A polytene chromosome study of four populations of Anopheles aquasalis from Venezuela

Genome ◽  
1992 ◽  
Vol 35 (2) ◽  
pp. 327-331 ◽  
Author(s):  
Alba Moncada Perez ◽  
Jan Conn

Polytene chromosome studies were undertaken to elucidate taxonomic relationships among populations of Anopheles aquasalis and A. emilianus in Venezuela. Four collection sites were chosen: two in Sucre state (Santa Fe and Guayana) where A. aquasalis (considered to be A. emilianus by Gabaldón and Escalante) is presumed to be the major regional vector of Plasmodium vivax; and two in areas where no malaria transmission occurs (Caño Rico, Aragua state, and Puerto Cabello, Carabobo state). The chromosome banding pattern of the four populations was identical and conformed to the standard chromosome map of A. aquasalis from Brazil. These results suggest that the population from Santa Fe and Guayana, considered to be A. emilianus, is conspecific with A. aquasalis. However, its status as a distinct species with a homosequential polytene chromosome banding pattern cannot be ruled out.Key words: polytene chromosomes, Anopheles aquasalis, malaria, chromosome banding.

1996 ◽  
Vol 74 (1) ◽  
pp. 171-191 ◽  
Author(s):  
Iya I. Kiknadze ◽  
Karlygash G. Aimanova ◽  
Larissa I. Gunderina ◽  
Malcolm G. Butler ◽  
J. Kevin Cooper

Polytene chromosomes of Chironomus (Camptochironomus) tentans from Europe, Siberia, and North America were examined to clarify genetic relationships among widely distributed populations of this Holarctic midge. This first extensive cytogenetic analysis of Siberian populations confirms earlier suppositions that C. tentans karyotypes are quite uniform across the Palearctic from western Europe to Yakutia. Greater differences exist among North American populations in Minnesota, Michigan, and Massachusetts, and as a group, these Nearctic populations share so few banding sequences with Palearctic C. tentans that recognition of discrete sibling species on each contintent is warranted. Photomaps of polytene chromosomes for both Palearctic and Nearctic sibling species are presented, and banding sequences are described with standardized notation. In total, 42 inversion sequences were found in the 18 Siberian populations examined, 15 of which were previously undescribed. Of the 19 sequences found in the three American populations studied, only 6 were shared with the Palearctic. Three of the seven chromosome arms in Nearctic C. tentans had no sequences in common with European populations and four shared none with Siberian populations.


2004 ◽  
Vol 82 (5) ◽  
pp. 808-816 ◽  
Author(s):  
Mike Spironello ◽  
Fiona F Hunter

The polytene chromosome banding pattern of Simulium exasperans (Craig, 1987) is described for the first time. Three populations of S. exasperans from Moorea and Tahiti were examined cytologically. Interspecific comparisons revealed that S. exasperans is homosequential in chromosomal banding pattern to Simulium cataractarum (Craig, 1987), but contains three species-characteristic floating inversions: IL-1ex.2ex, IIL-1ex,2ex, and IIIL-1ex. No sex-linked inversions were identified; males and females had undifferentiated sex chromosomes. The IIL-1ex,2ex inversion was in Hardy-Weinberg disequilibrium in two of the three populations. From this preliminary data, two cytotypes may exist: cytotype A (Belvedre Cascade population) and cytotype B (1st Afareaitu Cascade and Jardin Public Vaipahi populations). Contrary to phylogenetic and biogeographic data, it is hypothesized that the Belvedre Cascade population (cytotype A) is ancestral to the populations containing cytotype B. Furthermore, a heterozygote advantage may exist in cytotype B.


Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 598-611 ◽  
Author(s):  
D. G. Bedo

Polytene chromosome reference maps of the five autosomes of Ceratitis capitata from male pupal orbital bristle trichogen cells are presented and a correlation is established between two of them and the two largest of the five autosomes in the haploid mitotic complement. Characteristic features of each chromosome are described identifying areas that are difficult to analyze and noting the existence of common alternative band expression. A quantitative analysis of the mitotic karyotype of C. capitata indicates that the two smallest autosome pairs cannot be reliably distinguished. This may present problems with future attempts to establish homologies between the remaining mitotic and polytene chromosomes. A comparison of polytene chromosome banding patterns from salivary gland and trichogen cells failed to find any homologous regions, or even to identify homologous chromosomes. The banding differences are not explained by variation in puffing patterns, heterochromatin expression, or polyteny levels, but appear to reflect fundamental differences in banding patterns of the chromosomes in each tissue. Key words: Ceratitis capitata, polytene chromosome map, mitotic chromosome measurements.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
E. Adlaoui ◽  
C. Faraj ◽  
M. El Bouhmi ◽  
A. El Aboudi ◽  
S. Ouahabi ◽  
...  

Malaria resurgence risk in Morocco depends, among other factors, on environmental changes as well as the introduction of parasite carriers. The aim of this paper is to analyze the receptivity of the Loukkos area, large wetlands in Northern Morocco, to quantify and to map malaria transmission risk in this region using biological and environmental data. This risk was assessed on entomological risk basis and was mapped using environmental markers derived from satellite imagery. Maps showing spatial and temporal variations of entomological risk for Plasmodium vivax and P. falciparum were produced. Results showed this risk to be highly seasonal and much higher in rice fields than in swamps. This risk is lower for Afrotropical P. falciparum strains because of the low infectivity of Anopheles labranchiae, principal malaria vector in Morocco. However, it is very high for P. vivax mainly during summer corresponding to the rice cultivation period. Although the entomological risk is high in Loukkos region, malaria resurgence risk remains very low, because of the low vulnerability of the area.


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