past few decades to study development and disease. The in vitro three-dimensional (3D) culture system of organoids is well known, however, these 3D systems are both costly and difficult to culture and maintain. As such, less expensive, faster and less complex methods to maintain 3D cell culture models would complement the use of organoids. Chick embryos have been used as a model to study human biology for centuries, with many fundamental discoveries as a result. These include cell type induction, cell competence, plasticity and contact inhibition, which indicates the relevance of using chick embryos when studying developmental biology and disease mechanisms.

RESULTS: Here, we present an updated protocol that enables time efficient, cost effective and long-term expansion of fetal organ spheroids (FOSs) from chick embryos. Utilizing this protocol, we generated FOSs in an anchorage-independent growth pattern from seven different organs, including brain, lung, heart, liver, stomach, intestine and epidermis. These three-dimensional (3D) structures recapitulate many cellular and structural aspects of their in vivo counterpart organs and serve as a useful developmental model. In addition, we show a functional application of FOSs to analyze cell-cell interaction and cell invasion patterns as observed in cancer.

CONCLUSION: The establishment of a broad ranging and highly effective method to generate FOSs from different organs was successful in terms of the formation of healthy, proliferating 3D organ spheroids that exhibited organ-like characteristics. Potential applications of chick FOSs are their use in studies of cell-to-cell contact, cell fusion and tumor invasion under defined conditions. Future studies will reveal whether chick FOSs also can be applicable in scientific areas such as viral infections, drug screening, cancer diagnostics and/or tissue engineering.

Ort, förlag, år, upplaga, sidor
BioMed Central (BMC), 2021
Nyckelord
3D cell culture, Cancer, Chick, Development, Fetal organ spheroids, Invasion
Nationell ämneskategori
Cell- och molekylärbiologi
Identifikatorer
urn:nbn:se:umu:diva-186439 (URN)10.1186/s12860-021-00374-6 (DOI)000669871300001 ()34225662 (PubMedID)2-s2.0-85110859058 (Scopus ID)
Forskningsfinansiär
Cancerfonden, 18 0463Cancerforskningsfonden i Norrland
Tillgänglig från: 2021-08-02 Skapad: 2021-08-02 Senast uppdaterad: 2023-10-05Bibliografiskt granskad
Hickey, D. G., Davies, W. I. L., Hughes, S., Rodgers, J., Thavanesan, N., MacLaren, R. E. & Hankins, M. W. (2021). Chimeric human opsins as optogenetic light sensitisers. Journal of Experimental Biology, 224(14), Article ID jeb240580.
Öppna denna publikation i ny flik eller fönster >>Chimeric human opsins as optogenetic light sensitisers
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2021 (Engelska)Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 224, nr 14, artikel-id jeb240580Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Human opsin-based photopigments have great potential as light-sensitisers, but their requirement for phototransduction cascade-specific second messenger proteins may restrict their functionality in non-native cell types. In this study, eight chimeric human opsins were generated consisting of a backbone of either a rhodopsin (RHO) or long-wavelength-sensitive (LWS) opsin and intracellular domains from G(q/11)-coupled human melanopsin. Rhodopsin/melanopsin chimeric opsins coupled to both Gi and G(q/11) pathways. Greater substitution of the intracellular surface with corresponding melanopsin domains generally showed greater G(q/11) activity with a decrease in Gi activation. Unlike melanopsin, rhodopsin and rhodopsin/melanopsin chimeras were dependent upon exogenous chromophore to function. By contrast, wild-type LWS opsin and LWS opsin/melanopsin chimeras showed only weak Gi activation in response to light, whilst G(q/11) pathway activation was not detected. Immunocytochemistry (ICC) demonstrated that chimeric opsins with more intracellular domains of melanopsin were less likely to be trafficked to the plasma membrane. This study demonstrates the importance of Ga coupling efficiency to the speed of cellular responses and created human opsins with a unique combination of properties to expand the range of customised optogenetic biotools for basic research and translational therapies.

