scholarly journals Reappraising the human mitochondrial DNA recombination dogma

2018 ◽  
Author(s):  
Simόn Perera ◽  
Amanda Ramos ◽  
Luis Alvarez ◽  
Débora Jurado ◽  
Maria Guardiola ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Single Molecule ◽  
Dna Recombination ◽  
Recent Common Ancestor ◽  
Human Variation ◽  
Substantial Impact ◽  
Human Mitochondrial Dna ◽  
Mtdna Recombination ◽  
Most Recent Common Ancestor ◽  
Frequent Event

AbstractWith the “mitochondrial Eve” theory proposed by Rebecca Cann in the eighties, human mitochondrial DNA (mtDNA) has been used as a tool in studying human variation and evolution. Although the existence of recombination in human mtDNA has been previously advocated, studies dealing with human variation and evolution have assumed that human mtDNA does not recombine and should be considered as pathological or very infrequent. Using both direct and indirect approaches, we provide consistent evidence of mtDNA recombination in humans. We applied the single molecule PCR procedure to directly test for recombination in multiheteroplasmic individuals without any overt pathology. Moreover, we searched for past recombination events in the whole mitochondrial genomes of more than 15,000 individuals. Results from our study update and expand both the seminal indirect findings and the scarce direct evidence observed to date, paving the way for the definitive rejection of the non-recombination dogma for human mtDNA. Acknowledgment of recombination as a frequent event in mtDNA will require the description of the population recombination rate(s) and to apply it to past and future studies involving mtDNA. MtDNA recombination affects our knowledge of human evolutionary history, regarding haplogroup divergence times, as well as the time to the mitochondrial most recent common ancestor. Finally, mtDNA recombination will have a substantial impact on our understanding of the etiology and transmission of mitochondrial diseases.

scholarly journals Do Eve's Alleles Live On?

1992 ◽  
Vol 60 (3) ◽  
pp. 221-234 ◽  
Author(s):  
G. A. Watterson ◽  
P. Donnelly
Keyword(s):  
Mitochondrial Dna ◽  
Common Ancestor ◽  
Recent Common Ancestor ◽  
Rate Parameter ◽  
Human Mitochondrial Dna ◽  
Discrete Probability ◽  
Large Samples ◽  
Most Recent Common Ancestor ◽  
Number Of Genes ◽  
Allelic Type

SummaryConsider a random sample of genes at a locus, drawn from a population evolving according to the infinitely many, neutral, alleles model. The sample will have a most recent common ancestor gene, which we shall call ‘Eve’. The probability distribution, for the number of genes of oldest allelic type in a sample, is known and has a neat form. Rather less is known about the distribution for the number of genes in the sample which are of the same allelic type as Eve possessed. If the latter number is positive, then these genes are automatically of the oldest type in the sample. But Eve may have no non-mutant descendants in the sample; then, the oldest allele will be a mutant arising in a line of descent after Eve. The paper studies the number of non-mutant descendants from Eve, its distribution and moments. It seems that there may be few neat results. In large samples, the proportion of genes of Eve's type has an approximate β-like density, together with a discrete probability atom at zero, if the mutation rate parameter is low. Extinction of the allele of even the population's common ancestor is possible, but not certain, and bounds are obtained for its probability. Some comments are made about the applications and implications of the results for human mitochondrial DNA.

scholarly journals Evolution of NLR resistance genes with non-canonical N-terminal domains in wild tomato species

2019 ◽  
Author(s):  
Kyungyong Seong ◽  
Eunyoung Seo ◽  
Meng Li ◽  
Brian Staskawicz
Keyword(s):  
Single Molecule ◽  
Evolutionary Dynamics ◽  
Plant Immunity ◽  
Gene Families ◽  
Recent Common Ancestor ◽  
Wild Tomato Species ◽  
Most Recent Common Ancestor ◽  
Tomato Species ◽  
Large Gene ◽  
And Function

AbstractBackgroundNucleotide-binding and leucine-rich repeat immune receptors (NLRs) are an important component of plant immunity that provides resistance against diverse pathogens. NLRs often exist as large gene families, the members of which display diverse multi-domain architectures (MDAs) and evolve through various mechanisms of duplications and selections.ResultsWe conducted resistance gene enrichment sequencing (RenSeq) with single-molecule real time (SMRT) sequencing of PacBio for 18 accessions in Solanaceae including 15 wild tomatoes. We demonstrate what was previously known as Solanaceae Domain (SD) not only is more diverse in structure and function but also far anciently originated from the most recent common ancestor (MRCA) between Asterids and Amaranthaceae. In tomato, NLRs with the extended N-terminus displayed distinct patterns of evolution based on phylogenetic clades by proliferation, continuous elongation and domain losses.ConclusionsOur study provides high quality gene models of NLRs that can serve as resources for future studies for crop engineering and elucidates greater evolutionary dynamics of the extended NLRs than previously assumed.

