Expression of homeobox-containing genes in cDNA libraries derived from cattle oocytes and preimplantation stage embryo

The homeobox-containing gene family plays a pivotal role in regulating, pat terning, and axial morphogenesis in the developing embryo. But there is sti ll very little known about the expression and function of these genes in ma mmalian oocytes and preimplantation stage embryos. In this study we have us ed degenerate primers corresponding to the highly conserved regions of Ante nnapedia class homeodomains as a rapid and an efficient method to survey bo vine cDNA libraries derived from unfertilised oocytes, single 2-cell, 4-cel l, 8-cell, morula, and blastocyst stage embryos for the presence of homeobo x sequences. Our results provide, for the first time, evidence for the tran scription of Hoxa3 and Hoxd1 in oocytes; Cdx1 and Cdx2 in the 2-cell; Cdx1, Hoxa1, Hoxd1, and Hoxd4 in the 4-cell; Cdx1, Hoxa1, and Hoxc9 in the 8-cel l; Cdx2, Hoxb9, and Hoxc9 in the morula; Cdx2, Hoxb7, Hoxb9, and Hoxc9 in b lastocyst stage cattle embryos. These are candidate genes for the developme ntal capacity of in vivo and in vitro produced bovine embryos. (C) 2001 Wil ey-Liss, Inc.