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Wolbachia-based population control strategy targeting Culex quinquefasciatus mosquitoes proves efficient under semi-field conditions.

Atyame CM, Cattel J, Lebon C, Flores O, Dehecq JS, Weill M, Gouagna LC, Tortosa P - PLoS ONE (2015)

Bottom Line: This property can be used to reduce the density of mosquito field populations through inundative releases of incompatible males in order to sterilize females (Incompatible Insect Technique, or IIT, strategy).The results indicated that the LR[wPip(Is)] males successfully compete with field males in mating with field females, displaying even higher competitiveness than field males in April.Our results support the implementation of small-scale field tests in order to assess the feasibility of IIT against Cx. quinquefasciatus in the islands of southwestern Indian Ocean where this mosquito species is a proven competent vector for human pathogens.

View Article: PubMed Central - PubMed

Affiliation: CRVOI, Ste Clotilde, Réunion Island, France; University La Réunion, Réunion Island, France.

ABSTRACT
In mosquitoes, the maternally inherited bacterial Wolbachia induce a form of embryonic lethality called cytoplasmic incompatibility (CI). This property can be used to reduce the density of mosquito field populations through inundative releases of incompatible males in order to sterilize females (Incompatible Insect Technique, or IIT, strategy). We have previously constructed the LR[wPip(Is)] line representing a good candidate for controlling field populations of the Culex quinquefasciatus mosquito in the islands of the south-western Indian Ocean. The main purpose of the present study was to fill the gap between laboratory experiments and field implementation, i.e. assessing mating competitiveness of these incompatible males under semi-field conditions. In a first set of experiments, we analyzed crossing relationships between LR[wPip(Is)] males and La Réunion field females collected as larvae in 19 distinct localities throughout the island. This investigation revealed total embryonic mortality, confirming the strong sterilizing capacity of LR[wPip(Is)] males. Subsequently, mating competitiveness of LR[wPip(Is)] males was assessed under semi-field conditions in the presence of field males and females from La Réunion. Confrontations were carried out in April and December using different ratios of LR[wPip(Is)] to field males. The results indicated that the LR[wPip(Is)] males successfully compete with field males in mating with field females, displaying even higher competitiveness than field males in April. Our results support the implementation of small-scale field tests in order to assess the feasibility of IIT against Cx. quinquefasciatus in the islands of southwestern Indian Ocean where this mosquito species is a proven competent vector for human pathogens.

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Sample sites of Culex quinquefasciatus field populations in La Réunion Island.Localities in grey correspond to those sites where mosquitoes were sampled for semi-field tests.
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pone.0119288.g001: Sample sites of Culex quinquefasciatus field populations in La Réunion Island.Localities in grey correspond to those sites where mosquitoes were sampled for semi-field tests.

Mentions: Culex quinquefasciatus larvae and pupae were collected in breeding sites in 19 localities of La Réunion Island in March, April, May and June 2012; and in March, April, November and December 2013 (Fig. 1). Mosquitoes were reared in the laboratory until emergence and adults were used in crossing experiments. Several hundred field-caught four instar larvae (L4) and pupae were sampled from five arbitrarily chosen localities (Ste Marie, #12; Ste Suzanne, #13; St André, #14; Bras Panon, #15 and St Benoît, #16; Fig. 1) and mosquitoes from the five populations were mixed in order to provide the field mosquitoes required for the semi-field tests. The previously described incompatible LR[wPip(Is)] line, harboring the sterilizing wPip(Is) strain together with a nuclear background of La Réunion mosquitoes [4] was used for the production of incompatible males.


Wolbachia-based population control strategy targeting Culex quinquefasciatus mosquitoes proves efficient under semi-field conditions.

Atyame CM, Cattel J, Lebon C, Flores O, Dehecq JS, Weill M, Gouagna LC, Tortosa P - PLoS ONE (2015)

Sample sites of Culex quinquefasciatus field populations in La Réunion Island.Localities in grey correspond to those sites where mosquitoes were sampled for semi-field tests.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4359102&req=5

pone.0119288.g001: Sample sites of Culex quinquefasciatus field populations in La Réunion Island.Localities in grey correspond to those sites where mosquitoes were sampled for semi-field tests.
Mentions: Culex quinquefasciatus larvae and pupae were collected in breeding sites in 19 localities of La Réunion Island in March, April, May and June 2012; and in March, April, November and December 2013 (Fig. 1). Mosquitoes were reared in the laboratory until emergence and adults were used in crossing experiments. Several hundred field-caught four instar larvae (L4) and pupae were sampled from five arbitrarily chosen localities (Ste Marie, #12; Ste Suzanne, #13; St André, #14; Bras Panon, #15 and St Benoît, #16; Fig. 1) and mosquitoes from the five populations were mixed in order to provide the field mosquitoes required for the semi-field tests. The previously described incompatible LR[wPip(Is)] line, harboring the sterilizing wPip(Is) strain together with a nuclear background of La Réunion mosquitoes [4] was used for the production of incompatible males.

Bottom Line: This property can be used to reduce the density of mosquito field populations through inundative releases of incompatible males in order to sterilize females (Incompatible Insect Technique, or IIT, strategy).The results indicated that the LR[wPip(Is)] males successfully compete with field males in mating with field females, displaying even higher competitiveness than field males in April.Our results support the implementation of small-scale field tests in order to assess the feasibility of IIT against Cx. quinquefasciatus in the islands of southwestern Indian Ocean where this mosquito species is a proven competent vector for human pathogens.

View Article: PubMed Central - PubMed

Affiliation: CRVOI, Ste Clotilde, Réunion Island, France; University La Réunion, Réunion Island, France.

ABSTRACT
In mosquitoes, the maternally inherited bacterial Wolbachia induce a form of embryonic lethality called cytoplasmic incompatibility (CI). This property can be used to reduce the density of mosquito field populations through inundative releases of incompatible males in order to sterilize females (Incompatible Insect Technique, or IIT, strategy). We have previously constructed the LR[wPip(Is)] line representing a good candidate for controlling field populations of the Culex quinquefasciatus mosquito in the islands of the south-western Indian Ocean. The main purpose of the present study was to fill the gap between laboratory experiments and field implementation, i.e. assessing mating competitiveness of these incompatible males under semi-field conditions. In a first set of experiments, we analyzed crossing relationships between LR[wPip(Is)] males and La Réunion field females collected as larvae in 19 distinct localities throughout the island. This investigation revealed total embryonic mortality, confirming the strong sterilizing capacity of LR[wPip(Is)] males. Subsequently, mating competitiveness of LR[wPip(Is)] males was assessed under semi-field conditions in the presence of field males and females from La Réunion. Confrontations were carried out in April and December using different ratios of LR[wPip(Is)] to field males. The results indicated that the LR[wPip(Is)] males successfully compete with field males in mating with field females, displaying even higher competitiveness than field males in April. Our results support the implementation of small-scale field tests in order to assess the feasibility of IIT against Cx. quinquefasciatus in the islands of southwestern Indian Ocean where this mosquito species is a proven competent vector for human pathogens.

Show MeSH