Y. Zheng et Pa. Martindeleon, THE MURINE SPAM1 GENE - RNA EXPRESSION PATTERN AND LOWER STEADY-STATELEVELS ASSOCIATED WITH THE RB(6.16) TRANSLOCATION, Molecular reproduction and development, 46(3), 1997, pp. 252-257
Recently we mapped the murine Spam1 gene to the proximal region of chr
omosome 6 (MMU 6). Based on the map location and physiological charact
eristics of its encoded sperm antigen, the gene is an attractive candi
date for the sperm dysfunction seen in Rb(6.16) translocation heterozy
gotes and the reduced fertility of homozygotes. We have analyzed the e
xpression of Spam1 mRNA in normal and Rb(6.16) mice. The expression of
Spam1 mRNA was found to be: 1) tissue specific; it is expressed exclu
sively in testis; and 2) developmentally regulated, with a haploid exp
ression. Notably, the steady-state mRNA level of Spam1 in Rb(6.16) hom
ozygotes was 25-30% of that in chromosomally normal consomic mice and
those homozygous for Rb(2.8) (7.18). In Rb(6.16) and Rb(6.15) heterozy
gotes the levels were 61% and 66% of the normal. Studies are currently
under way to determine the protein levels and gene structure of Spam1
, to detect the underlying cause of the mRNA reduction associated with
these translocations. (C) 1997 Wiley-Liss, Inc.