Presence of Vi-transposon-like elements in the proopiomelanocortin gene A of Xenopus laevis does not affect gene activity

✍ Scribed by Deen, Peter M.T. ;Roubos, Eric W. ;Martens, Gerard J.M.

• Publisher: Springer
• Year: 1991
• Tongue: English
• Weight: 372 KB
• Volume: 230
• Category: Article
• ISSN: 0026-8925
• DOI: 10.1007/bf00280307

✦ Synopsis

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.