Expanded insecticide catabolic activity gained by a single nucleotide substitution in a bacterial carbamate hydrolase gene

A single amino acid substitution converts a carboxylesterase to an organophosphorus hydrolase and confers insecticide resistance on a blowfly.

Resistance to organophosphorus (OP) insecticides is associated with decreased carboxylesterase activity in several insect species. It has been proposed that the resistance may be the result of a mutation in a carboxylesterase that simultaneously reduces its carboxylesterase activity and confers an OP hydrolase activity (the "mutant ali-esterase hypothesis"). In the sheep blowfly, Lucilia cuprin...

A quantitative map of nucleotide substitution rates in bacterial rRNA.

A recently developed method for estimating the variability of nucleotide sites in a sequence alignment [Van de Peer, Y., Van der Auwera, G. and De Wachter, R. (1996) J. Mol. Evol. 42, 201-210] was applied to bacterial 16S, 5S and 23S rRNAs. In this method, the variability of each nucleotide site is defined as its evolutionary rate relative to the average evolutionary rate of all the nucleotide ...

Single-nucleotide substitution in pyruvate kinase deficiency.

Pyruvate kinase (PK) deficiency is the most common disorder among glycolytic enzyme defect causing hereditary hemolytic anemia. Since the first case was reported 30 years ago, over 300 cases have been reported. In 1988, we isolated the cDNA clones for human L-type PK,’ and last year we reported the cDNA cloning of R-type PK and the single amino acid substitution (ThIJg4 to Met) causedbyapointmu...

A carbamate insecticide: a case study of aldicarb.

Aldicarb, the active ingredient in the insecticide TEMIK, was introduced to the agricultural community over 25 years ago. It has been registered worldwide to control a wide variety of insect, mite, and nematode pests in agriculture. The toxicological research database supporting the registration and use of aldicarb was generated over more than 25 years and contains more than 280 animal studies ...

Transplacentally acquired carbamate insecticide (Baygon) poisoning in a neonate.