title: Cryptic clonal lineages and genetic diversity in the loach Misgurnus anguillicaudatus (Teleostei: Cobitidae) inferred from nuclear and mitochondrial DNA analyses.
abstract: In the loach Misgurnus anguillicaudatus, the asexual lineage, which produces unreduced clonal diploid eggs, has been identified. Among 833 specimens collected from 54 localities in Japan and two localities in China, 82 candidates of other lineage(s) of cryptic clones were screened by examining RFLP (restriction fragment length polymorphism)-PCR haplotypes in the control region of mtDNA. This analysis was performed because triploid loaches arise from the accidental incorporation of the sperm nucleus into unreduced diploid eggs of a clone. The categorization of members belonging to three newly identified lineages (clones 2-4) and the previously identified clonal lineage (clone 1) was verified by evaluating the genetic identity between two or more individuals from each clonal lineage based on RAPD (random amplified polymorphic DNA)-PCR and multilocus DNA fingerprints. We detected 75 haplotypes by observing the nucleotide status at variable sites from the control region of mtDNA. Phylogenic trees constructed from such sequences showed two highly diversified clades, A and B, that were beyond the level common for interspecific genetic differentiation. That result suggests that M. anguillicaudatus in Japan is not a single species entity. Two clone-specific mtDNA sequences were included in clade A, and the loaches with such sequences may be the maternal origin of the clones.
authors.affiliation: Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan. morikin@kindaisuiken.jp
authors.forename: Kagayaki
authors.initials: K
authors.lastname: Morishima
authors.forename: Yuka
authors.initials: Y
authors.lastname: Nakamura-Shiokawa
authors.forename: Etsuko
authors.initials: E
authors.lastname: Bando
authors.forename: Ya-Juan
authors.initials: YJ
authors.lastname: Li
authors.forename: Alicja
authors.initials: A
authors.lastname: Boroń
authors.forename: Md Mukhlesur Rahman
authors.initials: MM
authors.lastname: Khan
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Arai
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000235:genetics*; D002681:China; D019976:Cloning, Organism; D003531:Cypriniformes / Q000235:genetics* / Q000254:growth & development; D016172:DNA Fingerprinting; D004272:DNA, Mitochondrial / Q000235:genetics*; D004171:Diploidy; D005260:Female; D014644:Genetic Variation; D006239:Haplotypes; D007564:Japan; D008297:Male; D010063:Ovum; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D011123:Polyploidy; D019105:Random Amplified Polymorphic DNA Technique; D012100:Reproduction, Asexual / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial