GEPHE SUMMARY Print
Gephebase Gene
Entry Status
Published
GepheID
GP00002054
Main curator
Courtier
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
Trichoplusia ni - Bt-Cry2Ab susceptible
Trait State in Taxon B
Trichoplusia ni - Bt-Cry2Ab resistant
Ancestral State
Taxon A
Taxonomic Status
Taxon A
Common Name
cabbage looper
Synonyms
cabbage looper; Trichoplusia ni (Hubner, 1803); Trichopluisa ni; Trichopulsia ni
Rank
species
Lineage
Show more ... oda; Insecta; Dicondylia; Pterygota; Neoptera; Holometabola; Amphiesmenoptera; Lepidoptera; Glossata; Neolepidoptera; Heteroneura; Ditrysia; Obtectomera; Noctuoidea; Noctuidae; Plusiinae; Trichoplusia
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B
Common Name
cabbage looper
Synonyms
cabbage looper; Trichoplusia ni (Hubner, 1803); Trichopluisa ni; Trichopulsia ni
Rank
species
Lineage
Show more ... oda; Insecta; Dicondylia; Pterygota; Neoptera; Holometabola; Amphiesmenoptera; Lepidoptera; Glossata; Neolepidoptera; Heteroneura; Ditrysia; Obtectomera; Noctuoidea; Noctuidae; Plusiinae; Trichoplusia
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
GENOTYPIC CHANGE
Generic Gene Name
ABCA2
Synonyms
-
String
-
Sequence Similarities
-
GO - Biological Process
-
UniProtKB
Helicoverpa armigera
GenebankID or UniProtKB
Presumptive Null
Yes
Molecular Type
Aberration Type
Insertion Size
1-10 kb
Molecular Details of the Mutation
insertion of a transposon Tntransib (2581 bp) in ABCA2 which changes splicing sites in the transcript and lead to an indel in the coding region: change of 1551VETLAHALGFLRHLDKR1567 into 1551AHWGK- LYGSNTQN1563
Experimental Evidence
Authors
Yang X; Chen W; Song X; Ma X; Cotto-Rivera RO; Kain W; Chu H; Chen YR; et al. ... show more
Abstract
Insecticidal proteins from Bacillus thuringiensis (Bt) are the primary recombinant proteins expressed in transgenic crops (Bt-crops) to confer insect resistance. Development of resistance to Bt toxins in insect populations threatens the sustainable application of Bt-crops in agriculture. The Bt toxin Cry2Ab is a major insecticidal protein used in current Bt-crops, and resistance to Cry2Ab has been selected in several insects, including the cabbage looper, Trichoplusia ni. In this study, the Cry2Ab resistance gene in T. ni was mapped to Chromosome 17 by genetic linkage analyses using a whole genome resequencing approach, and was then finely mapped using RNA-seq-based bulked segregant analysis (BSA) and amplicon sequencing (AmpSeq)-based fine linkage mapping to a locus containing two genes, ABCA1 and ABCA2. Mutations in ABCA1 and ABCA2 in Cry2Ab resistant T. ni were identified by both genomic DNA and cDNA sequencing. Analysis of the expression of ABCA1 and ABCA2 in T. ni larvae indicated that ABCA2 is abundantly expressed in the larval midgut, but ABCA1 is not a midgut-expressed gene. The mutation in ABCA2 in Cry2Ab resistant T. ni was identified to be an insertion of a transposon Tntransib in ABCA2. For confirmation of ABCA2 as the Cry2Ab-resistance gene, T. ni mutants with frameshift mutations in ABCA1 and ABCA2 were generated by CRISPR/Cas9 mutagenesis. Bioassays of the T. ni mutants with Cry2Ab verified that the mutations of ABCA1 did not change larval susceptibility to Cry2Ab, but the ABCA2 mutants were highly resistant to Cry2Ab. Genetic complementation test of the ABCA2 allele in Cry2Ab resistant T. ni with an ABCA2 mutant generated by CRISPR/Cas9 confirmed that the ABCA2 mutation in the Cry2Ab resistant strain confers the resistance. The results from this study confirmed that ABCA2 is essential for the toxicity of Cry2Ab in T. ni and mutation of ABCA2 confers the resistance to Cry2Ab in the resistant T. ni strain derived from a Bt resistant greenhouse population.

Copyright © 2019 Elsevier Ltd. All rights reserved.
Additional References
RELATED GEPHE
Related Genes
Related Haplotypes
No matches found.
EXTERNAL LINKS
COMMENTS
@TE @Splicing
YOUR FEEDBACK is welcome!