Differential screening of ovarian cDNA libraries detected the expression of the porcine collagenase inhibitor gene in functional corpora lutea.

cDNA libraries were constructed from porcine granulosa cells of antral follicles as well as functional corpus luteum, and clones encoding stage-specific genes have been isolated by differential screening. A clone specific to the functional stage of corpus luteum was found to encode the porcine collagenase inhibitor gene and the stage-specific expression in luteinizing tissue was confirmed by Northern blot analysis. The complete open reading frame of the porcine collagenase inhibitor was deduced from the nucleotide sequence, and the localization of the product was examined by immunohistochemical staining as well in pig ovary; the inhibitor was detected in the intercellular space of luteal cells and in the connective tissue around blood vessels in the functional corpus luteum.