scholarly journals Evolutionary History of the Toll-Like Receptor Gene Family across Vertebrates

2019 ◽  
Vol 12 (1) ◽  
pp. 3615-3634 ◽  
Author(s):  
Guangshuai Liu ◽  
Huanxin Zhang ◽  
Chao Zhao ◽  
Honghai Zhang
Keyword(s):  
Positive Selection ◽  
Gene Family ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Receptor Gene ◽  
Purifying Selection ◽  
Protein Architecture ◽  
Wide Range ◽  
History Of ◽  
Membrane Bound

Abstract Adaptation to a wide range of pathogenic environments is a major aspect of the ecological adaptations of vertebrates during evolution. Toll-like receptors (TLRs) are ancient membrane-bound sensors in animals and are best known for their roles in detecting and defense against invading pathogenic microorganisms. To understand the evolutionary history of the vertebrate TLR gene family, we first traced the origin of single-cysteine cluster TLRs that share the same protein architecture with vertebrate TLRs in early-branching animals and then analyzed all members of the TLR family in over 200 species covering all major vertebrate clades. Our results indicate that although the emergence of single-cysteine cluster TLRs predates the separation of bilaterians and cnidarians, most vertebrate TLR members originated shortly after vertebrate emergence. Phylogenetic analyses divided 1,726 vertebrate TLRs into 8 subfamilies, and TLR3 may represent the most ancient subfamily that emerged before the branching of deuterostomes. Our analysis reveals that purifying selection predominated in the evolution of all vertebrate TLRs, with mean dN/dS (ω) values ranging from 0.082 for TLR21 in birds to 0.434 for TLR11 in mammals. However, we did observe patterns of positive selection acting on specific codons (527 of 60,294 codons across all vertebrate TLRs, 8.7‰), which are significantly concentrated in ligand-binding extracellular domains and suggest host–pathogen coevolutionary interactions. Additionally, we found stronger positive selection acting on nonviral compared with viral TLRs, indicating the more essential nonredundant function of viral TLRs in host immunity. Taken together, our findings provide comprehensive insight into the complex evolutionary processes of the vertebrate TLR gene family, involving gene duplication, pseudogenization, purification, and positive selection.

scholarly journals A test statistic to quantify treelikeness in phylogenetics

2021 ◽  
Author(s):  
Caitlin Cherryh ◽  
Bui Quang Minh ◽  
Rob Lanfear
Keyword(s):  
Evolutionary History ◽  
Incomplete Lineage Sorting ◽  
Phylogenetic Analyses ◽  
Phylogenetic Network ◽  
Parametric Bootstrap ◽  
Lineage Sorting ◽  
Test Statistic ◽  
Sequence Alignments ◽  
Wide Range ◽  
History Of

AbstractMost phylogenetic analyses assume that the evolutionary history of an alignment (either that of a single locus, or of multiple concatenated loci) can be described by a single bifurcating tree, the so-called the treelikeness assumption. Treelikeness can be violated by biological events such as recombination, introgression, or incomplete lineage sorting, and by systematic errors in phylogenetic analyses. The incorrect assumption of treelikeness may then mislead phylogenetic inferences. To quantify and test for treelikeness in alignments, we develop a test statistic which we call the tree proportion. This statistic quantifies the proportion of the edge weights in a phylogenetic network that are represented in a bifurcating phylogenetic tree of the same alignment. We extend this statistic to a statistical test of treelikeness using a parametric bootstrap. We use extensive simulations to compare tree proportion to a range of related approaches. We show that tree proportion successfully identifies non-treelikeness in a wide range of simulation scenarios, and discuss its strengths and weaknesses compared to other approaches. The power of the tree-proportion test to reject non-treelike alignments can be lower than some other approaches, but these approaches tend to be limited in their scope and/or the ease with which they can be interpreted. Our recommendation is to test treelikeness of sequence alignments with both tree proportion and mosaic methods such as 3Seq. The scripts necessary to replicate this study are available at https://github.com/caitlinch/treelikeness

scholarly journals Genomic signatures of G-protein-coupled receptor expansions reveal functional transitions in the evolution of cephalopod signal transduction

