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Roberts, R.

Publications and source records attributed to Roberts, R..

2 recordsLinked to original sources

Variation in pigmentation gene expression is associated with distinct aposematic color morphs in the poison frog, Dendrobates auratus

Color and pattern phenotypes have clear implications for survival and reproduction in many species. However, the mechanisms that produce this coloration are still poorly characterized, especially at the genomic level. Here we have taken a transcriptomics-based approach to elucidate the underlying genetic mechanisms affecting color and pattern in a highly polytypic poison frog. We sequenced RNA from the skin from four different color morphs during the final stage of metamorphosis and assembled a de novo transcriptome. We then investigated differential gene expression, with an emphasis on examining candidate color genes from other taxa. Overall, we found differential expression of a suite of genes that control melanogenesis, melanocyte differentiation, and melanocyte proliferation (e.g., tyrpl, lefl, leol, and mitf) as well as several differentially expressed genes involved in purine synthesis and iridophore development (e.g., arfgapl, arfgap2, airc, and gairt). Our results provide evidence that several gene networks known to affect color and pattern in vertebrates play a role in color and pattern variation in this species of poison frog.

evolutionary biology

Isoform and protein region abnormalities of dysbindin and copper transporter proteins in postmortem schizophrenia substantia nigra.

ObjectiveDysbindin is downregulated in several schizophrenia brain regions and modulates copper transport required for myelination and monoamine metabolism. We sought to determine dysbindin and copper transporter protein expression in schizophrenia subjects.\n\nMethodsWe studied the substantia nigra (which exhibits one of the highest copper contents of the human brain) using Western blot analysis. We characterized specific protein domains of copper transporters ATP7A, CTR1, ATP7B, and dysbindin isoforms 1A and 1B/C in postmortem substantia nigra in schizophrenia subjects (n=15) and matched controls (n=11). As a preliminary investigation, we examined medication status in medicated (n=11) versus unmedicated schizophrenia subjects (n=4).\n\nResultsThe combined schizophrenia group exhibited increased levels of C-terminus, but not N-terminus, ATP7A. Schizophrenia subjects expressed less transmembrane CTR1 and dysbindin 1B/C than controls. When subdivided, the increased C-terminus ATP7A protein was present only in medicated subjects versus controls. Unmedicated subjects exhibited less N-terminus ATP7A protein than controls and medicated subjects, suggesting medication-induced rescue of the ATP7A N-terminus. Transmembrane CTR1 was decreased to a similar extent in both treatment groups versus controls, suggesting no medication effect.\n\nConclusionsThese results provide the first evidence of disrupted copper transport into and within schizophrenia nigral cells that may be modulated by specific dysbindin isoforms and antipsychotic treatment.

neuroscience