Ort, förlag, år, upplaga, sidor
Cambridge: Company of Biologists LTD, 2021
Nyckelord
Retina, Opsin, Chimera, G protein, Optogenetics, Phototransduction
Nationell ämneskategori
Farmakologi och toxikologi Läkemedelskemi
Identifikatorer
urn:nbn:se:umu:diva-187339 (URN)10.1242/jeb.240580 (DOI)000681398200006 ()34151984 (PubMedID)2-s2.0-85111561747 (Scopus ID)
Tillgänglig från: 2021-09-13 Skapad: 2021-09-13 Senast uppdaterad: 2023-03-24Bibliografiskt granskad
Davies, W. I. L., Sghari, S., Upton, B. A., Nord, C., Hahn, M., Ahlgren, U., . . . Gunhaga, L. (2021). Distinct opsin 3 (Opn3) expression in the developing nervous system during mammalian embryogenesis. eNeuro, 8(5), Article ID ENEURO.0141-21.2021.
Öppna denna publikation i ny flik eller fönster >>Distinct opsin 3 (Opn3) expression in the developing nervous system during mammalian embryogenesis
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2021 (Engelska)Ingår i: eNeuro, E-ISSN 2373-2822, Vol. 8, nr 5, artikel-id ENEURO.0141-21.2021Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Opsin 3 (Opn3) is highly expressed in the adult brain, however, information for spatial and temporal expression patterns during embryogenesis is significantly lacking. Here, an Opn3-eGFP reporter mouse line was used to monitor cell body expression and axonal projections during embryonic and early postnatal to adult stages. By applying 2D and 3D fluorescence imaging techniques, we have identified the onset of Opn3 expression, which predominantly occurred during embryonic stages, in various structures during brain/head development. In ad-dition, this study defines over twenty Opn3-eGFP-positive neural structures never reported before. Opn3-eGFP was first observed at E9.5 in neural regions, including the ganglia that will ultimately form the trigeminal, facial and vestibulocochlear cranial nerves (CNs). As development proceeds, expanded Opn3-eGFP expression coincided with the formation and maturation of critical components of the central and peripheral nervous systems (CNS, PNS), including various motor-sensory tracts, such as the dorsal column-medial lemniscus (DCML) sensory tract, and olfactory, acoustic, and optic tracts. The widespread, yet distinct, detection of Opn3-eGFP already at early embryonic stages suggests that Opn3 might play important functional roles in the developing brain and spinal cord to regulate multiple motor and sensory circuitry systems, including proprio-ception, nociception, ocular movement, and olfaction, as well as memory, mood, and emotion. This study presents a crucial blueprint from which to investigate autonomic and cognitive opsin-dependent neural development and resultant behaviors under physiological and pathophysiological conditions.

Ort, förlag, år, upplaga, sidor
Society for Neuroscience, 2021
Nyckelord
Brain, Development, Encephalopsin, Nervous system, Opn3, OPT
Nationell ämneskategori
Neurovetenskaper Utvecklingsbiologi
Identifikatorer
urn:nbn:se:umu:diva-187852 (URN)10.1523/ENEURO.0141-21.2021 (DOI)000704430100013 ()34417283 (PubMedID)2-s2.0-85114912713 (Scopus ID)
Forskningsfinansiär
Vetenskapsrådet, 2017-01430Kempestiftelserna, SMK-1763Vetenskapsrådet, 2017-01307
Tillgänglig från: 2021-09-23 Skapad: 2021-09-23 Senast uppdaterad: 2023-09-05Bibliografiskt granskad
Schluessel, V., Rick, I. P., Seifert, F. D., Baumann, C. & Davies, W. I. L. (2021). Not just shades of grey: Life is full of colour for the ocellate river stingray (Potamotrygon motoro). Journal of Experimental Biology, 224(9), Article ID jeb226142.
Öppna denna publikation i ny flik eller fönster >>Not just shades of grey: Life is full of colour for the ocellate river stingray (Potamotrygon motoro)
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2021 (Engelska)Ingår i: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 224, nr 9, artikel-id jeb226142Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Previous studies have shown that marine stingrays have the anatomical and physiological basis for colour vision, with cone spectral sensitivity in the blue to green range of the visible spectrum. Behavioural studies on Glaucostegus typus also showed that blue and grey can be perceived and discriminated. The present study is the first to assess visual opsin genetics in the ocellate river stingray (Potamotrygon motoro) and test whether individuals perceive colour in two alternative forced choice experiments. Retinal transcriptome profiling using RNA-Seq and quantification demonstrated the presence of lws and rh2 cone opsin genes and a highly expressed single rod (rh1) opsin gene. Spectral tuning analysis predicted these vitamin A1-based visual photopigments to exhibit spectral absorbance maxima at 461 nm (rh2), 496 nm (rh1) and 555 nm (lws); suggesting the presence of dichromacy in this species. Indeed, P. motoro demonstrates the potential to be equally sensitive to wavelengths from 380 to 600 nm of the visible spectrum. Behavioural results showed that red and green plates, as well as blue and yellow plates, were readily discriminated based on colour; however, brightness differences also played a part in the discrimination of blue and yellow. Red hues of different brightness were distinguished significantly above chance level from one another. In conclusion, the genetic and behavioural results support prior data on marine stingrays. However, this study suggests that freshwater stingrays of the family Potamotrygonidae may have a visual colour system that has ecologically adapted to a riverine habitat.