2019 ◽  
Vol 286 (1897) ◽  
pp. 20182929 ◽  
Author(s):  
Elena A. Ritschard ◽  
Robert R. Fitak ◽  
Oleg Simakov ◽  
Sönke Johnsen
Keyword(s):  
Signal Transduction ◽  
Positive Selection ◽  
G Protein ◽  
Evolutionary History ◽  
Expression Profiles ◽  
Phylogenetic Analyses ◽  
Expression Patterns ◽  
Genomic Signatures ◽  
History Of ◽  
G Protein Coupled

Coleoid cephalopods show unique morphological and neural novelties, such as arms with tactile and chemosensory suckers and a large complex nervous system. The evolution of such cephalopod novelties has been attributed at a genomic level to independent gene family expansions, yet the exact association and the evolutionary timing remain unclear. In the octopus genome, one such expansion occurred in the G-protein-coupled receptors (GPCRs) repertoire, a superfamily of proteins that mediate signal transduction. Here, we assessed the evolutionary history of this expansion and its relationship with cephalopod novelties. Using phylogenetic analyses, at least two cephalopod- and two octopus-specific GPCR expansions were identified. Signatures of positive selection were analysed within the four groups, and the locations of these sequences in the Octopus bimaculoides genome were inspected. Additionally, the expression profiles of cephalopod GPCRs across various tissues were extracted from available transcriptomic data. Our results reveal the evolutionary history of cephalopod GPCRs. Unexpanded cephalopod GPCRs shared with other bilaterians were found to be mainly nervous tissue specific. By contrast, duplications that are shared between octopus and the bobtail squid or specific to the octopus' lineage generated copies with divergent expression patterns devoted to tissues outside of the brain. The acquisition of novel expression domains was accompanied by gene order rearrangement through either translocation or duplication and gene loss. Lastly, expansions showed signs of positive selection and some were found to form tandem clusters with shared conserved expression profiles in cephalopod innovations such as the axial nerve cord. Altogether, our results contribute to the understanding of the molecular and evolutionary history of signal transduction and provide insights into the role of this expansion during the emergence of cephalopod novelties and/or adaptations.

scholarly journals The complex evolution of the HSP70 gene family

2020 ◽  
Author(s):  
Er-meng Yu ◽  
Tatsuki Yoshinaga ◽  
Frank L. Jalufka ◽  
Hashimul Ehsan ◽  
David B. Mark Welch ◽  
...  
Keyword(s):  
Heat Shock ◽  
Evolutionary History ◽  
Brachionus Plicatilis ◽  
Phylogenetic Analyses ◽  
Expression Patterns ◽  
Evolutionary Genetics ◽  
Purifying Selection ◽  
Hsp70 Family ◽  
History Of ◽  
Species Specific

AbstractThe 70-kDa heat shock protein (HSP70) family contains several isoforms localized in different subcellular compartments. The cytosolic isoforms have been classified into stress-inducible HSP70s and constitutive heat shock cognates (HSC70s), but occasional reports of “constitutive HSP70s” and the lack of cross-phylum comparisons have been a source of confusion in the evolution of the metazoan HSP70 family. Here we provide novel insights into the evolutionary history of this important molecular chaperone. We first cloned two HSP70 genes from the rotifer Brachionus plicatilis, an emerging model in evolutionary genetics, and confirmed their stress inducibility. Subsequent phylogenetic analyses of 100 full-length HSP70 family member genes revealed an ancient duplication that gave rise to two lineages from which all metazoan cytosolic HSP70s descend. One lineage contains a relatively small number of Lophotrochozoan and Ecdysozoan genes, none of which have been shown to be constitutively expressed. The second included both inducible and constitutive genes from diverse phyla. Species-specific duplications are present in both lineages, and in the second there are well-supported phylum-specific clades for Rotifera, Nematoda, and Chordata. Some genes in this lineage have likely independently acquired stress inducibility, which may explain the sporadic distribution of genes designated as “HSP70” or “HSC70” in previous analyses. Consistent with the history of diversification within each group, stress-inducible members of the second lineage show lower purifying selection pressure compared to constitutive members. These results illustrate the evolutionary history of the HSP70 family independent from their expression patterns, encouraging the development of new nomenclature based on evolutionary history.

