Leishmania naiffi
            and
            Leishmania guyanensis
            reference genomes highlight genome structure and gene evolution in the
            Viannia
            subgenus

The unicellular protozoan parasite Leishmania causes the neglected tropical disease leishmaniasis, affecting 12 million people in 98 countries. In South America, where the Viannia subgenus predominates, so far only L. ( Viannia ) braziliensis and L. ( V. ) panamensis have been sequenced, assembled and annotated as reference genomes. Addressing this deficit in molecular information can inform species typing, epidemiological monitoring and clinical treatment. Here, L. ( V. ) naiffi and L. ( V. ) guyanensis genomic DNA was sequenced to assemble these two genomes as draft references from short sequence reads. The methods used were tested using short sequence reads for L. braziliensis M2904 against its published reference as a comparison. This assembly and annotation pipeline identified 70 additional genes not annotated on the original M2904 reference. Phylogenetic and evolutionary comparisons of L. guyanensis and L. naiffi with 10 other Viannia genomes revealed four traits common to all Viannia : aneuploidy, 22 orthologous groups of genes absent in other Leishmania subgenera, elevated TATE transposon copies and a high NADH-dependent fumarate reductase gene copy number. Within the Viannia , there were limited structural changes in genome architecture specific to individual species: a 45 Kb amplification on chromosome 34 was present in all bar L. lainsoni , L. naiffi had a higher copy number of the virulence factor leishmanolysin, and laboratory isolate L. shawi M8408 had a possible minichromosome derived from the 3’ end of chromosome 34 . This combination of genome assembly, phylogenetics and comparative analysis across an extended panel of diverse Viannia has uncovered new insights into the origin and evolution of this subgenus and can help improve diagnostics for leishmaniasis surveillance.

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Leishmania naiffi and Leishmania guyanensis reference genomes highlight genome structure and gene evolution in the Viannia subgenus

10.1101/233148 ◽

2017 ◽

Author(s):

Simone Coughlan ◽

Ali Shirley Taylor ◽

Eoghan Feane ◽

Mandy Sanders ◽

Gabriele Schonian ◽

...

Keyword(s):

Copy Number ◽

Structural Changes ◽

Gene Evolution ◽

Genome Structure ◽

Gene Copy Number ◽

Gene Copy ◽

Individual Species ◽

Short Sequence ◽

Origin And Evolution ◽

Reference Genomes

AbstractThe unicellular protozoan parasite Leishmania causes the neglected tropical disease leishmaniasis, affecting 12 million people in 98 countries. In South America where the Viannia subgenus predominates, so far only L. (Viannia) braziliensis and L. (V.) panamensis have been sequenced, assembled and annotated as reference genomes. Addressing this deficit in molecular information can inform species typing, epidemiological monitoring and clinical treatment. Here, L. (V.) naiffi and L. (V.) guyanensis genomic DNA was sequenced to assemble these two genomes as draft references from short sequence reads. The methods used were tested using short sequence reads for L. braziliensis M2904 against its published reference as a comparison. This assembly and annotation pipeline identified 70 additional genes not annotated on the original M2904 reference. Phylogenetic and evolutionary comparisons of L. guyanensis and L. naiffi with ten other Viannia genomes revealed four traits common to all Viannia: aneuploidy, 22 orthologous groups of genes absent in other Leishmania subgenera, elevated TATE transposon copies, and a high NADH-dependent fumarate reductase gene copy number. Within the Viannia, there were limited structural changes in genome architecture specific to individual species: a 45 Kb amplification on chromosome 34 was present in all bar L. lainsoni, L. naiffi had a higher copy number of the virulence factor leishmanolysin, and laboratory isolate L. shawi M8408 had a possible minichromosome derived from the 3’ end of chromosome 34. This combination of genome assembly, phylogenetics and comparative analysis across an extended panel of diverse Viannia has uncovered new insights into the origin and evolution of this subgenus and can help improve diagnostics for leishmaniasis surveillance.

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Collateral Toxicity Limits the Evolution of Bacterial Release Factor 2 toward Total Omnipotence

Molecular Biology and Evolution ◽

10.1093/molbev/msaa129 ◽

2020 ◽

Vol 37 (10) ◽

pp. 2918-2930

Author(s):

Hind Abdalaal ◽

Shreya Pundir ◽

Xueliang Ge ◽

Suparna Sanyal ◽

Joakim Näsvall

Keyword(s):

Copy Number ◽

Gene Evolution ◽

Gene Copy Number ◽

In Vitro Translation ◽

Gene Copy ◽

Release Factor ◽

Bacterial Growth Rate ◽

New Genes ◽

Peptide Release

Abstract When new genes evolve through modification of existing genes, there are often tradeoffs between the new and original functions, making gene duplication and amplification necessary to buffer deleterious effects on the original function. We have used experimental evolution of a bacterial strain lacking peptide release factor 1 (RF1) in order to study how peptide release factor 2 (RF2) evolves to compensate the loss of RF1. As expected, amplification of the RF2-encoding gene prfB to high copy number was a rapid initial response, followed by the appearance of mutations in RF2 and other components of the translation machinery. Characterization of the evolved RF2 variants by their effects on bacterial growth rate, reporter gene expression, and in vitro translation termination reveals a complex picture of reduced discrimination between the cognate and near-cognate stop codons and highlights a functional tradeoff that we term “collateral toxicity.” We suggest that this type of tradeoff may be a more serious obstacle in new gene evolution than the more commonly discussed evolutionary tradeoffs between “old” and “new” functions of a gene, as it cannot be overcome by gene copy number changes. Further, we suggest a model for how RF2 autoregulation responds to alterations in the demand not only for RF2 activity but also for RF1 activity.

