scholarly journals Novel repetitive sequences decipher the evolution and phylogeny in Carthamus L

2019 ◽  
Author(s):  
Shweta Mehrotra ◽  
Vinod Goyal

Abstract Repetitive sequences are ubiquitous features of eukaryotic genomes, which contribute up to 70-80% of the nuclear genomic DNA. They are known to impact genome evolution and organization and play important role in genome remodelling. The widespread distribution and sufficient conservation of repeats reinforce the value of repetitive DNA sequences as markers of evolutionary processes. The repetitive DNA-based phylogeny reconstruction method is consistent in resolving expected phylogenetic and evolutionary relationships. In the present study, we address the isolation and characterization of four novel repetitive sequences (pCtHaeIII-I, pCtHaeIII-II, pCtHaeIII-III and pCtTaqI-I) from Carthamus tinctorius. Detailed phylogenetic analysis of 18 taxa belonging to 7 species of Carthamus has also been done with pCtHaeIII-I, and pCtHaeIII-II which clearly indicated concerted evolution while delineating phylogenetic relationships among the 18 taxa studied. The above understanding can assist in the marker assisted genetic improvement/ enhancement programmes in this crop species.

2020 ◽  
Vol 160 (3) ◽  
pp. 141-147 ◽  
Author(s):  
Marcelo J. da Silva ◽  
Raquel Fogarin Destro ◽  
Thiago Gazoni ◽  
Hideki Narimatsu ◽  
Paulo S. Pereira dos Santos ◽  
...  

Most eukaryotic genomes contain substantial portions of repetitive DNA sequences. These are located primarily in highly compacted heterochromatin and, in many cases, are one of the most abundant components of the sex chromosomes. In this sense, the anuran Proceratophrys boiei represents an interesting model for analyses on repetitive sequences by means of cytogenetic techniques, since it has a karyotype with large blocks of heterochromatin and a ZZ/ZW sex chromosome system. The present study describes, for the first time, families of satellite DNA (satDNA) in the frog P. boiei. Its genome size was estimated at 1.6 Gb, of which 41% correspond to repetitive sequences, including satDNAs, rDNAs, transposable elements, and other elements characterized as non-repetitive. The satDNAs were mapped by FISH in the centromeric and pericentromeric regions of all chromosomes, suggesting a possible involvement of these sequences in centromere function. SatDNAs are also present in the W sex chromosome, occupying the entire heterochromatic area, indicating a probable contribution of this class of repetitive DNA to the differentiation of the sex chromosomes in this species. This study is a valuable contribution to the existing knowledge on repetitive sequences in amphibians. We show the presence of repetitive DNAs, especially satDNAs, in the genome of P. boiei that might be of relevance in genome organization and regulation, setting the stage for a deeper functional genome analysis of Proceratophrys.


2014 ◽  
Vol 13 (2) ◽  
pp. 142-152 ◽  
Author(s):  
Alexandra Marina Gottlieb ◽  
Lidia Poggio

The development of modern approaches to the genetic improvement of the tree crops Ilex paraguariensis (‘yerba mate’) and Ilex dumosa (‘yerba señorita’) is halted by the scarcity of basic genetic information. In this study, we characterized the implementation of low-cost methodologies such as representational difference analysis (RDA), single-strand conformation polymorphisms (SSCP), and reverse and direct dot-blot filter hybridization assays coupled with thorough bioinformatic characterization of sequence data for both species. Also, we estimated the genome size of each species using flow cytometry. This study contributes to the better understanding of the genetic differences between two cultivated species, by generating new quantitative and qualitative genome-level data. Using the RDA technique, we isolated a group of non-coding repetitive sequences, tentatively considered as Ilex-specific, which were 1.21- to 39.62-fold more abundant in the genome of I. paraguariensis. Another group of repetitive DNA sequences involved retrotransposons, which appeared 1.41- to 35.77-fold more abundantly in the genome of I. dumosa. The genomic DNA of each species showed different performances in filter hybridizations: while I. paraguariensis showed a high intraspecific affinity, I. dumosa exhibited a higher affinity for the genome of the former species (i.e. interspecific). These differences could be attributed to the occurrence of homologous but slightly divergent repetitive DNA sequences, highly amplified in the genome of I. paraguariensis but not in the genome of I. dumosa. Additionally, our hybridization outcomes suggest that the genomes of both species have less than 80% similarity. Moreover, for the first time, we report herein a genome size estimate of 1670 Mbp for I. paraguariensis and that of 1848 Mbp for I. dumosa.


1991 ◽  
Vol 81 (6) ◽  
pp. 740-744 ◽  
Author(s):  
V. Kuhrová ◽  
M. Bezděk ◽  
B. Vyskot ◽  
B. Koukalová ◽  
J. Fajkus

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Wenpan Zhang ◽  
Sheng Zuo ◽  
Zhanjie Li ◽  
Zhuang Meng ◽  
Jinlei Han ◽  
...  

1986 ◽  
Vol 72 (2) ◽  
pp. 207-210 ◽  
Author(s):  
M. Metzlaff ◽  
W. Troebner ◽  
F. Baldauf ◽  
R. Schlegel ◽  
J. Cullum

2020 ◽  
Vol 477 (2) ◽  
pp. 325-339 ◽  
Author(s):  
Vaclav Brazda ◽  
Miroslav Fojta ◽  
Richard P. Bowater

DNA is a fundamentally important molecule for all cellular organisms due to its biological role as the store of hereditary, genetic information. On the one hand, genomic DNA is very stable, both in chemical and biological contexts, and this assists its genetic functions. On the other hand, it is also a dynamic molecule, and constant changes in its structure and sequence drive many biological processes, including adaptation and evolution of organisms. DNA genomes contain significant amounts of repetitive sequences, which have divergent functions in the complex processes that involve DNA, including replication, recombination, repair, and transcription. Through their involvement in these processes, repetitive DNA sequences influence the genetic instability and evolution of DNA molecules and they are located non-randomly in all genomes. Mechanisms that influence such genetic instability have been studied in many organisms, including within human genomes where they are linked to various human diseases. Here, we review our understanding of short, simple DNA repeats across a diverse range of bacteria, comparing the prevalence of repetitive DNA sequences in different genomes. We describe the range of DNA structures that have been observed in such repeats, focusing on their propensity to form local, non-B-DNA structures. Finally, we discuss the biological significance of such unusual DNA structures and relate this to studies where the impacts of DNA metabolism on genetic stability are linked to human diseases. Overall, we show that simple DNA repeats in bacteria serve as excellent and tractable experimental models for biochemical studies of their cellular functions and influences.


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