Genetic and cytogenetic analysis of the fruit fly Rhagoletis cerasi (Diptera: Tephritidae)

Genome ◽  
2008 ◽  
Vol 51 (7) ◽  
pp. 479-491 ◽  
Author(s):  
Ilias Kounatidis ◽  
Nikolaos Papadopoulos ◽  
Kostas Bourtzis ◽  
Penelope Mavragani-Tsipidou
Keyword(s):  
Salivary Gland ◽  
Sex Chromosomes ◽  
Cytogenetic Analysis ◽  
Polytene Chromosomes ◽  
Fruit Fly ◽  
Pest Species ◽  
Heteromorphic Sex Chromosomes ◽  
Weak Points ◽  
Heterogametic Sex ◽  
Rhagoletis Cerasi

The European cherry fruit fly, Rhagoletis cerasi , is a major agricultural pest for which biological, genetic, and cytogenetic information is limited. We report here a cytogenetic analysis of 4 natural Greek populations of R. cerasi, all of them infected with the endosymbiotic bacterium Wolbachia pipientis . The mitotic karyotype and detailed photographic maps of the salivary gland polytene chromosomes of this pest species are presented here. The mitotic metaphase complement consists of 6 pairs of chromosomes, including one pair of heteromorphic sex chromosomes, with the male being the heterogametic sex. The analysis of the salivary gland polytene complement has shown a total of 5 long chromosomes (10 polytene arms) that correspond to the 5 autosomes of the mitotic nuclei and a heterochromatic mass corresponding to the sex chromosomes. The most prominent landmarks of each polytene chromosome, the “weak points”, and the unusual asynapsis of homologous pairs of polytene chromosomes at certain regions of the polytene elements are also presented and discussed.

scholarly journals The Diversity and Evolution of Sex Chromosomes in Frogs

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 483
Author(s):  
Wen-Juan Ma ◽  
Paris Veltsos
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Comparative Genomic ◽  
Ancestral State ◽  
Heteromorphic Sex Chromosomes ◽  
Genomic Studies ◽  
Evolutionary Trajectories ◽  
Heterogametic Sex

Frogs are ideal organisms for studying sex chromosome evolution because of their diversity in sex chromosome differentiation and sex-determination systems. We review 222 anuran frogs, spanning ~220 Myr of divergence, with characterized sex chromosomes, and discuss their evolution, phylogenetic distribution and transitions between homomorphic and heteromorphic states, as well as between sex-determination systems. Most (~75%) anurans have homomorphic sex chromosomes, with XY systems being three times more common than ZW systems. Most remaining anurans (~25%) have heteromorphic sex chromosomes, with XY and ZW systems almost equally represented. There are Y-autosome fusions in 11 species, and no W-/Z-/X-autosome fusions are known. The phylogeny represents at least 19 transitions between sex-determination systems and at least 16 cases of independent evolution of heteromorphic sex chromosomes from homomorphy, the likely ancestral state. Five lineages mostly have heteromorphic sex chromosomes, which might have evolved due to demographic and sexual selection attributes of those lineages. Males do not recombine over most of their genome, regardless of which is the heterogametic sex. Nevertheless, telomere-restricted recombination between ZW chromosomes has evolved at least once. More comparative genomic studies are needed to understand the evolutionary trajectories of sex chromosomes among frog lineages, especially in the ZW systems.

The genome of the olive fruit fly Bactrocera oleae: localization of molecular markers by in situ hybridization to the salivary gland polytene chromosomes

Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 744-751 ◽  
Author(s):  
Anna Zambetaki ◽  
Antigone Zacharopoulou ◽  
Zacharias G. Scouras ◽  
Penelope Mavragani-Tsipidou
Keyword(s):  
Salivary Gland ◽  
Molecular Markers ◽  
In Situ Hybridization ◽  
Polytene Chromosomes ◽  
Fruit Fly ◽  
Bactrocera Oleae ◽  
Olive Fruit Fly ◽  
Olive Fruit

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.

Cytogenetic analysis of mitotic and salivary gland chromosomes in the Medfly Ceratitis capitata

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 67-71 ◽  
Author(s):  
A. Zacharopoulou
Keyword(s):  
Salivary Gland ◽  
Key Words ◽  
Cytogenetic Analysis ◽  
Ceratitis Capitata ◽  
Polytene Chromosomes

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.

