CATHEPSIN-L GENE ORGANIZATION IN CRUSTACEANS

The gene structure of a cathepsin L of the shrimp Penaeus,la,vannamei has been determined by the polymerase chain reaction. It comprises six exons of various lengths spanning a total of 1792 bp. This architectu re is homologous to that of rat cathepsin L, three conserved sites of intron position have been effectively identified, with the exception o f the third intron break-point located immediately after the cysteinyl active site. In contrast, no similarity is observed with Drosophila o r Plasmodium cathepsin L-like gene organizations. This gene expresses a major cathepsin L enzyme in the hepatopancreas. The last intron is p olymorphic, suggesting the presence of at least three different genes. (C) 1998 Elsevier Science B.V. All rights reserved.