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Li X, Li H, Yang Z, Wu Y, Zhang M. Exploring objective feature sets in constructing the evolution relationship of animal genome sequences. BMC Genomics 2023; 24:634. [PMID: 37872534 PMCID: PMC10594854 DOI: 10.1186/s12864-023-09747-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 10/17/2023] [Indexed: 10/25/2023] Open
Abstract
BACKGROUND Exploring evolution regularities of genome sequences and constructing more objective species evolution relationships at the genomic level are high-profile topics. Based on the evolution mechanism of genome sequences proposed in our previous research, we found that only the 8-mers containing CG or TA dinucleotides correlate directly with the evolution of genome sequences, and the relative frequency rather than the actual frequency of these 8-mers is more suitable to characterize the evolution of genome sequences. RESULT Therefore, two types of feature sets were obtained, they are the relative frequency sets of CG1 + CG2 8-mers and TA1 + TA2 8-mers. The evolution relationships of mammals and reptiles were constructed by the relative frequency set of CG1 + CG2 8-mers, and two types of evolution relationships of insects were constructed by the relative frequency sets of CG1 + CG2 8-mers and TA1 + TA2 8-mers respectively. Through comparison and analysis, we found that evolution relationships are consistent with the known conclusions. According to the evolution mechanism, we considered that the evolution relationship constructed by CG1 + CG2 8-mers reflects the evolution state of genome sequences in current time, and the evolution relationship constructed by TA1 + TA2 8-mers reflects the evolution state in the early stage. CONCLUSION Our study provides objective feature sets in constructing evolution relationships at the genomic level.
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Affiliation(s)
- Xiaolong Li
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China
| | - Hong Li
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China.
| | - Zhenhua Yang
- School of Economics and Management, Inner Mongolia University of Science and Technology, Baotou, 014010, China
| | - Yuan Wu
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China
| | - Mengchuan Zhang
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China
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Yang Z, Li H, Jia Y, Zheng Y, Meng H, Bao T, Li X, Luo L. Intrinsic laws of k-mer spectra of genome sequences and evolution mechanism of genomes. BMC Evol Biol 2020; 20:157. [PMID: 33228538 PMCID: PMC7684957 DOI: 10.1186/s12862-020-01723-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 11/10/2020] [Indexed: 11/17/2022] Open
Abstract
Background K-mer spectra of DNA sequences contain important information about sequence composition and sequence evolution. We want to reveal the evolution rules of genome sequences by studying the k-mer spectra of genome sequences. Results The intrinsic laws of k-mer spectra of 920 genome sequences from primate to prokaryote were analyzed. We found that there are two types of evolution selection modes in genome sequences, named as CG Independent Selection and TA Independent Selection. There is a mutual inhibition relationship between CG and TA independent selections. We found that the intensity of CG and TA independent selections correlates closely with genome evolution and G + C content of genome sequences. The living habits of species are related closely to the independent selection modes adopted by species genomes. Consequently, we proposed an evolution mechanism of genomes in which the genome evolution is determined by the intensities of the CG and TA independent selections and the mutual inhibition relationship. Besides, by the evolution mechanism of genomes, we speculated the evolution modes of prokaryotes in mild and extreme environments in the anaerobic age and the evolving process of prokaryotes from anaerobic to aerobic environment on earth as well as the originations of different eukaryotes. Conclusion We found that there are two independent selection modes in genome sequences. The evolution of genome sequence is determined by the two independent selection modes and the mutual inhibition relationship between them.
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Affiliation(s)
- Zhenhua Yang
- Laboratory of Theoretical Biophysics, School of Physical Science & Technology, Inner Mongolia University, Hohhot, 010021, China.,School of Economics and Management, Inner Mongolia University of Science & Technology, Baotou, 014010, China
| | - Hong Li
- Laboratory of Theoretical Biophysics, School of Physical Science & Technology, Inner Mongolia University, Hohhot, 010021, China.
