Mitochondrial genomic comparisons of the subterranean termites from the Genus Reticulitermes (Insecta: Isoptera: Rhinotermitidae)

Genome ◽  
2007 ◽  
Vol 50 (2) ◽  
pp. 188-202 ◽  
Author(s):  
Stephen L. Cameron ◽  
Michael F. Whiting
Keyword(s):  
Control Region ◽  
Repeat Unit ◽  
General Characteristic ◽  
Nucleotide Composition ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Stem Loop ◽  
Protein Coding ◽  
Repeat Units ◽  
Mt Genome

Termites of the genus Reticulitermes are some of the most significant pests of structural timber and tree farming in the northern hemisphere, causing losses in the billions of dollars annually because of direct damage and termite control costs. This group has been frequently targeted for population genetic, phylogenetic, and species limit studies, most of which use mitochondrial (mt) genes; however, only a small fraction of the genome has been sequenced. The entire mt genome was sequenced for the eastern North American members of Reticulitermes: R. flavipes, R. santonensis, R. virginicus, and R. hageni. The mt genome has the same gene content and organization as that found in most insect species; however, the nucleotide composition and skew are highly biased (AT% low, strong A- and C-skew). Both the protein-coding and transfer RNA genes show high absolute levels of nucleotide substitution, suggesting that the high rates of mutation within Reticulitermes inferred from analyses of single mt genes are a general characteristic of the entire mt genome. The AT-rich or control region has a remarkable structure not previously observed in insect mt genomes. The majority of the control region is made up of 2 sets of repeat units, typically with 2 full and 1 partial copies of both the A (or small; 186 bp) and B (or large; 552 bp) repeats. The partial repeat units overlap by 36 bp. The size, location, and degree of overlap for the partial repeat units correspond to highly conserved stem/loop structures within the repeat units, suggesting that these structures are involved in the replication-mediated processes that govern repeat-unit evolution within mt genomes. Finally, molecular variation within the mt gene regions was compared with previous regions used in molecular diagnostics or phylogenetics of Reticulitermes. High numbers of single nucleotide polymorphisms were found in each of the mt genes, and some of the highest variability was found in gene regions that have not previously been investigated in this group. The whole mt genome sequence can thus be used to predict useful regions for future investigation.

Analysis of Inter-Chromosomal Distribution of Disease-Related Genes in Human Genome

2020 ◽  
Vol 21 (11) ◽  
pp. 1068-1077
Author(s):  
Xiaochao Sun ◽  
Bin Yang ◽  
Qunye Zhang
Keyword(s):  
Spatial Distribution ◽  
Model Organisms ◽  
Nucleotide Polymorphisms ◽  
Chromosomal Distribution ◽  
Single Nucleotide ◽  
Protein Coding ◽  
Single Chromosome ◽  
Deletion Mutations ◽  
Protein Coding Genes ◽  
Disease Related Genes

: Many studies have shown that the spatial distribution of genes within a single chromosome exhibits distinct patterns. However, little is known about the characteristics of inter-chromosomal distribution of genes (including protein-coding genes, processed transcripts and pseudogenes) in different genomes. In this study, we explored these issues using the available genomic data of both human and model organisms. Moreover, we also analyzed the distribution pattern of protein-coding genes that have been associated with 14 common diseases and the insert/deletion mutations and single nucleotide polymorphisms detected by whole genome sequencing in an acute promyelocyte leukemia patient. We obtained the following novel findings. Firstly, inter-chromosomal distribution of genes displays a nonstochastic pattern and the gene densities in different chromosomes are heterogeneous. This kind of heterogeneity is observed in genomes of both lower and higher species. Secondly, protein-coding genes involved in certain biological processes tend to be enriched in one or a few chromosomes. Our findings have added new insights into our understanding of the spatial distribution of genome and disease- related genes across chromosomes. These results could be useful in improving the efficiency of disease-associated gene screening studies by targeting specific chromosomes.

