Genetics of Natural Populations. XXVIII. Supplementary Data on the Chromosomal Polymorphism in Drosophila willistoni in its Relation to the Environment

Evolution ◽  
1959 ◽  
Vol 13 (3) ◽  
pp. 389 ◽  
Author(s):  
A. Brito da Cunha ◽  
Th. Dobzhansky ◽  
O. Pavlovsky ◽  
B. Spassky
Keyword(s):  
Natural Populations ◽  
Chromosomal Polymorphism ◽  
Supplementary Data ◽  
Drosophila Willistoni

scholarly journals Inversion polymorphism in some natural populations of Drosophila pseudoobscura from central Mexico

Genetika ◽  
2007 ◽  
Vol 39 (3) ◽  
pp. 343-354 ◽  
Author(s):  
Víctor Salceda ◽  
Judith Guzmán ◽  
Olga Olvera
Keyword(s):  
Relative Frequency ◽  
Polytene Chromosomes ◽  
Natural Populations ◽  
Chromosomal Polymorphism ◽  
Drosophila Pseudoobscura ◽  
Central Mexico ◽  
The Third ◽  
Grand Total ◽  
Different Populations ◽  
Single Larva

Samples of D. pseudoobscura were taken in seventeen localities in Central Mexico inside the parallels 18o - 20o N, with the purpose of determine the chromosomal polymorphism in the third of the different populations of this species. From each captured female a single larva of its offspring was taken, its salivary glands extracted and stained with a solution of aceto orcein to observe the polytene chromosomes. From these smears the corresponding karyotype of each larva was determined, keeping a record of them. With the information gathered the relative frequency of each one of the fourteen different inversions found was calculated. A grand total of 1894 third chromosomes were analyzed. The fourteen different inversions found are equivalent to a 34.1 % of the total chromosomal variation of the species. The most abundant inversions found were: TL 50.6 %, CU 27.2 5, SC 9.1 % and EP 5.5 %; the remaining ten inversions detected are in general grounds rare ones with variable relative frequencies depending on the locality. Analysis of the predominant inversions for each population was done. The presence of West-East gradients is reported, even if in cases not so well defined, since as one moves in a particular direction the ups and downs in relative frequency for the alternating pairs TL-CU; TL-SC in the western populations and TL-CU in the eastern ones were observed. The assignment of each population to a particular race was also done, and such a way we were able to recognize three different races coexisting in the area of study.

scholarly journals Micro-geographic variation of inversions in natural populations of Drosophila pseudoobscura

Genetika ◽  
2006 ◽  
Vol 38 (2) ◽  
pp. 97-105 ◽  
Author(s):  
Víctor Salceda ◽  
José Espinoza-Velazquez
Keyword(s):  
Geographic Variation ◽  
Population Sample ◽  
Polytene Chromosomes ◽  
Natural Populations ◽  
Chromosomal Polymorphism ◽  
Drosophila Pseudoobscura ◽  
Natural Habitats ◽  
San Luis ◽  
San Luis Potosi ◽  
San Luis Potosí

Chromosomal polymorphism for the third chromosome in Drosophila pseudoobscura has been widely studied for genetic variation in different environments or locations far apart. However, there is less information regarding sites geographically near one another. Targeting on possible micro-geographic variation in the species, a serial study was done on 12 Mexican populations grouped in four regions, including locations in Durango (DU), the border area of Guanajuato-San Luis Potosi states (GP), Chiapas (CH) and Saldilo (SA). Flies were trapped in their natural habitats using fermenting bananas as bait. They were individually cultivated in the laboratory for larvae production. In a given population sample several flies were cultivated together but only one larva per culture provided salivary tissue to observe polytene chromosomes. Gene arrangements or inversions were identified and frequencies were calculated. A total of 767 third chromosomes were studied and 11 different inversions detected. The type and relative frequencies of the arrangements varied among regions. From the 11 inversions observed, 10 were found in Durango, five in Guanajuato-San Luis Potosi and Chiapas, and eight in Saltillo. The inversion frequencies in the Durango locations varied in four cases, but only one in Chiapas, three cases in Guanajuato-San Luis Potosi, and five in Saltillo. It was also observed that there were geographical gradients for inversions within regions as follows: four arrangements in Saltillo and Durango, three in Guanajuato-San Luis Potos? and one in Chiapas. Moreover, all four regions studied showed evidences for micro-geographical variation. Nevertheless, more studies are needed to elucidate the relevance of the inversion frequencies changes in neighboring populations and also any seasonal-annual frequencies observed in the locations studied here.

