Characterization of a new laboratory colony of Anopheles funestus mosquitoes established in Ifakara, Tanzania
Loading...
Date
2025-11-24
Journal Title
Journal ISSN
Volume Title
Publisher
bioRxiv
Abstract
Background: Anopheles funestus, a major vector of malaria in Africa, has proven difficult to colonize
in laboratory settings, impeding research on its biology and control. After several attempts, our team
recently succeeded in colonizing a strain of An. funestus from Tanzania (FUTAZ). The objective of
this study was to analyse the key fitness and genotypic characteristics of these mosquitoes during
multiple filial generations of laboratory adaptation and compare them to wild An. funestus from
Tanzania and a pre-existing colony of An. funestus from Mozambique (FUMOZ).
Methods: Measures of mating success (percentage of female mosquitoes inseminated), body size
(wing length), fecundity (number of eggs laid per female), and insecticide susceptibility (percentage
of 24-hour mortality after exposure to insecticides) were compared between the newly established
colonies of Tanzanian An. funestus (FUTAZ colonies), the long-established FUMOZ colonies, and a
colony of Anopheles arabiensis maintained in the same laboratory. The maternal lineages of the An.
funestus mosquitoes were investigated through a hydrolysis probe analysis of their mitochondrial
DNA to identify distinct clades, I and II. Additionally, other intragenomic variations were examined
through a PCR analysis of restriction fragment length polymorphisms (RFLP) on the third domain of
28S ribosomal DNA. These molecular markers were used to compare the FUTAZ colonies, FUMOZ
colonies in Tanzania and South Africa, and the wild-collected An. funestus from Tanzania.
Result: The mating success and body size of FUTAZ females declined significantly from filial
generations F1 to F6 relative to the founder population (F0), but then increased from F7 onwards
eventually matching FUMOZ by F9. Fecundity was similar across all colonies tested. However, it
took significantly longer for 50% of the females in the FUTAZ and FUMOZ colonies (over 10 days)
to mate compared to females in the An. arabiensis colony (approximately 5 days). Insecticide
resistance appeared to be lost during colonization, but this varied with insecticide classes. Majority of
mosquitoes in the FUTAZ colony, as well as the wild-caught Tanzanian An. funestus belonged to
Clade I (80.4-89.4%) and RFLP type “Y” (90.5-91.4%), while the FUMOZ colonies were mostly
Clade II (65.5-88.5%) and RFLP type “MW” (90.5-91.5%).
Conclusion: This study suggests that the mating success and body size of An. funestus decreases
significantly during the early stages of colonization, then increase as the mosquitoes adapt to
laboratory conditions. It is therefore crucial to have a large enough founder population to persist
through these early generations in order to achieve stable colonization of An. funestus. The Clade and
RFLP genotyping demonstrated the genetic similarities between the FUTAZ mosquitoes and wild-
caught Tanzanian An. funestus, but also showed that the new colony can be distinguished from the
FUMOZ colony.
Sustainable Development Goals
SDG 3: Good Health and Well-being
SDG 4: Quality Education
SDG 9: Industry, Innovation and Infrastructure
SDG 17: Partnerships for the Goals
Keywords
Mating, Colonization, FUTAZ, FUMOZ, Clade analysis and D3-RFLP