In order to better understand the roles of carboxylesterase (CarE) genes in development and response to CO

2

exposure in the cigarette beetle

Lasioderma serricorne

we identified and cloned two full-length cDNAs of CarE genes using transcriptome data and RT-PCR technique. We analyzed their molecular characterization and phylogenetic relationship

and detected their expression profiles in different developmental stages and under different CO

2

stress conditions by using quantitative real-time PCR (qPCR). The open reading frames of two genes were 1 698 bp and 1 695 bp

encoding proteins comprised of 565 and 564 amino acid residues

respectively. The amino acid sequence homology and phylogenetic tree analysis indicated that both of them have typical conserved motifs of CarE protein and belong to β subfamily

and termed as

LsCarEB1

and

LsCarEB2

(GenBank accession no: MG189601 and MG189602)

respectively. The qPCR results showed that two genes were both expressed in all tested developmental stages

and the relative mRNA expression levels were significantly higher in lately larvae than those in early larvae

pupae and adults. In

L. serricorne

larvae exposed to CO

2

for 6 h

the mRNA levels of 〖

LsCarEB1

and

LsCarEB2

were significantly increased at different dose treatments compared to that of the control. We speculated that

LsCarEB1

and

LsCarEB2

may be involved in development and play important roles in response to CO

2

stress in

L. serricorne

.