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The Cytochrome P450 gene CYP6P12 confers pyrethroid resistance in kdr-free Malaysian populations of the dengue vector Aedes albopictus.

Ishak IH, Riveron JM, Ibrahim SS, Stott R, Longbottom J, Irving H, Wondji CS - Sci Rep (2016)

Bottom Line: Microarray-based transcription profiling revealed that metabolic resistance (cytochrome P450 up-regulation) and possibly a reduced penetration mechanism (consistent over-expression of cuticular protein genes) were associated with pyrethroid resistance.CYP6P12 over-expression was strongly associated with pyrethroid resistance whereas CYP6N3 was rather consistently over-expressed across carbamate and DDT resistant populations.The major role played by P450 in the absence of kdr mutations suggests that addition of the synergist PBO to pyrethroids could improve the efficacy of this insecticide class and overcome resistance in field populations of Ae. albopictus.

View Article: PubMed Central - PubMed

Affiliation: Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom.

ABSTRACT
Control of Aedes albopictus, major dengue and chikungunya vector, is threatened by growing cases of insecticide resistance. The mechanisms driving this resistance remain poorly characterised. This study investigated the molecular basis of insecticide resistance in Malaysian populations of Ae. albopictus. Microarray-based transcription profiling revealed that metabolic resistance (cytochrome P450 up-regulation) and possibly a reduced penetration mechanism (consistent over-expression of cuticular protein genes) were associated with pyrethroid resistance. CYP6P12 over-expression was strongly associated with pyrethroid resistance whereas CYP6N3 was rather consistently over-expressed across carbamate and DDT resistant populations. Other detoxification genes also up-regulated in permethrin resistant mosquitoes included a glucuronosyltransferase (AAEL014279-RA) and the glutathione-S transferases GSTS1 and GSTT3. Functional analyses further supported that CYP6P12 contributes to pyrethroid resistance in Ae. albopictus as transgenic expression of CYP6P12 in Drosophila was sufficient to confer pyrethroid resistance in these flies. Furthermore, molecular docking simulations predicted CYP6P12 possessing enzymatic activity towards pyrethroids. Patterns of polymorphism suggested early sign of selection acting on CYP6P12 but not on CYP6N3. The major role played by P450 in the absence of kdr mutations suggests that addition of the synergist PBO to pyrethroids could improve the efficacy of this insecticide class and overcome resistance in field populations of Ae. albopictus.

No MeSH data available.


Related in: MedlinePlus

Genetic diversity patterns of CYP6P12 and CYP6N3 across Malaysia from KL (Kuala Lumpur), PG (Penang), JB (Johor Bharu) and KB (Kota Bharu): (a) Maximum likelihood tree of CYP6P12, while (b) is for CYP6N3; (c) Genetic distance between populations across Malaysia based on CYP6P12 Nst estimates while (d) is for CYP6N3.
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f4: Genetic diversity patterns of CYP6P12 and CYP6N3 across Malaysia from KL (Kuala Lumpur), PG (Penang), JB (Johor Bharu) and KB (Kota Bharu): (a) Maximum likelihood tree of CYP6P12, while (b) is for CYP6N3; (c) Genetic distance between populations across Malaysia based on CYP6P12 Nst estimates while (d) is for CYP6N3.

Mentions: Analysis of the polymorphism patterns of the full-length cDNA sequences of CYP6P12 (1527 bp) and CYP6N3 (1500 bp) in the four populations in Malaysia revealed that both genes are highly polymorphic across Malaysia with a high number of substitution sites (129 and 88 respectively for CYP6P12 and CYP6N3) (Table S7). However, if the polymorphism level is similar between locations for CYP6N3, three of the four locations (KL, PG and KB) present a reduced diversity for the CYP6P12 genes as shown by lower substitution sites (0 to 15 compared to 85 in JB), lower number of haplotypes (1 to 2 compared to 5 in JB) possibly suggesting that a selection could be acting on this gene as a consequence of ongoing resistance. This is further supported for the KL sample for which a significant estimate of the neutrality test D* (Fu and Li) was observed. This could be associated with the pyrethroid resistance observed in KL. However, further analysis with more sequences is needed to establish the presence of such signature of selective sweep. A maximum likelihood phylogenetic tree of both genes revealed that CYP6P12 haplotypes cluster according to their location of origin with those from KL clustering with PG haplotypes but differently from JB and KB (Fig. 4a). In contrast, CYP6N3 appear to cluster randomly in accordance to the consistent high polymorphism in all locations (Fig. 4b). Overall, the level of genetic differentiation between locations appears similar for CYP6P12 and CYP6N3 as the Nst genetic distance tree shows that PG and KL cluster together for both genes (Fig. 4c,d).


