scholarly journals Coevolutionary and phylogenetic analysis of Mimiviral replication machinery suggest the cellular origin of Mimiviruses

2021 ◽  
Author(s):  
Supriya Patil ◽  
Kiran Kondabagil
Keyword(s):  
Phylogenetic Analysis ◽  
Large Fraction ◽  
Purifying Selection ◽  
Replication Proteins ◽  
Replication Machinery ◽  
Origin And Evolution ◽  
Cellular Origin ◽  
Clamp Loaders ◽  
Eukaryotic Origin ◽  
Unicellular Organisms

Abstract Mimivirus is one of the most complex and largest viruses known. The origin and evolution of Mimivirus and other giant viruses have been a subject of intense study in the last two decades. The two prevailing hypotheses on the origin of Mimivirus and other viruses are the reduction hypothesis, which posits that viruses emerged from modern unicellular organisms; whereas the virus-first hypothesis proposes viruses as relics of pre-cellular forms of life. In this study, to gain insights into the origin of Mimivirus, we have carried out extensive phylogenetic, correlation, and MultiDimensional Scaling (MDS) analyses of the putative proteins involved in the replication of its 1.2-Mb large genome. Correlation analysis and MDS methods were validated using bacteriophage, bacteria, archaea, and eukaryotic replication proteins before applying to Mimivirus. We show that a large fraction of mimiviral replication proteins, including polymerase B, clamp, and clamp loaders are of eukaryotic origin and are coevolving. Although phylogenetic analysis places some components along the lineages of phage and bacteria, we show that all the replication-related genes have been homogenized and are under purifying selection. Collectively our analysis supports the idea that Mimivirus originated from a complex cellular ancestor. We hypothesize that Mimivirus has largely retained complex replication machinery reminiscent of its progenitor while losing most of the other genes related to processes such as metabolism and translation.

scholarly journals Mosaic nature of the mitochondrial proteome: Implications for the origin and evolution of mitochondria

2015 ◽  
Vol 112 (33) ◽  
pp. 10133-10138 ◽  
Author(s):  
Michael W. Gray
Keyword(s):  
Phylogenetic Signal ◽  
Phylogenetic Analyses ◽  
Large Fraction ◽  
Mitochondrial Proteins ◽  
Surprising Result ◽  
Origin And Evolution ◽  
Mitochondrial Proteome ◽  
Mitochondrial Origin ◽  
Conserved Core ◽  
Evolution Of Mitochondria

Comparative studies of the mitochondrial proteome have identified a conserved core of proteins descended from the α-proteobacterial endosymbiont that gave rise to the mitochondrion and was the source of the mitochondrial genome in contemporary eukaryotes. A surprising result of phylogenetic analyses is the relatively small proportion (10–20%) of the mitochondrial proteome displaying a clear α-proteobacterial ancestry. A large fraction of mitochondrial proteins typically has detectable homologs only in other eukaryotes and is presumed to represent proteins that emerged specifically within eukaryotes. A further significant fraction of the mitochondrial proteome consists of proteins with homologs in prokaryotes, but without a robust phylogenetic signal affiliating them with specific prokaryotic lineages. The presumptive evolutionary source of these proteins is quite different in contending models of mitochondrial origin.

Sequence characterization and phylogenetic analysis of the 5S ribosomal DNA in species of the family Batrachoididae

Genome ◽  
2010 ◽  
Vol 53 (9) ◽  
pp. 723-730 ◽  
Author(s):  
María Úbeda-Manzanaro ◽  
Manuel Alejandro Merlo ◽  
José Luis Palazón ◽  
Carmen Sarasquete ◽  
Laureana Rebordinos
Keyword(s):  
Phylogenetic Analysis ◽  
Ribosomal Dna ◽  
5S Rdna ◽  
Purifying Selection ◽  
The Other ◽  
Fish Family ◽  
Sequence Characterization ◽  
Rdna Sequences ◽  
The Family ◽  
Clear Differentiation

5S ribosomal DNA (rDNA) sequences were analyzed in four species belonging to different genera of the fish family Batrachoididae. Several 5S rDNA variants differing in their non-transcribed spacers (NTSs) were found and were grouped into two main types. Two species showed both types of 5S rDNA, whereas the other two species showed only one type. One type of NTS of Amphichthys cryptocentrus showed a high polymorphism due to several deletions and insertions, and phylogenetic analysis showed a between-species clustering of this type of NTS in Amphichthys cryptocentrus. These results suggest a clear differentiation in the model of 5S rDNA evolution of these four species of Batrachoididae, which appear to have been subject to processes of concerted evolution and birth-and-death evolution with purifying selection.