scholarly journals The most recent common ancestor for Y chromosome lived about 3.67 million years ago

2021 ◽  
Author(s):  
Tingting Sun ◽  
Qing Liu ◽  
Meiqi Shang ◽  
Kejian Wang
Keyword(s):  
Mitochondrial Dna ◽  
Y Chromosome ◽  
Homo Sapiens ◽  
Homo Erectus ◽  
Recent Common Ancestor ◽  
Human Beings ◽  
Migration Routes ◽  
Modern Humans ◽  
Most Recent Common Ancestor ◽  
Expansion Time

The origin of human beings is one of the most important questions in science. A combination of numerous archaeological and genomic analyses has led to the widely accepted opinion that modern humans are the descendants of anatomically modern Homo sapiens that originated in Africa about 200 thousand years ago (KYA). In this study, we reanalysed the mitochondrial DNA and Y chromosome DNA of the 1000 Genomes Project, and found many minority-specific single-nucleotide polymorphisms. Using these polymorphisms, we recalculated the time taken for the evolution of modern humans. Analysis of mitochondrial DNA suggested that the most recent common female ancestor lived about 400 KYA and began to leave Africa about 180 KYA. In contrast, analysis of Y chromosome DNA revealed that the most recent common male ancestor lived about 3.67 million years ago (MYA) and began to migrate out of Africa about 2.05 MYA, a time which is consistent with the expansion time of Homo erectus identified by archaeological research. Based on the findings, we proposed a new migration routes and times of modern human, and speculated that anatomically modern Homo sapiens has been extensively interbred with local archaic human population during their dispersal across the globe.

scholarly journals Mitochondrial DNA duplication, recombination, and introgression during interspecific hybridization

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Silvia Bágeľová Poláková ◽  
Žaneta Lichtner ◽  
Tomáš Szemes ◽  
Martina Smolejová ◽  
Pavol Sulo
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Interspecific Hybridization ◽  
Mobile Elements ◽  
Variable Length ◽  
Mitochondrial Genomes ◽  
Free Standing ◽  
Saccharomyces Paradoxus ◽  
Mtdna Recombination

AbstractmtDNA recombination events in yeasts are known, but altered mitochondrial genomes were not completed. Therefore, we analyzed recombined mtDNAs in six Saccharomyces cerevisiae × Saccharomyces paradoxus hybrids in detail. Assembled molecules contain mostly segments with variable length introgressed to other mtDNA. All recombination sites are in the vicinity of the mobile elements, introns in cox1, cob genes and free standing ORF1, ORF4. The transplaced regions involve co-converted proximal exon regions. Thus, these selfish elements are beneficial to the host if the mother molecule is challenged with another molecule for transmission to the progeny. They trigger mtDNA recombination ensuring the transfer of adjacent regions, into the progeny of recombinant molecules. The recombination of the large segments may result in mitotically stable duplication of several genes.

scholarly journals Allelic Genealogies in Sporophytic Self-Incompatibility Systems in Plants

Genetics ◽  
1998 ◽  
Vol 150 (3) ◽  
pp. 1187-1198 ◽  
Author(s):  
Mikkel H Schierup ◽  
Xavier Vekemans ◽  
Freddy B Christiansen
Keyword(s):  
Dominance Hierarchy ◽  
Common Ancestor ◽  
Recent Common Ancestor ◽  
Self Incompatibility ◽  
Most Recent Common Ancestor ◽  
Dominance Interactions ◽  
Turnover Process ◽  
Neutral Gene ◽  
Interspecific Comparisons ◽  
Coalescence Times

Abstract Expectations for the time scale and structure of allelic genealogies in finite populations are formed under three models of sporophytic self-incompatibility. The models differ in the dominance interactions among the alleles that determine the self-incompatibility phenotype: In the SSIcod model, alleles act codominantly in both pollen and style, in the SSIdom model, alleles form a dominance hierarchy, and in SSIdomcod, alleles are codominant in the style and show a dominance hierarchy in the pollen. Coalescence times of alleles rarely differ more than threefold from those under gametophytic self-incompatibility, and transspecific polymorphism is therefore expected to be equally common. The previously reported directional turnover process of alleles in the SSIdomcod model results in coalescence times lower and substitution rates higher than those in the other models. The SSIdom model assumes strong asymmetries in allelic action, and the most recessive extant allele is likely to be the most recent common ancestor. Despite these asymmetries, the expected shape of the allele genealogies does not deviate markedly from the shape of a neutral gene genealogy. The application of the results to sequence surveys of alleles, including interspecific comparisons, is discussed.

