Regulation of the Larval Transcriptome of Diatraea saccharalis (Lepidoptera: Crambidae) by Maternal and Other Factors of the Parasitoid Cotesia flavipes (Hymenoptera: Braconidae)

Abstract

Koinobiont endoparasitoid wasps regulate the host’s physiology to their own benefit during their growth and development, using maternal, immature and/or derived-tissue weaponry. The tools used to subdue the wasps’ hosts interfere directly with host transcription activity. The broad range of host tissues and pathways affected impedes our overall understanding of the host-regulation process during parasitoid development. Next-generation sequencing and de novo transcriptomes are helpful approaches to broad questions, including in non-model organisms. In the present study, we used Illumina sequencing to assemble a de novo reference transcriptome of the sugarcane borer Diatraea saccharalis, to investigate the regulation of host gene expression by the larval endoparasitoid Cotesia flavipes. We obtained 174,809,358 reads and assembled 144,116 transcripts, of which 44,325 were putatively identified as lepidopteran genes and represented a substantial number of pathways that are well described in other lepidopteran species. Comparative transcriptome analyses of unparasitized versus parasitized larvae identified 1,432 transcripts of D. saccharalis that were up-regulated under parasitization by C. flavipes, while 1,027 transcripts were down-regulated. Comparison of the transcriptomes of unparasitized and pseudoparasitized D. saccharalis larvae led to the identification of 1,253 up-regulated transcripts and 972 down-regulated transcripts in the pseudoparasitized larvae. Analysis of the differentially expressed transcripts showed that C. flavipes regulated several pathways, including the Ca+2 transduction signaling pathway, glycolysis/gluconeogenesis, chitin metabolism, and hormone biosynthesis and degradation, as well as the immune system, allowing us to identify key target genes involved in the metabolism and development of D. saccharalis.

Comparative gut transcriptome analysis of Diatraea saccharalis in response to the dietary source

“…In this study, we generated a tissue-specific transcriptome of the sugarcane borer's gut. The number of transcripts in our assembly (115,346) was higher than the 84,678 transcripts reported in the previous transcriptome [21]. However, 66.5% of the transcripts in the current study were not annotated.…”

“…The available genomic data of D. saccharalis are very limited, and no public genome has been published to date. The first transcriptome of D. saccharalis was recently released, revealing the regulation of some key metabolic and developmental pathways by the larval endoparasitoid Cotesia flavipes [21]. Here, we investigated the intestinal transcriptome profile of D. saccharalis larvae, providing a tissue-specific, high-quality sequence database for gut metabolism.…”

“…The first transcriptome of D . saccharalis was recently released, revealing the regulation of some key metabolic and developmental pathways by the larval endoparasitoid Cotesia flavipes [ 21 ]. Here, we investigated the intestinal transcriptome profile of D .…”

First evidence of insecticidal potential of molecules produced during the parasitic phase of the endoparasitoid Cotesia flavipes

“…By releasing several host regulation molecules, parasitoids alter host physiological functions, leading to successful development of the endoparasitoid larva. For example, parasitoids alter immune competence (Rana et al, 2002; Ali et al, 2015; Pinto et al, 2021), the endocrine system (Pennacchio et al, 1994), host nutrition and digestion (Cônsoli et al, 2001; Salvador & Cônsoli, 2008; Rossi et al, 2014), protein synthesis (Kadono‐Okuda et al, 1998), host metamorphosis (Shi et al, 2016), neuropeptide reprogramming (Shi et al, 2015), and enzymatic degradation of host fat body (Nakamatsu et al, 2002), among others (Rana et al, 2002; Caccia et al, 2012; Merlin & Cônsoli, 2019).…”

MicroRNAs from Snellenius manilae bracovirus regulate innate and cellular immune responses of its host Spodoptera litura

“…These include the production of venoms, symbiosis with polydnaviruses (PDVs), and the release of teratocytes into the host body during egg hatching [1][2][3][4][5] . These parasitic factors help the wasp progeny to grow and to develop within the host by regulating the host immune responses, inhibiting host growth and development, affecting endocrine hormone levels, and regulating host nutrient metabolism [6][7][8][9] . PDVs are viruses belonging to the Polydnaviridae family and are divided into two genera, bracoviruses (BVs) and ichnoviruses (IVs), according to its associated host.…”