Expression of the Bufo arenarum oviductin

BARRERA, DANIEL; LLANOS, RICARDO; VALDECANTOS, PABLO; MICELI, DORA

Iguazú, Misiones (ARGENTINA)

Congreso; XL Reunión anual Sociedad Argentina de Investigación Bioquímica y Biología Molecular(SAIB); 2004

Sociedad Argentina de Investigación Bioquímica y Biología Celular

The unfertilizable vitelline envelope surrounding the Bufo arenarum (B.a.) egg is converted to a fertilizable form during the passage through of the oviduct. A protease from the first portion of the oviduct secretions produces the ultrastructural and biochemical changes of the vitelline envelope. The enzyme has characteristics of a serine protease with trypsin-like specifity. The sequence analysis of the cloned Xenopus laevis (X.l.) and Bufo japonicus (B.j.) cDNA oviductins reveals that the protease is translated comprising an arrangement by two protease domains that are interrupted by CUB1 and CUB2 domains, followed by CUB3 domain in the more C-terminal side. Taken into account that no direct evidence of B.a. oviductin expression has yet been reported, the aim of this work was to know if the oviductin gene is expressed in the B.a. oviductal Pars Recta (PR). Total RNA was isolated from PR of stimulated oviduct after injection of homologous pituitary. Based on the sequence of nucleotides from X.l. (Acc. No. U81291) and B.j. (Acc. No. AB070367) oviductins, a set of primers directed against the conserved sequences were designed. We amplified by RT-PCR a 530 bp cDNA, harboring the N-terminal protease domain and the CUB1 domain, which was cloned and sequenced (Acc. No. AY704215). The deduced amino acid sequence was determined to share 92% identity with the reported domains of B.j. oviductin (with four cysteine residues conserved in CUB1 domain) and 46% identity with the reported domains of X.l.