Expression of a Y-box protein, YB2/RYB-a, precedes protamine 2 expression during spermatogenesis in rodents.
Y-box binding proteins, a large family of proteins, are involved in a variety of functions. The present study describes the expression of YB2, a rat Y-box binding protein, and/or RYB-a, an alternatively spliced product of the YB2 gene during spermatogenesis. YB2/RYB-a is thought to be the rat orthologue of mouse Y-box protein 3 (MSY3). An antibody which recognizes YB2/RYB-a was developed and applied in an immunochemical study of rat and mouse testes. We also carried out an in-situ hybridization study and Northern blot analysis of YB2/RYB-a and protamine 2 mRNA expression. Both YB2/RYB-a mRNA and the proteins appeared in prepubertal mouse testes, prior to the expression of the mouse protamine 2 mRNA. The mRNA and protein were present at high levels in spermatocytes, decreased in round to elongated spermatids, and were absent in spermatozoa. Since the protamine 2 mRNA was present at high levels in round and elongating spermatids, the proposed function of the YB2/RYB-a protein as a translational repressor of the mRNA was supported in mouse. The level and localization of YB2/RYB-a mRNA and protein expression in the rat testis was comparable to that in mouse testis, although rat testis is known to express a very low level of protamine 2, but is also likely to affect the expression of other proteins (including protamine 1) during spermatogenesis.
Iuchi
Y
Y
Department of Biochemistry, Yamagata University School of Medicine, 2-2-2 Iidanishi, Yamagata 990-9585, Japan.
Kobayashi
T
T
Kaneko
T
T
Takahara
M
M
Ogino
T
T
Fujii
J
J
D000818:Animals; D000918:Antibody Specificity; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D010802:Phylogeny; D011479:Protamines / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar; D012377:Rodentia / Q000502:physiology*; D013045:Species Specificity; D013091:Spermatogenesis / Q000502:physiology*; D013737:Testis / Q000254:growth & development
D004268:DNA-Binding Proteins; D011479:Protamines; C088194:Ybx3 protein, rat; C068621:protamine 2