Reduced opsin gene expression in a cave-dwelling fish

作者：Tobler Michael^*; Coleman Seth W; Perkins Brian D; Rosenthal Gil G

来源：Biology Letters, 2010, 6(1): 98-101.

DOI：10.1098/rsbl.2009.0549

• regressive evolution
• vision
• qPCR
• Poecilia mexicana
• Poeciliidae

Regressive evolution of structures associated with vision in cave-dwelling organisms is the focus of intense research. Most work has focused on differences between extreme visual phenotypes: sighted, surface animals and their completely blind, cave-dwelling counterparts. We suggest that troglodytic systems, comprising multiple populations that vary along a gradient of visual function, may prove critical in understanding the mechanisms underlying initial regression in visual pathways. Gene expression assays of natural and laboratory-reared populations of the Atlantic molly (Poecilia mexicana) revealed reduced opsin expression in cave-dwelling populations compared with surface-dwelling conspecifics. Our results suggest that the reduction in opsin expression in cave-dwelling populations is not phenotypically plastic but reflects a hardwired system not rescued by exposure to light during retinal ontogeny. Changes in opsin gene expression may consequently represent a first evolutionary step in the regression of eyes in cave organisms.

• 出版日期2010-2-23