Cloning and characterization of Rab and Ran/TC4 cDNA clones in Trichinellaspp.

The cloning and characterization of seven Rab and three Ran/TC4 partial cDN A sequences in both cystic (Trichinella spiralis and T. britovi) and noncys tic species (T. pseudospiralis) are reported. These molecules were cloned b y rapid amplification of cDNA ends via polymerase chain reaction (RACE-PCR) , using cDNA from the aforementioned Trichinella spp. coupled to the AP1 ad aptor. As primers, AP1 and 5B (derived from the WDTAGQE sequence of region 2 specific for Rab and Ran proteins) sequences were included in the PCR. Th e cloned cDNAs were sequenced and characterized by both Southern-blot and N orthern-blot analysis. Trichinella spp. Rab- and Ran-like molecules showed divergences in both the nucleotide and the deduced amino acid sequences as compared with the corresponding homologues previously described in other or ganisms. In addition, differences were observed among the Trichinella speci es, mainly between the cystic and the noncystic species, in both DNA restri ction-enzyme polymorphism and expression of the six GTPases isolated.