The Cytochrome P450 gene CYP6P12 confers pyrethroid resistance in kdr-free Malaysian populations of the dengue vector Aedes albopictus.

Ishak IH, Riveron JM, Ibrahim SS, Stott R, Longbottom J, Irving H, Wondji CS - Sci Rep (2016)

Genetic diversity patterns of CYP6P12 and CYP6N3 across Malaysia from KL (Kuala Lumpur), PG (Penang), JB (Johor Bharu) and KB (Kota Bharu): (a) Maximum likelihood tree of CYP6P12, while (b) is for CYP6N3; (c) Genetic distance between populations across Malaysia based on CYP6P12 Nst estimates while (d) is for CYP6N3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837359&req=5

f4: Genetic diversity patterns of CYP6P12 and CYP6N3 across Malaysia from KL (Kuala Lumpur), PG (Penang), JB (Johor Bharu) and KB (Kota Bharu): (a) Maximum likelihood tree of CYP6P12, while (b) is for CYP6N3; (c) Genetic distance between populations across Malaysia based on CYP6P12 Nst estimates while (d) is for CYP6N3.
Mentions: Analysis of the polymorphism patterns of the full-length cDNA sequences of CYP6P12 (1527 bp) and CYP6N3 (1500 bp) in the four populations in Malaysia revealed that both genes are highly polymorphic across Malaysia with a high number of substitution sites (129 and 88 respectively for CYP6P12 and CYP6N3) (Table S7). However, if the polymorphism level is similar between locations for CYP6N3, three of the four locations (KL, PG and KB) present a reduced diversity for the CYP6P12 genes as shown by lower substitution sites (0 to 15 compared to 85 in JB), lower number of haplotypes (1 to 2 compared to 5 in JB) possibly suggesting that a selection could be acting on this gene as a consequence of ongoing resistance. This is further supported for the KL sample for which a significant estimate of the neutrality test D* (Fu and Li) was observed. This could be associated with the pyrethroid resistance observed in KL. However, further analysis with more sequences is needed to establish the presence of such signature of selective sweep. A maximum likelihood phylogenetic tree of both genes revealed that CYP6P12 haplotypes cluster according to their location of origin with those from KL clustering with PG haplotypes but differently from JB and KB (Fig. 4a). In contrast, CYP6N3 appear to cluster randomly in accordance to the consistent high polymorphism in all locations (Fig. 4b). Overall, the level of genetic differentiation between locations appears similar for CYP6P12 and CYP6N3 as the Nst genetic distance tree shows that PG and KL cluster together for both genes (Fig. 4c,d).

Bottom Line: Microarray-based transcription profiling revealed that metabolic resistance (cytochrome P450 up-regulation) and possibly a reduced penetration mechanism (consistent over-expression of cuticular protein genes) were associated with pyrethroid resistance.CYP6P12 over-expression was strongly associated with pyrethroid resistance whereas CYP6N3 was rather consistently over-expressed across carbamate and DDT resistant populations.The major role played by P450 in the absence of kdr mutations suggests that addition of the synergist PBO to pyrethroids could improve the efficacy of this insecticide class and overcome resistance in field populations of Ae. albopictus.

View Article: PubMed Central - PubMed

Affiliation: Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom.

ABSTRACT
Control of Aedes albopictus, major dengue and chikungunya vector, is threatened by growing cases of insecticide resistance. The mechanisms driving this resistance remain poorly characterised. This study investigated the molecular basis of insecticide resistance in Malaysian populations of Ae. albopictus. Microarray-based transcription profiling revealed that metabolic resistance (cytochrome P450 up-regulation) and possibly a reduced penetration mechanism (consistent over-expression of cuticular protein genes) were associated with pyrethroid resistance. CYP6P12 over-expression was strongly associated with pyrethroid resistance whereas CYP6N3 was rather consistently over-expressed across carbamate and DDT resistant populations. Other detoxification genes also up-regulated in permethrin resistant mosquitoes included a glucuronosyltransferase (AAEL014279-RA) and the glutathione-S transferases GSTS1 and GSTT3. Functional analyses further supported that CYP6P12 contributes to pyrethroid resistance in Ae. albopictus as transgenic expression of CYP6P12 in Drosophila was sufficient to confer pyrethroid resistance in these flies. Furthermore, molecular docking simulations predicted CYP6P12 possessing enzymatic activity towards pyrethroids. Patterns of polymorphism suggested early sign of selection acting on CYP6P12 but not on CYP6N3. The major role played by P450 in the absence of kdr mutations suggests that addition of the synergist PBO to pyrethroids could improve the efficacy of this insecticide class and overcome resistance in field populations of Ae. albopictus.

No MeSH data available.


Related in: MedlinePlus