Latest Articles from Comparative Cytogenetics Latest 3 Articles from Comparative Cytogenetics https://compcytogen.pensoft.net/ Fri, 29 Mar 2024 12:25:42 +0200 Pensoft FeedCreator https://compcytogen.pensoft.net/i/logo.jpg Latest Articles from Comparative Cytogenetics https://compcytogen.pensoft.net/ Linking karyotypes with DNA barcodes: proposal for a new standard in chromosomal analysis with an example based on the study of Neotropical Nymphalidae (Lepidoptera) https://compcytogen.pensoft.net/article/48368/ Comparative Cytogenetics 13(4): 435-449

DOI: 10.3897/CompCytogen.v13i4.48368

Authors: Vladimir A. Lukhtanov, Yaroslavna Iashenkova

Abstract: Chromosomal data are important for taxonomists, cytogeneticists and evolutionary biologists; however, the value of these data decreases sharply if they are obtained for individuals with inaccurate species identification or unclear species identity. To avoid this problem, here we suggest linking each karyotyped sample with its DNA barcode, photograph and precise geographic data, providing an opportunity for unambiguous identification of described taxa and for delimitation of undescribed species. Using this approach, we present new data on chromosome number diversity in neotropical butterflies of the subfamily Biblidinae (genus Vila Kirby, 1871) and the tribe Ithomiini (genera Oleria Hübner, 1816, Ithomia Hübner, 1816, Godyris Boisduval, 1870, Hypothyris Hübner, 1821, Napeogenes Bates, 1862, Pseudoscada Godman et Salvin, 1879 and Hyposcada Godman et Salvin, 1879). Combining new and previously published data we show that the species complex Oleria onega (Hewitson, [1852]) includes three discrete chromosomal clusters (with haploid chromosome numbers n = 15, n = 22 and n = 30) and at least four DNA barcode clusters. Then we discuss how the incomplete connection between these chromosomal and molecular data (karyotypes and DNA barcodes were obtained for different sets of individuals) complicates the taxonomic interpretation of the discovered clusters.

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Research Article Tue, 17 Dec 2019 21:54:57 +0200
Immunocytological analysis of meiotic recombination in two anole lizards (Squamata, Dactyloidae) https://compcytogen.pensoft.net/article/10916/ Comparative Cytogenetics 11(1): 129-141

DOI: 10.3897/CompCytogen.v11i1.10916

Authors: Artem P. Lisachov, Vladimir A. Trifonov, Massimo Giovannotti, Malcolm A. Ferguson-Smith, Pavel M. Borodin

Abstract: Although the evolutionary importance of meiotic recombination is not disputed, the significance of interspecies differences in the recombination rates and recombination landscapes remains under-appreciated. Recombination rates and distribution of chiasmata have been examined cytologically in many mammalian species, whereas data on other vertebrates are scarce. Immunolocalization of the protein of the synaptonemal complex (SYCP3), centromere proteins and the mismatch-repair protein MLH1 was used, which is associated with the most common type of recombination nodules, to analyze the pattern of meiotic recombination in the male of two species of iguanian lizards, Anolis carolinensis Voigt, 1832 and Deiroptyx coelestinus (Cope, 1862). These species are separated by a relatively long evolutionary history although they retain the ancestral iguanian karyotype. In both species similar and extremely uneven distributions of MLH1 foci along the macrochromosome bivalents were detected: approximately 90% of crossovers were located at the distal 20% of the chromosome arm length. Almost total suppression of recombination in the intermediate and proximal regions of the chromosome arms contradicts the hypothesis that “homogenous recombination” is responsible for the low variation in GC content across the anole genome. It also leads to strong linkage disequilibrium between the genes located in these regions, which may benefit conservation of co-adaptive gene arrays responsible for the ecological adaptations of the anoles.

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Research Article Mon, 6 Mar 2017 12:39:51 +0200
“Darwin’s butterflies”? DNA barcoding and the radiation of the endemic Caribbean butterfly genus Calisto (Lepidoptera, Nymphalidae, Satyrinae) https://compcytogen.pensoft.net/article/1724/ Comparative Cytogenetics 5(3): 191-210

DOI: 10.3897/compcytogen.v5i3.1730

Authors: Andrei Sourakov, Evgeny Zakharov

Abstract: The genus Calisto Hübner, 1823 is the only member of the diverse, global subfamily Satyrinae found in the West Indies, and by far the richest endemic Caribbean butterfly radiation. Calisto species occupy an extremely diverse array of habitats, suggestive of adaptive radiation on the scale of other classic examples such as the Galápagos or Darwin’s finches. However, a reliable species classification is a key requisite before further evolutionary or ecological research. An analysis of 111 DNA ‘barcodes’ (655 bp of the mitochondrial gene COI) from 29 putative Calisto species represented by 31 putative taxa was therefore conducted to elucidate taxonomic relationships among these often highly cryptic and confusing taxa. The sympatric, morphologically and ecologically similar taxa C. confusa Lathy, 1899 and C. confusa debarriera Clench, 1943 proved to be extremely divergent, and we therefore recognize Calisto debarriera stat. n. as a distinct species, with Calisto neiba Schwartz et Gali, 1984 as a junior synonym syn. n. Species status of certain allopatric, morphologically similar sister species has been confirmed: Calisto hysius (Godart, 1824) (including its subspecies C. hysius aleucosticha Correa et Schwartz, 1986, stat. n.), and its former subspecies C. batesi Michener, 1943 showed a high degree of divergence (above 6%) and should be considered separate species. Calisto lyceius Bates, 1935/C. crypta Gali, 1985/C. franciscoi Gali, 1985 complex, also showed a high degree of divergence (above 6%), confirming the species status of these taxa. In contrast, our data suggest that the Calisto grannus Bates, 1939 species complex (including Calisto grannus dilemma González, 1987, C. grannus amazona González, 1987, stat. n., C. grannus micrommata Schwartz et Gali, 1984, stat. n., C. grannus dystacta González, 1987, stat. n., C. grannus phoinix González, 1987, stat. n., C. grannus sommeri Schwartz et Gali, 1984, stat. n., and C. grannus micheneri Clench, 1944, stat. n.) should be treated as a single polytypic species, as genetic divergence among sampled populations representing these taxa is low (and stable morphological apomorphies are absent). A widely-distributed pest of sugar cane, Calisto pulchella Lathy, 1899 showed higher diversification among isolated populations (3.5%) than expected, hence supporting former separation of this species into two taxa (pulchella and darlingtoni Clench, 1943), of which the latter might prove to be a separate species rather than subspecies. The taxonomic revisions presented here result in Calisto now containing 34 species and 17 subspecies. Three species endemic to islands other than Hispaniola appear to be derived lineages of various Hispaniolan clades, indicating ancient dispersal events from Hispaniola to Puerto Rico, Cuba, and Jamaica. Overall, the degree of intrageneric and intraspecific divergence within Calisto suggests a long and continuous diversification period of 4–8 Myr. The maximum divergence within the genus (ca. 13.3%) is almost equivalent to the maximum divergence of Calisto from the distant pronophiline relative Auca Hayward, 1953 from the southern Andes (14.1%) and from the presumed closest relative Eretris Thieme, 1905 (14.4%), suggesting that the genus began to diversify soon after its split from its continental sister taxon. In general, this ‘barcode’ divergence corresponds to the high degree of morphological and ecological variation found among major lineages within the genus.

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Research Article Wed, 24 Aug 2011 00:00:00 +0300