NK1 Homeobox Protein 2 (NKX1-2)

A mouse homeobox gene, Nkx-1.2, (previously termed Sax-1) that is closely related to the Drosophila NK-1/S59 gene was cloned, and genomic DNA and cDNA were sequenced. Nine Nkx-1.2 cDNA clones were found that correspond to three species of Nkx-1.2 mRNA that are formed by alternative splicing at conventional 5' donor and 3' acceptor splice sites; however, seven cDNA clones were found that correspond to three species of Nkx-1.2 mRNA from testes that have novel TG/AC 5' and 3' splice sites.Nkx-1.2 mRNA was shown to be present in postmeiotic germ cells of the testis and in mature spermatozoa. Nkx-1.2 mRNA also was found in regions of the adult cerebral cortex, hippocampus, diencephalon, pons/medulla, and cerebellum. Nkx-1.2 mRNA was found in embryos in highest abundance in 10-day embryos; the mRNA levels decrease during further development.