title: 28S rDNA haplotypes of males are distinct from those of androgenetic hermaphrodites in the clam Corbicula leana.
abstract: The clam Corbicula leana exists in two forms, hermaphrodites and males. Our previous study on mitochondrial DNA suggested that the male nuclear DNA might have derived from hermaphrodite C. leana relatively recently. To clarify the origin of males in the clam, sequences of the nuclear 28S rDNA divergent domain (which is 441-444 bp long) in androgenetic hermaphrodites and males and dioecious (bisexual) species were analyzed. Unexpectedly, the nuclear 28S rDNA haplotypes of males and hermaphrodites were distinct. Haplotype network analysis indicated that males and hermaphrodites are reproductively isolated from each other without sharing the same nuclear haplotype. These results support a hypothesis that the egg nuclear genome of androgenetic hermaphrodites is replaced by the male sperm genome, and only males develop after fertilization by a male spermatozoon.
authors.affiliation: Graduate School of Bioresources, Mie University, Kurimamachiya 1577, Tsu, Mie Prefecture 514-8507, Japan. komaru@bio.mie-u.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Komaru
authors.forename: Shoji
authors.initials: S
authors.lastname: Houki
authors.forename: Mitsuya
authors.initials: M
authors.lastname: Yamada
authors.forename: Takuya
authors.initials: T
authors.lastname: Miyake
authors.forename: Mayu
authors.initials: M
authors.lastname: Obata
authors.forename: Kouichi
authors.initials: K
authors.lastname: Kawamura
mesh_terms: D000818:Animals; D049874:Corbicula / Q000145:classification* / Q000235:genetics* / Q000502:physiology; D004272:DNA, Mitochondrial / Q000235:genetics; D006239:Haplotypes; D057850:Hermaphroditic Organisms / Q000235:genetics*; D008297:Male; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D057885:Triploidy
chemical_list: D004272:DNA, Mitochondrial; D012339:RNA, Ribosomal, 28S