According to Pisani et al. (2008), the availability and the types of
nutrients offered to animals in the pre-mating period can altered
the expression of genes involved in developmental potential and
oocyte quality. To further assess oocyte quality, we performed
mRNA amplification for specific genes related to oocyte competence
in goats supplemented with different types of diet. Of all
genes tested, only GDF9 mRNA levels were affected by the diets,
showing lower levels in goats fed alternative food sources. This
GDF9 underexpression does not seem to have affected the meiotic
competence, as assessed by oocyte maturation rates, embryo
development, and cloned embryo yield. The fact that the differential
expression analysis of GDF9 transcripts does notinterfere in the
regulation of oocyte maturation and subsequent development may
be explained by the involvement of multiple genes in these processes
(Fair, 2013), several of which are stored during the growth
phase of the oocytes (Brevini Gandolfi and Gandolfi, 2001). Furthermore,
there may be a difference in GDF9 expression between
oocytes and cumulus cells that does not compromise the ability of
cumulus-oocyte complexes to generate blastocysts (Barros et al.,
2012).