Isolation, Cloning and Characterization of Cuticle Collagen Genes, Mi-dpy-10 and Mi-dpy-31, in Meloidogyne incognita Kohli Deshika1,2, Sirohi Anil3, Srinivasan Ramamurthy1, Bharadvaja Navneeta2, Jain Pradeep K.1,* 1ICAR-NRC on Plant Biotechnology, Pusa Campus, New Delhi, 110012, India 2Delhi Technological University, Shahbad, Daulatpur, Delhi-110042, India 3Division of Nematology, ICAR-Indian Agricultural Research Institute, Pusa, New Delhi, 110012, India *Corresponding author, E-mail: jainpmb@gmail.com
Online published on 27 November, 2018. Abstract Endoparasitic plant-parasitic nematodes (PPN) including Meloidogyne incognita inhabit the host body due to their unique body surface, the outer layer of which is cuticle. The nematode cuticle is an extracellular matrix, mainly composed of collagens which are encoded by a large gene family. Nematode cuticle acts as a shield against host's defense system thereby protecting parasitic nematodes. The cuticle of PPN is a less studied area of research with only few cuticle genes identified till date. In this study two new cuticle genes viz. dpy-10 and dpy-31 have been identified in M. incognita as orthologs of Caenorhabditis elegans dpy-10 and dpy31, respectively. The partial mRNA sequences of dpy-10 (1, 031 bp) and dpy-31 (1, 116 bp) were cloned. The conserved collagen triple helix Gly-X-Y pattern in Mi-dpy-10; where proline was preferred as X amino acid and conserved catalytic (HEVAHALGFWHEQSRPDRD) and methionine-turn (SIMHY) sites in Mi-dpy-31 classifies them in group Dpy-2 and subgroup V, respectively. A protein-protein interaction revealed a direct association between Mi-DPY-10, Mi-DPY-2, and Mi-DPY-7 together involved in post-embryonic development. While only a single Mi-SQT-3 (cuticle gene) was observed as the direct target for Mi-DPY-31 both involved in collagen processing. Phylogenetic analysis revealed a high order of conservation among the dumpy class of cuticle genes across phylum Nematoda. Since dumpy genes have a temporally regulated expression, qRT-PCR expression analyses of Mi-dpy-10 showed higher expression at the J2 stage of the nematode development in comparison to eggs and adult females. However, Mi-dpy-31 gene revealed higher expression in adult females in M. incognita suggesting different roles of dumpy genes during nematode development. Mutations in dumpy genes resulted in abnormal morphology in C. elegans; thus targeting such genes for developing resistance using Host-delivered RNA interference approach in M. incognita will be useful in managing these plant parasites. Top Keywords Cuticle collagen genes, Mi-dpy-10, Mi-dpy-31, Meloidogyne incognita, Nematode cuticle. Top |