title: Germ cell sex prior to meiosis in the rainbow trout.
abstract: Germ cells make two major decisions when they move from an indeterminate state to their final stage of gamete production. One decision is sexual commitment for sperm or egg production, and the other is to maintain mitotic division or entry into meiosis. It is unclear whether the two decisions are made as a single event or separate events, because there has been no evidence for the presence of germ cell sex prior to meiosis. Here we report direct evidence in the fish rainbow trout that gonia have distinct sexuality. We show that dazl expression occurs in both male and female gonia but exhibits differential intracellular distribution. More strikingly, we show that boule is highly expressed in male gonia but absent in female gonia. Therefore, mitotic gonia possess sex, sperm/egg decision and mitosis/meiosis decision are two independent events, and sperm/egg decision precedes mitosis/meiosis decision in rainbow trout, making this organism a unique vertebrate model for mechanistic understanding of germ cell sex differentiation and relationship between the two decisions.
authors.affiliation: Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
authors.forename: Mingyou
authors.initials: M
authors.lastname: Li
authors.forename: Qian
authors.initials: Q
authors.lastname: Shen
authors.forename: Foong Mei
authors.initials: FM
authors.lastname: Wong
authors.forename: Hongyan
authors.initials: H
authors.lastname: Xu
authors.forename: Ni
authors.initials: N
authors.lastname: Hong
authors.forename: Lingbing
authors.initials: L
authors.lastname: Zeng
authors.forename: Lin
authors.initials: L
authors.lastname: Liu
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Wei
authors.forename: Yunhan
authors.initials: Y
authors.lastname: Hong
mesh_terms: D000818:Animals; D005260:Female; D029941:Fish Proteins / Q000235:genetics; D005786:Gene Expression Regulation; D008297:Male; D008540:Meiosis; D017686:Oncorhynchus mykiss / Q000235:genetics* / Q000502:physiology; D010053:Ovary / Q000166:cytology / Q000378:metabolism; D010063:Ovum / Q000166:cytology* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics; D019849:Sex Determination Processes; D013094:Spermatozoa / Q000166:cytology* / Q000378:metabolism; D013737:Testis / Q000166:cytology / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins