Long-term persistence of supernumerary B chromosomes in multiple species of Astyanax fish

Abstract Background Eukaryote genomes frequently harbor supernumerary B chromosomes in addition to the “standard” A chromosome set. B chromosomes are thought to arise as byproducts of genome rearrangements and have mostly been considered intraspecific oddities. However, their evolutionary transcendence beyond species level has remained untested. Results Here we reveal that the large metacentric B chromosomes reported in several fish species of the genus Astyanax arose in a common ancestor at least 4 million years ago. We generated transcriptomes of A. scabripinnis and A. paranae 0B and 1B individuals and used these assemblies as a reference for mapping all gDNA and RNA libraries to quantify coverage differences between B-lacking and B-carrying genomes. We show that the B chromosomes of A. scabripinnis and A. paranae share 19 protein-coding genes, of which 14 and 11 were also present in the B chromosomes of A. bockmanni and A. fasciatus, respectively. Our search for B-specific single-nucleotide polymorphisms (SNPs) identified the presence of B-derived transcripts in B-carrying ovaries, 80% of which belonged to nobox, a gene involved in oogenesis regulation. Importantly, the B chromosome nobox paralog is expressed > 30× more than the A chromosome paralog. This indicates that the normal regulation of this gene is altered in B-carrying females, which could potentially facilitate B inheritance at higher rates than Mendelian law prediction. Conclusions Taken together, our results demonstrate the long-term survival of B chromosomes despite their lack of regular pairing and segregation during meiosis and that they can endure episodes of population divergence leading to species formation.

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

Current Protein and Peptide Science ◽

10.2174/1389203721666200426233158 ◽

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.

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B Chromosomes in Populations of Mammals Revisited

Genes ◽

10.3390/genes9100487 ◽

2018 ◽

Vol 9 (10) ◽

pp. 487 ◽

Cited By ~ 11

Author(s):

Mladen Vujošević ◽

Marija Rajičić ◽

Jelena Blagojević

Keyword(s):

Mammalian Species ◽

B Chromosome ◽

Molecular Techniques ◽

B Chromosomes ◽

General View ◽

Protein Coding ◽

Host Parasite Interactions ◽

Quantitative Characteristics ◽

Host Parasite

The study of B chromosomes (Bs) started more than a century ago, while their presence in mammals dates since 1965. As the past two decades have seen huge progress in application of molecular techniques, we decided to throw a glance on new data on Bs in mammals and to review them. We listed 85 mammals with Bs that make 1.94% of karyotypically studied species. Contrary to general view, a typical B chromosome in mammals appears both as sub- or metacentric that is the same size as small chromosomes of standard complement. Both karyotypically stable and unstable species possess Bs. The presence of Bs in certain species influences the cell division, the degree of recombination, the development, a number of quantitative characteristics, the host-parasite interactions and their behaviour. There is at least some data on molecular structure of Bs recorded in nearly a quarter of species. Nevertheless, a more detailed molecular composition of Bs presently known for six mammalian species, confirms the presence of protein coding genes, and the transcriptional activity for some of them. Therefore, the idea that Bs are inert is outdated, but the role of Bs is yet to be determined. The maintenance of Bs is obviously not the same for all species, so the current models must be adapted while bearing in mind that Bs are not inactive as it was once thought.

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

10.1101/2020.08.07.242263 ◽

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.

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Functional Inflammatory Genotypes in Ischemic Stroke: Could We Use Them to Predict Age of Onset and Long-Term Outcome?

Stroke Research and Treatment ◽

10.4061/2011/792923 ◽

2011 ◽

Vol 2011 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Stella Marousi ◽

Anna Antonacopoulou ◽

Haralambos Kalofonos ◽

Panagiotis Papathanasopoulos ◽

Marina Karakantza ◽

...

Keyword(s):

Ischemic Stroke ◽

Cox Regression ◽

Age Of Onset ◽

Adverse Outcome ◽

Nucleotide Polymorphisms ◽

Term Outcome ◽

Single Nucleotide ◽

Long Term Outcome ◽

Tnf Α

Functional single-nucleotide polymorphisms (SNPs) of inflammatory cytokines have been previously related to the occurrence of an ischemic stroke (IS). We investigated whether five functional SNPs (i.e., TNF-α-308G>A, IL6-174G>C, IL12B 1188A>C, IL4-589C>T, and IL10-1082G>A) might be associated with the age of onset and 6-month outcome of an acute IS. A probe-free real-time PCR methodology was used to genotype 145 consecutively admitted cases with a first-ever IS. Simple Kaplan-Mayer and adjusted Cox regression analyses showed no association between inflammatory genotypes and the age of IS onset. IL6-174G>C, IL12B 1188A>C, IL4-589C>T, and IL10-1082G>A were not found to significantly contribute to the long-term outcome of the disease. However, carriage of the TNF-α-308 GG genotype was significantly associated with reduced odds for an adverse outcome. Larger studies are needed to confirm our results.

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

GigaScience ◽

10.1093/gigascience/giz115 ◽

2019 ◽

Vol 8 (10) ◽

Cited By ~ 3

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.