scholarly journals The complex evolution of the metazoan HSP70 gene family

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Er-meng Yu ◽  
Tatsuki Yoshinaga ◽  
Frank L. Jalufka ◽  
Hashimul Ehsan ◽  
David B. Mark Welch ◽  
...  
Keyword(s):  
Heat Shock ◽  
Molecular Chaperones ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Evolutionary Relationship ◽  
Purifying Selection ◽  
Hsp70 Family ◽  
Number Of Genes ◽  
History Of ◽  
Species Specific

AbstractThe metazoan 70-kDa heat shock protein (HSP70) family contains several members localized in different subcellular compartments. The cytosolic members have been classified into inducible HSP70s and constitutive heat shock cognates (HSC70s), but their distinction and evolutionary relationship remain unclear because of occasional reports of “constitutive HSP70s” and the lack of cross-phylum comparisons. Here we provide novel insights into the evolution of these important molecular chaperones. Phylogenetic analyses of 125 full-length HSP70s from a broad range of phyla revealed an ancient duplication that gave rise to two lineages from which all metazoan cytosolic HSP70s descend. One lineage (A) contains a relatively small number of genes from many invertebrate phyla, none of which have been shown to be constitutively expressed (i.e., either inducible or unknown). The other lineage (B) included both inducible and constitutive genes from diverse phyla. Species-specific duplications are present in both lineages, and Lineage B contains well-supported phylum-specific clades for Platyhelminthes, Rotifera, Nematoda, Porifera/Cnidaria, and Chordata. Some genes in Lineage B have likely independently acquired inducibility, which may explain the sporadic distribution of “HSP70” or “HSC70” in previous phylogenetic analyses. Consistent with the diversification history within each group, inducible members show lower purifying selection pressure compared to constitutive members. These results illustrate the evolutionary history of the HSP70 family, encouraging us to propose a new nomenclature: “HSP70 + subcellular localization + linage + copy number in the organism + inducible or constitutive, if known.” e.g., HSP70cA1i for cytosolic Lineage A, copy 1, inducible.

scholarly journals Evolutionary History of the Globin Gene Family in Annelids

2020 ◽  
Vol 12 (10) ◽  
pp. 1719-1733 ◽  
Author(s):  
Flávia A Belato ◽  
Christopher J Coates ◽  
Kenneth M Halanych ◽  
Roy E Weber ◽  
Elisa M Costa-Paiva
Keyword(s):  
Gene Family ◽  
Evolutionary History ◽  
Organic Molecules ◽  
Phylogenetic Analyses ◽  
Globin Gene ◽  
Transport Proteins ◽  
Multiple Gene ◽  
History Of ◽  
Respiratory Proteins ◽  
Multiple Gene Duplication

Abstract Animals depend on the sequential oxidation of organic molecules to survive; thus, oxygen-carrying/transporting proteins play a fundamental role in aerobic metabolism. Globins are the most common and widespread group of respiratory proteins. They can be divided into three types: circulating intracellular, noncirculating intracellular, and extracellular, all of which have been reported in annelids. The diversity of oxygen transport proteins has been underestimated across metazoans. We probed 250 annelid transcriptomes in search of globin diversity in order to elucidate the evolutionary history of this gene family within this phylum. We report two new globin types in annelids, namely androglobins and cytoglobins. Although cytoglobins and myoglobins from vertebrates and from invertebrates are referred to by the same name, our data show they are not genuine orthologs. Our phylogenetic analyses show that extracellular globins from annelids are more closely related to extracellular globins from other metazoans than to the intracellular globins of annelids. Broadly, our findings indicate that multiple gene duplication and neo-functionalization events shaped the evolutionary history of the globin family.