scholarly journals Molecular epidemiological characteristics of echovirus 6 in mainland China: extensive circulation of genotype F from 2007 to 2018

2021 ◽  
Author(s):  
Wenjun Cheng ◽  
Tianjiao Ji ◽  
Shuaifeng Zhou ◽  
Yong Shi ◽  
Lili Jiang ◽  
...  
Keyword(s):  
Common Ancestor ◽  
Mainland China ◽  
Recent Common Ancestor ◽  
Genetic Characteristics ◽  
Most Recent Common Ancestor ◽  
Significant Difference ◽  
Echovirus 6 ◽  
Epidemiological Characteristics ◽  
Highest Posterior Density ◽  
Genotype F

AbstractEchovirus 6 (E6) is associated with various clinical diseases and is frequently detected in environmental sewage. Despite its high prevalence in humans and the environment, little is known about its molecular phylogeography in mainland China. In this study, 114 of 21,539 (0.53%) clinical specimens from hand, foot, and mouth disease (HFMD) cases collected between 2007 and 2018 were positive for E6. The complete VP1 sequences of 87 representative E6 strains, including 24 strains from this study, were used to investigate the evolutionary genetic characteristics and geographical spread of E6 strains. Phylogenetic analysis based on VP1 nucleotide sequence divergence showed that, globally, E6 strains can be grouped into six genotypes, designated A to F. Chinese E6 strains collected between 1988 and 2018 were found to belong to genotypes C, E, and F, with genotype F being predominant from 2007 to 2018. There was no significant difference in the geographical distribution of each genotype. The evolutionary rate of E6 was estimated to be 3.631 × 10-3 substitutions site-1 year-1 (95% highest posterior density [HPD]: 3.2406 × 10-3-4.031 × 10-3 substitutions site-1 year-1) by Bayesian MCMC analysis. The most recent common ancestor of the E6 genotypes was traced back to 1863, whereas their common ancestor in China was traced back to around 1962. A small genetic shift was detected in the Chinese E6 population size in 2009 according to Bayesian skyline analysis, which indicated that there might have been an epidemic around that year.

scholarly journals Molecular epidemiology of coxsackievirus A16 circulating in children in Beijing, China from 2010 to 2019

2021 ◽  
Author(s):  
Ya-Fang Hu ◽  
Li-Ping Jia ◽  
Fang-Yuan Yu ◽  
Li-Ying Liu ◽  
Qin-Wei Song ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Evolutionary Rate ◽  
Foot And Mouth Disease ◽  
Recent Common Ancestor ◽  
Rt Pcr ◽  
Coxsackievirus A16 ◽  
Most Recent Common Ancestor ◽  
Etiological Agents ◽  
High Level ◽  
And Control

Abstract Background Coxsackievirus A16 (CVA16) is one of the major etiological agents of hand, foot and mouth disease (HFMD). This study aimed to investigate the molecular epidemiology and evolutionary characteristics of CVA16. Methods Throat swabs were collected from children with HFMD and suspected HFMD during 2010–2019. Enteroviruses (EVs) were detected and typed by real-time reverse transcription-polymerase chain reaction (RT-PCR) and RT-PCR. The genotype, evolutionary rate, the most recent common ancestor, population dynamics and selection pressure of CVA16 were analyzed based on viral protein gene (VP1) by bioinformatics software. Results A total of 4709 throat swabs were screened. EVs were detected in 3180 samples and 814 were CVA16 positive. More than 81% of CVA16-positive children were under 5 years old. The prevalence of CVA16 showed obvious periodic fluctuations with a high level during 2010–2012 followed by an apparent decline during 2013–2017. However, the activities of CVA16 increased gradually during 2018–2019. All the Beijing CVA16 strains belonged to sub-genotype B1, and B1b was the dominant strain. One B1c strain was detected in Beijing for the first time in 2016. The estimated mean evolutionary rate of VP1 gene was 4.49 × 10–3 substitution/site/year. Methionine gradually fixed at site-23 of VP1 since 2012. Two sites were detected under episodic positive selection, one of which (site-223) located in neutralizing linear epitope PEP71. Conclusions The dominant strains of CVA16 belonged to clade B1b and evolved in a fast evolutionary rate during 2010–2019 in Beijing. To provide more favorable data for HFMD prevention and control, it is necessary to keep attention on molecular epidemiological and evolutionary characteristics of CVA16.

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