MODULATION OF EXPRESSION AT THE LEVEL OF SPLICING OF CUT-1 RNA IN THEINFECTIVE 2ND-STAGE JUVENILE OF THE PLANT-PARASITIC NEMATODE MELOIDOGYNE-ARTIELLIA

The cut-1 gene coding for cuticlin-1 has been isolated from the plant parasitic nematode Meloidogyne artiellia. The sequence of the cut-1 ge ne was compared with the corresponding sequence from the free-living n ematode Caenorhabditis elegans. The high degree of similarity between the amino acid sequences, together with the occurrence of characterist ic sequence motifs, indicates that the cuticlin-1 is a non-collagenous component of the cuticle also in plant parasitic nematodes. Studies o n the expression pattern during the development of M. artiellia indica te that there is a burst of expression of this gene during moulting. T hen, the expression rate is reduced in the infective juveniles, which migrate in the soil. In the sedentary females, in contrast, no express ion is detected, while in the males which move freely through the soil , the gene is expressed and the transcript fully processed. These data strongly suggest that the gene is developmentally regulated. It is pr oposed that the production of cuticlin plays an important role in dete rmining the mechanical properties of the cuticle. Furthermore, evidenc e is provided to indicate that the modulation of cut-1 expression is a chieved by regulation of the cis-splicing mechanism in the infective s econd-stage juvenile.