title: Genetic variation in Whitmania pigra, Hirudo nipponica and Poecilobdella manillensis, three endemic and endangered species in China using SSR and TRAP markers.
abstract: Leeches are not only important medicinal animals worldwide but also are endangered. We aimed to (i) explore the level of genetic diversity within/among populations of three leeches, (ii) assess genetic differentiation among these three leeches, and (iii) discuss an appropriate strategy for conserving leech germplasm. A total of 315 individuals of Whitmania pigra, Hirudo nipponica and Poecilobdella manillensis from 21 populations were collected in China and Vietnam. The genetic structure and genetic diversity among and within the 21 populations were evaluated using target region amplified polymorphism (TRAP) and simple sequence repeat (SSR) markers. Sixteen pairs of TRAP primers generated a total of 398 fragments, of which 396 (99.50%) were polymorphic; fourteen pairs of SSR primers generated a total of 60 fragments, of which 59 (98.33%) were polymorphic. Shannon's index (I) and Nei's gene diversity index (H) for the three leeches were high at the species level (I=0.4980 and H=0.3323 for TRAPs, I=0.4487 and H=0.2969 for SSRs in W. pigra; I=0.4147/0.3769, H=0.2788/0.2566 for H. nipponica; and I=0.4616/0.4717, H=0.3099/0.3203 for P. manillensis). However, low genetic diversity was determined at the population level; the average genetic diversity measures within populations were H=0.1767/0.1376, I=0.2589/0.2043 for W. pigra, H=0.2149/0.2021, I=0.3184/0.3000 for H. nipponica and H=0.2850/0.2724, I=0.4152/0.3967 for P. manillensis. We conclude that there was limited gene exchange within/among populations and species, as the gene flow number (Nm) was 0.5493/0.5807. However, for all three species, the genetic diversity was different at the population level. Gene differentiation (Gst) and Nm were 0.4682 /0.5364 and 0.5678/0.4321 for W. pigra, 0.2294/0.2127 and 1.6797/1.8512 for H. nipponica and 0.1214/0.1496 and 3.6202/2.8412 for P. manillensis. STRUCTURE analysis, Unweighted Pair-Group Method with Arithmetic means (UPGMA) cluster analysis and Principal Coordinates Analysis (PCOA) all yielded similar results. The isolation-by-distance pattern was not significant for any of the three species by the Mantel test. These data emphasize the need for management, conservation, and rehabilitation of this animal species. Finally, an appropriate strategy for conserving leech is proposed.
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing 210095, PR China; Biology Post-doctoral Mobile Stations, College of Life Science, Nanjing Agricultural University, Nanjing 210095, PR China; Key Laboratory for Aquaculture and Ecology of Coastal Pool of Jiangsu Province, Yancheng Institute of Technology, Yancheng 224051, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Qiao-Sheng
authors.initials: QS
authors.lastname: Guo
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: shihz@njau.edu.cn.
authors.forename: Hong-Zhuan
authors.initials: HZ
authors.lastname: Shi
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Bo-Xing
authors.initials: BX
authors.lastname: Cheng
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Yu-Xi
authors.initials: YX
authors.lastname: Lu
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Ling
authors.initials: L
authors.lastname: Gou
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Jia
authors.initials: J
authors.lastname: Wang
authors.affiliation: Biology Post-doctoral Mobile Stations, College of Life Science, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Wen-Biao
authors.initials: WB
authors.lastname: Shen
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Shi-Meng
authors.initials: SM
authors.lastname: Yan
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Man-Jun
authors.initials: MJ
authors.lastname: Wu
mesh_terms: D000818:Animals; D002681:China; D056727:Endangered Species; D014644:Genetic Variation; D007865:Leeches / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics*; D010802:Phylogeny
keywords: Genetic diversity; Genetic structure; Hirudo nipponica; Leech; Poecilobdella manillensis; Whitmania pigra