scholarly journals Worldwide tracing of mutations and the evolutionary dynamics of SARS-CoV-2

2020 ◽  
Author(s):  
Zhong-Yin Zhou ◽  
Hang Liu ◽  
Yue-Dong Zhang ◽  
Yin-Qiao Wu ◽  
Min-Sheng Peng ◽  
...  
Keyword(s):  
Substitution Rate ◽  
Evolutionary Dynamics ◽  
Vaccine Development ◽  
Sequence Data ◽  
Immune Recognition ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Protein Coding ◽  
Theoretical Support ◽  
Recurrent Mutations

AbstractUnderstanding the mutational and evolutionary dynamics of SARS-CoV-2 is essential for treating COVID-19 and the development of a vaccine. Here, we analyzed publicly available 15,818 assembled SARS-CoV-2 genome sequences, along with 2,350 raw sequence datasets sampled worldwide. We investigated the distribution of inter-host single nucleotide polymorphisms (inter-host SNPs) and intra-host single nucleotide variations (iSNVs). Mutations have been observed at 35.6% (10,649/29,903) of the bases in the genome. The substitution rate in some protein coding regions is higher than the average in SARS-CoV-2 viruses, and the high substitution rate in some regions might be driven to escape immune recognition by diversifying selection. Both recurrent mutations and human-to-human transmission are mechanisms that generate fitness advantageous mutations. Furthermore, the frequency of three mutations (S protein, F400L; ORF3a protein, T164I; and ORF1a protein, Q6383H) has gradual increased over time on lineages, which provides new clues for the early detection of fitness advantageous mutations. Our study provides theoretical support for vaccine development and the optimization of treatment for COVID-19. We call researchers to submit raw sequence data to public databases.

scholarly journals Draft genome sequence of Solanum aethiopicum provides insights into disease resistance, drought tolerance, and the evolution of the genome

GigaScience ◽  
2019 ◽  
Vol 8 (10) ◽  
Author(s):  
Bo Song ◽  
Yue Song ◽  
Yuan Fu ◽  
Elizabeth Balyejusa Kizito ◽  
Sandra Ndagire Kamenya ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Single Nucleotide Polymorphisms ◽  
Drought Tolerance ◽  
Resistance Genes ◽  
Draft Genome ◽  
Disease Resistance Genes ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Protein Coding ◽  
Protein Coding Genes

Abstract Background The African eggplant (Solanum aethiopicum) is a nutritious traditional vegetable used in many African countries, including Uganda and Nigeria. It is thought to have been domesticated in Africa from its wild relative, Solanum anguivi. S. aethiopicum has been routinely used as a source of disease resistance genes for several Solanaceae crops, including Solanum melongena. A lack of genomic resources has meant that breeding of S. aethiopicum has lagged behind other vegetable crops. Results We assembled a 1.02-Gb draft genome of S. aethiopicum, which contained predominantly repetitive sequences (78.9%). We annotated 37,681 gene models, including 34,906 protein-coding genes. Expansion of disease resistance genes was observed via 2 rounds of amplification of long terminal repeat retrotransposons, which may have occurred ∼1.25 and 3.5 million years ago, respectively. By resequencing 65 S. aethiopicum and S. anguivi genotypes, 18,614,838 single-nucleotide polymorphisms were identified, of which 34,171 were located within disease resistance genes. Analysis of domestication and demographic history revealed active selection for genes involved in drought tolerance in both “Gilo” and “Shum” groups. A pan-genome of S. aethiopicum was assembled, containing 51,351 protein-coding genes; 7,069 of these genes were missing from the reference genome. Conclusions The genome sequence of S. aethiopicum enhances our understanding of its biotic and abiotic resistance. The single-nucleotide polymorphisms identified are immediately available for use by breeders. The information provided here will accelerate selection and breeding of the African eggplant, as well as other crops within the Solanaceae family.

