Developmental regulation of hyaluronan-binding protein ( XXXX /IHABP) expression in early @entity291 embryos.

@entity1 @entity291 @entity62613 @entity7245
Hyaluronan or @entity7245 ( @entity7245 ) is a normal component of @entity1 follicular, oviduct, and uterine fluids. Granulosa and expanding cumulus cells secrete large amounts of @entity7245 , and when @entity7245 is added in maturation and culture media, it improves the developmental potential of oocytes and embryos. @entity7245 regulates gene expression, signaling, proliferation, motility, adhesion, and morphogenesis. Many of these biological activities of @entity7245 are mediated through binding to the receptor for @entity7245 -mediated motility/intracellular @entity7245 -binding protein ( @entity62613 /IHABP). We evaluated the presence and dynamics of @entity62613 /IHABP mRNA and protein expression in different stages of in vitro-produced @entity291 embryos using quantitative reverse transcriptase-real time-polymerase chain reaction and immunohistochemistry. We also analyzed the effects of different culture systems on the relative abundance of @entity62613 /IHABP transcripts. @entity62613 /IHABP mRNA levels decreased from the 2-cell to the 16-cell stage, increased again at the morula stage, and reached their highest level at the expanded blastocyst stage. @entity62613 /IHABP mRNA abundance was significantly (P < 0.05) lower in embryos recovered in serum-containing medium than in embryos from serum-free media. Immunohistochemistry revealed the presence of @entity62613 /IHABP first in 8-cell stages. Whereas @entity62613 staining in 8-cell and morula stages was intense, it was weaker in blastocysts. Embryonic secretion of @entity7245 increased from the 2-cell stage until the 8-cell stage and then decreased in 16-cell embryos. After this, @entity7245 secretion increased in expanded and hatched blastocyst stages. These data suggest that the positive effects of @entity7245 on in vitro-produced @entity291 embryos may be mediated at least in part by @entity62613 /IHABP.
