Objective: Vacuolating megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a recently described syndrome with autosomal recessive mode of inheritance. Its possible gene was located on chromosomal 22q ...Objective: Vacuolating megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a recently described syndrome with autosomal recessive mode of inheritance. Its possible gene was located on chromosomal 22q tel with 3-cM. The purpose of this study was to narrow down the genetical distance on chromosomal 22q tel with MLC. Methods: Thirty-nine MLC patients in 33 families were collected,and the linkage analysis and haplotype analysis of twelve informative families were done, using seven microsatellite markers and four SNP markers. Results: The maximum tow-point LOD score for marker 355c18 was 6.65 at recombination fraction 0.02. The haplotype analysis narrowed down the critical region of MLC to 250 kb on chromosomal 22q tel. Conclusion: One of the causing genes of MLC was located on chromosomal 22q tel with 250 kb. Four candidate genes were considered. The heterogeneity of one informative family indicated possible existence of a second locus for MLC.展开更多
Chlorfenapyr is a broad-spectrum halogenated pyrrole insecticide with a unique mode of action.Due to the misuse and overuse of this chemical,resistance has been reported in several arthropods,including Plutella xylost...Chlorfenapyr is a broad-spectrum halogenated pyrrole insecticide with a unique mode of action.Due to the misuse and overuse of this chemical,resistance has been reported in several arthropods,including Plutella xylostella,which is one of the most destructive insect pests afflicting crucifers worldwide.A better understanding of the cross-resistance and genetics of field-evolved chlorfenapyr resistance could effectively guide resistance management practices.Here,the chlorfenapyr resistance of a fieldderived population of P xylostella was introgressed into the susceptible IPP-S strain using a selection-assisted multigenerational backcrossing approach.The constructed nearisogenic strain,TH-BCsF2,shared 98.4%genetic background with the recurrent parent IPP-S strain.The TH-BCsF2 strain showed 275-fold resistance to chlorfenapyr,but no significant cross-resistance to spinosad,abamectin,chlorpyrifos,β-cypermethrin,indoxacarb,chlorantraniliprole,or broflanilide(no more than 4.2-fold).Genetic analysis revealed that resistance was autosomal,incompletely dominant,and conferred by 1 major gene or a few tightly linked loci.The synergism of metabolic inhibitors(PBO,DEM,and DEF)to chlorfenapyr was very weak(<1.7-fold),and the metabolic enzyme activities in the TH-BCsF2 strain were not significantly elevated compared with the IPP-S strain.The results enhances our understanding of the genetic traits of chlorfenapyr resistance,and provides essential information for improving resistance management strategies.展开更多
文摘Objective: Vacuolating megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a recently described syndrome with autosomal recessive mode of inheritance. Its possible gene was located on chromosomal 22q tel with 3-cM. The purpose of this study was to narrow down the genetical distance on chromosomal 22q tel with MLC. Methods: Thirty-nine MLC patients in 33 families were collected,and the linkage analysis and haplotype analysis of twelve informative families were done, using seven microsatellite markers and four SNP markers. Results: The maximum tow-point LOD score for marker 355c18 was 6.65 at recombination fraction 0.02. The haplotype analysis narrowed down the critical region of MLC to 250 kb on chromosomal 22q tel. Conclusion: One of the causing genes of MLC was located on chromosomal 22q tel with 250 kb. Four candidate genes were considered. The heterogeneity of one informative family indicated possible existence of a second locus for MLC.
基金supported by the National Natural Science Foundation of China(32072454)the Guidance Foundation of Sanya Institute of Nanjing Agricultural University(NAUSY-MS09).
文摘Chlorfenapyr is a broad-spectrum halogenated pyrrole insecticide with a unique mode of action.Due to the misuse and overuse of this chemical,resistance has been reported in several arthropods,including Plutella xylostella,which is one of the most destructive insect pests afflicting crucifers worldwide.A better understanding of the cross-resistance and genetics of field-evolved chlorfenapyr resistance could effectively guide resistance management practices.Here,the chlorfenapyr resistance of a fieldderived population of P xylostella was introgressed into the susceptible IPP-S strain using a selection-assisted multigenerational backcrossing approach.The constructed nearisogenic strain,TH-BCsF2,shared 98.4%genetic background with the recurrent parent IPP-S strain.The TH-BCsF2 strain showed 275-fold resistance to chlorfenapyr,but no significant cross-resistance to spinosad,abamectin,chlorpyrifos,β-cypermethrin,indoxacarb,chlorantraniliprole,or broflanilide(no more than 4.2-fold).Genetic analysis revealed that resistance was autosomal,incompletely dominant,and conferred by 1 major gene or a few tightly linked loci.The synergism of metabolic inhibitors(PBO,DEM,and DEF)to chlorfenapyr was very weak(<1.7-fold),and the metabolic enzyme activities in the TH-BCsF2 strain were not significantly elevated compared with the IPP-S strain.The results enhances our understanding of the genetic traits of chlorfenapyr resistance,and provides essential information for improving resistance management strategies.
