Presence of Vi-transposon-like elements in the proopiomelanocortin gene A of Xenopus laevis does not affect gene activity.
Restriction mapping of the two proopiomelanocortin (POMC) genes of the South African clawed toad Xenopus laevis revealed that POMC gene A is much larger than POMC gene B. Here we report that this size difference is mainly due to the presence of four vitellogenin (Vi)-transposon-like elements in POMC gene A, while Vi elements are absent from POMC gene B. Alignment of these elements with other Vi elements revealed a consensus sequence of 463 bp, which is bounded by a 16 bp inverted repeat and flanked by a 3 bp direct repeat. Since the amounts of mRNA produced by both POMC genes in the pars intermedia of the Xenopus pituitary are similar, the presence of the Vi-transposon-like elements in POMC gene A apparently has no effect on POMC gene expression at transcriptional or post-transcriptional levels.
Deen
P M
PM
Department of Animal Physiology, University of Nijmegen, The Netherlands.
Roubos
E W
EW
Martens
G J
GJ
D000818:Animals; D001483:Base Sequence; D016384:Consensus Sequence; D004251:DNA Transposable Elements; D007438:Introns; D008969:Molecular Sequence Data; D010902:Pituitary Gland / Q000378:metabolism; D011333:Pro-Opiomelanocortin / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D014819:Vitellogenins / Q000235:genetics*; D014982:Xenopus laevis / Q000235:genetics*
D004251:DNA Transposable Elements; D014819:Vitellogenins; D011333:Pro-Opiomelanocortin