scholarly journals Portiera gives new clues on the evolutionary history of whiteflies

2020 ◽  
Author(s):  
D. Santos-Garcia ◽  
N. Mestre-Rincon ◽  
D. Ouvrard ◽  
E. Zchori-Fein ◽  
S. Morin

AbstractWhiteflies (Hemiptera: Sternorrhyncha: Aleyrodidae) are a superfamily of small phloem-feeding insects. Their taxonomy is currently based on the morphology of nymphal stages that display phenotypic plasticity, which produces inconsistencies. To overcome this limitation, we developed a new phylogenetic framework that targets five genes of Candidatus Portiera aleyrodidarum, the primary endosymbiont of whiteflies. Portiera lineages have been co-diverging with whiteflies since their origin and therefore reflect their host evolutionary history. We also studied the origin of stability and instability in Portiera genomes by testing for the presence of two alternative gene rearrangements and the loss of a functional polymerase proofreading subunit (dnaQ), previously associated with genome instability. We present two phylogenetic reconstructions. One using the sequences of all five target genes from 22 whitefly species belonging to 17 genera. The second uses only two genes to include additional published Portiera sequences of 21 whitefly species, increasing our sampling size to 42 species from 25 genera. The developed framework showed low signal saturation, specificity to whitefly samples, and efficiency in solving inter-genera relationships and standing inconsistencies in the current taxonomy of the superfamily. Genome instability was found to be present only in the Aleurolobini tribe containing the Singhiella, Aleurolobus and Bemisia genera. This suggests that Portiera genome instability likely arose in the Aleurolobini tribe’s common ancestor, around 70 Mya. We propose a link between the switch from multi-bacteriocyte to a single-bacteriocyte mode of inheritance in the Aleurolobini tribe and the appearance of genome instability in Portiera.

2020 ◽  
Vol 12 (11) ◽  
pp. 2107-2124
Author(s):  
Diego Santos-Garcia ◽  
Natividad Mestre-Rincon ◽  
David Ouvrard ◽  
Einat Zchori-Fein ◽  
Shai Morin

Abstract Whiteflies (Hemiptera: Sternorrhyncha: Aleyrodidae) are a superfamily of small phloem-feeding insects. They rely on their primary endosymbionts "Candidatus Portiera aleyrodidarum" to produce essential amino acids not present in their diet. Portiera has been codiverging with whiteflies since their origin and therefore reflects its host’s evolutionary history. Like in most primary endosymbionts, the genome of Portiera stays stable across the Aleyrodidae superfamily after millions of years of codivergence. However, Portiera of the whitefly Bemisia tabaci has lost the ancestral genome order, reflecting a rare event in the endosymbiont evolution: the appearance of genome instability. To gain a better understanding of Portiera genome evolution, identify the time point in which genome instability appeared and contribute to the reconstruction of whitefly phylogeny, we developed a new phylogenetic framework. It targeted five Portiera genes and determined the presence of the DNA polymerase proofreading subunit (dnaQ) gene, previously associated with genome instability, and two alternative gene rearrangements. Our results indicated that Portiera gene sequences provide a robust tool for studying intergenera phylogenetic relationships in whiteflies. Using these new framework, we found that whitefly species from the Singhiella, Aleurolobus, and Bemisia genera form a monophyletic tribe, the Aleurolobini, and that their Portiera exhibit genome instability. This instability likely arose once in the common ancestor of the Aleurolobini tribe (at least 70 Ma), drawing a link between the appearance of genome instability in Portiera and the switch from multibacteriocyte to a single-bacteriocyte mode of inheritance in this tribe.


2019 ◽  
Author(s):  
Laura Hernández ◽  
Alberto Vicens ◽  
Luis Enrique Eguiarte ◽  
Valeria Souza ◽  
Valerie De Anda ◽  
...  

