XLPOU 1 and XLPOU 2, two novel POU domain genes expressed in the dorsoanterior region of Xenopus embryos.
POU domain genes have been shown to be important in tissue-specific gene regulation during development. We have cloned cDNA's encoding two unique Xenopus laevis POU-domain proteins, XLPOU 1 and XLPOU 2. Sequencing revealed that the POU domain of both of these genes have greater than 90% homology with that of the POU III class of proteins. XLPOU 1 gene expression begins at the neural plate stage, while XLPOU 2 gene expression is first detected at the neurula stage; both XLPOU 1 and XLPOU 2 transcripts continue to be expressed throughout development. In adults, XLPOU 1 expression is restricted to the skin and brain, while XLPOU 2 is observed in the kidney and brain. In dissected embryos, both XLPOU 1 and XLPOU 2 are expressed in the dorsoanterior portion of an early tailbud embryo. Consistent with this localization, uv treatment, a condition that "posteriorizes" embryos, greatly reduces the expression of XLPOU 1 and XLPOU 2. Whole-mount in situ hybridization demonstrates that at the neural fold stage, XLPOU 1 transcripts appear to be localized primarily in the anterior neural plate. In sections of embryos, in situ hybridization shows that XLPOU 1 transcripts are localized mostly in the anterior region of the nerve cord of neurula stage embryos. In tailbud stage embryos, the XLPOU 1 transcripts are found predominantly in the eye and brain, with weak expression along the length of the nerve cord. We believe that XLPOU 1 and XLPOU 2, because of their localized and early expression in embryos, may play an important role in the specification of neuronal phenotypes.
Agarwal
V R
VR
Clinical Endocrinology Branch, NIDDK NIH, Bethesda, Maryland 20892.
Sato
S M
SM
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism; D003001:Cloning, Molecular; D004625:Embryo, Nonmammalian / Q000378:metabolism*; D015870:Gene Expression / Q000528:radiation effects; D005801:Genes, Homeobox; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D012313:RNA / Q000032:analysis; D012689:Sequence Homology, Nucleic Acid; D012867:Skin / Q000378:metabolism; D014466:Ultraviolet Rays / Q000009:adverse effects; D014982:Xenopus laevis / Q000235:genetics*
D015345:Oligonucleotide Probes; D012313:RNA