scholarly journals Evolution of the Heme Peroxidases of Culicidae (Diptera)

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Austin L. Hughes

Phylogenetic analysis of heme peroxidases (HPXs) of Culicidae and other insects revealed six highly conserved ancient HPX lineages, each of which originated by gene duplication prior to the most recent common ancestor (MRCA) of Hemimetabola and Holmetabola. In addition, culicid HPX7 and HPX12 arose by gene duplication after the MRCA of Culicidae and Drosophilidae, while HPX2 orthologs were not found in any other order analyzed except Diptera. Within Diptera, HPX2, HPX7, and HPX12 were relatively poorly conserved at the amino acid level in comparison to the six ancient lineages. The genome ofAnopheles gambiaeincluded genes ecoding five proteins (HPX10, HPX11, HPX13, HXP14, and HPX15) without ortholgs in other genomes analyzed. Overall, gene expression patterns did not seem to reflect phylogenetic relationships, but genes that evolved rapidly at the amino acid sequence level tended to have divergent expression patterns as well. The uniquely high level of duplication of HPXs inA. gambiaemay have played a role in coevolution with malaria parasites.

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1525
Author(s):  
Safia Zeghbib ◽  
Balázs A. Somogyi ◽  
Brigitta Zana ◽  
Gábor Kemenesi ◽  
Róbert Herczeg ◽  
...  

To explore the SARS-CoV-2 pandemic in Algeria, a dataset comprising ninety-five genomes originating from SARS-CoV-2 sampled from Algeria and other countries worldwide, from 24 December 2019, through 4 March 2021, was thoroughly examined. While performing a multi-component analysis regarding the Algerian outbreak, the toolkit of phylogenetic, phylogeographic, haplotype, and genomic analysis were effectively implemented. We estimated the Time to the Most Recent Common Ancestor (TMRCA) in reference to the Algerian pandemic and highlighted the multiple introductions of the disease and the missing data depicted in the transmission loop. In addition, we emphasized the significant role played by local and international travels in disease dissemination. Most importantly, we unveiled mutational patterns, the effect of unique mutations on corresponding proteins, and the relatedness regarding the Algerian sequences to other sequences worldwide. Our results revealed individual amino-acid replacements such as the deleterious replacement A23T in the orf3a gene in Algeria_EPI_ISL_418241. Additionally, a connection between Algeria_EPI_ISL_420037 and sequences originating from the USA was observed through a USA characteristic amino-acid replacement T1004I in the nsp3 gene, found in the aforementioned Algerian sequence. Similarly, successful tracing could be established, such as Algeria/G37318-8849/2020|EPI_ISL_766863, which was imported from Saudi Arabia during the pilgrimage. Lastly, we assessed the Algerian mitigation measures regarding disease containment using statistical analyses.


Author(s):  
Chenglong Xiong ◽  
Lufang Jiang ◽  
Yue Chen ◽  
Qingwu Jiang

AbstractBackgroundThe current outbreak caused by novel coronavirus (2019-nCoV) in China has become a worldwide concern. As of 28 January 2020, there were 4631 confirmed cases and 106 deaths, and 11 countries or regions were affected.MethodsWe downloaded the genomes of 2019-nCoVs and similar isolates from the Global Initiative on Sharing Avian Influenza Database (GISAID and nucleotide database of the National Center for Biotechnology Information (NCBI). Lasergene 7.0 and MEGA 6.0 softwares were used to calculate genetic distances of the sequences, to construct phylogenetic trees, and to align amino acid sequences. Bayesian coalescent phylogenetic analysis, implemented in the BEAST software package, was used to calculate the molecular clock related characteristics such as the nucleotide substitution rate and the most recent common ancestor (tMRCA) of 2019-nCoVs.ResultsAn isolate numbered EPI_ISL_403928 showed different phylogenetic trees and genetic distances of the whole length genome, the coding sequences (CDS) of ployprotein (P), spike protein (S), and nucleoprotein (N) from other 2019-nCoVs. There are 22, 4, 2 variations in P, S, and N at the level of amino acid residues. The nucleotide substitution rates from high to low are 1·05 × 10−2 (nucleotide substitutions/site/year, with 95% HPD interval being 6.27 × 10−4 to 2.72 × 10−2) for N, 5.34 × 10−3 (5.10 × 10−4, 1.28 × 10−2) for S, 1.69 × 10−3 (3.94 × 10−4, 3.60 × 10−3) for P, 1.65 × 10−3 (4.47 × 10−4, 3.24 × 10−3) for the whole genome, respectively. At this nucleotide substitution rate, the most recent common ancestor (tMRCA) of 2019-nCoVs appeared about 0.253-0.594 year before the epidemic.ConclusionOur analysis suggests that at least two different viral strains of 2019-nCoV are involved in this outbreak that might occur a few months earlier before it was officially reported.


