Trans-splicing of a Meloidogyne incognita mRNA encoding a putative esophageal gland protein.

A monoclonal antibody, 7A9, specific for antigens in the subventral esophageal glands of adult female Meloidogyne incognita and for antigens in the longitudinal muscles of second-stage juveniles, was used to isolate a clone from a M. incognita cDNA expression library. The corresponding genomic DNA was isolated by hybridization and the gene designated sec-1. DNA sequence analysis of sec-1 revealed the presence of 9 introns having structural similarities to introns from the free-living nematode Caenorhabditis elegans. The sec-1 message was also trans-spliced and the leader sequence differed in one position from the sequence of the C. elegans trans-spliced leader SL1. Sequences analogous to sec-1 were specific to the genus Meloidogyne, and regulation of sec-1 expression did not involve differences in overall rates of transcript accumulation. The deduced amino acid sequence of the protein encoded by sec-1 had some similarities to the rod portions of several myosin heavy chains.