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Schlagwörter:
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Zusammenfassung:
Repat (REsponse to PAThogens) genes were first identified in the midgut of Spodoptera exigua (Lepidoptera:
Noctuidae) in response to Bacillus thuringiensis and baculovirus exposure. Since then, additional repat gene
homologs have been identified in different studies. In this study the comprehensive larval transcriptome
from S. exigua was analyzed for the presence of novel repat-homolog sequences. These analyses revealed
the presence of at least 46 repat genes in S. exigua, establishing a new gene superfamily in this species.
Phylogenetic analysis and studies of conserved motifs in these hypothetical proteins have allowed their
classification in two main classes, αREPAT and βREPAT. Studies on the transcriptional response of repat
genes have shown that αREPAT and βREPAT differ in their sequence but also in the pattern of regulation.
The αREPAT were mainly regulated in response to the Cry1Ca toxin from B. thuringiensis but not to the
increase in the midgut microbiota load. In contrast, βREPAT were neither responding to Cry1Ca toxin nor
to midgut microbiota. Differential expression between midgut stem cells and the whole midgut tissue was
studied for the different repat genes revealing changes in the gene expression distribution between midgut
stem cells and midgut tissue in response to midgut microbiota. This high diversity found in their sequence
and in their expression profile suggests that REPAT proteins may be involved in multiple processes thatcould be of relevance for the understanding of the insect gut physiology.