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Assessment of HER-2/neu, с-MYC and CCNE1 gene copy number variations and protein expression in endometrial carcinomas

Experimental Oncology ◽

10.32471/exp-oncology.2312-8852.vol-41-no-2.12973 ◽

2019 ◽

Vol 41 (2) ◽

Author(s):

L.G. Buchynska ◽

◽

O.V. Brieieva* ◽

N.P. Iurchenko ◽

◽

...

Keyword(s):

Protein Expression ◽

Copy Number ◽

Gene Copy Number ◽

Copy Number Variations ◽

Gene Copy ◽

Her 2 ◽

Endometrial Carcinomas

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Faculty Opinions recommendation of Diet and the evolution of human amylase gene copy number variation.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1092307.546722 ◽

2007 ◽

Author(s):

Magnus Ingelman-Sundberg

Keyword(s):

Copy Number Variation ◽

Copy Number ◽

Gene Copy Number ◽

Gene Copy ◽

Amylase Gene ◽

Gene Copy Number Variation ◽

Number Variation

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Faculty Opinions recommendation of RNA polymerase I activators count and adjust ribosomal RNA gene copy number.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.734776122.793556076 ◽

2019 ◽

Author(s):

Angela Taddei

Keyword(s):

Rna Polymerase ◽

Ribosomal Rna ◽

Copy Number ◽

Gene Copy Number ◽

Rna Polymerase I ◽

Gene Copy ◽

Ribosomal Rna Gene ◽

Polymerase I

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Estimating Copy-Number Proportions: The Comeback of Sanger Sequencing

Genes ◽

10.3390/genes12020283 ◽

2021 ◽

Vol 12 (2) ◽

pp. 283

Author(s):

Eyal Seroussi

Keyword(s):

Copy Number ◽

Sanger Sequencing ◽

Cytosine Methylation ◽

Direct Sequencing ◽

Information Source ◽

Gene Copy Number ◽

Cost Effective ◽

Gene Copy ◽

Base Editing ◽

Recent Developments

Determination of the relative copy numbers of mixed molecular species in nucleic acid samples is often the objective of biological experiments, including Single-Nucleotide Polymorphism (SNP), indel and gene copy-number characterization, and quantification of CRISPR-Cas9 base editing, cytosine methylation, and RNA editing. Standard dye-terminator chromatograms are a widely accessible, cost-effective information source from which copy-number proportions can be inferred. However, the rate of incorporation of dye terminators is dependent on the dye type, the adjacent sequence string, and the secondary structure of the sequenced strand. These variable rates complicate inferences and have driven scientists to resort to complex and costly quantification methods. Because these complex methods introduce their own biases, researchers are rethinking whether rectifying distortions in sequencing trace files and using direct sequencing for quantification will enable comparable accurate assessment. Indeed, recent developments in software tools (e.g., TIDE, ICE, EditR, BEEP and BEAT) indicate that quantification based on direct Sanger sequencing is gaining in scientific acceptance. This commentary reviews the common obstacles in quantification and the latest insights and developments relevant to estimating copy-number proportions based on direct Sanger sequencing, concluding that bidirectional sequencing and sophisticated base calling are the keys to identifying and avoiding sequence distortions.

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Nongenotoxic ABCB1 activator tetraphenylphosphonium can contribute to doxorubicin resistance in MX-1 breast cancer cell line

Scientific Reports ◽

10.1038/s41598-021-86120-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Raimonda Kubiliute ◽

Indre Januskeviciene ◽

Ruta Urbanaviciute ◽

Kristina Daniunaite ◽

Monika Drobniene ◽

...

Keyword(s):

Breast Cancer ◽

Cell Line ◽

Protein Level ◽

Copy Number ◽

Gene Copy Number ◽

Gene Copy ◽

Common Mechanism ◽

Dna Hypomethylation ◽

Mesenchymal Transition ◽

Molecular Features

AbstractHyperactivation of ABC transporter ABCB1 and induction of epithelial–mesenchymal transition (EMT) are the most common mechanism of acquired cancer chemoresistance. This study describes possible mechanisms, that might contribute to upregulation of ABCB1 and synergistically boost the acquisition of doxorubicin (DOX) resistance in breast cancer MX-1 cell line. DOX resistance in MX-1 cell line was induced by a stepwise increase of drug concentration or by pretreatment of cells with an ABCB1 transporter activator tetraphenylphosphonium (TPP+) followed by DOX exposure. Transcriptome analysis of derived cells was performed by human gene expression microarrays and by quantitative PCR. Genetic and epigenetic mechanisms of ABCB1 regulation were evaluated by pyrosequencing and gene copy number variation analysis. Gradual activation of canonical EMT transcription factors with later activation of ABCB1 at the transcript level was observed in DOX-only treated cells, while TPP+ exposure induced considerable activation of ABCB1 at both, mRNA and protein level. The changes in ABCB1 mRNA and protein level were related to the promoter DNA hypomethylation and the increase in gene copy number. ABCB1-active cells were highly resistant to DOX and showed morphological and molecular features of EMT. The study suggests that nongenotoxic ABCB1 inducer can possibly accelerate development of DOX resistance.

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