Alternative splicing of the human luteal LH receptor during luteolysis and maternal recognition of pregnancy.

Deletion of exon 10 of the human LH receptor impairs LH but not hCG action. Other splice variants of the LH receptor impair both LH and hCG action in other species. We hypothesized that alternatively spliced LH receptors are involved in luteolysis and luteal rescue with hCG in women. mRNA was extracted from human luteinized granulosa cells and from corpora lutea from across the luteal phase and after luteal rescue in vivo with exogenous hCG. Splice variants were detected by RT-PCR using carefully designed primer pairs. Products were visualized on agarose gels, extracted, purified and sequenced. Three splice variants of the human LH receptor were detected and characterized. These demonstrate a region of multiple splicing between exons 8 and 11 of the receptor. A naturally occurring splice variant with exon 10 alone removed was not identified. There was no obvious change in the pattern of splice variants across the luteal phase in the presence or absence of hCG. These data do not support the hypothesis that qualitative changes in LH receptor splicing have a role in luteolysis or that a naturally occurring LH receptor lacking exon 10 has a role in maternal recognition of pregnancy.