scholarly journals A New and More Accurate Estimate of the Rate of Concurrent Tandem-Base Substitution Mutations in the Human Germline: ∼0.4% of the Single-Nucleotide Substitution Mutation Rate

2014 ◽  
Vol 35 (3) ◽  
pp. 392-394 ◽  
Author(s):  
Jian-Min Chen ◽  
David N. Cooper ◽  
Claude Férec
Keyword(s):  
Mutation Rate ◽  
Nucleotide Substitution ◽  
Accurate Estimate ◽  
Base Substitution ◽  
Single Nucleotide Substitution ◽  
Single Nucleotide ◽  
Substitution Mutations ◽  
Substitution Mutation

scholarly journals Low base-substitution mutation rate in the germline genome of the ciliate Tetrahymena thermophila

2015 ◽  
Author(s):  
Hongan Long ◽  
David J. Winter ◽  
Allan Y.-C Chang ◽  
Way Sung ◽  
Steven H. Wu ◽  
...  
Keyword(s):  
Mutation Rate ◽  
Tetrahymena Thermophila ◽  
Mutation Rates ◽  
Base Substitution ◽  
Paramecium Tetraurelia ◽  
Epigenetic Factors ◽  
Detection Approach ◽  
Evolution Experiment ◽  
Substitution Mutations ◽  
Substitution Mutation

AbstractMutation is the ultimate source of all genetic variation and is, therefore, central to evolutionary change. Previous work on Paramecium tetraurelia found an unusually low germline base-substitution mutation rate in this ciliate. Here, we tested the generality of this result among ciliates using Tetrahymena thermophila. We sequenced the genomes of 10 lines of T. thermophila that had each undergone approximately 1,000 generations of mutation accumulation (MA). We applied an existing mutation-calling pipeline and developed a new probabilistic mutation detection approach that directly models the design of an MA experiment and accommodates the noise introduced by mismapped reads. Our probabilistic mutation-calling method provides a straightforward way of estimating the number of sites at which a mutation could have been called if one was present, providing the denominator for our mutation rate calculations. From these methods, we find that T. thermophila has a germline base-substitution mutation rate of 7.61 × 10−12 per site, per cell division, which is consistent with the low base-substitution mutation rate in P. tetraurelia. Over the course of the evolution experiment, genomic exclusion lines derived from the MA lines experienced a fitness decline that cannot be accounted for by germline base-substitution mutations alone, suggesting that other genetic or epigenetic factors must be involved. Because selection can only operate to reduce mutation rates based upon the “visible” mutational load, asexual reproduction with a transcriptionally silent germline may allow ciliates to evolve extremely low germline mutation rates.

scholarly journals Single nucleotide substitution mutations and polymorphisms in ECM1 gene in lipoid proteinosis in siblings of a Pakistani family

2011 ◽  
Vol 10 (53) ◽  
pp. 10825-10830 ◽  
Author(s):  
M Shahid Syed ◽  
Azhar Abid ◽  
N Nawab Syeda ◽  
Shaikh Rozeena ◽  
Ismail Muhammad ◽  
...  
Keyword(s):  
Nucleotide Substitution ◽  
Pakistani Family ◽  
Single Nucleotide Substitution ◽  
Single Nucleotide ◽  
Lipoid Proteinosis ◽  
Substitution Mutations

scholarly journals A single nucleotide substitution in the coding region of Ogura male sterile gene, orf138, determines effectiveness of a fertility restorer gene, Rfo, in radish

2021 ◽  
Author(s):  
Hiroshi Yamagishi ◽  
Megumi Jikuya ◽  
Kanako Okushiro ◽  
Ayako Hashimoto ◽  
Asumi Fukunaga ◽  
...  
Keyword(s):  
Male Sterility ◽  
Nucleotide Substitution ◽  
Fertility Restoration ◽  
Type A ◽  
Restorer Gene ◽  
Single Nucleotide Substitution ◽  
Coding Region ◽  
Fertility Restorer ◽  
Single Nucleotide ◽  
Fertility Restorer Gene

