Colony-Stimulating Factor 2 (CSF-2) Improves Development and Posttransfer Survival of Bovine Embryos Produced in Vitro

Abstract

In this study, we tested the role of colony-stimulating factor 2 (CSF2) as one of the regulatory molecules that mediate maternal effects on embryonic development during the preimplantation period. Our objective was to verify effects of CSF2 on blastocyst yield, determine posttransfer survival, and evaluate properties of the blastocyst formed after CSF2 treatment. In vitro, CSF2 increased the percentage of oocytes that became morulae and blastocysts. Blastocysts that were treated with CSF2 tended to have a greater number of inner cell mass cells and had a higher ratio of inner cell mass to trophectoderm cells. There was no effect of CSF2 on the incidence of apoptosis. Treatment with CSF2 from d 5 to 7 after insemination increased embryonic survival as indicated by improved pregnancy rate at d 30-35 of gestation. Moreover, treatment with CSF2 from either d 1-7 or 5-7 after insemination reduced pregnancy loss after d 30-35. Results indicate that treatment with CSF2 can affect embryonic development and enhance embryo competence for posttransfer survival. The fact that treatment with CSF2 during such a narrow window of development altered embryonic function much later in pregnancy suggests that CSF2 may exert epigenetic effects on the developing embryo that result in persistent changes in function during the embryonic and fetal periods of development.

Porcine Granulocyte-Macrophage Colony-Stimulating Factor Improves the <i>in vitro</i> Development of Cloned Porcine Embryos

“…In this study, the observation that blastocysts from embryos treated with pGM-CSF had more ICM and TE cells than the control indicates the capacity of pGM-CSF to affect SCNT-derived blastocyst differentiation. Similarly, in human [42], mouse [22] and bovine [28] embryos, GM-CSF treatment during IVC results in more cells in the ICM of blastocysts. ICM cells are a crucial part of embryos, because they eventually give rise to the definite structure of the fetus.…”

“…Therefore, treatment with GM-CSF may improve the efficiency of transgenic pig production and also the establishment of SCNT-derived embryonic stem cells. Similarly, treatment with GM-CSF improves not only blastocyst formation in vitro but also posttransfer embryonic survival in murine [40] and bovine [28] embryos. Treatment with pGM-CSF during IVC affected not only ICM cells but also TE cells and the expression of Cdx-2 mRNA in cloned blastocysts.…”

Maternal embryokines that regulate development of the bovine preimplantation embryo

“…in the presence of CSF2 have increased numbers of cells in the ICM (37). Moreover, CSF2 improves survival of isolated ICM maintained in culture (41).…”

“…Blastocysts formed in the presence of IGF1 have increased capacity to establish pregnancy when transferred to females (37,77,78). However, as shown in Figure 1, this property has only been shown to occur when recipients were exposed to heat stress.…”

Reproductive systems biology tackles global issues of population growth, food safety and reproductive health

“…Similarly, livestock embryos conceived by artificial insemination (AI) or produced in vitro and transferred to recipients are prone to early embryonic death resulting in early pregnancy losses that lower AI conception rates down to 35-45 % and account for millions of lost dollars in the beef and dairy cattle industries (Hansen et al 2004). In this regard, P. Hansen et al discuss the sex-specific expression of colony stimulating factor CSF2 (Loureiro et al 2009) and related mechanisms guiding preimplantation embryo programming, which leads to the establishment and sustenance of pregnancy, a developmental milestone that is equally important for the management of human and animal reproductive health (Hansen et al 2015). Among possible causes of preimplantation embryo changes that may lead to developmental arrest and epigenetic abnormalities, the endoplasmatic reticulum stress (Hao et al 2009), caused by exogenous factors during laboratory procedures necessary for human/animal embryo production, is discussed by Latham (2015).…”