The cloning and characterization of a localized maternal transcript in Xenopus laevis whose zygotic counterpart is detected in the CNS.
We have cloned a cDNA (xlan4) from a Xenopus laevis oocyte cDNA library whose cognate mRNA is localized in the animal pole region of full grown oocytes. The cDNA can be translated in vitro to produce a predicted size protein of 35 kDa and, is also expressed in E. coli as a fusion protein. The conceptual protein encoded by the xlan4 cDNA is 17.5% proline rich and possesses several PEST sequences found in proteins with short half-lives. The xlan4 mRNA is 2.6 kb and during early development its titer decreases until the neurula stage after which it begins to reaccumulate. Northern blots on dissected embryos and in situ hybridization revealed that the zygotic expression is limited to the dorsal axial structures consisting primarily of the CNS. UV irradiation of the vegetal pole region immediately following fertilization that produces ventralized embryos results in a loss of zygotic xlan4 expression. In the adult, xlan4 mRNA is limited primarily to the brain. The presence of this mRNA in animal pole region which contributes to the future neural cell lineages suggests that this gene product may function either in the specification of neural cell types or in a neural specific function.
Reddy
B A
BA
Department of Molecular Genetics, University of Texas, M.D. Anderson Cancer Center, Houston 77030.
Kloc
M
M
Etkin
L D
LD
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002490:Central Nervous System / Q000378:metabolism*; D003001:Cloning, Molecular; D046508:Culture Techniques; D004625:Embryo, Nonmammalian / Q000378:metabolism*; D015870:Gene Expression; D005796:Genes / Q000235:genetics; D017403:In Situ Hybridization; D007814:Larva / Q000378:metabolism; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics*; D009865:Oocytes / Q000378:metabolism* / Q000528:radiation effects; D016366:Open Reading Frames / Q000502:physiology; D014176:Protein Biosynthesis; D012313:RNA / Q000032:analysis / Q000302:isolation & purification; D014158:Transcription, Genetic; D014162:Transfection; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000235:genetics*
D009419:Nerve Tissue Proteins; D029867:Xenopus Proteins; C080040:xlan4 protein, Xenopus laevis; D012313:RNA