Molecular cloning of mouse allantoicase cDNA

The uric acid degradation pathway is progressively lost during vertebrate e volution. In mammals, the end product of this catabolic pathway is allantoi n and, therefore, no allantoicase should be present in mouse tissues. Surpr isingly, we have found an expressed sequence tag (EST) from mouse testis wi th high similarity to allantoicase. To characterize this transcript, we hav e completely sequenced the corresponding EST clone insert and found a 1495 bp long cDNA coding for a 414 amino acid long protein. Identities of mouse versus microorganism allantoicases range from 25 to 30%. Identity reaches 5 4% when compared to Xenopus allantoicase. Among the tested tissues, only te stis possesses the allantoicase transcript. Although no deleterious mutatio ns were found in the coding region, no allantoicase activity could be detec ted in mouse testis. (C) 2001 Elsevier Science B.V. All rights reserved.