Activin‐A receptor expression patterns in prepubertal goat oocytes and derived embryos

Abstract

Contents This study examines the presence of activin IIA and IIB receptors (ActR‐IIA and ActR‐IIB) by Western blotting and immunocytochemistry in immature and IVM‐oocytes, 2 to 8‐cells embryos and blastocysts from prepubertal goats. Western blotting revealed that activin receptors are synthesized during oocyte maturation and embryo development. In the immunocytochemistry experiments, no immunostaining for either receptor was detected in oocytes while both receptors were immunolabelled in all the cells of cleaved embryos. In blastocysts, while ActR‐IIA expression appeared evenly distributed in the two cell lineages, inner cell mass and trophectoderm, the ActR‐IIB immunosignal was restricted mainly to the inner cell mass. Our findings reveal the presence of activin type II receptors (ActR‐IIA and ActR‐IIB) in in vitro matured prepubertal goat oocytes and blastocyst‐stage embryos. The expression of these receptors could be a key factor in understanding differences between competent and incompetent oocytes.

Gonadotropin elevation is ootoxic to ovulatory oocytes and inhibits oocyte maturation, and activin decoy receptor ActRIIB:Fc therapeutically restores maturation

“…Several isoforms of activin and inhibin mRNAs and proteins are expressed in granulosa and thecal cells, and several activin and inhibin protein isoforms are found in follicular fluid [ 7 ]. Type II activin receptors ActRIIA and ActRIIB mRNAs are expressed in follicular cells and in oocytes during oocyte maturation [ 8 ] and references therein; [ 9 ]. They are also expressed in fallopian tube, endometrium, and placenta.…”