C. Osterlund et al., Specific localization of RBM1a in the nuclei of all cell types except elongated spermatids within seminiferous tubules of the human, INT J ANDR, 24(5), 2001, pp. 272-277
Recent studies have indicated that at least three regions (AZF a-c) on the
long arm of the Y-chromosome code for factors are involved in spermatogenes
is. One of the candidate genes in the AZFb region is RBM1a, coding for a pr
otein with an RNA binding motif In this study, poly clonal antibodies raise
d against a 15 amino acid peptide, corresponding to residues 263-304 of the
deduced amino acid sequence of RBM1a, has been used to localize the RBM1a
protein in the human testis. Immunohistochemistry on normal human testis us
ing this RBM1a antibody, localized the antigen to the nuclei of spermatogon
ia, primary spermatocytes, and round spermatids but not to the nuclei of el
ongated spermatids. The antibody also specifically identified the nuclei of
Sertoli cells, although the fluorescence was not as strong as in the germ
cell nuclei it identified. No specific fluorescence was seen in the nuclei
of either peritubular. endothelial or Leydig cells. Western blot of normal
human testicular tissue using the anti-RBM1a antibody gave rise to a single
specific band of approximately 55 kDa, corresponding to the expected size
of RBM1a. In view of its expression in germ cells, and because RBM1a has an
RNA binding domain, RBM1a may be involved in RNA processing, such as RNA s
plicing or RNA export which are events necessary for normal spermatogenesis
.