STRUCTURE AND EXPRESSION OF LEYDIG INSULIN-LIKE PEPTIDE MESSENGER-RNAIN THE SHEEP

We have used PCR to isolate and characterise Leydig insulin-like pepti de (Ley I-L) rnRNA from sheep ovary. The deduced amino acid sequence o f sheep Ley I-L has good homology with the pig and human peptides, hav ing 93% and 77% amino acid identity, respectively. Northern blot analy sis revealed abundant expression in both ovary and testis. An examinat ion of ovarian RNA from non-pregnant and pregnant sheep showed that pr egnancy did not significantly increase Ley I-L, mRNA levels. However m RNA levels did alter depending on whether ovaries contained a corpus l uteum. Also ovaries were examined by hybridisation histochemistry to l ocate the site of expression, Abundant Ley I-L, mRNA levels were found in the theca interna cells of the ovary.