Expression of Cdx‐2 in the mouse embryo and placenta: Possible role in patterning of the extra‐embryonic membranes

Abstract

Three mouse homologues of the Drosophila homeotic gene Caudal (Cad) have been described. They are currently designated Cdx-1, Cdz-2, and Cdz-4. Cdx-1 and 2 are both strongly expressed in the adult mid-and hindgut, while Cdx-1 and 4 have been shown to be activated in the embryonic primitive streak. Using a polyclonal antibody against a fusion protein containing the amino terminal 109 amino acids of murine Cdx-2, we here describe the topographical location of the gene product from early cleavage to 12.5 days of embryonic development. Cdx-2 expression begins at 3.5 days and is confined to the trophectoderm, being absent from the inner cell mass. Subsequently, staining is located in the extra-embryonic ectoderm adjacent to the epiblast, but sparing the more superficially placed polar, as well as the mural trophoblastic cells. Continuing expression in the fetal membranes involves the chorion, the allantoic bud, and, at even later stages, the spongiotrophoblast. From 8.5 days, Cdx-2 begins to be expressed in embryonic tissues, principally (unlike Cdx-1) in the posterior part of the gut from its earliest formation, as well as in the tail bud and in the caudal part of the neural tube. Cdz-2 is, therefore, transcribed well before any other membrane of the Cad homologue group and of the related H a -C group; its expression in the extra-embryonic membranes and in the hindgut reflects the phylogenetic relationship between the cloaca and the chorio-allantois and suggests the possibility that homeobox genes may be involved in placental development andlor patterning. o 1995 Wiley-Liss, Inc.

Effect of sperm entry on blastocyst development after in vitro fertilization and intracytoplasmic sperm injection — mouse model

“…One of them, the POU-family transcription factor Oct4, is expressed throughout early embryonic development and becomes progressively restricted first to the entire inner cell mass (ICM) and then to the epiblast (EPI) at the blastocyst stage [35,46]. The reverse expression pattern is observed in a second transcription factor, caudal-related homeobox 2 (Cdx2), whose expression is restricted to the trophectoderm (TE) by the blastocyst stage [4]. Targeted deletion of Oct4 in mice leads to lethality at implantation, and blastocysts fail to generate an ICM [30].…”

Pancreas organogenesis: From bud to plexus to gland

“…mesodermal derivatives, but how these interact with endoderm-autonomous regional cuing needs much more detailed study. There are several notable endodermal region-or organ-specific transcription factors (TFs) that are differentially expressed along the A-P axis, which include Six1 and Six4 (pharyngeal endoderm) (Zou et al, 2006), Sox2 (stomach) (Que et al, 2007), Nkx2.1 (lung) (Minoo et al, 1999), Hhex (liver) (MartinezBarbera et al, 2000;Keng et al, 2000), Pdx1 (pancreas, duodenum, posterior stomach, common bile duct) (Offield et al, 1996), and the caudal homeobox genes Cdx1 and Cdx2 (intestine) (Beck et al, 1995(Beck et al, , 2003.…”

Cell and molecular regulation of the mouse blastocyst

“…Molecularly, TE and ICM lineages can be distinguished by the expression patterns of several lineage-specific transcription factors. Cdx2, which is related to Drosophila Caudal, is expressed in the TE of the blastocyst where it is required for promoting TE fate (Beck et al, 1995;Strumpf et al, 2005). Two ICMspecific transcription factors are Oct4, a POU domain protein, and Nanog, a homeodomain protein (Palmieri et al, 1994;Chambers et al, 2003;Mitsui et al, 2003).…”

“…Furthermore, Oct4 protein is not detectable in nuclei A gene important for early TE development also has been identified. Cdx2 encodes a Caudal-like transcription factor and is expressed in the TE of the blastocyst (Beck et al, 1995;Strumpf et al, 2005). Cdx2 protein is first detectable in the nuclei of select cells at the eight-cell stage (Niwa et al, 2005) and becomes restricted to outer cells of the late morula (Niwa et al, 2005;Strumpf et al, 2005).…”