Characterization of the gorilla carboxyl ester lipase locus, and the appearance of the carboxyl ester lipase pseudogene during primate evolution.

In this study we report on the isolation and characterization of the gorilla carboxyl ester lipase gene, CEL, and the corresponding CEL pseudogene. We also report on the age of the CEL pseudogene. The gorilla CEL gene is 10.5kb long and comprises 11exons intervened by introns similar to the situation in man, mouse and rat. The encoded protein is 998amino acids long and includes a 23amino acid-long leader peptide. Comparison of the coding sequence, excluding exon 11, of CEL from gorilla and man reveals a 97% similarity. Exon 11, which encodes the characteristic proline rich repeats, contains 39 repeated units in gorilla compared to 16 in man. A truncated CEL pseudogene, with the same organization as that found in man, is also shown to be present in the gorilla genome. The gorilla CEL pseudogene is 4.9kb in length and consists of 5exons interrupted by introns. Southern analysis of the gorilla CEL locus shows that the locus is arranged in a similar way as in man with the functional CEL gene being the most 5' one. To bring further insight to the events involved in the rearrangement of the CEL locus, genomic Southern analyses were performed across several primates; Homo sapiens, Pan troglodytes, Gorilla gorilla, Pongo pygmaeus and Macaca arctoides. Results presented show that the CEL gene duplication occurred prior to the separation of Hominidae (man, chimpanzee, gorilla and orangutan) from Old World monkeys (macaque). The deletion of the original CEL gene giving rise to the truncated version of the CEL gene seems, however, to be restricted to man and the great apes only.