Effects of GABA-ergic agonists and antagonists were examined on the melanophores of a carp C. mrigala in vitro. GABA and baclofen both induced concentration - related dispersion in fish melanophores. Denervation of the melanophores by reserpine treatment potentiated the sensitivity of the melanophores to GABA. While denervation by cooling treatment inhibited the sensitivity of the melanophores to GABA, atropine, bicuculline and pentylenetetrazole all inhibited the dispersal responses of the melanophores induced by higher concentrations of GABA. 5-aminovaleric acid also significantly inhibited the dispersion of the melanophores induced either by GABA or baclofen. It is concluded that GABA-ergic agonist induced dispersal responses in C mrigala melanophores are mediated through specific GABA receptors. The presence of both GABAA and GABAB receptors in this fish melanophores has been indicated.
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Pigment Cell Melanoma Res
January 2025
Department of Cell Biology and Anatomy, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.
Circadian regulation of skin pigmentation is essential for thermoregulation, ultraviolet (UV) protection, and synchronization of skin cell renewal. This regulation involves both cell-autonomous photic responses and non-cell-autonomous hormonal control, particularly through melatonin produced in a light-sensitive manner. Photosensitive opsins, cryptochromes, and melatonin regulate circadian rhythms in skin pigment cells.
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January 2025
Department of Genetics and Biotechnology, Graduate School of Biotechnology, College of Life Sciences, Kyung Hee University, Yongin, Korea.
Melanosome transport is regulated by major proteins, including Rab27a, Melanophilin (Mlph), and Myosin Va (Myo-Va), that form a tripartite complex. Mutation of these proteins causes melanosome aggregation around the nucleus. Among these proteins, Mlph is a linker between Rab27a and Myo-Va.
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December 2024
Department of Pathology, Faculty of Veterinary Medicine, Cairo University, Giza, 12211, Egypt.
In this study, 10 fish species, Jayan flounder (Pseudorhombus javanicus); Oriental sole (Eurgglossa arientalis); Oange-spotted grouper (Epinephelus coioides); Blacktip trevally (Caranx heberi); Towbar seabream (Acanthopagrus bifascia); Smalltooth emperor (Lethrinus microdon); Spangled emperio (Lethrinus nebulous); Sharptooth hammer croaker (Johnius vogleri); Bigeye croaker (Pennahia anea) and Redspine thread bream (Nemipterus nemurus), were examined in El-Jubail province, Saudi Arabia, Arabian Gulf region over three years from 2017 to 2020. The examined fish species showed muscular atrophy in a total percent of 1.1%, but with variable percentages of affections in each species.
View Article and Find Full Text PDFAnimals (Basel)
December 2024
Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610213, China.
Background color matching is essential for camouflage and thermoregulation in ectothermic vertebrates, yet several key cellular-level questions remain unresolved. For instance, it is unclear whether the number of chromatophores or the activity of individual chromatophores plays a more critical role in this process. Using single-cell RNA sequencing (scRNA-seq), we investigated the cellular and molecular mechanisms underlying color change in , which adapted to its background by displaying light-green skin on white and black skin on black within two days.
View Article and Find Full Text PDFAbstractHormones can induce trait development in one species yet have no effect on the same trait in a closely related species, but the mechanisms underlying these differences are unclear. Here, we compare two closely related lizard species to explore the cellular mechanisms associated with the evolutionary loss of hormonally mediated ventral coloration. The eastern fence lizard () has sexually dimorphic blue and black ventral coloration that develops when maturational increases in androgens induce melanin synthesis in males.
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