Evolution of an adaptive behavior and its sensory receptors promotes eye regression in blind cavefish

Yoshizawa, Masato; O’Quin, Kelly E; Jeffery, William R

Evolution of an adaptive behavior and its sensory receptors promotes eye regression in blind cavefish

dc.contributor.author	Yoshizawa, Masato
dc.contributor.author	O’Quin, Kelly E
dc.contributor.author	Jeffery, William R
dc.date.accessioned	2021-09-27T18:07:50Z
dc.date.available	2021-09-27T18:07:50Z
dc.date.issued	2013-07-11
dc.description.abstract	How and why animals lose eyesight during adaptation to the dark and food-limited cave environment has puzzled biologists since the time of Darwin. More recently, several different adaptive hypotheses have been proposed to explain eye degeneration based on studies in the teleost Astyanax mexicanus, which consists of blind cave-dwelling (cavefish) and sighted surface-dwelling (surface fish) forms. One of these hypotheses is that eye regression is the result of indirect selection for constructive characters that are negatively linked to eye development through the pleiotropic effects of Sonic Hedgehog (SHH) signaling. However, subsequent genetic analyses suggested that other mechanisms also contribute to eye regression in Astyanax cavefish. Here, we introduce a new approach to this problem by investigating the phenotypic and genetic relationships between a suite of non-visual constructive traits and eye regression. Using quantitative genetic analysis of crosses between surface fish, the Pachón cavefish population and their hybrid progeny, we show that the adaptive vibration attraction behavior (VAB) and its sensory receptors, superficial neuromasts (SN) specifically found within the cavefish eye orbit (EO), are genetically correlated with reduced eye size. The quantitative trait loci (QTL) for these three traits form two clusters of congruent or overlapping QTL on Astyanax linkage groups (LG) 2 and 17, but not at the shh locus on LG 13. Ablation of EO SN in cavefish demonstrated a major role for these sensory receptors in VAB expression. Furthermore, experimental induction of eye regression in surface fish via shh overexpression showed that the absence of eyes was insufficient to promote the appearance of VAB or EO SN. We conclude that natural selection for the enhancement of VAB and EO SN indirectly promotes eye regression in the Pachón cavefish population through an antagonistic relationship involving genetic linkage or pleiotropy among the genetic factors underlying these traits. This study demonstrates a trade-off between the evolution of a non-visual sensory system and eye regression during the adaptive evolution of Astyanax to the cave environment.	en_US
dc.description.uri	https://doi.org/10.1186/1741-7007-10-108
dc.description.uri	https://doi.org/10.1186/1741-7007-11-82
dc.identifier	https://doi.org/10.13016/0iil-juzx
dc.identifier.citation	Yoshizawa, M., Yamamoto, Y., O'Quin, K.E. et al. Evolution of an adaptive behavior and its sensory receptors promotes eye regression in blind cavefish. BMC Biol 10, 108 (2012).	en_US
dc.identifier.uri	http://hdl.handle.net/1903/28024
dc.language.iso	en_US	en_US
dc.publisher	Springer Nature	en_US
dc.relation.isAvailableAt	College of Computer, Mathematical & Physical Sciences	en_us
dc.relation.isAvailableAt	Digital Repository at the University of Maryland	en_us
dc.relation.isAvailableAt	Biology	en_us
dc.relation.isAvailableAt	University of Maryland (College Park, MD)	en_us
dc.subject	Animal behavior	en_US
dc.subject	Regressive evolution	en_US
dc.subject	Constructive evolution	en_US
dc.subject	Neuromast	en_US
dc.subject	Tradeoff	en_US
dc.subject	hedgehog	en_US
dc.subject	Quantitative trait locus	en_US
dc.subject	Eye	en_US
dc.subject	QTL cluster	en_US
dc.subject	Adaptation	en_US
dc.title	Evolution of an adaptive behavior and its sensory receptors promotes eye regression in blind cavefish	en_US
dc.type	Article	en_US