Limits...
A virulent Wolbachia infection decreases the viability of the dengue vector Aedes aegypti during periods of embryonic quiescence.

McMeniman CJ, O'Neill SL - PLoS Negl Trop Dis (2010)

Bottom Line: Minor costs of wMelPop-CLA infection for pre-imaginal survivorship, development and adult size were found.These results reveal a general pattern associated with wMelPop-CLA induced pathogenesis in this mosquito species, where host fitness costs increase during aging of both immature and adult life-history stages.In addition to influencing the invasion dynamics of this particular Wolbachia strain, we suggest that the negative impact of wMelPop-CLA on embryonic quiescence may have applied utility as a tool to reduce mosquito population size in regions with pronounced dry seasons or in regions that experience cool winters.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, The University of Queensland, St Lucia, Queensland, Australia.

ABSTRACT
A new approach for dengue control has been proposed that relies on life-shortening strains of the obligate intracellular bacterium Wolbachia pipientis to modify mosquito population age structure and reduce pathogen transmission. Previously we reported the stable transinfection of the major dengue vector Aedes aegypti with a life-shortening Wolbachia strain (wMelPop-CLA) from the vinegar fly Drosophila melanogaster. Here, we report a further characterization of the phenotypic effects of this virulent Wolbachia infection on several life-history traits of Ae. aegypti. Minor costs of wMelPop-CLA infection for pre-imaginal survivorship, development and adult size were found. However, we discovered that the wMelPop-CLA infection dramatically decreased the viability of desiccated Ae. aegypti eggs over time. Similarly, the reproductive fitness of wMelPop-CLA infected Ae. aegypti females declined with age. These results reveal a general pattern associated with wMelPop-CLA induced pathogenesis in this mosquito species, where host fitness costs increase during aging of both immature and adult life-history stages. In addition to influencing the invasion dynamics of this particular Wolbachia strain, we suggest that the negative impact of wMelPop-CLA on embryonic quiescence may have applied utility as a tool to reduce mosquito population size in regions with pronounced dry seasons or in regions that experience cool winters.

Show MeSH

Related in: MedlinePlus

Viability of quiescent embryos from PGYP1 and PGYP1.tet strains over time at different temperatures.After embryonic maturation (120 h post oviposition), eggs were stored at either: (A) 25°C and (B) 18°C, with 85% relative humidity. Average proportion of eggs hatching (n = 20 oviposition papers per time point) and standard error bars are shown.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2903475&req=5

pntd-0000748-g002: Viability of quiescent embryos from PGYP1 and PGYP1.tet strains over time at different temperatures.After embryonic maturation (120 h post oviposition), eggs were stored at either: (A) 25°C and (B) 18°C, with 85% relative humidity. Average proportion of eggs hatching (n = 20 oviposition papers per time point) and standard error bars are shown.

Mentions: The viability of quiescent embryos from the wMelPop-CLA infected PGYP1 strain decreased over time at 25°C and 18°C, whereas viability of embryos from the tetracycline-cured PGYP1.tet strain was relatively stable at both storage temperatures (Fig. 2). At 25°C (Fig. 2A), there was no significant difference in embryonic viability between PGYP1 (80.93±5.12%) and PGYP1.tet strains (74.96±4.37%) at 5 days post oviposition (MWU, U = 146.50, P = 0.1478). As quiescent embryos aged, however, PGYP1 embryonic viability decreased rapidly over time (R2 = 0.6539, F1,138 = 260.73, P<0.001), such that by 40 days post oviposition very few PGYP1 eggs hatched (0.44±0.24%). In contrast, PGYP1.tet embryonic viability remained relatively constant over time (R2 = 0.0005, F1,138 = 0.07, P = 0.7897) with ∼75% of quiescent eggs hatching at each time point. An analogous trend was observed at 18°C (Fig. 2B), where initially hatch rates were comparable between the two strains, but subsequently a greater loss in embryonic viability was observed for PGYP1 (R2 = 0.4035, F1,138 = 93.34, P<0.001) relative to PGYP1.tet (R2 = 0.0803, F1,138 = 12.05, P<0.001). This was particularly evident at 12 days post oviposition where embryonic viability declined more rapidly in PGYP1 (9.88±2.96%) compared to PGYP1.tet (68.06±4.12%) after being moved to a cooler storage temperature (MWU, U = 5.00, P<0.0001).