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LB1. Regional Assessment and Containment of Candida auris Transmission in Post-Acute Care Settings—Orange County, California, 2019

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz415.2484 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S993-S993 ◽

Cited By ~ 2

Author(s):

Ellora Karmarkar ◽

Kathleen O’Donnell ◽

Christopher Prestel ◽

Kaitlin Forsberg ◽

...

Keyword(s):

Acute Care ◽

Orange County ◽

Invasive Disease ◽

Nucleotide Polymorphisms ◽

Nursing Facilities ◽

Candida Auris ◽

Single Nucleotide ◽

Skilled Nursing ◽

And Control

Abstract Background Patients in long-term acute care hospitals (LTACHs) and skilled nursing facilities with ventilator units (VSNFs) are at high risk for Candida auris colonization; among patients colonized with this emerging pathogen, 5%–10% develop invasive disease with >45% mortality. In September 2018, a California LTACH-affiliated laboratory began enhanced C. auris surveillance by classifying species of Candida isolated from routine urine specimens. In February 2019, the first known Southern California case was detected in an Orange County (OC) LTACH; the patient had not traveled outside the region, indicating local acquisition. We performed point prevalence surveys (PPS) and infection prevention (IP) assessments at all OC LTACHs and VSNF subacute units to identify patients colonized with C. auris and control transmission. Methods During March–August 2019, we conducted PPS at facilities by collecting composite axilla and groin swabs for C. auris polymerase chain reaction testing and reflex culture from all patients who assented. Facilities with ≥1 C. auris-colonized patient repeated a PPS every 2 weeks to assess for new transmission. Isolate relatedness was assessed by whole-genome sequencing (WGS). We evaluated hand hygiene (HH) adherence, access to alcohol-based hand rubs (ABHR), and cleaning of high-touch surfaces to guide IP recommendations. Results The first PPS at all OC LTACHs (n = 3) and adult VSNFs (n = 14) identified 45 C. auris-colonized patients in 3 (100%) LTACHs and 6 (43%) VSNFs; after repeated PPS, the total count reached 124. Most patients (70%) were at 2 facilities (Table 1). Three of 124 patients developed candidemia. To date, isolates from 48 patients have completed WGS; all were highly related (<11 single-nucleotide polymorphisms) in the African clade. Of 9 facilities with C. auris, 5 had HH adherence < 50%, 3 had limited ABHR, and at 2, <60% of assessed high-touch surfaces were clean. We recommended regular HH and cleaning audits, and increased ABHR. Conclusion Our investigation, prompted by enhanced surveillance, identified C. auris at 9 OC facilities. WGS indicated a single introduction and local transmission. Early detection, followed by rapid county-wide investigation and IP support, enabled containment efforts for C. auris in OC. Disclosures All authors: No reported disclosures.

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

Journal of Bacteriology ◽

10.1128/jb.00124-06 ◽

2006 ◽

Vol 188 (12) ◽

pp. 4453-4463 ◽

Cited By ~ 114

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.

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

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1706168114 ◽

2017 ◽

Vol 114 (34) ◽

pp. 9158-9163 ◽

Cited By ~ 14

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.

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

Molecular Biology International ◽

10.1155/2014/967565 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 17

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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Interaction between M. tuberculosis Lineage and Human Genetic Variants Reveals Novel Pathway Associations with Severity of TB

Pathogens ◽

10.3390/pathogens10111487 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1487

Author(s):

Michael L. McHenry ◽

Eddie M. Wampande ◽

Moses L. Joloba ◽

LaShaunda L. Malone ◽

Harriet Mayanja-Kizza ◽

...

Keyword(s):

Genetic Variation ◽

Clinical Presentation ◽

Sub Saharan Africa ◽

Nucleotide Polymorphisms ◽

Single Nucleotide ◽

Human Genomes ◽

Genome Wide ◽

Sub Saharan ◽

Cellular Replication

Tuberculosis (TB) remains a major public health threat globally, especially in sub-Saharan Africa. Both human and Mycobacterium tuberculosis (MTBC) genetic variation affect TB outcomes, but few studies have examined if and how the two genomes interact to affect disease. We hypothesize that long-term coexistence between human genomes and MTBC lineages modulates disease to affect its severity. We examined this hypothesis in our TB household contact study in Kampala, Uganda, in which we identified three MTBC lineages, of which one, L4.6-Uganda, is clearly derived and hence recent. We quantified TB severity using the Bandim TBscore and examined the interaction between MTBC lineage and human single-nucleotide polymorphisms (SNPs) genome-wide, in two independent cohorts of TB cases (n = 149 and n = 127). We found a significant interaction between an SNP in PPIAP2 and the Uganda lineage (combined p = 4 × 10−8). PPIAP2 is a pseudogene that is highly expressed in immune cells. Pathway and eQTL analyses indicated potential roles between coevolving SNPs and cellular replication and metabolism as well as platelet aggregation and coagulation. This finding provides further evidence that host–pathogen interactions affect clinical presentation differently than host and pathogen genetic variation independently, and that human–MTBC coevolution is likely to explain patterns of disease severity.

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