ABSTRACTDimethylsulfoniopropionate (DMSP), an osmolyte produced by oceanic phytoplankton, is predominantly degraded by bacteria belonging to the Roseobacter lineage and other marine Alphaproteobacteria via DMSP-dependent demethylase A protein (DmdA). To date, the evolutionary history of DmdA gene family is unclear. Some studies indicate a common ancestry between DmdA and GcvT gene families and a co-evolution between Roseobacter and the DMSP-producing-phytoplankton around 250 million years ago (Mya). In this work, we analyzed the evolution of DmdA under three possible evolutionary scenarios: 1) a recent common ancestor of DmdA and GcvT, 2) a coevolution between Roseobacter and the DMSP-producing-phytoplankton, and 3) pre-adapted enzymes to DMSP prior to Roseobacter origin. Our analyses indicate that DmdA is a new gene family originated from GcvT genes by duplication and functional divergence driven by positive selection before a coevolution between Roseobacter and phytoplankton. Our data suggest that Roseobacter acquired dmdA by horizontal gene transfer prior to exposition to an environment with higher DMSP. Here, we propose that the ancestor that carried the DMSP demethylation pathway genes evolved in the Archean, and was exposed to a higher concentration of DMSP in a sulfur rich atmosphere and anoxic ocean, compared to recent Roseobacter ecoparalogs (copies performing the same function under different conditions), which should be adapted to lower concentrations of DMSP.


Hemoglobin ◽  
2018 ◽  
pp. 94-123
Author(s):  
Jay F. Storz

Chapter 5 provides an overview of the evolutionary history of the globin gene superfamily and places the evolution of vertebrate-specific globins in phylogenetic context. The duplication and functional divergence of globin genes has promoted key physiological innovations in respiratory gas transport and other physiological functions during animal evolution. A combination of both tandem gene duplication and whole-genome duplication contributed to the diversification of vertebrate globins. Phylogenetic reconstructions arrange vertebrate globins into those that derive from vertebrate-specific duplications (cytoglobin, globin E, globin Y, and the independently derived myoglobin-like and hemoglobin-like genes of jawed vertebrates and jawless fishes [lampreys and hagfish]) and those that derive from far more ancient duplication events that predate the divergence between deuterostomes and protostomes (androglobin, globin X, and neuroglobin). Tracing the evolutionary history of deuterostome globins reveals evidence for the repeated culling of ancestral diversity, followed by lineage-specific diversification of surviving gene lineages via repeated rounds of duplication and divergence.


Author(s):  
Francisco Prosdocimi ◽  
Sávio Torres de Farias

Genes and gene trees have been extensively used to study the evolutionary relationships among populations, species, families and higher systematic clades of organisms. This brought modern Biology into a sophisticated level of understanding about the evolutionary relationships and diversification patterns that happened along the entire history of organismal evolution in Earth. Genes however have not been placed in the center of questions when one aims to unravel the evolutionary history of genes themselves. Thus, we still ignore whether Insulin share a more recent common ancestor to Hexokinase or DNA polymerase. This brought modern Genetics into a very poor level of understanding about sister group relationships that happened along the entire evolutionary history of genes. Many conceptual challenges must be overcome to allow this broader comprehension about gene evolution. Here we aim to clear the intellectual path in order to provide a fertile research program that will help geneticists to understand the deep ancestry and sister group relationships among different gene families (or orthologs). We aim to propose methods to study gene formation starting from the establishment of the genetic code in pre-cellular organisms like the FUCA (First Universal Common Ancestor) until the formation of the highly complex genome of LUCA (Last UCA), that harbors hundreds of genes families working coordinated into a cellular organism. The deep understanding of ancestral relationships among orthologs will certainly inspire biotechnological and biomedical approaches and allow a deep understanding about how Darwinian molecular evolution operates inside cells and before the appearance of cellular organisms.


