J. Don et al., DEVELOPMENTALLY-REGULATED EXPRESSION DURING GAMETOGENESIS OF THE MURINE GENE MEG1 SUGGESTS A ROLE IN MEIOSIS, Molecular reproduction and development, 38(1), 1994, pp. 16-23
Previous studies have shown that in adult male mice, expression of the
meg1 gene is restricted to meiotic and early postmeiotic testicular g
erm cells. We have now analyzed the expression of meg1 during postnata
l testicular development and the comparable meiotic stages in the fema
le. The 0.75 kb transcript for meg1 begins to accumulate in testes at
d8-9 of postnatal (pn) development, coincident with the entry of germ
cells into meiosis, and is expressed most abundantly at pn d14 and sub
sequent stages, when the spermatocytes have entered pachytene. In situ
hybridization analysis shows that meg1 is expressed at very low level
s in leptotene cells and increases as the cells progress through zygot
ene and pachytene stages. In the embryonic ovary, meg1 is not detected
until after day 15 of gestation when the cells have entered the pachy
tene stage of meiosis I. In situ hybridization analysis suggests that
meg1 transcripts are expressed at higher levels in degenerating rather
than in healthy pachytene stage oocytes; meg1 is not expressed in any
cells of the adult ovary, regardless of the stage of follicular devel
opment. These results suggest that meg1 is indeed a meiosis-associated
gene in both male and female germ cells through the pachytene stage o
f meiosis I and appears to exhibit sex-specific differences in its exp
ression thereafter. (C) 1994 Wiley-Liss, Inc.