CHROMOSOMAL ORGANIZATION OF A REPEATED GENE-CLUSTER EXPRESSED IN MAMMALIAN STAGES OF LEISHMANIA

The genomic organisation of a large Leishmania gene cluster, expressed predominantly in intracellular, infective parasite stages, has been d etermined. Using cosmid cloning, parasite DNA fingerprinting, partial digestion and mapping with 'end-specific' probes, the LmcDNA2 gene arr ay has been localised to a 55-kb ClaI fragment within the L. major gen ome. Six tandemly linked gene copies are transcribed to produce an abu ndant 6-kb transcript; the seventh and last copy of the cluster is tru ncated at its 3' end. It is likely that these genes encode one or more proteins specific to infective stages of the parasite life cycle.