Author(s):  
Laura M. Carroll ◽  
Martin Wiedmann

AbstractCereulide-producing members of Bacillus cereus sensu lato (B. cereus s.l.) Group III, also known as “emetic B. cereus”, possess cereulide synthetase, a plasmid-encoded, non-ribosomal peptide synthetase encoded by the ces gene cluster. Despite the documented risks that cereulide-producing strains pose to public health, the level of genomic diversity encompassed by “emetic B. cereus” has never been evaluated at a whole-genome scale. Here, we employ a phylogenomic approach to characterize Group III B. cereus s.l. genomes which possess ces (ces-positive) alongside their closely related ces-negative counterparts to (i) assess the genomic diversity encompassed by “emetic B. cereus”, and (ii) identify potential ces loss and/or gain events within the evolutionary history of the high-risk and medically relevant sequence type (ST) 26 lineage often associated with emetic foodborne illness. Using all publicly available ces-positive Group III B. cereus s.l. genomes and the ces-negative genomes interspersed among them (n = 150), we show that “emetic B. cereus” is not clonal; rather, multiple lineages within Group III harbor cereulide-producing strains, all of which share a common ancestor incapable of producing cereulide (posterior probability [PP] 0.86-0.89). The ST 26 common ancestor was predicted to have emerged as ces-negative (PP 0.60-0.93) circa 1904 (95% highest posterior density [HPD] interval 1837.1-1957.8) and first acquired the ability to produce cereulide before 1931 (95% HPD 1893.2-1959.0). Three subsequent ces loss events within ST 26 were observed, including among isolates responsible for B. cereus s.l. toxicoinfection (i.e., “diarrheal” illness).Importance“B. cereus” is responsible for thousands of cases of foodborne disease each year worldwide, causing two distinct forms of illness: (i) intoxication via cereulide (i.e., “emetic” syndrome) or (ii) toxicoinfection via multiple enterotoxins (i.e., “diarrheal” syndrome). Here, we show that “emetic B. cereus” is not a clonal, homogenous unit that resulted from a single cereulide synthetase gain event followed by subsequent proliferation; rather, cereulide synthetase acquisition and loss is a dynamic, ongoing process that occurs across lineages, allowing some Group III B. cereus s.l. populations to oscillate between diarrheal and emetic foodborne pathogen over the course of their evolutionary histories. We also highlight the care that must be taken when selecting a reference genome for whole-genome sequencing-based investigation of emetic B. cereus s.l. outbreaks, as some reference genome selections can lead to a confounding loss of resolution and potentially hinder epidemiological investigations.


2021 ◽  
Author(s):  
Stéphane Peyrégne ◽  
Janet Kelso ◽  
Benjamin Marco Peter ◽  
Svante Pääbo

Proteins associated with the spindle apparatus, a cytoskeletal structure that ensures the proper segregation of chromosomes during cell division, experienced an unusual number of amino acid substitutions in modern humans after the split from the ancestors of Neandertals and Denisovans. Here, we analyze the history of these substitutions and show that some of the genes in which they occur may have been targets of positive selection. We also find that the two changes in the kinetochore scaffold 1 (KNL1) protein, previously believed to be specific to modern humans, were present in some Neandertals. We show that the KNL1 gene of these Neandertals shared a common ancestor with present-day Africans about 200,000 years ago due to gene flow from the ancestors (or relatives) of modern humans into Neandertals. Subsequently, some non-Africans inherited this modern human-like gene variant from Neandertals, but none inherited the ancestral gene variants. These results add to the growing evidence of early contacts between modern humans and archaic groups in Eurasia and illustrate the intricate relationships among these groups.


2020 ◽  
Author(s):  
Roberto Feuda ◽  
Matthew Goulty ◽  
Nicola Zadra ◽  
Tiziana Gasparetti ◽  
Ezio Rosato ◽  
...  