Polytene chromosomes of three species of blackflies in the Simulium pictipes group (Diptera: Simuliidae)

1975 ◽  
Vol 53 (8) ◽  
pp. 1147-1164 ◽  
Author(s):  
Daniel G. Bedo
Keyword(s):  
Salivary Gland ◽  
Chromosome Number ◽  
Sibling Species ◽  
Sex Chromosomes ◽  
Polytene Chromosomes ◽  
Fluorescence Staining ◽  
Haploid Chromosome Number ◽  
Quinacrine Fluorescence ◽  
Individual Bands ◽  
Staining Methods

The salivary gland chromosomes of members of the Simulium pictipes group were examined by conventional staining and quinacrine fluorescence staining methods which proved to be a useful tool to show otherwise hidden details, especially in expanded centromere regions. Three cytologically definable species were found, one of which must represent a previously unrecognized species. Simulium longistylatum Shewell was the only species among the three siblings identified with certainty. The remaining pair were designated as S. pictipes A and S. pictipes B. In all three siblings the haploid chromosome number was three. Specific differences include a simple and a complex inversion, a shift of basal bands between the short arms of the second and third chromosome, details of the sex chromosomes, and the amount of DNA in certain individual bands and expanded centromere regions. Y chromosome markers are located in a different element of the complement in each of the three species, a unique situation within closely related blackfly sibling species. These findings are discussed in connection with the evolution of sex chromosomes and sibling species. A cytophylogeny is presented.

Cytotaxonomy of Simulium siamense Takaoka and Suzuki (Diptera: Simuliidae) in Thailand

Genome ◽  
2008 ◽  
Vol 51 (12) ◽  
pp. 972-987 ◽  
Author(s):  
Chaliow Kuvangkadilok ◽  
Unchulee Lualon ◽  
Visut Baimai
Keyword(s):  
Sex Chromosomes ◽  
Polytene Chromosomes ◽  
Taxonomic Status ◽  
Sex Linkage ◽  
Geographic Ranges ◽  
Heterogametic Sex ◽  
Ecological Habitats ◽  
Central Thailand

Larval polytene chromosomes of 1824 individuals of Simulium siamense Takaoka and Suzuki from 32 locations in northern, northeastern, eastern, and central Thailand were examined. Differences in sex chromosomes, fixed inversions, and the kind and frequency of floating inversions revealed five cytoforms (A, B, C, D, and E). In contrast to most Simulium species, females of S. siamense are the heterogametic sex (ZW) and males are the homogametic sex (ZZ). Cytoform A differs from the others by having 23 floating inversions and undifferentiated sex chromosomes (W0 was undifferentiated from Z0). Cytoforms B, C, and D differ from each other by having different W chromosomes (W1, W2, and W3) in females. Cytoform E is characterized by having two fixed inversions, IS-1 and IIIS-2. Cytoform A is widely distributed throughout the geographic ranges of the species in northern, northeastern, eastern, and central Thailand, whereas cytoforms B, C, and D are restricted to a few locations in central Thailand. Although the larvae of the five cytoforms are morphologically similar, they seem to occupy different ecological habitats, which should be further investigated. At present, no definite conclusion can be drawn as to the taxonomic status of the cytoforms of S. siamense. However, this study indicates that S. siamense is represented by at least five cytoforms, of which cytoform B is the most distinct by having complete sex linkage and no floating inversions.

scholarly journals Toxic Y chromosome: increased repeat expression and age-associated heterochromatin loss in male Drosophila with a young Y chromosome

2020 ◽  
Author(s):  
Alison H. Nguyen ◽  
Doris Bachtrog
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Young Male ◽  
Heterochromatin Formation ◽  
Young Males ◽  
Repeat Content ◽  
Y Chromosomes ◽  
Heteromorphic Sex Chromosomes ◽  
Heterogametic Sex ◽  
Effects Of Aging