scholarly journals Novel SARS-CoV-2 encoded small RNAs in the passage to humans

2020 ◽  
Author(s):  
Gabriela A Merino ◽  
Jonathan Raad ◽  
Leandro A Bugnon ◽  
Cristian Yones ◽  
Laura Kamenetzky ◽  
...  
Keyword(s):  
Mature Mirnas ◽  
Human Cells ◽  
Species Boundaries ◽  
Rna Seq ◽  
New Host ◽  
Single Nucleotide ◽  
Stem Loop ◽  
Protein Coding ◽  
Transcriptional Reprogramming ◽  
Human Genes

Abstract Motivation The Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) has recently emerged as the responsible for the pandemic outbreak of the coronavirus disease (COVID-19). This virus is closely related to coronaviruses infecting bats and Malayan pangolins, species suspected to be an intermediate host in the passage to humans. Several genomic mutations affecting viral proteins have been identified, contributing to the understanding of the recent animal-to-human transmission. However, the capacity of SARS-CoV-2 to encode functional putative microRNAs (miRNAs) remains largely unexplored. Results We have used deep learning to discover 12 candidate stem-loop structures hidden in the viral protein-coding genome. Among the precursors, the expression of eight mature miRNAs-like sequences was confirmed in small RNA-seq data from SARS-CoV-2 infected human cells. Predicted miRNAs are likely to target a subset of human genes of which 109 are transcriptionally deregulated upon infection. Remarkably, 28 of those genes potentially targeted by SARS-CoV-2 miRNAs are down-regulated in infected human cells. Interestingly, most of them have been related to respiratory diseases and viral infection, including several afflictions previously associated with SARS-CoV-1 and SARS-CoV-2. The comparison of SARS-CoV-2 pre-miRNA sequences with those from bat and pangolin coronaviruses suggests that single nucleotide mutations could have helped its progenitors jumping inter-species boundaries, allowing the gain of novel mature miRNAs targeting human mRNAs. Our results suggest that the recent acquisition of novel miRNAs-like sequences in the SARS-CoV-2 genome may have contributed to modulate the transcriptional reprogramming of the new host upon infection.

scholarly journals Complete Genome Sequence of Yersinia pestis Strains Antiqua and Nepal516: Evidence of Gene Reduction in an Emerging Pathogen

2006 ◽  
Vol 188 (12) ◽  
pp. 4453-4463 ◽  
Author(s):  
Patrick S. G. Chain ◽  
Ping Hu ◽  
Stephanie A. Malfatti ◽  
Lyndsay Radnedge ◽  
Frank Larimer ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Yersinia Pestis ◽  
Yersinia Pseudotuberculosis ◽  
Open Reading Frames ◽  
Genomic Diversity ◽  
Avirulent Strain ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Protein Coding ◽  
Definition Of

ABSTRACT Yersinia pestis, the causative agent of bubonic and pneumonic plagues, has undergone detailed study at the molecular level. To further investigate the genomic diversity among this group and to help characterize lineages of the plague organism that have no sequenced members, we present here the genomes of two isolates of the “classical” antiqua biovar, strains Antiqua and Nepal516. The genomes of Antiqua and Nepal516 are 4.7 Mb and 4.5 Mb and encode 4,138 and 3,956 open reading frames, respectively. Though both strains belong to one of the three classical biovars, they represent separate lineages defined by recent phylogenetic studies. We compare all five currently sequenced Y. pestis genomes and the corresponding features in Yersinia pseudotuberculosis. There are strain-specific rearrangements, insertions, deletions, single nucleotide polymorphisms, and a unique distribution of insertion sequences. We found 453 single nucleotide polymorphisms in protein-coding regions, which were used to assess the evolutionary relationships of these Y. pestis strains. Gene reduction analysis revealed that the gene deletion processes are under selective pressure, and many of the inactivations are probably related to the organism's interaction with its host environment. The results presented here clearly demonstrate the differences between the two biovar antiqua lineages and support the notion that grouping Y. pestis strains based strictly on the classical definition of biovars (predicated upon two biochemical assays) does not accurately reflect the phylogenetic relationships within this species. A comparison of four virulent Y. pestis strains with the human-avirulent strain 91001 provides further insight into the genetic basis of virulence to humans.

