Submitted to: Embryo Transfer Newsletter
Publication Type: Other
Publication Acceptance Date: September 23, 2004
Publication Date: September 30, 2004
Citation: Zuelke, K.A., Blomberg, L. 2004. Serial analysis of gene expression (SAGE) during porcine embryo elongation. Embryo Transfer Newsletter. 22(3):10-14.
Interpretive Summary: A long-term objective of our laboratory is to establish comprehensive gene expression profiles from the 3 critical stages of porcine embryo development: 1) oocyte maturation; 2) blastocyst development; and 3) embryo elongation. Of these three stages, gene expression events during pig embryo elongation are perhaps the most characterized to date. During elongation, the pig embryo is transformed from a sphere of a few mm diameter to a long, thin filament ~ 20 cm in length between days 11 (D11) and 12 (D12) after insemination [Patten, 1948; Anderson, 1978; Geisert et al. 1982]. Embryo elongation coincides pregnancy recognition in the pig and is also often associated with a high level of embryonic loss [Anderson, 1978; Geisert et al., 1982].
Mammalian embryo development represents a continuum of molecular and cellular interactions whereby early events dictate and influence subsequent developmental outcomes. For example, conditions under which oocytes are matured can dramatically impact the rates of pronuclear and blastocyst development after in vitro fertilization and embryo culture [Brackett and Zuelke, 1993]. Swine often exhibit high rates (~20%) of early embryonic mortality following either artificial insemination or natural mating [Pope and First, 1985]. The efficiencies of producing swine embryos in vitro are also poor compared to other livestock species. Typically, approximately 20% of transferred in vitro produced swine embryos develop into live offspring after embryo transfer [Abeydeera, 2002]. In order to develop strategies to reduce embryonic mortality in the pig and to improve the efficiency of producing porcine embryos in vitro, it is necessary to identify and better understand critical gene expression events that occur during and between key stages of early porcine embryo development.