The gonadotrophins LH and FSH are known to regulate gonadal growth, and dif
ferentiation, endocrine function and gametogenesis. The LH receptor is expr
essed in ovarian theca, granulosa and luteal cells, and in testicular Leydi
g cells. The FSH receptor is expressed only in ovarian granulosa cells and
in testicular Sertoli cells. The expression of the FSH and LH receptors was
analysed by RT-PCR to study the role of these receptors in early mouse dev
elopment. After reverse transcription, strategically designed nested primer
s were used for amplification from cDNA. Transcripts for the receptors were
present in mouse oocytes and preimplantation embryos. The presence of mRNA
for FSH and LH receptors in oocytes, zygotes and preimplantation embryos i
ndicates a potential role for the gonadotrophins in the modulation of meiot
ic resumption and completion of oocyte maturation, as well as a beneficial
effect on early embryonic development in mice.