抄録
In this study we sequentially investigated the expressions of CD44, the principal hyaluronan (HA) receptor, in porcine cumulus-oocyte complexes (COCs) during in vitro maturation. The mRNA expressions of CD44 were analyzed in porcine cumulus cells and oocytes. In reverse transcription-polymerase chain reaction (RT-PCR) analysis, the expression of CD44 was identified only in cumulus cells, indicating that cumulus cells express CD44 mRNAs. The transcript of CD44 was weakly detectable in fresh (0 h) cumulus cells, but was clearly detected after 12 h of culture. In immunostaining, CD44 was distributed on the cytoplasm along the perimembrane of cumulus cells and at the junctions between cumulus cells and oocytes. The level of CD44 expression reached a peak at 24 h of culture although its expression was very weak at 0 h. These findings implied that the level of CD44 expression depends on the extent of cumulus expansion. These results suggest that CD44 may be involved in HA retention in the extracellular matrix of COCs during oocyte maturation.
