Polytene chromosome mapping in Ceratitis capitata (Diptera: Tephritidae)

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.

Genome ◽  
1991 ◽  
Vol 34 (2) ◽  
pp. 215-219 ◽  
Author(s):  
A. Zacharopoulou ◽  
K. Bourtzis ◽  
Ph. Kerremans

The banding patterns of polytene chromosomes in different tissues of the Mediterranean fruit fly, Ceratitis capitata, vary to such an extent that homologous chromosomes cannot be recognised. However, analyses of autosomal breakpoints in several translocation strains allowed chromosomes from the two tissues to be aligned despite their difference in banding pattern. These results were discussed, considering the different hypotheses of the origin and biological significance of polytene chromosome bands.Key words: polytene chromosomes, salivary gland chromosomes, orbital bristle trichogen cell chromosomes, Ceratitis capitata.


Genome ◽  
2002 ◽  
Vol 45 (6) ◽  
pp. 1167-1174 ◽  
Author(s):  
Reza M Shahjahan ◽  
Farzana Yesmin

Standard photographic maps of the polytene chromosomes are presented for the melon fly Bactrocera cucurbitae, a serious pest of fleshy fruits and vegetables. Five larval salivary gland polytene chromosomes (10 polytene arms) were isolated, and their characteristic features and landmarks have been recognized. Banding patterns of each of the polytene arms are presented, where variation in band intensity and puffs appear to reflect fundamental differences in chromosomes. The whole polytene genome has been typically mapped by dividing it into 100 sections and the subsections were lettered. The mitotic chromosomes of larval brain ganglia are also examined, five pairs of autosomes and an XX/XY sex chromosome pair. In addition, a heterochromatic mass corresponding to the sex chromosomes are observed in the polytene nuclei of salivary gland tissue. This investigation showed that B. cucurbitae has excellent cytological material for polytene chromosome analysis and proved to be very useful for obtaining more detailed genetic information on the pest's natural populations.Key words: Bactrocera cucurbitae, salivary gland, banding patterns, polytene maps.


Genome ◽  
1990 ◽  
Vol 33 (2) ◽  
pp. 184-197 ◽  
Author(s):  
A. Zacharopoulou

Polytene chromosome maps of the five autosomes from salivary gland cells in Ceratitis capitata are presented, and the more characteristic features of each element are described. The correlation of the polytene elements to miotic chromosomes and linkage groups is established by using various Y-autosome and autosome-autosome translocation lines. Two loci, dp (black pupal case) and w (white pupal case), are mapped to the third and fifth chromosome, respectively. In addition to the polytene maps presented, some extra figures of specific chromosomal regions are given for easier identification of each polytene element.Key words: polytene chromosome maps, Ceratitis capitata.


1986 ◽  
Vol 28 (2) ◽  
pp. 180-188 ◽  
Author(s):  
D. G. Bedo

Polytene chromosomes were found in several larval and pupal tissues of the Medfly, Ceratitis capitata, during a search for chromosomes suitable for detailed cytological analysis. Well-banded highly polytene chromosomes, which could be adequately separated and spread, were found in trichogen cells of the spatulate superior orbital bristles of male pupae. These chromosomes proved suitable for full polytene analysis. Thoracic trichogen cells of both male and female pupae also contain useful polytene chromosomes, although they are considerably thinner and thus more difficult to analyze. Contrasting with those in pupal trichogen cells, the chromosomes in the salivary glands, Malphighian tubules, midgut, hindgut, and fat body of larvae and pupae were difficult to prepare because of high levels of ectopic pairing and chromosome fragmentation. In hindgut preparations partial separation of up to three chromosomes was achieved, but in all other tissues no useful chromosome separation was possible. In trichogen polytene cells, five banded chromosomes and a prominent heterochromatic network associated with a nucleolus are found. The mitotic chromosomes respond to C- and Q-banding and silver staining with considerable variation. This is especially so in the X chromosome, which displays an extensive array of bands following both Q-banding and silver staining. Comparison of Q-banded metaphase and polytene chromosomes demonstrates that the five autosomes are represented by conventional polytene chromosomes, while the sex chromosomes are contained in the heterochromatic net, most of which fluoresces strongly. This suggests that the Q-bands of the mitotic X chromosome are replicated to a greater extent than the nonfluorescent material in polytene cells. This investigation shows C. capitata to have excellent cytological material for both polytene and mitotic analysis.Key words: Ceratitis capitata, Medfly, chromosomes (polytene), banding (chromosome).