scholarly journals Origin and evolution of overlapping genes in the family Microviridae

2006 ◽  
Vol 87 (4) ◽  
pp. 1013-1017 ◽  
Author(s):  
Angelo Pavesi
Keyword(s):  
Purifying Selection ◽  
Synonymous Substitution ◽  
Ancestral State ◽  
Overlapping Genes ◽  
Novel Genes ◽  
Origin And Evolution ◽  
The Family ◽  
Genes Encoding ◽  
Phage Growth ◽  
Gene Overlap

The possibility of creating novel genes from pre-existing sequences, known as overprinting, is a widespread phenomenon in small viruses. Here, the origin and evolution of gene overlap in the bacteriophages belonging to the family Microviridae have been investigated. The distinction between ancestral and derived frames was carried out by comparing the patterns of codon usage in overlapping and non-overlapping genes. By this approach, a gradual increase in complexity of the phage genome – from an ancestral state lacking gene overlap to a derived state with a high density of genetic information – was inferred. Genes encoding less-essential proteins, yet playing a role in phage growth and diffusion, were predicted to be novel genes that originated by overprinting. Evaluation of the rates of synonymous and non-synonymous substitution yielded evidence for overlapping genes under positive selection in one frame and purifying selection in the alternative frame.

scholarly journals Placenta-Specific Protein 1 Is Conserved throughout the Placentalia under Purifying Selection

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Eric J. Devor
Keyword(s):  
Phylogenetic Analysis ◽  
Common Ancestor ◽  
Phylogenetic Analyses ◽  
Mammalian Species ◽  
Purifying Selection ◽  
Specific Protein ◽  
Mammal Species ◽  
Crucial Component ◽  
Successful Group ◽  
The Common

Placental mammals (Placentalia) are a very successful group that, today, comprise 94% of all mammalian species. Recent phylogenetic analyses, coupled with new, quite complete fossils, suggest that the crown orders were all established rapidly from a common ancestor just after the Cretaceous/Tertiary (K/T) boundary 65 million years ago. Extensive molecular and morphologic evidence has led to a description of the common ancestor of all Placentalia in which a two-horned uterus and a hemochorial placenta are present. Thus, the process of placentation in which the placenta invades and anchors to the uterine epithelium was already established. One factor that has been suggested as a crucial component of this process is placenta-specific protein 1 (PLAC1). A phylogenetic analysis of the PLAC1 protein in 25 placental mammal species, representing nine of the sixteen crown orders of the Placentalia, suggests that this protein was present in the placental common ancestor in the form we see it today, that it evolved in the Placentalia and has been subject to the effects of purifying selection since its appearance.

scholarly journals A molecular phylogenetic analysis of the genera of fruit doves and allies using dense taxonomic sampling

2019 ◽  
Vol 42 ◽  
pp. 2019001
Author(s):  
Jennifer Nowak ◽  
Andrew Sweet ◽  
Jason Weckstein ◽  
Kevin Johnson
Keyword(s):  
Phylogenetic Analysis ◽  
Phylogenetic Relationships ◽  
Large Fraction ◽  
Nuclear Gene ◽  
Data Sets ◽  
Foraging Mode ◽  
Biogeographic Patterns ◽  
Reconstruction Methods ◽  
Molecular Phylogenetic ◽  
History Of