Author(s):  
Guilherme Gainett ◽  
Prashant P. Sharma

AbstractBackgroundThe resurgence of interest in the comparative developmental study of chelicerates has led to important insights, such as the discovery of a genome duplication shared by spiders and scorpions, inferred to have occurred at the most recent common ancestor of Arachnopulmonata (a clade comprised of the five book lung-bearing arachnid orders). Nonetheless, several arachnid groups remain understudied in the context of development and genomics, such as the order Amblypygi (whip spiders). The phylogenetic position of Amblypygi in Arachnopulmonata posits them as an interesting group to test the incidence of the proposed genome duplication in the common ancestor of Arachnopulmonata, as well as the degree of retention of duplicates over 450 Myr. Moreover, whip spiders have their first pair of walking legs elongated and modified into sensory appendages (a convergence with the antenna of mandibulates), but the genetic patterning of these antenniform legs has never been investigated.ResultsWe established genomic resources and protocols for cultivation of embryos and gene expression assays by in situ hybridization to study the development of the whip spider Phrynus marginemaculatus. Using embryonic transcriptomes from three species of Amblypygi, we show that the ancestral whip spider exhibited duplications of all ten Hox genes. We deploy these resources to show that paralogs of the leg gap genes dachshund and homothorax retain arachnopulmonate-specific expression patterns in P. marginemaculatus. We characterize the expression of leg gap genes Distal-less, dachshund-1/2 and homothorax-1/2 in the embryonic antenniform leg and other appendages, and provide evidence that allometry, and by extension the antenniform leg fate, is specified early in embryogenesis.ConclusionThis study is the first step in establishing P. marginemaculatus as a model for modern chelicerate evolutionary developmental study, and provides the first resources sampling whip spiders for comparative genomics. Our results suggest that Amblypygi share a genome duplication with spiders and scorpions, and set up a framework to study the genetic specification of antenniform legs. Future efforts to study whip spider development must emphasize the development of tools for functional experiments in P. marginemaculatus.


2017 ◽  
Vol 177 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Roberto Salvatori ◽  
Serban Radian ◽  
Yoan Diekmann ◽  
Donato Iacovazzo ◽  
Alessia David ◽  
...  

Objective Mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene are associated with pituitary adenoma, acromegaly and gigantism. Identical alleles in unrelated pedigrees could be inherited from a common ancestor or result from recurrent mutation events. Design and methods Observational, inferential and experimental study, including: AIP mutation testing; reconstruction of 14 AIP-region (8.3 Mbp) haplotypes; coalescent-based approximate Bayesian estimation of the time to most recent common ancestor (tMRCA) of the derived allele; forward population simulations to estimate current number of allele carriers; proposal of mutation mechanism; protein structure predictions; co-immunoprecipitation and cycloheximide chase experiments. Results Nine European-origin, unrelated c.805_825dup-positive pedigrees (four familial, five sporadic from the UK, USA and France) included 16 affected (nine gigantism/four acromegaly/two non-functioning pituitary adenoma patients and one prospectively diagnosed acromegaly patient) and nine unaffected carriers. All pedigrees shared a 2.79 Mbp haploblock around AIP with additional haploblocks privately shared between subsets of the pedigrees, indicating the existence of an evolutionarily recent common ancestor, the ‘English founder’, with an estimated median tMRCA of 47 generations (corresponding to 1175 years) with a confidence interval (9–113 generations, equivalent to 225–2825 years). The mutation occurred in a small tandem repeat region predisposed to slipped strand mispairing. The resulting seven amino-acid duplication disrupts interaction with HSP90 and leads to a marked reduction in protein stability. Conclusions The c.805_825dup allele, originating from a common ancestor, associates with a severe clinical phenotype and a high frequency of gigantism. The mutation is likely to be the result of slipped strand mispairing and affects protein–protein interactions and AIP protein stability.


Genetics ◽  
1998 ◽  
Vol 150 (3) ◽  
pp. 1187-1198 ◽  
Author(s):  
Mikkel H Schierup ◽  
Xavier Vekemans ◽  
Freddy B Christiansen

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.


Author(s):  
Wenjun Cheng ◽  
Tianjiao Ji ◽  
Shuaifeng Zhou ◽  
Yong Shi ◽  
Lili Jiang ◽  
...  

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.


Author(s):  
Ya-Fang Hu ◽  
Li-Ping Jia ◽  
Fang-Yuan Yu ◽  
Li-Ying Liu ◽  
Qin-Wei Song ◽  
...  

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.


