Heterozygous genotypes and molecular characteristics of Organophosphorus resistance associated esterase B2 genes of Culex pipiens complex / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the heterozygous genotype and molecular characteristics of Organophosphorus resistance associated with heterozygous Estbeta2 of esterase B2 gene from natural population of Culex pipiens complex.</p><p><b>METHODS</b>Genomic DNA was extracted from natural populations of Culex pipiens complex in Hangzhou. The PCR-restriction fragment length polymorphism (PCR-RFLP) assay was applied to type the resistance associated esterase gene. Estbeta2 of esterase B2 gene was identified by PCR-RFLP, and the genotyping for heterozygous Estbeta2 was carried out after restriction enzyme digesting by Bfm I endonuclease.</p><p><b>RESULTS</b>The DNA was isolated from 207 Culex pipiens respectively, while 156 PCR samples showed positive and the positive rate was 75.36% (156/207). The PCR-RFLP assay of esterase B2 gene revealed that the Estbeta2 was accounted about 28.20% (44/156) in 156 positive samples. There were two genotypes identified, namely homozygous Estbeta2 (90.90%, 30/33) and heterozygous Estbeta2 (9%, 3/33), heterozygous Estbeta2 was in existence of a hybrid form as which combined with Estbeta2 and a subtype (Estbeta2/Estbeta2(1)).</p><p><b>CONCLUSION</b>Heterozygous Estbeta2 of Organophosphorus resistance associated with esterase genotype was determined in natural population of Culex pipiens, and a genotyping method was established.</p>

Genotypes, allele frequencies and dynamic distribution on resistance-associated esterase genes of Culex pipiens complex in Hangzhou / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the genotypes , allele frequencies and dynamic distribution on resistance associated esterase genes of Culex pipiens complex in Hangzhou.</p><p><b>METHODS</b>The PCR-restriction fragment length polymorphism (PCR-RFLP) assay was applied to type the resistance associated esterase genes, and dynamic surveillance on frequencies of the resistance associated esterase gene of natural population of Culex pipiens complex in Hangzhou during 2003-2005, and phenotype of the resistance associated esterase genes were detected by esterase starch gel electrophoresis technique.</p><p><b>RESULTS</b>The PCR-RFLP assay of esterase allele genes for three consecutive years disclosed four esterase genotypes, namely, the world-wide highly active homozygous Est beta 1(1) (50%-54%), homozygous Est beta 2 (29%-34%), heterozygous Est beta 1(1)/beta 2 (5%-10%) and Est beta N (3.13%) of a new homozygous genotype. The research of the resistance associated esterase genes phenotype in natural population of Culex pipiens complex in Hangzhou in 2005 with esterase starch gel electrophoresis technique revealed four major types, namely, Est beta 1(1) (61%), Est alpha 2/beta 2 (12%), Est alpha 8/beta 8 (7%) and sensitive phenotype (29%).</p><p><b>CONCLUSION</b>There should be various resistance associated esterase genotypes in natural population of Culex pipiens complex in Hangzhou. During the period of 2003-2005, Est beta 1(1) was the major type; Est alpha 2/beta 2 was the second. Est beta N was a new esterase genotype detected in 2005 only with a mere percentage of 3.13%. As for its resistance to the new insecticide, a follow-up study should be needed. The molecular typing of the amplified esterase gene should be consistent with the resistance associated esterase genes phenotype.</p>

Cloning and sequence analysis of MYB transcriptional regulator SmP gene of Saussurea medusa Maxim / 生物工程学报

A full-length cDNA encoding a MYB-related regulatory gene was isolated from a cDNA library prepared from mRNAs of the red line callus of S. medusa by TD-PCR. The cDNA, designated SmP, is 969 nucleotides long and has an open reading frame of 771 bp with a deduced amino acid sequence of 256 residues. The putative protein of SmP has two typical conversed R2R3-Myb DNA-binding domains in N-terminal and displays a rather high degree of similarity to OsMYB from rice and LBMI from tobacco, showing 73% and 70% identity within the DNA-binding domains. However, the C-terminal domain of the SmP protein does not show obvious similarity to any other known protein sequence. It is rich in hydrophilic amino acids, especially in serine residues (18.38%), partly organized in homopolymeric stretches, a feature often found in activation domain of transcription factors.