Ort, förlag, år, upplaga, sidor
The Company of Biologists, 2021
Nyckelord
Behaviour, Cognition, Colour discrimination, Colour vision, Elasmobranch, Opsins, Stingray
Nationell ämneskategori
Zoologi
Identifikatorer
urn:nbn:se:umu:diva-183704 (URN)10.1242/jeb.226142 (DOI)000651507000002 ()2-s2.0-85106069842 (Scopus ID)
Forskningsfinansiär
Kempestiftelserna
Tillgänglig från: 2021-05-31 Skapad: 2021-05-31 Senast uppdaterad: 2023-09-05Bibliografiskt granskad
Warrington, R. E., Davies, W. I. L., Hemmi, J. M., Hart, N. S., Potter, I. C., Collin, S. P. & Hunt, D. M. (2021). Visual opsin expression and morphological characterization of retinal photoreceptors in the pouched lamprey (Geotria australis, Gray). Journal of Comparative Neurology, 529(9), 2265-2282
Öppna denna publikation i ny flik eller fönster >>Visual opsin expression and morphological characterization of retinal photoreceptors in the pouched lamprey (Geotria australis, Gray)
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2021 (Engelska)Ingår i: Journal of Comparative Neurology, ISSN 0021-9967, E-ISSN 1096-9861, Vol. 529, nr 9, s. 2265-2282Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Lampreys are extant members of the agnathan (jawless) vertebrates that diverged ~500 million years ago, during a critical stage of vertebrate evolution when image‐forming eyes first emerged. Among lamprey species assessed thus far, the retina of the southern hemisphere pouched lamprey, Geotria australis, is unique, in that it possesses morphologically distinct photoreceptors and expresses five visual photopigments. This study focused on determining the number of different photoreceptors present in the retina of G. australis and whether each cell type expresses a single opsin class. Five photoreceptor subtypes were identified based on ultrastructure and differential expression of one of each of the five different visual opsin classes (lws, sws1, sws2, rh1, and rh2) known to be expressed in the retina. This suggests, therefore, that the retina of G. australis possesses five spectrally and morphologically distinct photoreceptors, with the potential for complex color vision. Each photoreceptor subtype was shown to have a specific spatial distribution in the retina, which is potentially associated with changes in spectral radiance across different lines of sight. These results suggest that there have been strong selection pressures for G. australis to maintain broad spectral sensitivity for the brightly lit surface waters that this species inhabits during its marine phase. These findings provide important insights into the functional anatomy of the early vertebrate retina and the selection pressures that may have led to the evolution of complex color vision.

Ort, förlag, år, upplaga, sidor
John Wiley & Sons, 2021
Nyckelord
color vision, Geotria australis, lamprey, opsin, photoreceptor
Nationell ämneskategori
Zoologi
Identifikatorer
urn:nbn:se:umu:diva-178964 (URN)10.1002/cne.25092 (DOI)000603419100001 ()33336375 (PubMedID)2-s2.0-85098280066 (Scopus ID)
Tillgänglig från: 2021-02-05 Skapad: 2021-02-05 Senast uppdaterad: 2021-07-14Bibliografiskt granskad
Organisationer
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0003-0232-1812

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