Journal Article
Comparative transcriptomics reveals the molecular genetic basis of pigmentation loss in Sinocyclocheilus cavefishes
Li, C., Chen, H., Zhao, Y., Chen, S. and Xiao, H.
Record Number:
5030
Year:
2020
Journal:
Ecology and Evolution
Pages:
14256–14271
Volume:
10
Abstract:
Cave-dwelling animals evolve distinct troglomorphic traits, such as loss of eyes,
skin pigmentation, and augmentation of senses following long-term adaptation to
perpetual darkness. However, the molecular genetic mechanisms underlying these
phenotypic variations remain unclear. In this study, we conducted comparative histology
and comparative transcriptomics study of the skin of eight Sinocyclocheilus
species (Cypriniformes: Cyprinidae) that included surface- and cave-dwelling species.
We analyzed four surface and four cavefish species by using next-generation sequencing,
and a total of 802,798,907 clean reads were generated and assembled into
505,495,009 transcripts, which contributed to 1,037,334 unigenes. Bioinformatic
comparisons revealed 10,629 and 6,442 significantly differentially expressed unigenes
between four different surface-cave fish groups. Further, tens of differentially
expressed genes (DEGs) potentially related to skin pigmentation were identified.
Most of these DEGs (including GNAQ, PKA, NRAS, and p38) are downregulated in
cavefish species. They are involved in key signaling pathways of pigment synthesis,
such as the melanogenesis, Wnt, and MAPK pathways. This trend of downregulation
was confirmed through qPCR experiments. This study will deepen our understanding
of the formation of troglomorphic traits in cavefishes.
K E Y W O R D S
cavefish, comparative transcriptomics, pigmentation, Sinocyclocheilus, troglomorphic trait
Times Cited:
4