Journal Article

Eye degeneration and loss of otx5b expression in the cavefish Sinocyclocheilus tileihornes

Huang, Z., Titus, T., Postlethwait, J.H. and Meng, F.

Record Number:
4389
Year:
2019
Journal:
Journal of Molecular Evolution
Abstract:
Cave animals possess remarkable phenotypes associated with existence in their dark environments. The Chinese cavefish Sinocyclocheilus tileihornes shows substantial eye degeneration, a trait shared by most cave species. The extent to which independent evolution of troglomorphic traits uses convergent molecular genetic mechanisms is as yet unknown. We performed transcriptome-wide gene expression profiling in S. tileihornes eyes and compared results with those from the closely related surface species S. angustiporus and an independently derived congeneric cavefish, S. anophthalmus. In total, 52.85 million 100 bp long paired-end clean reads were generated for S. tileihornes, and we identified differentially expressed genes between the three possible pairs of species. Functional analysis of genes differentially expressed between S. tileihornes and S. angustiporus revealed that phototransduction (KEGG id: dre04744) was the most significantly enriched pathway, indicating the obvious differences in response to captured photons between the cavefish S. tileihornes and the surface species S. angustiporus. Analysis of key genes regulating eye development showed complete absence of otx5b (orthodenticle homolog 5) expression in S. tileihornes eyes, probably related to degradation of rods, but normal expression of crx (cone-rod homeobox). The enriched pathways and Otx5 are involved in phototransduction, photoreceptor formation, and regulation of photoreceptor-related gene expression. Unlike the S. tileihornes reported here, S. anophthalmus has reduced crx and otx5 expression. These results show that different species of cavefish within the same genus that independently evolved troglodyte characteristics can have different genetic mechanisms of eye degeneration.
Times Cited:
2
Related Records:
Chen, Y. R., Chu, X. L., Luo, Z. and Wu, J. (1988)
A new blind cyprinid fish from Yunnan, China with a reference to the evolution of its characters
Chen, Y.R. and Yang, J.X. (1993)
Species and origin of cave dwelling Sinocyclocheilus fishes
Chen, Y.R. and Yang, J.X. (1993)
A synopsis of cavefishes from China
Yang, J. X. and Chen, Y. R. (1993)
The cavefishes from Jiuxiang Limestone Cave of Yunnan, China with reference to character evolutions
Yue, P. and Chen, Y. (1998)
China Red Data Book of Endangered Animals. Pisces
Wang, D and Chen, YY (1998)
On the diagnosis of Sinocyclocheilus and the taxonomic position of its closely related genus Anchicyclocheilus (Cypriniformes: Cyprinidae: Barbinae)
Xiao, H, Zhang, R, Feng, J, Ou, Y., M, Li, W, Chen, S and Zan, R (2002)
Nuclear DNA content and ploidy of seventeen species of fishes in Sinocyclocheilus
Mao, WN, Lu, ZM, Li, WX, Ma, HM and Huang, G (2003)
A new species of Sinocyclocheilus (Cyprinidae) from cave of Yunnan, China
Meng, F.W., Braasch, I., Phillips, J.B., Lin, X.W., Titus, T., Zhang, C.G. and Postlethwait, J.H. (2013)
Evolution of the eye transcriptome under constant darkness in Sinocyclocheilus cavefish
Meng, F.W., Zhao, Y.H., Postlethwait, J.H. and Zhang, C.G. (2013)
Differentially-expressed opsin genes identified in Sinocyclocheilus cavefish endemic to China
Li, C.Q., Huang, H.T., Yang, S., He, H., Fu, Q.Y., Chen, S.Y. and Xiao, H. (2018)
Complete mitochondrial genome and phylogenetic analysis of Sinocyclocheilus oxycephalus (Cypriniformes: Cyprinidae)
Meng, F., Zhao, Y.H., Titus, T., Zhang, C.G. and Postlethwait, J.H. (2018)
Brain of the blind: transcriptomics of the golden-line cavefish brain
Niu, C., Luo, J., Yang, J. and Zhao, Y. (2018)
Length–weight relationships of four cavefish species from China
Chen, H., Li, C., Liu, T., Chen, S. and Xiao, H. (2019)
A metagenomic study of intestinal microbial diversity in relation to feeding habits of surface and cave-dwelling Sinocyclocheilus species
Chen, H., Li, C., Liu, T., Chen, S. and Xiao, H. (2019)
A metagenomic study of intestinal microbial diversity in relation to feeding habits of surface and cave-dwelling Sinocyclocheilus species
Huang, Z., Titus, T., Postlethwait, J.H. and Meng, F. (2019)
Eye degeneration and loss of otx5b expression in the cavefish Sinocyclocheilus tileihornes
Huang, Z., Titus, T., Postlethwait, J.H. and Meng, F. (2019)
Eye degeneration and loss of otx5b expression in the cavefish Sinocyclocheilus tileihornes
Lunghi, E., Zhao, Y., Sun, X. and Zhao, Y. (2019)
Morphometrics of eight Chinese cavefish species
Lunghi, E., Zhao, Y., Sun, X. and Zhao, Y. (2019)
Morphometrics of eight Chinese cavefish species
Mao, T.-R., Liu, Y.-W., Meegaskumbura, M., Yang, J., Ellepola, G., Senevirathne, G., Fu, C.-H., Gross, J.B. and Pie, M.R. (2020)
Evolution in Sinocyclocheilus cavefish is marked by rate shifts, reversals and origin of novel traits