Sex differences in response of the bovine embryo to colony-stimulating factor 2

Abstract

We tested whether gene expression of the bovine morula is modified by CSF2 in a sex-dependent manner and if sex determines the effect of CSF2 on competence of embryos to become blastocysts. Embryos were produced in vitro using X- or Y-sorted semen and treated at Day 5 of culture with 10 ng/mL bovine CSF2 or control. In experiment 1, morulae were collected at Day 6 and biological replicates (n = 8) were evaluated for transcript abundance of 90 genes by RT-qPCR using the Fluidigm Delta Gene assay. Expression of more than one-third (33 of 90) of genes examined was affected by sex. The effect of CSF2 on gene expression was modified by sex (P < 0.05) for five genes (DDX3Y/DDX3X-like, NANOG, MYF6, POU5F1 and RIPK3) and tended (P < 0.10) to be modified by sex for five other genes (DAPK1, HOXA5, PPP2R3A, PTEN and TNFSF8). In experiment 2, embryos were treated at Day 5 with control or CSF2 and blastocysts were collected at Day 7 for immunolabeling to determine the number of inner cell mass (ICM) and trophectoderm (TE) cells. CSF2 increased the percent of putative zygotes that became blastocysts for females, but did not affect the development of males. There was no effect of CSF2 or interaction of CSF2 with sex on the total number of blastomeres in blastocysts or in the number of inner cell mass or trophectoderm cells. In conclusion, CSF2 exerted divergent responses on gene expression and development of female and male embryos. These results are evidence of sexually dimorphic responses of the preimplantation embryo to this embryokine.

Sexual dimorphic expression and release of transcription factors in bovine embryos exposed to oxidative stress

“…Moreover, higher cell number was observed in male embryos than female cultured under 5% oxygen level in presence FCS or BSA-ITS, which was not in agreement with the current study (Dallemagne et al, 2018). Supporting to our results, no significant difference in total cell numbers was observed between male and female bovine embryos cultured under low oxygen tension (Siqueira & Hansen, 2016), which indicates the contribution of culture media in the variation between male and female embryos under either normal or stress conditions.…”

Consequences of endogenous and exogenous WNT signaling for development of the preimplantation bovine embryo†

“…Indeed, changes in gene expression in the bovine morula induced by DKK1 were different in some cases for male embryos than for female embryos [ 63 ]. Sex has an even larger effect on response of the bovine embryo to colony stimulating factor 2 [ 64 , 65 ]. Despite these observations, the lack of effect of DKK1 on TE numbers was seen for both male and female embryos.…”

Genetic and nongenetic profiling of milk pregnancy-associated glycoproteins in Holstein cattle

“…Gene P4HA2 is related to collagen synthesis and reported as candidate gene for protein content in Holsteins (Cole et al, 2011), with differential expression in cattle mammary gland (Cui et al, 2014), and the CSF2 and IL3 genes encode, respectively, a cytokine and interleukin both related to immune response by stimulating the proliferation of defense cells. Gene CSF2 is differentially expressed depending on the sex of bovine embryos, and the expression of IL3 has been reported in mouse embryos (Robin et al, 2006;Siqueira and Hansen, 2016). Robin et al (2006) also concluded that the IL3 gene has an important role as a survival factor for early hematopoietic stem cells in the mouse embryos (Robin et al, 2006).…”