Latest Articles from Comparative Cytogenetics Latest 3 Articles from Comparative Cytogenetics https://compcytogen.pensoft.net/ Fri, 29 Mar 2024 12:35:06 +0200 Pensoft FeedCreator https://compcytogen.pensoft.net/i/logo.jpg Latest Articles from Comparative Cytogenetics https://compcytogen.pensoft.net/ Comparative molecular cytogenetic characterization of five wild Vigna species (Fabaceae) https://compcytogen.pensoft.net/article/51154/ Comparative Cytogenetics 14(2): 243-264

DOI: 10.3897/CompCytogen.v14i2.51154

Authors: Chao-Wen She, Ying Mao, Xiang-Hui Jiang, Chun-Ping He

Abstract: To extend our knowledge on karyotype variation of the genus Vigna Savi, 1824, the chromosomal organization of rRNA genes and fluorochrome banding patterns of five wild Vigna species were studied. Sequential combined PI (propidium iodide) and DAPI (4',6-diamidino-2-phenylindole) (CPD) staining and fluorescence in situ hybridization (FISH) with 5S and 45S rDNA probes were used to analyze the karyotypes of V. luteola (Jacquin, 1771) Bentham, 1959, V. vexillata (Linnaeus, 1753) A. Richard, 1845, V. minima (Roxburgh, 1832) Ohwi & H. Ohashi, 1969, V. trilobata (Linnaeus, 1753) Verdcourt, 1968, and V. caracalla (Linnaeus, 1753) Verdcourt,1970. For further phylogenetic analysis, genomic in situ hybridization (GISH) with the genomic DNA of V. umbellata (Thunberg, 1794) Ohwi & H.Ohashi, 1969 onto the chromosomes of five wild Vigna species was also performed. Detailed karyotypes were established for the first time using chromosome measurements, fluorochrome bands, and rDNA-FISH signals. All species had chromosome number 2n = 2x = 22, and symmetrical karyotypes that composed of only metacentric or metacentric and submetacentric chromosomes. CPD staining revealed all 45S rDNA sites in the five species analyzed, (peri)centromeric GC-rich heterochromatin in V. luteola, V. trilobata and V. caracalla, interstitial GC-rich and pericentromeric AT-rich heterochromatin in V. caracalla. rDNA-FISH revealed two 5S loci in V. caracalla and one 5S locus in the other four species; one 45S locus in V. luteola and V. caracalla, two 45S loci in V. vexillata and V. trilobata, and five 45S loci in V. minima. The karyotypes of the studied species could be clearly distinguished by the karyotypic parameters, and the patterns of the fluorochrome bands and the rDNA sites, which revealed high interspecific variation among the five species. The V. umbellata genomic DNA probe produced weak signals in all proximal regions of V. luteola and all (peri)centromeric regions of V. trilobata. The combined data demonstrate that distinct genome differentiation has occurred among the five species during evolution. The phylogenetic relationships between the five wild species and related cultivated species of Vigna are discussed based on our present and previous molecular cytogenetic data.

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Research Article Fri, 26 Jun 2020 22:57:45 +0300
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
Genomic characterisation of Arachis porphyrocalyx (Valls & C.E. Simpson, 2005) (Leguminosae): multiple origin of Arachis species with x = 9 https://compcytogen.pensoft.net/article/10339/ Comparative Cytogenetics 11(1): 29-43

DOI: 10.3897/CompCytogen.v11i1.10339

Authors: Silvestri María Celeste, Alejandra Marcela Ortiz, Germán Ariel Robledo, José Francisco Montenegro Valls, Graciela Inés Lavia

Abstract: The genus Arachis Linnaeus, 1753 comprises four species with x = 9, three belong to the section Arachis: Arachis praecox (Krapov. W.C. Greg. & Valls, 1994), Arachis palustris (Krapov. W.C. Greg. & Valls, 1994) and Arachis decora (Krapov. W.C. Greg. & Valls, 1994) and only one belongs to the section Erectoides: Arachis porphyrocalyx (Valls & C.E. Simpson, 2005). Recently, the x = 9 species of section Arachis have been assigned to G genome, the latest described so far. The genomic relationship of A. porphyrocalyx with these species is controversial. In the present work, we carried out a karyotypic characterisation of A. porphyrocalyx to evaluate its genomic structure and analyse the origin of all x = 9 Arachis species. Arachis porphyrocalyx showed a karyotype formula of 14m+4st, one pair of A chromosomes, satellited chromosomes type 8, one pair of 45S rDNA sites in the SAT chromosomes, one pair of 5S rDNA sites and pericentromeric C-DAPI+ bands in all chromosomes. Karyotype structure indicates that A. porphyrocalyx does not share the same genome type with the other three x = 9 species and neither with the remaining Erectoides species. Taking into account the geographic distribution, morphological and cytogenetic features, the origin of species with x = 9 of the genus Arachis cannot be unique; instead, they originated at least twice in the evolutionary history of the genus.

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Research Article Mon, 9 Jan 2017 18:58:00 +0200