Heterosis Increases Fertility, Fecundity, and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii.
The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized >35 and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments, widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health.
Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire ST5 5BG, UK.
Nkiru E
NE
Ekechukwu
Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire ST5 5BG, UK.
Rowida
R
Baeshen
Malaria Research and Training Center, Faculty of Medicine and Dentistry, University of Mali, BP E.2528, Bamako, Mali.
Sékou F
SF
Traorè
Malaria Research and Training Center, Faculty of Medicine and Dentistry, University of Mali, BP E.2528, Bamako, Mali.
Mamadou
M
Coulibaly
Institut de Recherche en Sciences de la Santé/Centre Muratz, 01 BP 390 Bobo-Dioulasso, Burkina Faso.
Abdoulaye
A
Diabate
Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115 Dipartimento di Medicina Sperimentale e Scienze Biochimiche, Università degli Studi di Perugia, 06132 Perugia, Italy.
Flaminia
F
Catteruccia
Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire ST5 5BG, UK f.tripet@keele.ac.uk.
Frédéric
http://orcid.org/0000-0002-7939-0712
F
Tripet
D000818:Animals; D000852:Anopheles / Q000235:genetics*; D005260:Female; D005298:Fertility / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype; D006823:Hybrid Vigor / Q000235:genetics*; D006824:Hybridization, Genetic; D007178:Inbreeding; D007303:Insect Vectors / Q000235:genetics; D008136:Longevity; D008288:Malaria / Q000635:transmission; D008297:Male; D009032:Mosquito Control; D012726:Sexual Behavior, Animal; D013094:Spermatozoa / Q000502:physiology
colonization; heterosis; hybrid vigor; inbreeding; mating competitiveness