Biomaterial Database

Implications of gene amplification for evolution and management of insecticide resistance. 1990

B E Tabashnik

Department of Entomology, University of Hawaii, Honolulu 96822.

Simulations were used to compare evolution of insecticide resistance predicted by a conventional two-allele model with predictions from three- and four-allele models that assume resistance is based on gene amplification. Results were similar between models when insecticide concentration was low or moderate. In contrast, when 10% of the population was not exposed to insecticide each generation, high insecticide concentrations slowed resistance development in the two-allele model, but caused rapid development of high levels of resistance in the three- and four-allele models. The presence of a third allele at an initial frequency as low as 10-7 doubled or tripled the rate of resistance development in some cases. Attempts to slow evolution of resistance by overwhelming it with high concentrations of insecticides are not likely to succeed if gene amplification or other mechanisms generate alleles that confer high levels of resistance.

UI	MeSH Term	Description	Entries
D007305	Insecticide Resistance	The development by insects of resistance to insecticides.	Insecticide Resistances,Resistance, Insecticide,Resistances, Insecticide
D007313	Insecta	Members of the phylum ARTHROPODA composed or organisms characterized by division into three parts: head, thorax, and abdomen. They are the dominant group of animals on earth with several hundred thousand different kinds. Three orders, HEMIPTERA; DIPTERA; and SIPHONAPTERA; are of medical interest in that they cause disease in humans and animals. (From Borror et al., An Introduction to the Study of Insects, 4th ed, p1).	Insects,Insect
D003198	Computer Simulation	Computer-based representation of physical systems and phenomena such as chemical processes.	Computational Modeling,Computational Modelling,Computer Models,In silico Modeling,In silico Models,In silico Simulation,Models, Computer,Computerized Models,Computer Model,Computer Simulations,Computerized Model,In silico Model,Model, Computer,Model, Computerized,Model, In silico,Modeling, Computational,Modeling, In silico,Modelling, Computational,Simulation, Computer,Simulation, In silico,Simulations, Computer
D005784	Gene Amplification	A selective increase in the number of copies of a gene coding for a specific protein without a proportional increase in other genes. It occurs naturally via the excision of a copy of the repeating sequence from the chromosome and its extrachromosomal replication in a plasmid, or via the production of an RNA transcript of the entire repeating sequence of ribosomal RNA followed by the reverse transcription of the molecule to produce an additional copy of the original DNA sequence. Laboratory techniques have been introduced for inducing disproportional replication by unequal crossing over, uptake of DNA from lysed cells, or generation of extrachromosomal sequences from rolling circle replication.	Amplification, Gene
D000483	Alleles	Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.	Allelomorphs,Allele,Allelomorph
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia