Comparative analysis of the Monochamus alternatus immune system

Abstract

The pine sawyer beetle, Monochamus alternatus, is regarded as a notorious forest pest in Asia, vectoring an invasive pathogenic nematode, Bursaphelenchus xylophilus, which is known to cause pine wilt disease. However, little sequence information is available for this vector beetle. This hampered the research on its immune system. Based on the transcriptome of M. alternatus, we have identified and characterized 194 immunity-related genes in M. alternatus, and compared them with homologues molecules from other species known to exhibit immune responses against invading microbes. The lower number of putative immunity-related genes in M. alternatus were attributed to fewer C-type lectin, serine protease (SP) and anti-microbial peptide (AMP) genes. Phylogenetic analysis revealed that M. alternatus had a unique recognition gene, galectin3, orthologues of which were not identified in Tribolium castaneum, Drosophila melanogastor, Anopheles gambiae and Apis mellifera. This suggested a lineage-specific gene evolution for coleopteran insects. Our study provides the comprehensive sequence resources of the immunity-related genes of M. alternatus, presenting valuable information for better understanding of the molecular mechanism of innate immunity processes in M. alternatus against B. xylophilus.

Mitogenome Analysis of Four Lamiinae Species (Coleoptera: Cerambycidae) and Gene Expression Responses by Monochamus alternatus When Infected with the Parasitic Nematode, Bursaphelenchus mucronatus

“…Some immune genes in the epidermis and trachea are up-regulated, and the expression level of most immune genes remains unchanged. M. alternatus maintains immune homeostasis between the two through the regulation of ROS [ 31 , 78 ]. Some researchers believe that longicorn beetles and nematodes have a symbiotic relationship [ 33 , 79 ].…”

Comparative Transcriptome Analysis of the Heat Stress Response in Monochamus alternatus Hope (Coleoptera: Cerambycidae)

“…It was notable that previous studies have certified that HSPs could act as a regulator of immune response (Mehlen et al, 1996;Ravagnan et al, 2001). When blocking HSP70 with special antibody, the production of immune activity (TNF-α released from macrophages) decreased and mammalian HSPs could bind with antigenic peptides (Udono, 1993;Zhou et al, 2018). FIGURE 9 | qRT-PCR analysis of the expression levels of 13 unigenes.…”

Immune-related genes of the larval Holotrichia parallela in response to entomopathogenic nematodes Heterorhabditis beicherriana LF

“…PGRPs are important members of insect PRRs and play an important role in innate immunity [48,49]. Previous studies have shown that PGRP-LB1, −LB2, −LC2, −LC3 and -LD in Monochamus alternatus are likely to encode membrane proteins [50]; PGRP-SC1 of H. parallela contains a similar structure (without a signal peptide but containing a transmembrane segment), indicating that it may function on the cell membrane to recognize and trigger immune responses. Moreover, 2 of 5 key residues responsible for zinc binding and amidase catalytic activity were substituted, indicating that H. parallela PGRP-SC1 has no amidase activity and cannot cleave the bacterial peptidoglycan (PGN) [51].…”