Metatranscriptome of the protistan community in Reticulitermes flaviceps

Abstract

The hindgut of lower termites harbors various symbiotic protists, which perform varied functions in lignocellulose decomposition. As termites are social insects, the species and numbers of these flagellated protists in the termite gut vary among the different castes. Juvenile hormones (JHs) can regulate caste differentiation in termites. In this study, we used the juvenile hormone analog fenoxycarb to induce termite workers (Reticulitermes flaviceps) to differentiate into pre-soldiers. A metatranscriptomic investigation of the protistan community was then performed by 454 pyrosequencing. From a thorough analysis based on 597 312 generated reads, we found that the starch and sucrose metabolism pathway was the most abundant pathway across the metatranscriptome. The current study demonstrates that the metatranscriptome of the protistan community in termites contains an abundance of lignocellulase, which plays a vital role in termite nutrition.

Optimization of a metatranscriptomic approach to study the lignocellulolytic potential of the higher termite gut microbiome

“…There has been no other study in the context of the higher termite gut microbiome that could serve as a guideline to the researchers to efficiently perform metatranscriptomic studies. This lack of methodology might be the primary reason for the scarce metatranscriptomic reports concerning the higher termite gut symbionts in comparison to their lower termite counterparts [ 18 , 50 – 52 ].…”

Meta-Omics Tools in the World of Insect-Microorganism Interactions

“…For example, Warnecke et al [71] used a low-throughput metagenomic analysis to study the function of hindgut microbiota in the termite Nasutitermes ephratae (Holmgren), revealing a wide presence of genes responsible of cellulose and xylan hydrolysis. It has been also shown that protistan communities hosted by Coptotermes formosanus Shiraki and Reticulitermes flaviceps (Oshima) are responsible to positively influence lignocellulolytic system, thus enhancing insects’ nutrition [72,73]. The use of the microbiota associated with wood-feeding beetles as source of novel enzymes, potentially useful in industrial bioprocesses, has been investigated by different studies [74,75,76,77,78,79].…”

A Bridge Too Far? An Integrative Framework Linking Classical Protist Taxonomy and Metabarcoding in Lower Termites

“…The in-situ detection of flagellate protists, through metabarcoding approaches is available but requires database data for bioinformatics comparison to obtain organisms' identification and biological role inference. Other studies, such as meta-transcriptomics are actually overcoming the drawback of the need of protists individual identification and focus on protists community of symbionts functional role by transcript inference (e.g., on lignocellulolytic process; Scharf et al, 2011 ; Xie et al, 2012 ; Raychoudhury et al, 2013 , Liu et al, 2016 ). Even if the use of differential gene expression analyses for understanding community responses to specific conditions does overcome the need of flagellate protists species knowledge, these analyses do not contribute to our understanding of the protistan diversity nor to the identification of a given species (only community information) needed for a specific biotechnological purpose.…”