Mammalian male and female germ cells express a germ cell-specific Y-Box protein, MSY2.
Here we report the isolation and characterization of mouse testicular cDNAs encoding the mammalian homologue of the Xenopus germ cell-specific nucleic acid-binding protein FRGY2 (mRNP3+4), hereafter designated MSY2. MSY2 is a member of the Y box multigene family of proteins; it contains the cold shock domain that is highly conserved among all Y box proteins and four basic/aromatic islands that are closely related to the other known germline Y box proteins from Xenopus, FRGY2, and goldfish, GFYP2. Msy2 undergoes alternative splicing to yield alternate N-terminal regions upstream of the cold shock domain. Although MSY2 is a member of a large family of nucleic acid-binding proteins, Southern blotting detects only a limited number of genomic DNA fragments, suggesting that Msy2 is a single copy gene. By Northern blotting and immunoblotting, MSY2 appears to be a germ cell-specific protein in the testis. Analysis of Msy2 mRNA expression in prepubertal and adult mouse testes, and in isolated populations of germ cells, reveals maximal expression in postmeiotic round spermatids, a cell type with abundant amounts of stored messenger ribonucleoproteins. In the ovary, MSY2 is present exclusively in diplotene-stage and mature oocytes. MSY2 is maternally inherited in the one-cell-stage embryo but is not detected in the late two-cell-stage embryo. This loss of MSY2 is coincident with the bulk degradation of maternal mRNAs in the two-cell embryo.
Department of Biology, Tufts University, Medford, Massachusetts 02155, USA.
W
W
Gu
S
S
Tekur
R
R
Reinbold
J J
JJ
Eppig
Y C
YC
Choi
J Z
JZ
Zheng
M T
MT
Murray
N B
NB
Hecht
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005854:Germ Cells / Q000378:metabolism*; D006054:Goldfish; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D015183:Restriction Mapping; D017421:Sequence Analysis; D013091:Spermatogenesis; D013094:Spermatozoa / Q000378:metabolism; D013737:Testis / Q000737:chemistry; D014981:Xenopus
D016601:RNA-Binding Proteins; C116047:Ybx2 protein, mouse