title: Non-sex specific genes associated with the secondary mitotic period of primordial germ cell proliferation in the gonads of embryonic rainbow trout (Oncorhynchus mykiss).
abstract: The purposes of this study were to quantify the secondary proliferation of primordial germ cells (PGCs) in both sexes of rainbow trout, determine if a sex difference in the timing of PGC proliferation and eventual pre-meiotic number exists, and use microarray data collected during this period to identify genes that are associated with PGC mitosis. The experiments used vasa-green fluorescent protein (vasa-GFP) transgenic rainbow trout of known genetic sex that allowed for the identification and collection of PGCs in vivo. An increase was observed in the number of PGCs counted in the gonads of both female and male embryonic vasa-GFP rainbow trout, from 300 to 700° days (water temperature in °C × days post-fertilization). For both sexes, a statistically significant (P < 0.05) increase in the PGC number was first noted at either 350 or 400° days of development. By 700° days, a 20-50-fold increase in germ cell number was apparent. No sex-specific differences in the timing of PGC proliferation or number were notable in any of the families until 700° days. In conjunction, a custom microarray based on cDNA libraries from embryonic rainbow trout gonads was used to identify genes involved in PGC mitosis. Five genes were discovered: guanine nucleotide binding protein, integral membrane protein 2B, transmembrane protein 47, C-src tyrosine-protein kinase, and the decorin precursor protein. All the genes identified have not been previously associated with germ cell mitosis, but are known to be involved with the cell plasma membrane and/or cell signaling pathways.
authors.affiliation: Department of Biological Sciences, University of Idaho, Moscow, Idaho; Center for Reproductive Biology, University of Idaho, Moscow, ID 83844, USA. jamesn@uidaho.edu
authors.forename: James J
authors.initials: JJ
authors.lastname: Nagler
authors.forename: Tim
authors.initials: T
authors.lastname: Cavileer
authors.forename: Sam
authors.initials: S
authors.lastname: Hunter
authors.forename: Robert
authors.initials: R
authors.lastname: Drew
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Okutsu
authors.forename: Takashi
authors.initials: T
authors.lastname: Sakamoto
authors.forename: Goro
authors.initials: G
authors.lastname: Yoshizaki
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D058575:Decorin / Q000235:genetics; D005260:Female; D019204:GTP-Binding Proteins / Q000235:genetics; D005854:Germ Cells / Q000502:physiology*; D006066:Gonads / Q000502:physiology*; D049452:Green Fluorescent Proteins; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D046228:Microarray Analysis; D008938:Mitosis / Q000235:genetics / Q000502:physiology*; D017686:Oncorhynchus mykiss / Q000235:genetics* / Q000502:physiology; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D013696:Temperature; D013997:Time Factors
chemical_list: D058575:Decorin; D008565:Membrane Proteins; D049452:Green Fluorescent Proteins; D011505:Protein-Tyrosine Kinases; D019204:GTP-Binding Proteins