Latest Articles from Comparative Cytogenetics Latest 5 Articles from Comparative Cytogenetics https://compcytogen.pensoft.net/ Fri, 29 Mar 2024 00:05:03 +0200 Pensoft FeedCreator https://compcytogen.pensoft.net/i/logo.jpg Latest Articles from Comparative Cytogenetics https://compcytogen.pensoft.net/ Karyotype of Polyommatus (Agrodiaetus) eriwanensis Forster, 1960 and taxonomic position of P. (A.) interjectus de Lesse, 1960 (Lepidoptera, Lycaenidae) https://compcytogen.pensoft.net/article/46897/ Comparative Cytogenetics 13(4): 359-366

DOI: 10.3897/CompCytogen.v13i4.46897

Authors: Vladimir Lukhtanov, Alexander Dantchenko

Abstract: The karyotype of Polyommatus (Agrodiaetus) eriwanensis Forster, 1960 from the type locality (“Eriwan” [Yerevan, Armenia]) and other localities in Armenia was investigated. The number of chromosomal elements (bivalents+ multivalents) observed in male meiosis I was found to vary from 29 to 34. In individuals with n = 34, all observed elements were represented by bivalents. In other specimens, heterozygosity for different number of chromosomal fusions resulted in multivalent formation at MI stage and consequently in a lower number of recognizable chromosomal elements. We show that all karyotype peculiarities of P. (A.) interjectus de Lesse, 1960 (n = 29–32) from Turkey are similar to those in A. eriwanensis. The butterflies of these taxa have allopatric distribution and can be considered as conspecific.

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Short Communication Tue, 12 Nov 2019 18:20:43 +0200
Chromosomal evidence of species status and evolutionary relationships of the black fly Prosimulium petrosum (Diptera, Simuliidae) in Armenia https://compcytogen.pensoft.net/article/6551/ Comparative Cytogenetics 10(1): 33-44

DOI: 10.3897/CompCytogen.v10i1.6551

Authors: Sergey Vlasov, Maria Harutyunova, Karine Harutyunova, Peter Adler

Abstract: The karyotype of Armenian populations of the black fly Prosimulium petrosum Rubtsov, 1955 was characterized and compared with that of all other chromosomally known Palearctic members of the Prosimulium hirtipes group. Analysis of the polytene chromosomes established that Prosimulium petrosum is most closely related to European populations of Prosimulium latimucro (Enderlein, 1925) with which it shares an identical fixed chromosomal banding sequence. Its validity as a species, separate from Prosimulium latimucro, is based on its unique sex-differential sections in the expanded centromere region of chromosome I, in agreement with the unique structural configuration of the hypostomal teeth of its larvae. Prosimulium petrosum and Prosimulium latimucro, therefore, are homosequential species, demonstrating the value of a combined chromosomal and morphological approach in determining species status.

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Research Article Fri, 22 Jan 2016 12:55:01 +0200
Sex chromosome diversity in Armenian toad grasshoppers (Orthoptera, Acridoidea, Pamphagidae) https://compcytogen.pensoft.net/article/6407/ Comparative Cytogenetics 10(1): 45-59

DOI: 10.3897/CompCytogen.v10i1.6407

Authors: Alexander G. Bugrov, Ilyas E. Jetybayev, Gayane H. Karagyan, Nicolay B. Rubtsov

Abstract: Although previous cytogenetic analysis of Pamphagidae grasshoppers pointed to considerable karyotype uniformity among most of the species in the family, our study of species from Armenia has discovered other, previously unknown karyotypes, differing from the standard for Pamphagidae mainly in having unusual sets of sex chromosomes. Asiotmethis turritus (Fischer von Waldheim, 1833), Paranocaracris rubripes (Fischer von Waldheim, 1846), and Nocaracris cyanipes (Fischer von Waldheim, 1846) were found to have the karyotype 2n♂=16+neo-XY and 2n♀=16+neo-XX, the neo-X chromosome being the result of centromeric fusion of an ancient acrocentric X chromosome and a large acrocentric autosome. The karyotype of Paranothrotes opacus (Brunner von Wattenwyl, 1882) was found to be 2n♂=14+X1X2Y and 2n♀=14+X1X1X2X2., the result of an additional chromosome rearrangement involving translocation of the neo-Y and another large autosome. Furthermore, evolution of the sex chromosomes in these species has involved different variants of heterochromatinization and miniaturization of the neo-Y. The karyotype of Eremopeza festiva (Saussure, 1884), in turn, appeared to have the standard sex determination system described earlier for Pamphagidae grasshoppers, 2n♂=18+X0 and 2n♀=18+XX, but all the chromosomes of this species were found to have small second C-positive arms. Using fluorescent in situ hybridization (FISH) with 18S rDNA and telomeric (TTAGG)n DNA repeats to yield new data on the structural organization of chromosomes in the species studied, we found that for most of them, clusters of repeats homologous to 18S rDNA localize on two, three or four pairs of autosomes and on the X. In E. festiva, however, FISH with labelled 18S rDNA painted C-positive regions of all autosomes and the X chromosome; clusters of telomeric repeats localized primarily on the ends of the chromosome arms. Overall, we conclude that the different stages of neo-Y degradation revealed in the Pamphagidae species studied make the family a very promising and useful model for studying sex chromosome evolution.

