CLONING AND SEQUENCING OF A CDNA-ENCODING AN OVINE ESTRUS-ASSOCIATED OVIDUCAL PROTEIN

Ovine oestrus-associated oviducal glycoprotein (oEGP) is synthesized a nd secreted specifically by the ampullary region of the ovine oviduct during the peri-ovulatory stages of the oestrous cycle. A cDNA that en codes oEGP was isolated and sequenced. Isolation of oEGP was achieved using the polymerase chain reaction (PCR) with primers based on a bovi ne oestrus-associated oviducal glycoprotein cDNA (bOGP) sequence. A 15 99-bp cDNA encodes, in part, a deduced 519-amino acid sequence of matu re protein which carries two potential N-linked glycosylation sites. T he deduced amino acid sequence is more than 95% identical to that of b OGP and more than 74% identical to the first 491 amino acids of human oestrogen-dependent oviducal glycoprotein (hOGP). Northern blot hybrid izations of RNA from several sheep tissues detected mRNA (2.4 kb) only in an ampulla oviduct sample.