Expression of heparanase mRNA in bovine placenta during gestation

This study reports the identification and sequence of a partial cDNA for bo vine heparanase and the expression of its mRNA in the placenta during gesta tion. The 364 amino acid residues deduced from the 1092 bp cDNA fragment sh are 81.9% and 80.5% identity with amino acid sequences of human and rat hep aranase, respectively. Northern blot hybridization showed that two mRNAs (2 .0 and 3.5 kb) are strongly expressed in placenta, and weakly expressed in the kidney, lung, spleen and non-pregnant uterus. In the placenta, these tr anscripts were detected in the cotyledon at all stages of gestation examine d, and in the intercotyledonary fetal membrane and caruncle on day 60, day 120 and day 260. Quantitative real-time RT-PCR analysis showed very low exp ression of heparanase mRNA in the conceptus before implantation (day 17), b ut high expression in the cotyledon-containing fetal membrane (days 27-34) after implantation. Furthermore, heparanase mRNA was detected in the cotyle don, intercotyledonary fetal membrane and caruncle after days 60-64 of gest ation. However, no significant expression of heparanase mRNA was observed i n intercaruncular endometrium at all stages of gestation examined. These re sults demonstrate that heparanase mRNA is expressed in the placentome, indi cating that heparanase may play a role in implantation, and in placental de velopment and function.