In silicoIdentification of Novel Chitinase-Like Proteins in the Silkworm,Bombyx mori, Genome

Abstract

In insects, chitinases participate in the periodic shedding of old exoskeletons and the turnover of peritrophic membranes. Chitinase family members have been identified in dozens of species, including Tribolium castaneum, Drosophila melanogaster, and Anopheles gambiae. In this study, nine chitinases and three hypothetical chitinases have been identified in Bombyx mori L. (Lepidoptera: Bombycidae) through genome-wide searching. Phylogenetic analyses revealed that seven of them belong to the seven chitinase groups, respectively. BmCht25 and BmCht26 could not be grouped into the known chitinase groups, and might belong to two new groups of the chitinase family. BmCht10, BmCht25, and BmIDGF have glutamate amino acid substitutions in the active catalytic domain. Only BmCht5 and BmCht10 contain CBD domain and PEST sequences (rich in proline, glutamic acid, serine, and threonine). BmCht5 and BmCht26 are located on chromosome 7, and others (BmCht6, BmCht7, BmCht10, BmCht11, BmCht20, BmIDGF) are located on separate chromosomes of Bombyx mori, respectively. The present study provides important background information for future studies using Bombyx mori as a model organism for insect development and virus and host interaction.

The functional difference of eight chitinase genes between male and female of the cotton mealybug, Phenacoccus solenopsis

“…The red flour beetle‏ T. castaneum has 16 chitinase genes‏, and the fruit fly D. melanogaster has 18 chitinase genes (Zhu et al ., ). The silkworm B. mori (Pan et al ., ) and the pea aphid A. pisum (Nakabachi et al ., ) both have nine chitinase genes‏. In this study, we made an exhaustive search to identify chitinase genes from transcriptome data of cotton mealybugs, finding that the cotton mealybug has eight chitinase genes.…”

Chitinase‐like gene family in the brown planthopper, Nilaparvata lugens

“…To date, more than 100 cDNAs encoding chitinases and chitinase-like proteins from numerous insect species in different orders have been reported. There are now rather large and diverse groups of chitinase-like genes identified in many insect species, for example, Drosophila melanogaster (Zhu et al, 2004), Tribolium castaneum (Zhu et al, 2008a), Anopheles gambiae (Zhang et al, 2011a), Bombyx mori (Pan et al, 2012) and Acyrthosiphon pisum (Nakabachi et al, 2010). Based on amino acid sequence similarity and phylogenetic analysis, insect chitinase genes have been classified into eight groups.…”

Two chitinase 5 genes from Locusta migratoria: Molecular characteristics and functional differentiation

“…They are highly diverse enzymes encoded by many different genes as implicated in all sequenced insect transcriptoms or genomes (Zhu et al, 2004(Zhu et al, , 2008aNakabachi et al, 2010;Pan et al, 2012). In Drosophila melanogaster, Tribolium castaneum and Anopheles gambiae, 16, 22 and 20 chitinase and chitinase-like genes have been reported, respectively (Zhang et al, 2011a).…”