EQUINE CRISP-3 - PRIMARY STRUCTURE AND EXPRESSION IN THE MALE GENITAL-TRACT

Although originally described in the male rodent genital tract, cystei ne-rich secretory proteins (CRISPs) are expressed in a variety of mamm alian tissue and cell types. The proteins of the male genital tract ha ve been observed associated to spermatozoa and are believed to play a role in mammalian fertilization. Here we describe the identification a nd primary structure of the first equine member of the CRISP family. E quine CRISP-3 is transcribed and expressed in the stallion salivary gl and, in the ampulla and the seminal vesicle. It displays all 16 conser ved cysteine residues and shows 82% homology to human and 78% to guine a pig CRISP-2 (AA1, TPX 1) and 77% to human CRISP-3. In contrast to ot her mammalia, in the horse CRISP-3 is synthesized in great amounts in the accessory sexual glands, ampulla and seminal vesicle, thus allowin g the isolation of equine CRISP-3 in amounts suitable for biochemical, physiological and structural studies from stallion seminal plasma. (C ) 1998 Elsevier Science B.V. All rights reserved.