Genetics ◽  
1999 ◽  
Vol 151 (3) ◽  
pp. 1217-1228 ◽  
Author(s):  
Carsten Wiuf ◽  
Jotun Hein

Abstract In this article we discuss the ancestry of sequences sampled from the coalescent with recombination with constant population size 2N. We have studied a number of variables based on simulations of sample histories, and some analytical results are derived. Consider the leftmost nucleotide in the sequences. We show that the number of nucleotides sharing a most recent common ancestor (MRCA) with the leftmost nucleotide is ≈log(1 + 4N Lr)/4Nr when two sequences are compared, where L denotes sequence length in nucleotides, and r the recombination rate between any two neighboring nucleotides per generation. For larger samples, the number of nucleotides sharing MRCA with the leftmost nucleotide decreases and becomes almost independent of 4N Lr. Further, we show that a segment of the sequences sharing a MRCA consists in mean of 3/8Nr nucleotides, when two sequences are compared, and that this decreases toward 1/4Nr nucleotides when the whole population is sampled. A measure of the correlation between the genealogies of two nucleotides on two sequences is introduced. We show analytically that even when the nucleotides are separated by a large genetic distance, but share MRCA, the genealogies will show only little correlation. This is surprising, because the time until the two nucleotides shared MRCA is reciprocal to the genetic distance. Using simulations, the mean time until all positions in the sample have found a MRCA increases logarithmically with increasing sequence length and is considerably lower than a theoretically predicted upper bound. On the basis of simulations, it turns out that important properties of the coalescent with recombinations of the whole population are reflected in the properties of a sample of low size.


Botany ◽  
2013 ◽  
Vol 91 (9) ◽  
pp. 605-613 ◽  
Author(s):  
Claudia Ciotir ◽  
Chris Yesson ◽  
Joanna Freeland

Understanding the spatial distribution of genetic diversity and its evolutionary history is an essential part of developing effective biodiversity management plans. This may be particularly true when considering the value of peripheral or disjunct populations. Although conservation decisions are often made with reference to geopolitical boundaries, many policy-makers also consider global distributions, and therefore a species’ global status may temper its regional status. Many disjunct populations can be found in the Great Lakes region of North America, including those of Bartonia paniculata subsp. paniculata, a species that has been designated as threatened in Canada but globally secure. We compared chloroplast sequences between disjunct (Canada) and core (USA) populations of B. paniculata subsp. paniculata separated by 600 km, which is the minimum distance between disjunct and core populations in this subspecies. We found that although lineages within the disjunct populations shared a relatively recent common ancestor, the genetic divergence between plants from Ontario and New Jersey was substantially greater than expected for a consubspecific comparison. A coalescence-based analysis dated the most recent common ancestor of the Canadian and US populations at approximately 534 000 years ago with the lower confidence estimate at 226 000 years ago. This substantially predates the Last Glacial Maximum and suggests that disjunct and core populations have followed independent evolutionary trajectories throughout multiple glacial–interglacial cycles. Our findings provide important insight into the diverse processes that have resulted in numerous disjunct species in the Great Lakes region and highlight a need for additional work on Canadian B. paniculata subsp. paniculata taxonomy prior to a reevaluation of its conservation value.


Author(s):  
Satoshi Nakano ◽  
Takao Fujisawa ◽  
Bin Chang ◽  
Yutaka Ito ◽  
Hideki Akeda ◽  
...  

After the introduction of the seven-valent pneumococcal conjugate vaccine, the global spread of multidrug resistant serotype 19A-ST320 strains became a public health concern. In Japan, the main genotype of serotype 19A was ST3111, and the identification rate of ST320 was low. Although the isolates were sporadically detected in both adults and children, their origin remains unknown. Thus, by combining pneumococcal isolates collected in three nationwide pneumococcal surveillance studies conducted in Japan between 2008 and 2020, we analyzed 56 serotype 19A-ST320 isolates along with 931 global isolates, using whole-genome sequencing to uncover the transmission route of the globally distributed clone in Japan. The clone was frequently detected in Okinawa Prefecture, where the U.S. returned to Japan in 1972. Phylogenetic analysis demonstrated that the isolates from Japan were genetically related to those from the U.S.; therefore, the common ancestor may have originated in the U.S. In addition, Bayesian analysis suggested that the time to the most recent common ancestor of the isolates form Japan and the U.S. was approximately the 1990s to 2000, suggesting the possibility that the common ancestor could have already spread in the U.S. before the Taiwan 19F-14 isolate was first identified in a Taiwanese hospital in 1997. The phylogeographical analysis supported the transmission of the clone from the U.S. to Japan, but the analysis could be influenced by sampling bias. These results suggested the possibility that the serotype 19A-ST320 clone had already spread in the U.S. before being imported into Japan.


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