AbstractCytoplasmic male sterility (CMS) observed in many plants leads defect in the production of functional pollen, while the expression of CMS is suppressed by a fertility restorer gene in the nuclear genome. Ogura CMS of radish is induced by a mitochondrial orf138, and a fertility restorer gene, Rfo, encodes a P-type PPR protein, ORF687, acting at the translational level. But, the exact function of ORF687 is still unclear. We found a Japanese variety showing male sterility even in the presence of Rfo. We examined the pollen fertility, Rfo expression, and orf138 mRNA in progenies of this variety. The progeny with Type H orf138 and Rfo showed male sterility when their orf138 mRNA was unprocessed within the coding region. By contrast, all progeny with Type A orf138 were fertile though orf138 mRNA remained unprocessed in the coding region, demonstrating that ORF687 functions on Type A but not on Type H. In silico analysis suggested a specific binding site of ORF687 in the coding region, not the 5′ untranslated region estimated previously, of Type A. A single nucleotide substitution in the putative binding site diminishes affinity of ORF687 in Type H and is most likely the cause of the ineffectiveness of ORF687. Furthermore, fertility restoration by RNA processing at a novel site in some progeny plants indicated a new and the third fertility restorer gene, Rfs, for orf138. This study clarified that direct ORF687 binding to the coding region of orf138 is essential for fertility restoration by Rfo.

A novel single‐nucleotide substitution in the proximal ABO promoter gives rise to the B 3 phenotype

Transfusion ◽  
2019 ◽  
Vol 59 (10) ◽  
Author(s):  
åsa Hellberg ◽  
Annika K. Hult ◽  
Ines Moser ◽  
Beatriz Tomaz ◽  
Maria Rodrigues ◽  
...  
Keyword(s):  
Nucleotide Substitution ◽  
Single Nucleotide Substitution ◽  
Single Nucleotide

scholarly journals Expanded insecticide catabolic activity gained by a single nucleotide substitution in a bacterial carbamate hydrolase gene

2016 ◽  
Vol 18 (12) ◽  
pp. 4878-4887 ◽  
Author(s):  
Başak Öztürk ◽  
Maarten Ghequire ◽  
Thi Phi Oanh Nguyen ◽  
René De Mot ◽  
Ruddy Wattiez ◽  
...  
Keyword(s):  
Nucleotide Substitution ◽  
Single Nucleotide Substitution ◽  
Single Nucleotide ◽  
Catabolic Activity

scholarly journals Codon Substitution Mutations at Two Positions in the L Polymerase Protein of Human Parainfluenza Virus Type 1 Yield Viruses with a Spectrum of Attenuation In Vivo and Increased Phenotypic Stability In Vitro

2004 ◽  
Vol 78 (4) ◽  
pp. 2029-2036 ◽  
Author(s):  
Josephine M. McAuliffe ◽  
Sonja R. Surman ◽  
Jason T. Newman ◽  
Jeffrey M. Riggs ◽  
Peter L. Collins ◽  
...  
Keyword(s):  
Amino Acid ◽  
Nucleotide Substitution ◽  
Wild Type ◽  
Phenotypic Stability ◽  
Single Nucleotide ◽  
Codon Substitution ◽  
Substitution Mutations ◽  
Human Parainfluenza Virus

ABSTRACT The Y942H and L992F temperature-sensitive (ts) and attenuating amino acid substitution mutations, previously identified in the L polymerase of the HPIV3cp45 vaccine candidate, were introduced into homologous positions of the L polymerase of recombinant human parainfluenza virus type 1 (rHPIV1). In rHPIV1, the Y942H mutation specified the ts phenotype in vitro and the attenuation (att) phenotype in hamsters, whereas the L992F mutation specified neither phenotype. Each of these codon mutations was generated by a single nucleotide substitution and therefore had the potential to readily revert to a codon specifying the wild-type amino acid residue. We introduced alternative amino acid assignments at codon 942 or 992 as a strategy to increase genetic stability and to generate mutants that exhibit a range of attenuation. Twenty-three recombinants with codon substitutions at position 942 or 992 of the L protein were viable. One highly ts and att mutant, the Y942A virus, which had a difference of three nucleotides from the codon encoding a wild-type tyrosine, also possessed a high level of genetic and phenotypic stability upon serial passage in vitro at restrictive temperatures compared to that of the parent Y942H virus, which possessed a single nucleotide substitution. We obtained mutants with substitutions at position 992 that, in contrast to the L992F virus, possessed the ts and att phenotypes. These findings identify the use of alternative codon substitution mutations as a method that can be used to generate candidate vaccine viruses with increased genetic stability and/or a modified level of attenuation.

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