Genome-wide comparison of genes involved in the biosynthesis, metabolism, and signaling of juvenile hormone between silkworm and other insects

Abstract

Juvenile hormone (JH) contributes to the regulation of larval molting and metamorphosis in insects. Herein, we comprehensively identified 55 genes involved in JH biosynthesis, metabolism and signaling in the silkworm (Bombyx mori) as well as 35 in Drosophila melanogaster, 35 in Anopheles gambiae, 36 in Apis mellifera, 47 in Tribolium castaneum, and 44 in Danaus plexippus. Comparative analysis showed that each gene involved in the early steps of the mevalonate (MVA) pathway, in the neuropeptide regulation of JH biosynthesis, or in JH signaling is a single copy in B. mori and other surveyed insects, indicating that these JH-related pathways or steps are likely conserved in all surveyed insects. However, each gene participating in the isoprenoid branch of JH biosynthesis and JH metabolism, together with the FPPS genes for catalyzing the final step of the MVA pathway of JH biosynthesis, exhibited an obvious duplication in Lepidoptera, including B. mori and D. plexippus. Microarray and real-time RT-PCR analysis revealed that different copies of several JH-related genes presented expression changes that correlated with the dynamics of JH titer during larval growth and metamorphosis. Taken together, the findings suggest that duplication-derived copy variation of JH-related genes might be evolutionarily associated with the variation of JH types between Lepidoptera and other insect orders. In conclusion, our results provide useful clues for further functional analysis of JH-related genes in B. mori and other insects.

Characterization of two juvenile hormone epoxide hydrolases by RNA interference in the Colorado potato beetle

“…JHEH, JHEH-l2, JHEH-l4, and JHEH-l5 were mainly expressed before wandering. JHEH-l1 and JHEH-l3 displayed a high expression in females during pupa-adult transition (Cheng et al, 2014). Similarly, clones of TcJHEH-3, possessing strong JH-degrading activity, were found only in T. castaneum larval stage .…”

“…The copy numbers of the JHEH genes vary. B. mori genome shows the presence of an authentic JHEH and five JHEH-like genes Seino et al, 2010;Cheng et al, 2014), while there are three JHEH-like genes in Drosophila melanogaster, three in Anopheles gambiae, one in A. mellifera, five in T. castaneum, and seven in Danaus plexippus (Mackert et al, 2010;Cheng et al, 2014).…”

“…Moreover, pieces of experimental evidence revealed that JHEH in other insect species also showed specific tissue expression profiles, although there were no comparative studies on expression levels of different JHEH genes. In B. mori, for example, JHEH was highly expressed in the gut, Malpighian tubule and silk gland (Cheng et al, 2014). In Gryllus assimilis, midgut and fat bodies JHEH activities exhibited a mid-stadium peak (Anand et al, 2008).…”

“…LdJHEH1 was highly expressed in the thoracic muscles, foregut, midgut and hindgut, whereas LdJHEH2 was highly expressed in the brain-corpora cardiaca-corpora allata complex, hindgut, Malpighian tubules and female ovaries. In other insect species, there were also several copy numbers of the JHEH genes Mackert et al, 2010;Seino et al, 2010;Cheng et al, 2014). Moreover, pieces of experimental evidence revealed that JHEH in other insect species also showed specific tissue expression profiles, although there were no comparative studies on expression levels of different JHEH genes.…”

Differential expression of miRNAs related to caste differentiation in the honey bee, Apis mellifera

“…Dozens of JH-related genes, which involved in JH signaling, biosynthesis, and metabolism, have been recently identified in the honey bee genome (Bomtorin et al 2014;Cheng et al 2014). One of them is juvenile hormone acid methyltransferase (NCBI Reference Sequence database: XM_001119986), which is differentially expressed during the caste differentiation .…”