title: Genetic Diversity of Daphnia pulex in the Middle and Lower Reaches of the Yangtze River.
abstract: Increased human activities and environmental changes may lead to genetic diversity variations of Cladocerans in water. Daphnia pulex are distributed throughout the world and often regarded as a model organism. The 16S rDNA, cytochrome c oxidase subunit I (COI), and 18S genes were used as molecular marks. The genetic diversity and phylogeny of D. pulex obtained from 10 water bodies in the middle and lower reaches of the Yangtze River were studied. For 16S rDNA, COI gene, and 18S gene, the A+T content (65.4%, 58.4%, and 54.6%) was significantly higher than the G+C content (34.6%, 41.6% and 45.4%). This result was consistent with higher A and T contents among invertebrates. Based on the genetic distances of 16S rDNA and COI genes, the genetic differences of D. pulex from 10 water bodies located in the middle and lower reaches of the Yangtze River in China was minimal (0%-0.8% for 16S rDNA and 0%-1.5% for COI gene). However, D. pulex evolved into two branches in the phylogenetic trees, which coincided with its geographical distribution. Compared with D. pulex from other countries, the average genetic distance of D. pulex obtained from 10 water bodies in the middle and lower reaches of the Yangtze River reached 9.1%-10.5%, thereby indicating that D. pulex may have evolved into different subspecies.
authors.affiliation: School of Life Science, Huaibei Normal University, Anhui Key Laboratory of Resource and Plant Biology, Huaibei, 235000, China.
authors.forename: Wenping
authors.initials: W
authors.lastname: Wang
authors.affiliation: School of Life Science, Huaibei Normal University, Anhui Key Laboratory of Resource and Plant Biology, Huaibei, 235000, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Zhang
authors.affiliation: School of Life Science, Huaibei Normal University, Anhui Key Laboratory of Resource and Plant Biology, Huaibei, 235000, China.
authors.forename: Daogui
authors.initials: D
authors.lastname: Deng
authors.affiliation: School of Life Science, Huaibei Normal University, Anhui Key Laboratory of Resource and Plant Biology, Huaibei, 235000, China.
authors.forename: Ya-Nan
authors.initials: YN
authors.lastname: Zhang
authors.affiliation: School of Life Science, Huaibei Normal University, Anhui Key Laboratory of Resource and Plant Biology, Huaibei, 235000, China.
authors.forename: Shuixiu
authors.initials: S
authors.lastname: Peng
authors.affiliation: School of Life Science, Huaibei Normal University, Anhui Key Laboratory of Resource and Plant Biology, Huaibei, 235000, China.
authors.forename: Xiaoxue
authors.initials: X
authors.lastname: Xu
mesh_terms: D000818:Animals; D001482:Base Composition; D001499:Bayes Theorem; D044822:Biodiversity; D002681:China; D003621:Daphnia / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D016013:Likelihood Functions; D010802:Phylogeny; D058974:Phylogeography; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D045483:Rivers; D017422:Sequence Analysis, DNA
chemical_list: D012336:RNA, Ribosomal, 16S; D012337:RNA, Ribosomal, 18S; D003576:Electron Transport Complex IV