Microsatellite and Single Nucleotide Polymorphisms in the β-Globin Locus Control Region-Hypersensitive Site 2: Specificity of Tunisian βSChromosomes

Hemoglobin ◽  
2012 ◽  
Vol 36 (6) ◽  
pp. 533-544 ◽  
Author(s):  
Maha Ben Mustapha ◽  
Imen Moumni ◽  
Amine Zorai ◽  
Kaïs Douzi ◽  
Abderraouf Ghanem ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Control Region ◽  
Locus Control Region ◽  
Nucleotide Polymorphisms ◽  
Hypersensitive Site ◽  
Single Nucleotide

scholarly journals Complete overview of protein-inactivating sequence variations in 36 sequenced mouse inbred strains

2017 ◽  
Vol 114 (34) ◽  
pp. 9158-9163 ◽  
Author(s):  
Steven Timmermans ◽  
Marc Van Montagu ◽  
Claude Libert
Keyword(s):  
Mouse Genome ◽  
Inbred Strains ◽  
Nucleotide Polymorphisms ◽  
Genome Sequences ◽  
Single Nucleotide ◽  
Protein Coding ◽  
Stop Codons ◽  
Protein Coding Genes ◽  
Sequence Variations ◽  
Genetic Background Effects

Mouse inbred strains remain essential in science. We have analyzed the publicly available genome sequences of 36 popular inbred strains and provide lists for each strain of protein-coding genes that acquired sequence variations that cause premature STOP codons, loss of STOP codons and single nucleotide polymorphisms, and short in-frame insertions and deletions. Our data give an overview of predicted defective proteins, including predicted impact scores, of all these strains compared with the reference mouse genome of C57BL/6J. These data can also be retrieved via a searchable website (mousepost.be) and allow a global, better interpretation of genetic background effects and a source of naturally defective alleles in these 36 sequenced classical and high-priority mouse inbred strains.

Single nucleotide polymorphisms in the mitochondrial control region are associated with metabolic phenotypes and oxidative stress

Gene ◽  
2013 ◽  
Vol 531 (2) ◽  
pp. 370-376 ◽  
Author(s):  
Shao-Wen Weng ◽  
Tsu-Kung Lin ◽  
Pei-Wen Wang ◽  
Shang-Der Chen ◽  
Yao-Chung Chuang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Single Nucleotide Polymorphisms ◽  
Control Region ◽  
Mitochondrial Control Region ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Metabolic Phenotypes ◽  
And Oxidative Stress

scholarly journals Regulatory Variants and Disease: The E-Cadherin −160C/A SNP as an Example

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Gongcheng Li ◽  
Tiejun Pan ◽  
Dan Guo ◽  
Long-Cheng Li
Keyword(s):  
Association Studies ◽  
Genome Wide Association Studies ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Protein Coding ◽  
Regulate Gene Expression ◽  
Regulatory Variants ◽  
Genome Wide ◽  
Regulatory Snps ◽  
E Cadherin

Single nucleotide polymorphisms (SNPs) occurring in noncoding sequences have largely been ignored in genome-wide association studies (GWAS). Yet, amounting evidence suggests that many noncoding SNPs especially those that are in the vicinity of protein coding genes play important roles in shaping chromatin structure and regulate gene expression and, as such, are implicated in a wide variety of diseases. One of such regulatory SNPs (rSNPs) is the E-cadherin (CDH1) promoter −160C/A SNP (rs16260) which is known to affect E-cadherin promoter transcription by displacing transcription factor binding and has been extensively scrutinized for its association with several diseases especially malignancies. Findings from studying this SNP highlight important clinical relevance of rSNPs and justify their inclusion in future GWAS to identify novel disease causing SNPs.

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