Genome ◽  
2009 ◽  
Vol 52 (1) ◽  
pp. 20-30 ◽  
Author(s):  
V. Garcia-Martinez ◽  
E. Hernandez-Ortiz ◽  
C. S. Zepeta-Cisneros ◽  
A. S. Robinson ◽  
A. Zacharopoulou ◽  
...  

The present study constitutes the first attempt to construct a polytene chromosome map of an Anastrepha species, Anastrepha ludens (Loew), a major agricultural pest. The mitotic karyotype has a diploid complement of 12 acrocentric chromosomes, including five pairs of autosomes and an XX/XY sex chromosome pair. The analysis of salivary gland polytene chromosomes has shown a total number of five polytene elements that correspond to the five autosomes. The characteristic features and the most prominent landmarks of each chromosome are described. By comparing chromosome banding patterns, the possible chromosomal homology between A. ludens and Ceratitis capitata (Wiedemann) is presented. This work shows that polytene maps of A. ludens are suitable for cytogenetic studies in this species and may be used as reference for other Anastrepha species, most of which are also serious agricultural pests.


1977 ◽  
Vol 19 (2) ◽  
pp. 265-270
Author(s):  
Richard D. Kreutzer

Interspecific crosses were made between the Palearctic species Anopheles atroparvus Van Thiel and the Nearctic species A. punctipennis Say. Except for most of the X chromosomes, an inverted region in 3R, and band intensity differences the salivary gland chromosome banding patterns are the same in both species. Despite this high level of chromosomal homology very little synapsis of identically banded regions was observed in hybrid complements. This asynapsis and the fact that no adults were produced from either the cross or the reciprocal indicate that there are significant genetic differences between the species.


Genome ◽  
1995 ◽  
Vol 38 (3) ◽  
pp. 426-434 ◽  
Author(s):  
Anan Poopittayasataporn ◽  
Visut Baimai

Photographic maps and rearrangements of each salivary gland polytene chromosome arm of Anopheles nemophilous (species F) and of An. dirus species A, B, C, and D of the Dirus group from natural populations in Thailand are presented. Structural conformation of heterokaryotypes and comparison of chromosome banding sequences reveal 10 paracentric inversions. The data on fixed inversion of 3Rb and inversion polymorphism of the X chromosome shared by these species were used to construct a phylogeny of the five members of the An. dirus complex, thereby outlining their patterns of speciation through chromosomal rearrangements.Key words: polytene chromosome rearrangements, Anopheles dirus, phylogeny.


Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 510-515 ◽  
Author(s):  
C. Brockhouse ◽  
J. A. B. Bass ◽  
N. A. Straus

The polytene chromosomes of the black fly species Simulium (Nevermannia) costatum are joined at the centromeres in a strongly heterochromatic chromocentre. Examination of the larval salivary gland chromosomes revealed two populations with a unique polymorphism for attachment to the chromocentre involving all centromeres. All three homologous pairs of chromosomes are polymorphic for centromeres that do not join to the chromocentre. Samples from one of these populations were large enough for thorough study. In this population, the attachment polymorphism is in Hardy-Weinberg equilibrium for two of the centromeres and was in the same frequency for 2 successive years of sampling. The polymorphism could be either primary, retained from an ancestral nonchromocentric state, or secondary, evolving independently or introduced via hybrid introgression. The evolution of chromocentres is discussed in the context of species in the Simulium vernum group.Key words: black fly, polytene chromosome, chromocentre, polymorphism, evolution.


Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 67-71 ◽  
Author(s):  
A. Zacharopoulou

The present investigation constitutes a first attempt to study the salivary gland chromosomes of Ceratitis capitata. A photographic representation of the polytene chromosomes from the salivary gland of this species is provided and the tips, as well as some important landmarks, are recognized in each arm. There is an XX/XY pair and five pairs of autosomes in the metaphases, but neither the X nor the Y are represented among the banded polytene chromosomes. Key words: Ceratitis capitata, chromosomes (polytene), chromosomes (mitotic), salivary gland chromosomes.


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