scholarly journals The First Co-Opted Endogenous Foamy Viruses and the Evolutionary History of Reptilian Foamy Viruses

Viruses ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 641 ◽  
Author(s):  
Pakorn Aiewsakun ◽  
Peter Simmonds ◽  
Aris Katzourakis
Keyword(s):  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Foamy Virus ◽  
Purifying Selection ◽  
The Other ◽  
Cellular Functions ◽  
Foamy Viruses ◽  
History Of ◽  
Flanking Sequences ◽  
Reading Frames

A recent study reported the discovery of an endogenous reptilian foamy virus (FV), termed ERV-Spuma-Spu, found in the genome of tuatara. Here, we report two novel reptilian foamy viruses also identified as endogenous FVs (EFVs) in the genomes of panther gecko (ERV-Spuma-Ppi) and Schlegel’s Japanese gecko (ERV-Spuma-Gja). Their presence indicates that FVs are capable of infecting reptiles in addition to mammals, amphibians, and fish. Numerous copies of full length ERV-Spuma-Spu elements were found in the tuatara genome littered with in-frame stop codons and transposable elements, suggesting that they are indeed endogenous and are not functional. ERV-Spuma-Ppi and ERV-Spuma-Gja, on the other hand, consist solely of a foamy virus-like env gene. Examination of host flanking sequences revealed that they are orthologous, and despite being more than 96 million years old, their env reading frames are fully coding competent with evidence for strong purifying selection to maintain expression and for them likely being transcriptionally active. These make them the oldest EFVs discovered thus far and the first documented EFVs that may have been co-opted for potential cellular functions. Phylogenetic analyses revealed a complex virus–host co-evolutionary history and cross-species transmission routes of ancient FVs.

scholarly journals Genome-Wide Characterization of the Nuclear Receptor Gene Family in Macrostomum lignano Imply Its Evolutionary Diversification

2021 ◽  
Vol 8 ◽  
Author(s):  
Yunying Cheng ◽  
Jinlin Chen ◽  
Irum Mukhtar ◽  
Jianming Chen
Keyword(s):  
Gene Family ◽  
Adaptive Evolution ◽  
Phylogenetic Analyses ◽  
Receptor Gene ◽  
Clonorchis Sinensis ◽  
Purifying Selection ◽  
Intron Loss ◽  
Evolutionary Diversification ◽  
Macrostomum Lignano ◽  
Duplication Events

Nuclear receptors (NRs), a series of key transcription factors that are mostly activated by endogenous ligands or environmental xenobiotics, are reportedly good phylogenetic markers of animal genome evolution. As the early diverging class of bilaterians, however, a comprehensive view of the NR family in a marine free-living flatworm Macrostomum lignano and comparative information in flatworms are still lacking, which is of significance to address the evolutionary diversification of the NR family and imply the adaptive evolution in the early diverging Bilateria. Herein, a total of 51, 26, and 23 putative NR genes were identified in M. lignano, Sparganum proliferum, and Clonorchis sinensis, respectively, which were classified into eight subfamilies, implying an extensive expansion of the NR family in M. lignano. It is presumed that the extensive expansion was mainly attributed to the M. lignano-specific hidden polyploidy, segmental, and tandem duplication events. The duplicated NR pairs in M. lignano and the NR orthologs in flatworms all experienced the purifying selection. Phylogenetic analyses indicated the presence of NR3-like genes in M. lignano, which is first reported in flatworms. Intron loss and reduced intron size were mainly contributed to the structural divergence of NR genes in flatworms. The combined data provide indispensable information for a better understanding of the complexity and the adaptive evolution of the NR gene family in metazoans.

scholarly journals Ancient mitochondrial genomes from Chinese cave hyenas provide insights into the evolutionary history of the genus Crocuta