| | - Yun Jia
- College of Science, Inner Mongolia University of Technology, Hohhot, 010051, China
| | - Yan Zheng
- Baotou Medical College, Inner Mongolia University of Science & Technology, Baotou, 014040, China
| | - Hu Meng
- School of Life Science & Technology, Inner Mongolia University of Science & Technology, Baotou, 014010, China
| | - Tonglaga Bao
- Laboratory of Theoretical Biophysics, School of Physical Science & Technology, Inner Mongolia University, Hohhot, 010021, China
| | - Xiaolong Li
- Laboratory of Theoretical Biophysics, School of Physical Science & Technology, Inner Mongolia University, Hohhot, 010021, China
| | - Liaofu Luo
- Laboratory of Theoretical Biophysics, School of Physical Science & Technology, Inner Mongolia University, Hohhot, 010021, China
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Jia Y, Li H, Wang J, Meng H, Yang Z. Spectrum structures and biological functions of 8-mers in the human genome. Genomics 2018. [PMID: 29522801 DOI: 10.1016/j.ygeno.2018.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The spectra of k-mer frequencies can reveal the structures and evolution of genome sequences. We confirmed that the trimodal spectrum of 8-mers in human genome sequences is distinguished only by CG2, CG1 and CG0 8-mer sets, containing 2,1 or 0 CpG, respectively. This phenomenon is called independent selection law. The three types of CG 8-mers were considered as different functional elements. We conjectured that (1) nucleosome binding motifs are mainly characterized by CG1 8-mers and (2) the core structural units of CpG island sequences are predominantly characterized by CG2 8-mers. To validate our conjectures, nucleosome occupied sequences and CGI sequences were extracted, then the sequence parameters were constructed through the information of the three CG 8-mer sets respectively. ROC analysis showed that CG1 8-mers are more preference in nucleosome occupied segments (AUC > 0.7) and CG2 8-mers are more preference in CGI sequences (AUC > 0.99). This validates our conjecture in principle.
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Affiliation(s)
- Yun Jia
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China; College of Science, Inner Mongolia University of Technology, Hohhot 010051, China
| | - Hong Li
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China.
| | - Jingfeng Wang
- College of Science, Inner Mongolia University of Technology, Hohhot 010051, China
| | - Hu Meng
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China
| | - Zhenhua Yang
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China
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Meng H, Li H, Zheng Y, Yang Z, Jia Y, Bo S. Evolutionary analysis of nucleosome positioning sequences based on New Symmetric Relative Entropy. Genomics 2017; 110:154-161. [PMID: 28917635 DOI: 10.1016/j.ygeno.2017.09.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 09/06/2017] [Accepted: 09/12/2017] [Indexed: 10/18/2022]
Abstract
New Symmetric Relative Entropy (NSRE) was applied innovatively to analyze the nucleosome sequences in S. cerevisiae, S. pombe and Drosophila. NSRE distributions could well reflect the characteristic differences of nucleosome sequences among three organisms, and the differences indicate a concerted evolution in the sequence usage of nucleosome. Further analysis about the nucleosomes around TSS shows that the constitutive property of +1/-1 nucleosomes in S. cerevisiae is different from that in S. pombe and Drosophila, which indicates that S. cerevisiae has a different transcription regulation mechanism based on nucleosome. However, in either case, the nucleosome dyad region is conserved and always has a higher NSRE. Base composition analysis shows that this conservative property in nucleosome dyad region is mainly determined by base A and T, and the dependence degrees on base A and T are consistent in three organisms.
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Affiliation(s)
- Hu Meng
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China
| | - Hong Li
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China.
| | - Yan Zheng
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China
| | - Zhenhua Yang
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China
| | - Yun Jia
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China
| | - Suling Bo
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China
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Zheng Y, Li H, Wang Y, Meng H, Zhang Q, Zhao X. Evolutionary mechanism and biological functions of 8-mers containing CG dinucleotide in yeast. Chromosome Res 2017; 25:173-189. [PMID: 28181048 DOI: 10.1007/s10577-017-9554-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 12/27/2016] [Accepted: 01/27/2017] [Indexed: 01/01/2023]
Abstract
The rules of k-mer non-random usage and the biological functions are worthy of special attention. Firstly, the article studied human 8-mer spectra and found that only the spectra of cytosine-guanine (CG) dinucleotide classification formed independent unimodal distributions when the 8-mers were classified into three subsets under 16 dinucleotide classifications. Secondly, the distribution rules were reproduced by other seven species including yeast, which showed that the evolution phenomenon had species universality. It followed that we proposed two theoretical conjectures: (1) CG1 motifs (8-mers including 1 CG) are the nucleosome-binding motifs. (2) CG2 motifs (8-mers including two or more than two CG) are the modular units of CpG islands. Our conjectures were confirmed in yeast by the following results: a maximum of average area under the receiver operating characteristic (AUC) resulted from CG1 information during nucleosome core sequences, and linker sequences were distinguished by three CG subsets; there was a one-to-one relationship between abundant CG1 signal regions and histone positions; the sequence changing of squeezed nucleosomes was relevant with the strength of CG1 signals; and the AUC value of 0.986 was based on CG2 information when CpG islands and non-CpG islands were distinguished by the three CG subsets.
