Polytene chromosome maps of the melon fly Bactrocera cucurbitae (Diptera: Tephritidae)

Genome ◽  
2002 ◽  
Vol 45 (6) ◽  
pp. 1167-1174 ◽  
Author(s):  
Reza M Shahjahan ◽  
Farzana Yesmin
Keyword(s):  
Salivary Gland ◽  
Polytene Chromosome ◽  
Sex Chromosome ◽  
Polytene Chromosomes ◽  
Chromosome Analysis ◽  
Bactrocera Cucurbitae ◽  
Mitotic Chromosomes ◽  
Larval Brain ◽  
Banding Patterns ◽  
Melon Fly

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.

Mitotic and polytene chromosome analysis in the Mexican fruit fly, Anastrepha ludens (Loew) (Diptera: Tephritidae)

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 ◽  
...  
Keyword(s):  
Polytene Chromosome ◽  
Sex Chromosome ◽  
Polytene Chromosomes ◽  
Chromosome Analysis ◽  
Fruit Fly ◽  
Anastrepha Ludens ◽  
Agricultural Pests ◽  
Diploid Complement ◽  
Acrocentric Chromosomes ◽  
Characteristic Features

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.

Mitotic and polytene chromosome analysis in Dacus oleae (Diptera: Tephritidae)

Genome ◽  
1992 ◽  
Vol 35 (3) ◽  
pp. 373-378 ◽  
Author(s):  
P. Mavragani-Tsipidou ◽  
G. Karamanlidou ◽  
A. Zacharopoulou ◽  
S. Koliais ◽  
C. Kastritsis
Keyword(s):  
Olive Oil ◽  
Polytene Chromosome ◽  
Genetic Information ◽  
Cytogenetic Analysis ◽  
Fat Body ◽  
Polytene Chromosomes ◽  
Chromosome Analysis ◽  
Olive Tree ◽  
Mitotic Chromosomes ◽  
Dacus Oleae

The present study constitutes the first attempt to construct a photographic map of the polytene chromosomes of Dacus oleae, a pest of the olive tree that causes serious financial damage in all olive oil producing countries. The map was constructed by using the larval fat body cells, the chromosomes of which are representative of the polytene chromosomes of other polytene tissues. In addition, the mitotic chromosomes of brain ganglia were examined, permitting tentative correlations between mitotic and polytene elements. This investigation shows that D. oleae is suitable for cytogenetic analysis in both mitotic and polytene chromosomes, a fact that may prove very useful for obtaining more detailed genetic information on the pest's natural populations.Key words: Dacus oleae, polytene chromosomes, mitotic chromosomes.

Polytene chromosome mapping in Ceratitis capitata (Diptera: Tephritidae)

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 598-611 ◽  
Author(s):  
D. G. Bedo
Keyword(s):  
Salivary Gland ◽  
Polytene Chromosome ◽  
Chromosome Banding ◽  
Mitotic Chromosome ◽  
Ceratitis Capitata ◽  
Polytene Chromosomes ◽  
Chromosome Mapping ◽  
Banding Patterns ◽  
Homologous Chromosomes ◽  
Characteristic Features

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.

Polytene and mitotic chromosome analysis in Ceratitis capitata (Diptera; Tephritidae)

1986 ◽  
Vol 28 (2) ◽  
pp. 180-188 ◽  
Author(s):  
D. G. Bedo
Keyword(s):  
X Chromosome ◽  
Silver Staining ◽  
Mitotic Chromosome ◽  
Ceratitis Capitata ◽  
Fat Body ◽  
Polytene Chromosomes ◽  
Chromosome Analysis ◽  
Mitotic Chromosomes ◽  
Chromosome Separation ◽  
Ectopic Pairing

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).

A comparison of polytene chromosomes in salivary glands and orbital bristle trichogen cells in Ceratitis capitata

Genome ◽  
1991 ◽  
Vol 34 (2) ◽  
pp. 215-219 ◽  
Author(s):  
A. Zacharopoulou ◽  
K. Bourtzis ◽  
Ph. Kerremans
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Banding Pattern ◽  
Ceratitis Capitata ◽  
Polytene Chromosomes ◽  
Biological Significance ◽  
Fruit Fly ◽  
Banding Patterns ◽  
Homologous Chromosomes ◽  
Different Tissues

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.

Sibling species and sex chromosome differentiation in Simulium neornatipes (Diptera: Simuliidae)

1984 ◽  
Vol 26 (3) ◽  
pp. 318-325 ◽  
Author(s):  
D. G. Bedo
Keyword(s):  
Polytene Chromosome ◽  
Sibling Species ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Close Association ◽  
Chromosome Analysis ◽  
Sex Linkage ◽  
Direct Role ◽  
Chromosome Differentiation ◽  
Close Relationship

Polytene chromosome analysis of five Simulium neornatipes populations not only confirms the existence of the two sibling species, S. neornatipes 1 and 2, proposed earlier but reveals a third. S. neornatipes 3. These sibling species share a common standard polytene chromosome banding sequence which differs from the Australian S. ornatipes complex standard by five fixed inversions. The sharing of polymorphic inversions between the ornatipes and neornatipes complexes indicates their close relationship. The neornatipes species are distinguished from each other by additional fixed inversions and differentiated sex chromosomes. Extensive sex chromosome differentiation involving chromosome III has occurred in S. neornatipes 1 and 2. A period of incomplete sex-linkage allowing reassortment of inversions must have preceded the currently observed strong sex-linkage of differentiated sex chromosomes to account for the complex array of sex chromosomes found. The close association of sex chromosome differentiation with speciation in black flies is discussed in relation to appropriate speciation mechanisms. It is concluded that the rearrangements themselves have no direct role in the speciation process.Key words: sibling species, sex chromosomes, Simuliidae.

