RNA of AmVegT, the axolotl orthologue of the Xenopus meso-endodermal determinant, is not localized in the oocyte.
The transcription factor, VegT, is the meso-endodermal determinant in Xenopus laevis, and the localization of VegT RNA to the vegetal cortex of the oocyte is an important starting point for embryonic patterning. We have cloned the VegT orthologue from the urodele amphibian, Ambystoma mexicanum, the Mexican axolotl. Axolotl VegT (AmVegT) is expressed zygotically in the presumptive mesoderm and Rohon-Beard neurons as in X. laevis, and its expression persists at the tip of the tail as with zebrafish and chicken orthologues. Unlike in X. laevis, AmVegT RNA is not localized in the oocyte. This result highlights a major difference in the molecular organization of oocytes of these two amphibian orders.
Nath
Kimberly
K
Department of Biological Sciences, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA 15282, USA.
Elinson
Richard P
RP
D000558:Ambystoma mexicanum / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D005260:Female; D018507:Gene Expression Regulation, Developmental; D009865:Oocytes / Q000378:metabolism; D012313:RNA / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D020825:T-Box Domain Proteins / Q000235:genetics* / Q000378:metabolism; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics / Q000378:metabolism
D017931:DNA Primers; D020825:T-Box Domain Proteins; C103966:VegT protein, Xenopus; D029867:Xenopus Proteins; D012313:RNA