scholarly journals Molecular cytogenetic characterization and phylogenetic analysis of four Miscanthus species (Poaceae)

2019 ◽  
Vol 13 (3) ◽  
pp. 211-230 ◽  
Author(s):  
Yan-Mei Tang ◽  
Liang Xiao ◽  
Yasir Iqbal ◽  
Jian-Feng Liao ◽  
Long-Qian Xiao ◽  
...  

Chromosomes of four Miscanthus (Andersson, 1855) species including M. sinensis (Andersson, 1855), M. floridulus (Schumann & Lauterb, 1901), M. sacchariflorus (Hackel, 1882) and M. lutarioriparius (Chen & Renvoize, 2005) were analyzed using sequentially combined PI and DAPI (CPD) staining and fluorescence in situ hybridization (FISH) with 45S rDNA probe. To elucidate the phylogenetic relationship among the four Miscanthus species, the homology of repetitive sequences among the four species was analyzed by comparative genomic in situ hybridization (cGISH). Subsequently four Miscanthus species were clustered based on the internal transcribed spacer (ITS) of 45S rDNA. Molecular cytogenetic karyotypes of the four Miscanthus species were established for the first time using chromosome measurements, fluorochrome bands and 45S rDNA FISH signals, which will provide a cytogenetic tool for the identification of these four species. All the four have the karyotype formula of Miscanthus species, which is 2n = 2x = 38 = 34m(2SAT) + 4sm, and one pair of 45S rDNA sites. The latter were shown as strong red bands by CPD staining. A non-rDNA CPD band emerged in M. floridulus and some blue DAPI bands appeared in M. sinensis and M. floridulus. The hybridization signals of M. floridulus genomic DNA to the chromosomes of M. sinensis and M. lutarioriparius genomic DNA to the chromosomes of M. sacchariflorus were stronger and more evenly distributed than other combinations. Molecular phylogenetic trees showed that M. sinensis and M. floridulus were closest relatives, and M. sacchariflorus and M. lutarioriparius were also closely related. These findings were consistent with the phylogenetic relationships inferred from the cGISH patterns.

2020 ◽  
Vol 14 (2) ◽  
pp. 243-264
Author(s):  
Chao-Wen She ◽  
Ying Mao ◽  
Xiang-Hui Jiang ◽  
Chun-Ping He

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.


Crustaceana ◽  
2011 ◽  
Vol 84 (12-13) ◽  
pp. 1497-1510 ◽  
Author(s):  
M. Pavlica ◽  
M. Mcžić ◽  
G. Klobučar ◽  
M. Šrut ◽  
I. Maguire ◽  
...  

AbstractThis study reports on the chromosome number and karyological characteristics of the endangered species of European crayfish, Astacus astacus and A. leptodactylus (Decapoda, Astacidae), both native to Croatian freshwater habitats. The karyotype of A. astacus and A. leptodactylus consists of 2n = 176 and 2n = 180 chromosomes, respectively. The haploid chromosome complement of A. astacus consists of 52 metacentric, 35 metacentric-submetacentric, and 1 acrocentric chromosomes. Fluorochrome staining with 4,6-diamino-2-phenylindole (DAPI) has revealed that the karyotypes of A. astacus and A. leptodactylus are characterized by large heterochromatic blocks located at centromeric and intercalary positions on the chromosomes. Interstitial heterochromatic blocks were more frequent in A. astacus than in A. leptodactylus. In both species pairing of chromosomes in meiosis was regular with the majority of bivalents in a ring- and a dumbbell-form. Fluorescence in situ hybridization (FISH) has revealed that two 45S rDNA loci were present in the investigated species. In A. astacus one of the two 45S rDNA-bearing chromosome pairs was highly heteromorphic, exhibiting a three-fold size difference between 45S rDNA sites on homologous chromosomes. Such a size difference was significantly less pronounced in A. leptodactylus. The karyotype differences between A. astacus and A. leptodactylus suggest changes in chromosome number as well as position of repetitive DNAs have played a role in the karyotype evolution of the species of Astacus.


Genomics ◽  
1993 ◽  
Vol 17 (2) ◽  
pp. 403-407 ◽  
Author(s):  
Elizabeth A. Lindsay ◽  
Stephanie Halford ◽  
Roy Wadey ◽  
Peter J. Scambler ◽  
Antonio Baldini

2009 ◽  
Vol 55 (2) ◽  
pp. 145-149 ◽  
Author(s):  
Ke Bi ◽  
James P. Bogart ◽  
Jinzhong Fu

Abstract The chromosomal localization of 45S ribosomal RNA genes in Ambystoma jeffersonianum was determined by fluorescence in situ hybridization with 18S rDNA fragment as a probe (FISH-rDNA). Our results revealed the presence of rDNA polymorphism among A. jeffersonianum populations in terms of number, location and FISH signal intensity on the chromosomes. Nine rDNA cytotypes were found in ten geographically isolated populations and most of them contained derivative rDNA sites. Our preliminary study provides strong indication of karyotypic diversification of A. Jeffersonianum that is demonstrated by intraspecific variation of 45S rDNA cytotypes. rDNA cytotype polymorphism has been described in many other caudate amphibians. We predict that habitat isolation, low dispersal ability and decline of effective population size could facilitate the fixation and accumulation of variable rDNA cytotypes during their chromosome evolution.


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