Anopheles darlingi polytene chromosomes: revised maps including newly described inversions and evidence for population structure in Manaus

Salivary gland polytene chromosomes of 4th instar Anopheles darlingi Root were examined from multiple locations in the Brazilian Amazon. Minor modifications were made to existing polytene photomaps. These included changes to the breakpoint positions of several previously described paracentric inversions and descriptions of four new paracentric inversions, two on the right arm of chromosome 3 and two on the left arm of chromosome 3 that were found in multiple locations. A total of 18 inversions on the X (n = 1) chromosome, chromosome 2 (n = 7) and 3 (n = 11) were scored for 83 individuals from Manaus, Macapá and Porto Velho municipalities. The frequency of 2Ra inversion karyotypes in Manaus shows significant deficiency of heterozygotes (p < 0.0009). No significant linkage disequilibrium was found between inversions on chromosome 2 and 3. We hypothesize that at least two sympatric subpopulations exist within the An. darlingi population at Manaus based on inversion frequencies.

Genetic variation among natural and laboratory colony populations of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) from Colombia

Genetic diversity among three field populations of Lutzomyia longipalpis in Colombia was studied using isozyme analysis. Study sites were as much as 598 km apart and included populations separated by the eastern Cordillera of the Andes. Genetic variability among populations, estimated by heterozygosity, was within values typical for insects in general (8.1 per cent). Heterozygosity for field populations were compared with a laboratory colony from Colombia (Melgar colony) and were only slightly lower. These results suggest that establishment and long term maintenance of the Melgar colony has had little effect on the level of isozyme variability it carries. Genetic divergences between populations was evaluated using estimates of genetic distance. Genetic divergence among the three field populations was low (D=0.021), suggesting that they represent local populations within a single species. Genetic distance between field populations and the Melgar colony was also low (D=0.016), suggesting that this colony population does not depart significantly from natural populations. Finally, comparisons were made between Colombian populations and colonies from Brazil and Costa Rica. Genetic distance values were high between Colombian and both Brazil and Costa Rica colony populations (D=0.199 and 0.098 respectively) providing additional support for our earlier report that populations from the three countries represent distinct species.

Evidencia genetica de un complejo de especie en Anopheles pseudopunctipennis pseudopunctipennis / Genetic evidence of a species complex in Anopheles pseudopunctipennis pseudopunctipennis

Debido a inconsistencias en el patron de la transmision de la malaria en las zonas geográficas donde habita Anopheles pseudopunctipennis pseudopunctipennis, se investigo la posibilidad de que este vector representara un complejo de especie. Se hicieron estudios de hibridacion, localizacion electroforetica de enzimas y analisis restrictivo del ADN en mosquitos capturados en nueve localidades de México, Bolivia y el Perú. La esterilidad de las generaciones resultantes de cruzamientos entre hembras mexicanas y machos sudamericanos, dos localizaciones enzimaticas capaces de diferenciar ambas poblaciones y el valor de 0,13 de distancia genetica comprobaron la presencia de un complejo de especie probablemente producido por especiacion alopatrica. Se concluye que es necesario establecer la extension geográfica de las especies recien descubiertas por su efecto potencial en el control de la malaria