Nr6a1 (nuclear receptor subfamily 6, group A, member 1; also called Gcnf) is expressed in fetal ovarian cells, peaking at embryonic day 14.5 (E14.5). Both somatic stem cells and embryonic stem cells require NR6A1 to silence the activities of Pou5f1 (POU domain, class 5, transcription factor 1; also called Oct4) and Nanog (Nanog homeobox) in the transition from pluripotent to differentiated cell state. Interestingly, the gene is not required for this process in fetal ovarian germ cells and it is not required for initiation of meiosis and oogenesis.
Exon 7 of the Nr6a1 gene, encoding the beginning of the ligand binding domain, is flanked by loxP sites in this mutant strain. Homozygous floxed animals are phenotypically normal for gross morphology, behavior, fertility, and viability.
Cre-mediated recombination can be carried out to produce a knockout allele in which exon 7 is deleted. Crosses with tamoxifen-inducible UBC-cre/ERT2 mice (e.g. Stock No. 008085) produce a widespread knockout of the gene. Homozygous knockout embryos die prenatally and display reduced size, impaired neural tube closure, and failure to turn from the lordotic to the fetal position.
