title: Comparative Studies of 5S rDNA Profiles and Cyt b Sequences in two Onychostoma Species (Cyprinidae).
abstract: Onychostoma barbatulum and O. alticorpus, two primarily freshwater cyprinid fish, have similar morphological characters and partially overlapping ecological habitats. In order to explore the genetic differences between these two species, chromosomal characteristics and genetic variations were examined by fluorescence in situ hybridization (FISH) of 5S rDNA and cytochrome (Cyt) b gene analysis. Ten specimens of O. barbatulum and O. alticorpus were collected from the Nanzihsian Stream in southern Taiwan. FISH revealed that the 5S rDNA loci of O. barbatulum and O. alticorpus were found at a pericentromeric and subtelomeric position, respectively, in a pair of submetacentric chromosomes. Cyt b genes were amplified and sequenced from five individuals of each species. Intraspecific genetic distances ranged from 0.001-0.004 in O. barbatulum and from 0.001-0.006 in O. alticorpus. Genetic distances between these two species ranged from 0.132-0.142. The phylogenetic tree showed these two species are not sister species. In conclusion, FISH cytogenetic information and Cyt b gene analyses indicated that these two species have significantly different genetic characteristics; nevertheless, their morphological similarities may be due to environmental adaptation.
authors.affiliation: National Museum of Marine Biology and Aquarium, Pingtung 944, Taiwan. hancc@nmmba.gov.tw.|Graduate Institute of Marine Biology, National Dong Hwa University, Hualien 974, Taiwan. hancc@nmmba.gov.tw.
authors.forename: Chiao-Chuan
authors.initials: CC
authors.lastname: Han
authors.affiliation: Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, Pingtung 912, Taiwan. tbyen@mail.npust.edu.tw.
authors.forename: Tsair-Bor
authors.initials: TB
authors.lastname: Yen
authors.affiliation: Institute of Aquaculture, National Pingtung University of Science and Technology, Pingtung 912, Taiwan. niancih0701@gmail.com.
authors.forename: Nian-Cih
authors.initials: NC
authors.lastname: Chen
authors.affiliation: Institute of Aquaculture, National Pingtung University of Science and Technology, Pingtung 912, Taiwan. mctseng@mail.npust.edu.tw.
authors.forename: Mei-Chen
authors.initials: MC
authors.lastname: Tseng
mesh_terms: D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence; D003530:Cyprinidae / Q000235:genetics*; D045303:Cytochromes b / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics*; D029941:Fish Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D004275:DNA, Ribosomal; D029941:Fish Proteins; D045303:Cytochromes b
keywords: Taiwan; adaptation; cyprinid; cytogenetic; genetic distance