A virulent Wolbachia infection decreases the viability of the dengue vector Aedes aegypti during periods of embryonic quiescence.

McMeniman CJ, O'Neill SL - PLoS Negl Trop Dis (2010)

Viability of quiescent embryos from PGYP1 and PGYP1.tet strains over time at different temperatures.After embryonic maturation (120 h post oviposition), eggs were stored at either: (A) 25°C and (B) 18°C, with 85% relative humidity. Average proportion of eggs hatching (n = 20 oviposition papers per time point) and standard error bars are shown.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2903475&req=5

pntd-0000748-g002: Viability of quiescent embryos from PGYP1 and PGYP1.tet strains over time at different temperatures.After embryonic maturation (120 h post oviposition), eggs were stored at either: (A) 25°C and (B) 18°C, with 85% relative humidity. Average proportion of eggs hatching (n = 20 oviposition papers per time point) and standard error bars are shown.
Mentions: The viability of quiescent embryos from the wMelPop-CLA infected PGYP1 strain decreased over time at 25°C and 18°C, whereas viability of embryos from the tetracycline-cured PGYP1.tet strain was relatively stable at both storage temperatures (Fig. 2). At 25°C (Fig. 2A), there was no significant difference in embryonic viability between PGYP1 (80.93±5.12%) and PGYP1.tet strains (74.96±4.37%) at 5 days post oviposition (MWU, U = 146.50, P = 0.1478). As quiescent embryos aged, however, PGYP1 embryonic viability decreased rapidly over time (R2 = 0.6539, F1,138 = 260.73, P<0.001), such that by 40 days post oviposition very few PGYP1 eggs hatched (0.44±0.24%). In contrast, PGYP1.tet embryonic viability remained relatively constant over time (R2 = 0.0005, F1,138 = 0.07, P = 0.7897) with ∼75% of quiescent eggs hatching at each time point. An analogous trend was observed at 18°C (Fig. 2B), where initially hatch rates were comparable between the two strains, but subsequently a greater loss in embryonic viability was observed for PGYP1 (R2 = 0.4035, F1,138 = 93.34, P<0.001) relative to PGYP1.tet (R2 = 0.0803, F1,138 = 12.05, P<0.001). This was particularly evident at 12 days post oviposition where embryonic viability declined more rapidly in PGYP1 (9.88±2.96%) compared to PGYP1.tet (68.06±4.12%) after being moved to a cooler storage temperature (MWU, U = 5.00, P<0.0001).

Bottom Line: Minor costs of wMelPop-CLA infection for pre-imaginal survivorship, development and adult size were found.These results reveal a general pattern associated with wMelPop-CLA induced pathogenesis in this mosquito species, where host fitness costs increase during aging of both immature and adult life-history stages.In addition to influencing the invasion dynamics of this particular Wolbachia strain, we suggest that the negative impact of wMelPop-CLA on embryonic quiescence may have applied utility as a tool to reduce mosquito population size in regions with pronounced dry seasons or in regions that experience cool winters.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, The University of Queensland, St Lucia, Queensland, Australia.

ABSTRACT
A new approach for dengue control has been proposed that relies on life-shortening strains of the obligate intracellular bacterium Wolbachia pipientis to modify mosquito population age structure and reduce pathogen transmission. Previously we reported the stable transinfection of the major dengue vector Aedes aegypti with a life-shortening Wolbachia strain (wMelPop-CLA) from the vinegar fly Drosophila melanogaster. Here, we report a further characterization of the phenotypic effects of this virulent Wolbachia infection on several life-history traits of Ae. aegypti. Minor costs of wMelPop-CLA infection for pre-imaginal survivorship, development and adult size were found. However, we discovered that the wMelPop-CLA infection dramatically decreased the viability of desiccated Ae. aegypti eggs over time. Similarly, the reproductive fitness of wMelPop-CLA infected Ae. aegypti females declined with age. These results reveal a general pattern associated with wMelPop-CLA induced pathogenesis in this mosquito species, where host fitness costs increase during aging of both immature and adult life-history stages. In addition to influencing the invasion dynamics of this particular Wolbachia strain, we suggest that the negative impact of wMelPop-CLA on embryonic quiescence may have applied utility as a tool to reduce mosquito population size in regions with pronounced dry seasons or in regions that experience cool winters.

Show MeSH
Related in: MedlinePlus