2021 ◽  
Vol 288 (1943) ◽  
pp. 20202934
Author(s):  
Jiaming Hu ◽  
Michael V. Westbury ◽  
Junxia Yuan ◽  
Zhen Zhang ◽  
Shungang Chen ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Mitochondrial Genomes ◽  
Effective Population ◽  
Wide Range ◽  
Two Samples ◽  
Spotted Hyenas ◽  
History Of ◽  
Close Relatives

Cave hyenas (genus Crocuta ) are extinct bone-cracking carnivores from the family Hyaenidae and are generally split into two taxa that correspond to a European/Eurasian and an (East) Asian lineage. They are close relatives of the extant African spotted hyenas, the only extant member of the genus Crocuta . Cave hyenas inhabited a wide range across Eurasia during the Pleistocene, but became extinct at the end of the Late Pleistocene. Using genetic and genomic datasets, previous studies have proposed different scenarios about the evolutionary history of Crocuta. However, causes of the extinction of cave hyenas are widely speculative and samples from China are severely understudied. In this study, we assembled near-complete mitochondrial genomes from two cave hyenas from northeastern China dating to 20 240 and 20 253 calBP, representing the youngest directly dated fossils of Crocuta in Asia. Phylogenetic analyses suggest a monophyletic clade of these two samples within a deeply diverging mitochondrial haplogroup of Crocuta . Bayesian analyses suggest that the split of this Asian cave hyena mitochondrial lineage from their European and African relatives occurred approximately 1.85 Ma (95% CI 1.62–2.09 Ma), which is broadly concordant with the earliest Eurasian Crocuta fossil dating to approximately 2 Ma. Comparisons of mean genetic distance indicate that cave hyenas harboured higher genetic diversity than extant spotted hyenas, brown hyenas and aardwolves, but this is probably at least partially due to the fact that their mitochondrial lineages do not represent a monophyletic group, although this is also true for extant spotted hyenas. Moreover, the joint female effective population size of Crocuta (both cave hyenas and extant spotted hyenas) has sustained two declines during the Late Pleistocene. Combining this mitochondrial phylogeny, previous nuclear findings and fossil records, we discuss the possible relationship of fossil Crocuta in China and the extinction of cave hyenas.

scholarly journals A Sister Lineage of Sampled Retroviruses Corroborates the Complex Evolution of Retroviruses

2020 ◽  
Author(s):  
Jianhua Wang ◽  
Guan-Zhu Han
Keyword(s):  
Evolutionary History ◽  
Rna Viruses ◽  
Phylogenetic Analyses ◽  
Ribonuclease H ◽  
Genome Architecture ◽  
Major Lineage ◽  
Wide Range ◽  
History Of ◽  
Negative Sense ◽  
Complex Evolutionary History

Abstract The origin and deep history of retroviruses remain mysterious and contentious, largely because the diversity of retroviruses is incompletely understood. Here, we report the discovery of lokiretroviruses, a novel major lineage of retroviruses, within the genomes of a wide range of vertebrates (at least 137 species), including lampreys, ray-finned fishes, lobe-finned fishes, amphibians, and reptiles. Lokiretroviruses share a similar genome architecture with known retroviruses, but display some unique features. Interestingly, lokiretrovirus Env proteins share detectable similarity with fusion glycoproteins of viruses within the Mononegavirales order, blurring the boundary between retroviruses and negative sense single-stranded RNA viruses. Phylogenetic analyses based on reverse transcriptase demonstrate that lokiretroviruses are sister to all the retroviruses sampled to date, providing a crucial nexus for studying the deep history of retroviruses. Comparing congruence between host and virus phylogenies suggests lokiretroviruses mainly underwent cross-species transmission. Moreover, we find that retroviruses replaced their ribonuclease H and integrase domains multiple times during their evolutionary course, revealing the importance of domain shuffling in the evolution of retroviruses. Overall, our findings greatly expand our views of the diversity of retroviruses, and provide novel insights into the origin and complex evolutionary history of retroviruses.

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