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Research Article Fri, 22 Jan 2016 12:43:43 +0200
Karyotype analysis of four jewel-beetle species (Coleoptera, Buprestidae) detected by standard staining, C-banding, AgNOR-banding and CMA3/DAPI staining https://compcytogen.pensoft.net/article/1751/ Comparative Cytogenetics 6(2): 183-197

DOI: 10.3897/compcytogen.v6i2.2950

Authors: Gayane Karagyan, Dorota Lachowska, Mark Kalashian

Abstract: The male karyotypes of Acmaeodera pilosellae persica Mannerheim, 1837 with 2n=20 (18+neoXY), Sphenoptera scovitzii Faldermann, 1835 (2n=38–46), Dicerca aenea validiuscula Semenov, 1895 – 2n=20 (18+Xyp) and Sphaerobothris aghababiani Volkovitsh et Kalashian, 1998 – 2n=16 (14+Xyp) were studied using conventional staining and different chromosome banding techniques: C-banding, AgNOR-banding, as well as fluorochrome Chromomycin A3 (CMA3) and DAPI. It is shown that C-positive segments are weakly visible in all four species which indicates a small amount of constitutive heterochromatin (CH). There were no signals after DAPI staining and some positive signals were discovered using CMA3 staining demonstrating absence of AT-rich DNA and presence of GC-rich clusters of CH. Nucleolus organizing regions (NORs) were revealed using Ag-NOR technique; argentophilic material mostly coincides with positive signals obtained using CMA3 staining.

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Research Article Fri, 27 Apr 2012 00:00:00 +0300
Features of the karyotypes of Pelophylax ridibundus Pallas, 1771 and Rana macrocnemis Boulenger, 1885 (Amphibia: Ranidae) from Armenia https://compcytogen.pensoft.net/article/1671/ Comparative Cytogenetics 3(1): 11-24

DOI: 10.3897/compcytogen.v3i1.4

Authors: A Martirosyan, Ilona Stepanyan

Abstract: Сhromosomal complements of Pelophylax ridibundus Pallas, 1771 from 9 localities (Northern, Central and South Armenia) and Rana macrocnemis Boulenger, 1885 from one locality (North-West Armenia) have been analyzed. The chromosome sets of P. ridibundus collected from 8 localities showed 2n=26, (10m+12sm+4st; NF=52). A secondary constriction has been observed in all studied individuals on the 10-th chromosome pair showing NOR-positive reaction. C-positive heterochromatin blocks have been observed on long arms of the 2-nd and 10-th pairs of chromosomes (7 localities). In addition, C-heterochromatin blocks have been found on interstitial regions of short arms of the 12-th pairs, as well as in telomeric regions of long arms of the 9-th pairs and on short arms of the 5-th pair in the frogs from 2 localities. The karyotype of P. ridibundus from populations near Ejmiatsin differs from other populations (2n=26, 12m+10sm+4st). Diploid number of chromosomes of R. macrocnemis was also 26 (8m+12sm+6st, NF=52). Blocks of C-positive heterochromatin have been revealed in telomeric parts of the 1-st, 2-nd (p), 3-rd (q), 4-th (q), 6-th, 9-th (p), 10-th (p,q) and 13-th (q) pairs, as well as in interstitial regions of the 1-st and 2-nd pairs of chromosomes. Intrapopulation and interpopulation geographic variations of karyotypes and C-heterochromatin banding patterns of P. ridibundus have been revealed. Karyotypically, morphotypes “macrocnemis” and “camerani” are closely related.

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Research Article Thu, 6 Aug 2009 00:00:00 +0300