Fruit doves and their allies are a diverse group within the pigeon and dove family (Aves: Columbidae). Progress towards subfamilial classification of Columbidae relies on identifying major groups and the phylogenetic relationships within these groups. One such recently proposed group is the Raphinae based on previous evidence that the extinct dodo is potentially within what was formerly recognized as the Treroninae (fruit doves and allies). Although several studies have explored the phylogenetic relationships within Columbidae, most have focused either on broad-scale, familial level relationships or finer scale, species level relationships. Here we use mitochondrial and nuclear gene sequences from a diverse taxonomic sample to identify relationships among the genera and species of fruit doves and their allies. In particular our goal is to identify which of these genera should be included within Raphinae (the name which has taxonomic priority over Treroninae), focusing on an inclusive, well-supported monophyletic group. We also use dense taxon sampling to explore relationships among genera and species in this group, expanding on previous studies. In addition, we use resulting phylogenetic hypotheses to reconstruct the ancestral evolutionary history of foraging mode and biogeographic patterns of dispersal within the group. We used two data sets for our phylogenetic analysis: the first consisting of novel sequences generated for this project and the second with additional, previously published sequences from the fruit dove genus (Ptilinopus). Our analyses found support for the monophyly of a clade that contains a large fraction of the genera currently classified within Raphinae and also found several well-supported clades within this group of pigeons and doves. Character reconstruction methods based on the resulting phylogeny recover multiple transitions from a terrestrial to an arboreal foraging mode and evidence for multiple dispersal events from Asia to Africa throughout the history of the clade.

scholarly journals Evolution of the insect PPK gene family

2021 ◽  
Author(s):  
Jose Manuel Latorre-Estivalis ◽  
Francisca Cunha Almeida ◽  
Gina Pontes ◽  
Hernán Dopazo ◽  
Romina Barrozo ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Gene Family ◽  
Transmembrane Domain ◽  
Purifying Selection ◽  
Calmodulin Binding ◽  
Pediculus Humanus ◽  
Relevant Role ◽  
Specific Expansion ◽  
High Gene ◽  
Sensory Responses

ABSTRACTInsect Pickpocket (PPK) receptors mediate the detection of stimuli of diverse sensory modalities, therefore having a relevant role for environmental sounding. Notwithstanding their relevance, studies on their evolution are scarce. We have analyzed the genomes of 26 species belonging to 8 insect orders (Blattodea, Orthoptera, Hemiptera, Phthiraptera, Hymenoptera, Lepidoptera, Coleoptera, and Diptera) to identify their PPK repertoires and study the evolution of this gene family. PPKs were detected in all genomes analyzed, with a total of 578 genes identified that distributed in 7 subfamilies. Our phylogenetic analysis allowed clarifying that the ppk17 gene appears to be the most divergent family member, composing a new group designed as subfamily VII. According to our analysis, PPKs evolved under a birth-and-death model that generated lineage-specific expansions usually located in clusters and the effect of strong purifying selection was seen for several orthogroups. Subfamily V was the largest one, presenting half of all PPKs studied, including a mosquito-specific expansion that can be considered a new target for pest control. Consistently with their sensory role, PPKs present a high gene turnover that generated considerable variation in the size of insect repertoires: Musca domestica (59), Blattella germanica (41), Culex quinquefasciatus (48), and Aedes albopictus (51) presented the largest PPK repertoires, while Pediculus humanus (only ppk17), bees and ants (6-9) had the smallest ones. The expansions identified in M. domestica and Bl. germanica also show promise as specific targets for controlling these nuisance insects. Our phylogenetic analysis revealed a subset of prevalent PPKs across insect genomes, suggesting a very conserved function that resembles the case of antennal ionotropic receptors. Finally, we identified new highly conserved residues in the second transmembrane domain that may be key for receptor function. Besides, more than a hundred PPK sequences presented calmodulin binding motifs, suggesting that at least some members of this family may amplify sensory responses as previously proposed for D. melanogaster ppk25. Overall, our study is a first attempt to characterize the evolutionary history of this family of sensory receptors, revealing relevant unknown features and clade-specific expansions.

scholarly journals DNA Replication in the Archaea

2006 ◽  
Vol 70 (4) ◽  
pp. 876-887 ◽  
Author(s):  
Elizabeth R. Barry ◽  
Stephen D. Bell
Keyword(s):  
Dna Replication ◽  
Higher Order ◽  
Striking Similarity ◽  
Replication Proteins ◽  
Replication Machinery ◽  
Replication Factors ◽  
Archaeal Dna Replication ◽  
Made In

SUMMARY The archaeal DNA replication machinery bears striking similarity to that of eukaryotes and is clearly distinct from the bacterial apparatus. In recent years, considerable advances have been made in understanding the biochemistry of the archaeal replication proteins. Furthermore, a number of structures have now been obtained for individual components and higher-order assemblies of archaeal replication factors, yielding important insights into the mechanisms of DNA replication in both archaea and eukaryotes.

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