AbstractOpsin receptors mediate the visual process in animals and their evolutionary history can provide precious hints on the ecological factors that underpin their diversification. Here we mined the genomes of more than 60 Dipteran species and reconstructed the evolution of their opsin genes in a phylogenetic framework. Our phylogenies indicate that dipterans possess an ancestral set of five core opsins which have undergone several lineage-specific events including an independent expansion of low wavelength opsins in flies and mosquitoes and numerous family specific duplications and losses. Molecular evolutionary studies indicate that gene turnover rate, overall mutation rate, and site-specific selective pressure are higher in Anopheles than in Drosophila; we found signs of positive selection in both lineages, including events possibly associated with their peculiar behaviour. Our findings indicate an extremely variable pattern of opsin evolution in dipterans, showcasing how two similarly aged radiations - Anopheles and Drosophila - can be characterized by contrasting dynamics in the evolution of this gene family.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dayana E. Salas-Leiva ◽  
Eelco C. Tromer ◽  
Bruce A. Curtis ◽  
Jon Jerlström-Hultqvist ◽  
Martin Kolisko ◽  
...  

AbstractCells replicate and segregate their DNA with precision. Previous studies showed that these regulated cell-cycle processes were present in the last eukaryotic common ancestor and that their core molecular parts are conserved across eukaryotes. However, some metamonad parasites have secondarily lost components of the DNA processing and segregation apparatuses. To clarify the evolutionary history of these systems in these unusual eukaryotes, we generated a genome assembly for the free-living metamonad Carpediemonas membranifera and carried out a comparative genomics analysis. Here, we show that parasitic and free-living metamonads harbor an incomplete set of proteins for processing and segregating DNA. Unexpectedly, Carpediemonas species are further streamlined, lacking the origin recognition complex, Cdc6 and most structural kinetochore subunits. Carpediemonas species are thus the first known eukaryotes that appear to lack this suite of conserved complexes, suggesting that they likely rely on yet-to-be-discovered or alternative mechanisms to carry out these fundamental processes.


2020 ◽  
Author(s):  
Sumanth Kumar Mutte ◽  
Dolf Weijers

ABSTRACTProtein oligomerization is a fundamental process to build complex functional modules. Domains that facilitate the oligomerization process are diverse and widespread in nature across all kingdoms of life. One such domain is the Phox and Bem1 (PB1) domain, which is functionally (relatively) well understood in the animal kingdom. However, beyond animals, neither the origin nor the evolutionary patterns of PB1-containing proteins are understood. While PB1 domain proteins have been found in other kingdoms, including plants, it is unclear how these relate to animal PB1 proteins.To address this question, we utilized large transcriptome datasets along with the proteomes of a broad range of species. We discovered eight PB1 domain-containing protein families in plants, along with three each in Protozoa and Chromista and four families in Fungi. Studying the deep evolutionary history of PB1 domains throughout eukaryotes revealed the presence of at least two, but likely three, ancestral PB1 copies in the Last Eukaryotic Common Ancestor (LECA). These three ancestral copies gave rise to multiple orthologues later in evolution. Tertiary structural models of these plant PB1 families, combined with Random Forest based classification, indicated family-specific differences attributed to the length of PB1 domain and the proportion of β-sheets.This study identifies novel PB1 families and reveals considerable complexity in the protein oligomerization potential at the origin of eukaryotes. The newly identified relationships provide an evolutionary basis to understand the diverse functional interactions of key regulatory proteins carrying PB1 domains across eukaryotic life.


2019 ◽  
Vol 127 (4) ◽  
pp. 863-875 ◽  
Author(s):  
Paula Lado ◽  
Hans Klompen

Abstract This study integrates biogeographical and phylogenetic data to determine the evolutionary history of the New World Dermacentor, and the origin of D. variabilis. The phylogenetic reconstructions presented here strongly support the hypothesis of an Afrotropical origin for Dermacentor, with later dispersal to Eurasia and the Nearctic. Phylogenetic and biogeographical data suggest that the genus reached the New World through the Beringia land bridge, from south-east Asia. The monophyly of the genus is supported, and most of the New World Dermacentor species appear as monophyletic. Dermacentor occidentals constitutes the sister lineage of D. variabilis, and the latter is subdivided into two well-supported clades: an eastern and a western clade. The western clade is genetically more variable than the eastern. The genus Dermacentor probably originated in Africa, and dispersed to the Palearctic and then to the New World through the Beringian route. Dermacentor variabilis appears to have originated in western North America, and then dispersed to eastern North America, probably in a single migration event.


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