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Affiliation(s)
- Yan Zheng
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China
| | - Hong Li
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China. .,, No.235, West University Street, Hohhot, Inner Mongolia, China.
| | - Yue Wang
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China
| | - Hu Meng
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China
| | - Qiang Zhang
- College of Science, Inner Mongolia Agricultural University, Hohhot, 010018, China
| | - Xiaoqing Zhao
- Biotechnology research centre, Inner Mongolia Academy of Agricultural and Animal Husbandry Science, Hohhot, 010021, China
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Rare k-mer DNA: Identification of sequence motifs and prediction of CpG island and promoter. J Theor Biol 2015; 387:88-100. [PMID: 26427337 DOI: 10.1016/j.jtbi.2015.09.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Revised: 09/10/2015] [Accepted: 09/15/2015] [Indexed: 12/20/2022]
Abstract
Empirical analysis on k-mer DNA has been proven as an effective tool in finding unique patterns in DNA sequences which can lead to the discovery of potential sequence motifs. In an extensive study of empirical k-mer DNA on hundreds of organisms, the researchers found unique multi-modal k-mer spectra occur in the genomes of organisms from the tetrapod clade only which includes all mammals. The multi-modality is caused by the formation of the two lowest modes where k-mers under them are referred as the rare k-mers. The suppression of the two lowest modes (or the rare k-mers) can be attributed to the CG dinucleotide inclusions in them. Apart from that, the rare k-mers are selectively distributed in certain genomic features of CpG Island (CGI), promoter, 5' UTR, and exon. We correlated the rare k-mers with hundreds of annotated features using several bioinformatic tools, performed further intrinsic rare k-mer analyses within the correlated features, and modeled the elucidated rare k-mer clustering feature into a classifier to predict the correlated CGI and promoter features. Our correlation results show that rare k-mers are highly associated with several annotated features of CGI, promoter, 5' UTR, and open chromatin regions. Our intrinsic results show that rare k-mers have several unique topological, compositional, and clustering properties in CGI and promoter features. Finally, the performances of our RWC (rare-word clustering) method in predicting the CGI and promoter features are ranked among the top three, in eight of the CGI and promoter evaluations, among eight of the benchmarked datasets.
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Zhang Q, Li H, Zhao X, Zheng Y, Zhou D. Distribution bias of the sequence matching between exons and introns in exon joint and EJC binding region in C. elegans. J Theor Biol 2014; 364:295-304. [PMID: 25234235 DOI: 10.1016/j.jtbi.2014.09.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Revised: 08/30/2014] [Accepted: 09/04/2014] [Indexed: 11/17/2022]
Abstract
We propose a mechanism that there are matching relations between mRNA sequences and corresponding post-spliced introns, and introns play a significant role in the process of gene expression. In order to reveal the sequence matching features, Smith-Waterman local alignment method is used on C. elegans mRNA sequences to obtain optimal matched segments between exon-exon sequences and their corresponding introns. Distribution characters of matching frequency on exon-exon sequences and sequence characters of optimal matched segments are studied. Results show that distributions of matching frequency on exon-exon junction region have obvious differences, and the exon boundary is revealed. Distributions of the length and matching rate of optimal matched segments are consistent with sequence features of siRNA and miRNA. The optimal matched segments have special sequence characters compared with their host sequences. As for the first introns and long introns, matching frequency values of optimal matched segments with high GC content, rich CG dinucleotides and high λCG values show the minimum distribution in exon junction complex (EJC) binding region. High λCG values in optimal matched segments are main characters in distinguishing EJC binding region. Results indicate that EJC and introns have competitive and cooperative relations in the process of combining on protein coding sequences. Also intron sequences and protein coding sequences do have concerted evolution relations.
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Affiliation(s)
- Qiang Zhang
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China
| | - Hong Li
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China.
| | - Xiaoqing Zhao
- Biotechnology Research Centre, Inner Mongolia Academy of Agricultural and Animal Husbandry Science, Hohhot, 010021, China
| | - Yan Zheng
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China
| | - Deliang Zhou
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China
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