Sex‐specific differences in lifespan are prevalent across the tree of life and influenced by heteromorphic sex chromosomes. In species with XY sex chromosomes, females often outlive males. Males and females can differ in their overall repeat content due to the repetitive Y chromosome, and repeats on the Y might lower survival of the heterogametic sex (toxic Y effect). Here, we take advantage of the well‐assembled young Y chromosome of Drosophila miranda to study the sex‐specific dynamics of chromatin structure and repeat expression during aging in male and female flies. Male D. miranda have about twice as much repetitive DNA compared to females, and live shorter than females. Heterochromatin is crucial for silencing of repetitive elements, yet old D. miranda flies lose H3K9me3 modifications in their pericentromere, with heterochromatin loss being more severe during aging in males than females. Satellite DNA becomes de‐repressed more rapidly in old vs. young male flies relative to females. In contrast to what is observed in D. melanogaster, we find that transposable elements (TEs) are expressed at higher levels in male D. miranda throughout their life. We show that epigenetic silencing via heterochromatin formation is ineffective on the large TE‐ rich neo‐Y chromosome, resulting in up‐regulation of Y‐linked TEs already in young males. This is consistent with an interaction between the age of the Y chromosome and the genomic effects of aging. Our data support growing evidence that “toxic Y chromosomes” can diminish male fitness and a reduction in heterochromatin can contribute to sex‐specific aging.

The genome of the olive fruit fly Bactrocera oleae: localization of molecular markers by in situ hybridization to the salivary gland polytene chromosomes

Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 744-751 ◽  
Author(s):  
Anna Zambetaki ◽  
Antigone Zacharopoulou ◽  
Zacharias G Scouras ◽  
Penelope Mavragani-Tsipidou
Keyword(s):  
Salivary Gland ◽  
Molecular Markers ◽  
In Situ Hybridization ◽  
Polytene Chromosomes ◽  
Fruit Fly ◽  
Bactrocera Oleae ◽  
Olive Fruit Fly ◽  
Olive Fruit ◽  
Hybridization Mapping

Nine specific DNA probes (genomic or cDNA) from Ceratitis capitata have been mapped by in situ hybridization to the salivary gland polytene chromosomes of the olive fruit fly Bactrocera oleae, a major agricultural pest, thus establishing molecular markers for the 5 autosomal chromosomes. Taking into account the present results, as well as previous data obtained mainly by in situ hybridizations, chromosomal homologies among B. oleae, C. capitata and B. tryoni are established. Data show extensive linkage group conservation among the 3 taxa of the economically important and globally distributed family, the Tephritidae.Key words: Bactrocera oleae, Tephritidae, salivary gland, polytene chromosomes, in situ hybridization, mapping.

scholarly journals Inferring Modes of Colonization for Pest Species Using Heterozygosity Comparisons and a Shared-Allele Test

Genetics ◽  
2003 ◽  
Vol 163 (2) ◽  
pp. 823-831
Author(s):  
J A Sved ◽  
H Yu ◽  
B Dominiak ◽  
A S Gilchrist
Keyword(s):  
Distance Measure ◽  
Fruit Fly ◽  
Small Samples ◽  
Pest Species ◽  
Long Distance ◽  
Resampling Methods ◽  
Shared Allele ◽  
The Core ◽  
Direct Sampling ◽  
Long Distance Movement

Abstract Long-range dispersal of a species may involve either a single long-distance movement from a core population or spreading via unobserved intermediate populations. Where the new populations originate as small propagules, genetic drift may be extreme and gene frequency or assignment methods may not prove useful in determining the relation between the core population and outbreak samples. We describe computationally simple resampling methods for use in this situation to distinguish between the different modes of dispersal. First, estimates of heterozygosity can be used to test for direct sampling from the core population and to estimate the effective size of intermediate populations. Second, a test of sharing of alleles, particularly rare alleles, can show whether outbreaks are related to each other rather than arriving as independent samples from the core population. The shared-allele statistic also serves as a genetic distance measure that is appropriate for small samples. These methods were applied to data on a fruit fly pest species, Bactrocera tryoni, which is quarantined from some horticultural areas in Australia. We concluded that the outbreaks in the quarantine zone came from a heterogeneous set of genetically differentiated populations, possibly ones that overwinter in the vicinity of the quarantine zone.

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