A cytological study of Simulium ruficorne (Diptera: Simuliidae) and its relationship to the S. ornatipes species complex

Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 570-579 ◽  
Author(s):  
D. G. Bedo
Keyword(s):  
Polytene Chromosome ◽  
Species Complex ◽  
Sex Chromosome ◽  
New Caledonia ◽  
Island Population ◽  
Chromosome Inversion ◽  
Banding Patterns ◽  
Close Relationship ◽  
Santiago Island

Polytene chromosome banding patterns in Simulium ruficorne populations from two island and a continental African locality were analyzed and a standard map was prepared. Distinct arrays of fixed and polymorphic rearrangements characterize unique cytotypes in Santiago Island, Tenerife, and Ivory Coast populations. Sex-chromosome differentiation where an inversion linked to the male determiner marks a Y chromosome also occurs in the Santiago Island population. No sibling species can be defined at present because of the absence of sympatric population samples. Comparison of banding patterns between S. ruficorne and the S. ornatipes–neornatipes species complex in Australia and New Caledonia shows striking similarities. Banding homology is readily established with about 90% of polytene banding recognizable between the two standards. Three inversions are shared between the lineages, further emphasizing their similarity. These results provide independent corroboration of the close relationship between S. ruficorne and S. ornatipes established from conventional taxonomy. The validity of using shared inversions and common breakpoints in phylogenetic comparisons is discussed in relation to the possibility of confusing similar but distinct rearrangements and the inversion-generating role of transposable elements. The possibility of transposable element mediated identical, independently derived, rearrangements seems unlikely, but in all studies the confusion of phylogenies by similar inversions must be carefully considered.Key words: Simulium ruficorne, polytene chromosome, inversion phylogeny.

Chromocentre polymorphism in polytene chromosomes of Simulium costatum (Diptera: Simuliidae)

Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 510-515 ◽  
Author(s):  
C. Brockhouse ◽  
J. A. B. Bass ◽  
N. A. Straus
Keyword(s):  
Salivary Gland ◽  
Polytene Chromosome ◽  
Polytene Chromosomes ◽  
Black Fly ◽  
Weinberg Equilibrium ◽  
Larval Salivary Gland ◽  
Hybrid Introgression ◽  
Hardy Weinberg Equilibrium ◽  
Two Populations

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.

scholarly journals Analysis of Mitotic and Polytene Chromosomes and Photographic Polytene Chromosome Maps in Bactrocera cucurbitae (Diptera: Tephritidae)

2011 ◽  
Vol 104 (2) ◽  
pp. 306-318 ◽  
Author(s):  
A. Zacharopoulou ◽  
W.A.A. Sayed ◽  
A. A. Augustinos ◽  
F. Yesmin ◽  
A. S. Robinson ◽  
...  
Keyword(s):  
Polytene Chromosome ◽  
Polytene Chromosomes ◽  
Bactrocera Cucurbitae ◽  
Chromosome Maps

scholarly journals The Drosophila salivary gland chromocenter contains highly polytenized subdomains of mitotic heterochromatin.

Genetics ◽  
1995 ◽  
Vol 139 (2) ◽  
pp. 659-670 ◽  
Author(s):  
P Zhang ◽  
A C Spradling
Keyword(s):  
Salivary Gland ◽  
Dna Sequences ◽  
Polytene Chromosomes ◽  
Centromeric Heterochromatin ◽  
Mitotic Chromosomes ◽  
Satellite Dnas ◽  
Central Mass ◽  
P Elements

Abstract Peri-centromeric regions of Drosophila melanogaster chromosomes appear heterochromatic in mitotic cells and become greatly underrepresented in giant polytene chromosomes, where they aggregate into a central mass called the chromocenter. We used P elements inserted at sites dispersed throughout much of the mitotic heterochromatin to analyze the fate of 31 individual sites during polytenization. Analysis of DNA sequences flanking many of these elements revealed that middle repetitive or unique sequence DNAs frequently are interspersed with satellite DNAs in mitotic heterochromatin. All nine Y chromosome sites tested were underrepresented > 20-fold on Southern blots of polytene DNA and were rarely or never detected by in situ hybridization to salivary gland chromosomes. In contrast, nine tested insertions in autosomal centromeric heterochromatin were represented fully in salivary gland DNA, despite the fact that at least six were located proximal to known blocks of satellite DNA. The inserted sequences formed diverse, site-specific morphologies in the chromocenter of salivary gland chromosomes, suggesting that domains dispersed at multiple sites in the centromeric heterochromatin of mitotic chromosomes contribute to polytene beta-heterochromatin. We suggest that regions containing heterochromatic genes are organized into dispersed chromatin configurations that are important for their function in vivo.

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