Adaptive Chromosomal Polymorphism in Drosophila willistoni

Evolution ◽  
1950 ◽  
Vol 4 (3) ◽  
pp. 212 ◽  
Author(s):  
A. Brito da Cunha ◽  
H. Burla ◽  
Th. Dobzhansky
Keyword(s):  
Chromosomal Polymorphism ◽  
Drosophila Willistoni

TRIPLOIDY IN NATURAL POPULATIONS OF THE BLACK FLY CNEPHIA MUTATA (MALLOCH)

1959 ◽  
Vol 37 (4) ◽  
pp. 571-589 ◽  
Author(s):  
V. R. Basrur ◽  
K. H. Rothfels
Keyword(s):  
Salivary Gland ◽  
Banding Pattern ◽  
Natural Populations ◽  
Chromosomal Polymorphism ◽  
Genetic Exchange ◽  
Black Flies ◽  
Female Progeny ◽  
Southern Ontario ◽  
Black Fly ◽  
Standard Sequence

Populations of Cnephia mutata in southern Ontario contain both diploid and triploid individuals. The diploid form is bisexual and lacks chromosomal polymorphism except for a rearrangement involved in its cytological sex determining mechanism. The triploids are parthenogenetic; they produce female progeny only and are highly heterozygous for inversions. The banding pattern of the salivary gland chromosomes of diploids and triploids is very similar; the identical standard sequence occurs in both. The complete lack of autosomal inversions in diploids contrasted with their abundance in triploids indicates that effective genetic exchange does not occur between the two forms; they are reproductively completely isolated, although opportunity for cross-mating would seem to exist. The origin of polyploid parthenogenetic forms in black flies is discussed and the view is favored that they are autopolyploid and automictic.

scholarly journals Chromosomal Thermal Index: a comprehensive way to integrate the thermal adaptation of Drosophila subobscura whole karyotype

Genome ◽  
2018 ◽  
Vol 61 (2) ◽  
pp. 73-78 ◽  
Author(s):  
Conxita Arenas ◽  
Goran Zivanovic ◽  
Francesc Mestres
Keyword(s):  
Global Warming ◽  
Natural Populations ◽  
Thermal Adaptation ◽  
Chromosomal Polymorphism ◽  
Thermal Index ◽  
Homologous Chromosomes ◽  
Cold Adapted ◽  
Using Data ◽  
Over Time ◽  
European Populations

Drosophila has demonstrated to be an excellent model to study the adaptation of organisms to global warming, with inversion chromosomal polymorphism having a key role in this adaptation. Here, we introduce a new index (Chromosomal Thermal Index or CTI) to quantify the thermal adaptation of a population according to its composition of “warm” and “cold” adapted inversions. This index is intuitive, has good statistical properties, and can be used to hypothesis on the effect of global warming on natural populations. We show the usefulness of CTI using data from European populations of D. subobscura, sampled in different years. Out of 15 comparisons over time, nine showed significant increase of CTI, in accordance with global warming expectations. Although large regions of the genome outside inversions contain thermal adaptation genes, our results show that the total amount of warm or cold inversions in populations seems to be directly involved in thermal adaptation, whereas the interactions between the inversions content of homologous and non-homologous chromosomes are not relevant.

C-heterochromatin polymorphism in holocentric chromosomes of Triatoma infestans (Hemiptera: Reduviidae)

Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 1068-1074 ◽  
Author(s):  
Fco Panzera ◽  
F. Alvarez ◽  
J. Sanchez-Rufas ◽  
R. Pérez ◽  
J. A. Suja ◽  
...  
Keyword(s):  
Chagas Disease ◽  
Intraspecific Variation ◽  
Natural Populations ◽  
Chromosomal Polymorphism ◽  
Triatoma Infestans ◽  
Holocentric Chromosomes ◽  
Marked Variation ◽  
Geographical Pattern ◽  
First Report ◽  
Heterochromatin Polymorphism

This is the first report of intraspecific variation of C-bands in Heteroptera, described in natural populations of Triatoma infestans (Hemiptera: Reduviidae), the main vector of Chagas disease in Uruguay. Marked variation in number, position, and size of C-heterochromatic bands was found in the three large autosomal pairs. A geographical pattern of this chromosomal polymorphism was observed. Evolutionary importance and epidemiological relevance are discussed.Key words: Triatoma infestans, cytogenetics, C-band polymorphism, holocentric chromosomes, Chagas disease.

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