Molecular phylogeny of Sinocyclocheilus (Cypriniformes: Cyprinidae) inferred from mitochondrial DNA sequences.
More than 10 species within the freshwater fish genus Sinoncyclocheilus adapt to caves and show different degrees of degeneration of eyes and pigmentation. Therefore, this genus can be useful for studying evolutionary developmental mechanisms, role of natural selection and adaptation in cave animals. To better understand these processes, it is indispensable to have background knowledge about phylogenetic relationships of surface and cave species within this genus. To investigate phylogenetic relationships among species within this genus, we determined nucleotide sequences of complete mitochondrial cytochrome b gene (1140 bp) and partial ND4 gene (1032 bp) of 31 recognized ingroup species and one outgroup species Barbodes laticeps. Phylogenetic trees were reconstructed using maximum parsimony, Bayesian, and maximum likelihood analyses. Our phylogenetic results showed that all species except for two surface species S. jii and S. macrolepis clustered as five major monophyletic clades (I, II, III, IV, and V) with strong supports. S. jii was the most basal species in all analyses, but the position of S. macrolepis was not resolved. The cave species were polyphyletic and occurred in these five major clades. Our results indicate that adaptation to cave environments has occurred multiple times during the evolutionary history of Sinocyclocheilus. The branching orders among the clades I, II, III, and IV were not resolved, and this might be due to early rapid radiation in Sinocyclocheilus. All species distributed in Yunnan except for S. rhinocerous and S. hyalinus formed a strongly supported monophyletic group (clade V), probably reflecting their common origins. This result suggested that the diversification of Sinocyclocheilus in Yunnan may correlate with the uplifting of Yunnan Plateau.
Xiao
Heng
H
Laboratory for Conservation and Utilization of Bio-resource, Yunnan University, Kunming 650091, China.
Chen
Shan-Yuan
SY
Liu
Zhong-Min
ZM
Zhang
Ren-Dong
RD
Li
Wei-Xian
WX
Zan
Rui-Guang
RG
Zhang
Ya-Ping
YP
D000222:Adaptation, Physiological; D000818:Animals; D001483:Base Sequence; D002681:China; D003530:Cyprinidae / Q000145:classification* / Q000235:genetics* / Q000502:physiology; D045303:Cytochromes b / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D019143:Evolution, Molecular; D005843:Geography; D009245:NADH Dehydrogenase / Q000235:genetics; D010802:Phylogeny; D012641:Selection, Genetic
D004272:DNA, Mitochondrial; C098483:NADH dehydrogenase subunit 4; D045303:Cytochromes b; D009245:NADH Dehydrogenase