A Determining Factor for Insect Feeding Preference in the Silkworm, Bombyx mori

Authors

Zhong-Jie Zhang, Zhejiang Academy of Agricultural Sciences, China
Shuai-Shuai Zhang, Chinese Academy of Sciences, China
Bao-Long Niu, Zhejiang Academy of Agricultural Sciences, China
Dong-Feng Ji, Zhejiang Academy of Agricultural Sciences, China
Xiao-Jing Liu, Chinese Academy of Sciences, China
Mu-Wang Li, Jiangsu University of Science and Technology, China
Hua Bai, Iowa State University
Subba Reddy Palli, University of KentuckyFollow
Chen-Zhu Wang, Chinese Academy of Sciences, China
An-Jiang Tan, Chinese Academy of Sciences, China

Abstract

Feeding preference is critical for insect adaptation and survival. However, little is known regarding the determination of insect feeding preference, and the genetic basis is poorly understood. As a model lepidopteran insect with economic importance, the domesticated silkworm, Bombyx mori, is a well-known monophagous insect that predominantly feeds on fresh mulberry leaves. This species-specific feeding preference provides an excellent model for investigation of host-plant selection of insects, although the molecular mechanism underlying this phenomenon remains unknown. Here, we describe the gene GR66, which encodes a putative bitter gustatory receptor (GR) that is responsible for the mulberry-specific feeding preference of B. mori. With the aid of a transposon-based, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 nuclease (Cas9) system, the GR66 locus was genetically mutated, and homozygous mutant silkworm strains with truncated gustatory receptor 66 (GR66) proteins were established. GR66 mutant larvae acquired new feeding activity, exhibiting the ability to feed on a number of plant species in addition to mulberry leaves, including fresh fruits and grain seeds that are not normally consumed by wild-type (WT) silkworms. Furthermore, a feeding choice assay revealed that the mutant larvae lost their specificity for mulberry. Overall, our findings provide the first genetic and phenotypic evidences that a single bitter GR is a major factor affecting the insect feeding preference.

Document Type

Article

Publication Date

2-27-2019

Notes/Citation Information

Published in PLOS Biology, v. 17, no. 2, e3000162, p. 1-17.

© 2019 Zhang et al.

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Digital Object Identifier (DOI)

https://doi.org/10.1371/journal.pbio.3000162

Funding Information

National Natural Science Foundation of China (grant number No.U1738110 and No.31572330) received by A.T.

Related Content

S1 Fig. Deletions in GR66 caused by CRISPR/Cas9 and an experimental diagram for generation of the homozygous mutant lines. https://doi.org/10.1371/journal.pbio.3000162.s001 (TIF)

S2 Fig. Comparison of GR66 among WT, ΔGR66-1, and ΔGR66-2. https://doi.org/10.1371/journal.pbio.3000162.s002 (TIF)

S3 Fig. The feeding preference of the ΔGR66-1line was expanded. https://doi.org/10.1371/journal.pbio.3000162.s003 (TIF)

S4 Fig. Survival assays with ΔGR66-2 mutant neonate larvae. https://doi.org/10.1371/journal.pbio.3000162.s004 (TIF)

S5 Fig. Two-choice assays with neonate larvae. https://doi.org/10.1371/journal.pbio.3000162.s005 (TIF)

S6 Fig. Electrophysiological responses to sucrose and myo-inositol in lateral sensilla and caffeine and salicin in medial sensilla. https://doi.org/10.1371/journal.pbio.3000162.s006 (TIF)

S1 Table. Primers used in this work. https://doi.org/10.1371/journal.pbio.3000162.s007 (DOCX)

S1 Data. Numerical data used in the figures. https://doi.org/10.1371/journal.pbio.3000162.s008 (XLSX)

S1 Movie. ΔGR66-2 mutant fifth-instar larva fed on leaves of mulberry. https://doi.org/10.1371/journal.pbio.3000162.s009 (AVI)

S2 Movie. ΔGR66-2 mutant fifth-instar larva fed on leaves of Mongolian oak. https://doi.org/10.1371/journal.pbio.3000162.s010 (AVI)

S3 Movie. ΔGR66-2 mutant fifth-instar larva fed on fruits of apple. https://doi.org/10.1371/journal.pbio.3000162.s011 (AVI)

S4 Movie. ΔGR66-2 mutant fifth-instar larva fed on fruits of pear. https://doi.org/10.1371/journal.pbio.3000162.s012 (AVI)

S5 Movie. ΔGR66-2 mutant fifth-instar larva fed on seeds of soybean. https://doi.org/10.1371/journal.pbio.3000162.s013 (AVI)

S6 Movie. ΔGR66-2 mutant fifth-instar larva fed on seeds of corn. https://doi.org/10.1371/journal.pbio.3000162.s014 (AVI)

Repository Citation

Zhang, Zhong-Jie; Zhang, Shuai-Shuai; Niu, Bao-Long; Ji, Dong-Feng; Liu, Xiao-Jing; Li, Mu-Wang; Bai, Hua; Palli, Subba Reddy; Wang, Chen-Zhu; and Tan, An-Jiang, "A Determining Factor for Insect Feeding Preference in the Silkworm, Bombyx mori" (2019). Entomology Faculty Publications. 187.
https://uknowledge.uky.edu/entomology_facpub/187