Latest Articles from Comparative Cytogenetics Latest 3 Articles from Comparative Cytogenetics https://compcytogen.pensoft.net/ Fri, 29 Mar 2024 13:26:29 +0200 Pensoft FeedCreator https://compcytogen.pensoft.net/i/logo.jpg Latest Articles from Comparative Cytogenetics https://compcytogen.pensoft.net/ Detection of cryptic diversity in lizards (Squamata) from two Biosphere Reserves in Mesoamerica https://compcytogen.pensoft.net/article/57765/ Comparative Cytogenetics 14(4): 613-638

DOI: 10.3897/CompCytogen.v14.i4.57765

Authors: Riccardo Castiglia, Oscar Alberto Flores-Villela, Alexandra M. R. Bezerra, Ekaterina Gornung, Flavia Annesi, Luis Antonio Muñoz-Alonso, Emanuela Solano

Abstract: A combined approach based on karyology and DNA taxonomy allowed us to characterize the taxonomic peculiarities in 10 Mesoamerican lizard species, belonging to six genera and five families, inhabiting two Biosphere Reserve in Chiapas, Mexico: La Sepultura Biosphere Reserve, and Montes Azules Biosphere. The karyotypes of four species, Phyllodactylus sp. 3 (P. tuberculosus species group) (2n = 38), Holcosus festivus (Lichtenstein et von Martens, 1856) (2n = 50), Anolis lemurinus Cope, 1861 (2n = 40), and A. uniformis Cope, 1885 (2n = 29–30) are described for the first time, the last one showing a particular X1X1X2X2/X1X2Y condition. In Aspidoscelis deppii (Wiegmann, 1834) (2n = 50) and Anolis capito Peters, 1863 (2n = 42), we found a different karyotype from the ones previously reported for these species. Moreover, in A. capito, the cytogenetic observation is concurrent with a considerable genetic divergence (9%) at the studied mtDNA marker (MT-ND2), which is indicative of a putative new cryptic species. The skink Scincella cherriei (Cope, 1893), showed high values of genetic divergence (5.2% at 16S gene) between the specimens from Montes Azules and those from Costa Rica and Nicaragua, comparable to the values typical of sister species in skinks. A lower level of genetic divergence, compatible with an intraspecific phylogeographic structure, has been identified in Lepidophyma flavimaculatum Duméril, 1851. These new data identify taxa that urgently require more in-depth taxonomic studies especially in these areas where habitat alteration is proceeding at an alarming rate.

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Research Article Tue, 22 Dec 2020 07:21:27 +0200
Patterns of chromosomal variation in Mexican species of Aeschynomene (Fabaceae, Papilionoideae) and their evolutionary and taxonomic implications https://compcytogen.pensoft.net/article/47264/ Comparative Cytogenetics 14(1): 157-182

DOI: 10.3897/CompCytogen.v14i1.47264

Authors: Fernando Tapia-Pastrana, Alfonso Delgado-Salinas, Javier Caballero

Abstract: A cytogenetic analysis of sixteen taxa of the genus Aeschynomene Linnaeus, 1753, which includes species belonging to both subgenera Aeschynomene (Léonard, 1954) and Ochopodium (Vogel, 1838) J. Léonard, 1954, was performed. All studied species had the same chromosome number (2n = 20) but exhibited karyotype diversity originating in different combinations of metacentric, submetacentric and subtelocentric chromosomes, chromosome size and number of SAT chromosomes. The plasticity of the genomes included the observation in a taxon belonging to the subgenus Aeschynomene of an isolated spherical structure similar in appearance to the extra chromosomal circular DNA observed in other plant genera. By superimposing the karyotypes in a recent phylogenetic tree, a correspondence between morphology, phylogeny and cytogenetic characteristics of the taxa included in the subgenus Aeschynomene is observed. Unlike subgenus Aeschynomene, the species of Ochopodium exhibit notable karyotype heterogeneity. However the limited cytogenetic information recorded prevents us from supporting the proposal of their taxonomic separation and raise it to the genus category. It is shown that karyotype information is useful in the taxonomic delimitation of Aeschynomene and that the diversity in the diploid level preceded the hybridization/polyploidization demonstrated in the genus. The systematic implications of our results and their value can be extended to other Dalbergieae genera as knowledge about the chromosomal structure and its evolution increases.

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Research Article Wed, 11 Mar 2020 17:13:40 +0200
Physical mapping of 5S and 18S ribosomal DNA in three species of Agave (Asparagales, Asparagaceae) https://compcytogen.pensoft.net/article/1798/ Comparative Cytogenetics 7(3): 191-203

DOI: 10.3897/compcytogen.v7i3.5337

Authors: Victor Manuel Gomez-Rodriguez, Benjamin Rodriguez-Garay, Guadalupe Palomino, Javier Martínez, Rodrigo Barba-Gonzalez

Abstract: Agave Linnaeus, 1753 is endemic of America and is considered one of the most important crops in Mexico due to its key role in the country’s economy. Cytogenetic analysis was carried out in A. tequilana Weber, 1902 ‘Azul’, A. cupreata Trelease et Berger, 1915 and A. angustifolia Haworth, 1812. The analysis showed that in all species the diploid chromosome number was 2n = 60, with bimodal karyotypes composed of five pairs of large chromosomes and 25 pairs of small chromosomes. Furthermore, different karyotypical formulae as well as a secondary constriction in a large chromosome pair were found in all species. Fluorescent in situ hybridization (FISH) was used for physical mapping of 5S and 18S ribosomal DNA (rDNA). All species analyzed showed that 5S rDNA was located in both arms of a small chromosome pair, while 18S rDNA was associated with the secondary constriction of a large chromosome pair. Data of FISH analysis provides new information about the position and number of rDNA loci and helps for detection of hybrids in breeding programs as well as evolutionary studies.

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Research Article Mon, 12 Aug 2013 00:00:00 +0300