Mitochondrial DNA divergence between wild and laboratory populations of Anopheles albimanus Wiedemann (Diptera: Culicidae)

Abstract

Divergencia del ADN Mitocondrial entre Poblaciones del Campo y de Colonia de Anopheles albimanusWiedemann (Diptera: Culicidae)RESUMEN -Las colonias de laboratorio facilitan el estudio de los insectos vectores; sin embargo, se ha sugerido que tales colonias de insectos no son representativas de las poblaciones naturales, llevando en algunos casos, a interpretaciones erróneas respecto a la variación intraespecífica entre los individuos. En el presente estudio se evaluó la variabilidad del gen mitocondrial citocromo b entre una colonia de laboratorio de Anopheles albimanus Wiedemann fundada hace 20 años y la población del campo de la cual se derivó. Los análisis revelan la presencia de cinco y tres haplotipos en las poblaciones del campo y la colonia, respectivamente; los individuos del campo presentaron una mayor variabilidad que los de la colonia basada en el numero de sitios polimórficos, la diversidad haplotípica, la diversidad nucleotídica y el valor promedio de las diferencias nucleotídicas. El promedio y el número neto de sustituciones nucleotídicas por sitio entre las poblaciones y los valores calculados para el F ST (0,37179, P = 0.05) indican que existe un considerable grado de diferenciación genética entre ellas; el árbol filogenético muestra que los haplotipos de la colonia parecen derivarse de las poblaciones del campo. Estos resultados sugieren una mayor variabilidad genética existente entre los especimenes del campo en comparación con los individuos de la colonia debido en parte, al largo tiempo de colonización. PALABRAS-CLAVE: Variabilidad genética, malaria, mosquitoABSTRACT -Studies of insect vectors may be facilitated by using laboratory colonies. However, it has been suggested that the colony insects are not representative of natural populations, sometimes yealding to erroneous interpretations of the intraspecific genetic variation between the individuals. In the present study the variability of the mitochondrial gene cytochrome b was evaluated among a closed laboratory colony of Anopheles albimanus that was founded 20 years ago and the field population from which it was derived. The analyses revealed the presence of five and three nucleotide haplotypes in the wild and colony populations, respectively. Wild individuals presented greater variability than those of the colony based on the number of polymorphic sites, haplotype diversity, nucleotide diversity and mean values of nucleotide differences. The mean and net numbers of nucleotide substitutions per site between populations and the significant F ST value calculated (0,37179, P = 0.05) indicate that there is a considerable degree of genetic differentiation between them. The phylogenetic tree showed that the colony haplotypes appear to be derived from the wild population. These results suggest a great genetic variability in wild specimens compared with the laboratory ones as a consequence of a long time of colonization.

Conserved Mosquito/Parasite Interactions Affect Development of Plasmodium falciparum in Africa

“…A previous study had demonstrated strong loss of polymorphisms and considerable divergence from natural populations in a 20-year old laboratory colony of a different mosquito, the neotropical species A. albimanus [22]. We examined to what extend the Yaoundé strain mosquitoes are representative of local populations, by determining the respective genetic diversities and calculating their genetic distance (divergence) from field-collected local A. gambiae .…”

Genetic Diversity and Differentiation among Laboratory and Field Populations of the Soybean Aphid,Aphis glycines

“…However, the genetic composition of these soybean aphid laboratory populations is unknown. Comparisons of laboratory and field populations in other systems have documented less genetic diversity and higher levels of genetic divergence among laboratory and field populations (Lanzaro et al , 1998; Fuller et al , 1999; Arias et al , 2005; Kim et al , 2007). This is expected, since laboratory populations likely contain lower effective population sizes, increased inbreeding pressures and may suffer from founder effects, depending on the initial population size.…”

Establishment of a large semi-field system for experimental study of African malaria vector ecology and control in Tanzania

“…A second scientific concern is that vector populations established within SFS will likely be considerably smaller than those in the wild and thus experience inbreeding and a resultant reduction in genetic diversity which could impede fitness. It is well known that genetic diversity within insect vectors can be considerably reduced during laboratory colonization [ 84 - 86 ]. Free-living populations established within SFS may be considerably larger than typical laboratory colonies and thus avoid a similar intensity of inbreeding, however it is unlikely they will escape some bottle-necking and an associated loss of diversity from founder populations.…”