scholarly journals Ancient origins of arthropod moulting pathway components

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
André Luiz de Oliveira ◽  
Andrew Calcino ◽  
Andreas Wanninger
Keyword(s):  
Common Ancestor ◽  
Mnemiopsis Leidyi ◽  
Last Common Ancestor ◽  
Prothoracicotropic Hormone ◽  
Eclosion Hormone ◽  
First Case ◽  
Signalling Molecule ◽  
Ecdysis Triggering Hormone ◽  
Extracellular Signalling ◽  
Signalling Cascade

Ecdysis (moulting) is the defining character of Ecdysoza (arthropods, nematodes and related phyla). Despite superficial similarities, the signalling cascade underlying moulting differs between Panarthropoda and the remaining ecdysozoans. Here, we reconstruct the evolution of major components of the ecdysis pathway. Its key elements evolved much earlier than previously thought and are present in non-moulting lophotrochozoans and deuterostomes. Eclosion hormone (EH) and bursicon originated prior to the cnidarian-bilaterian split, whereas ecdysis-triggering hormone (ETH) and crustacean cardioactive peptide (CCAP) evolved in the bilaterian last common ancestor (LCA). Identification of EH, CCAP and bursicon in Onychophora and EH, ETH and CCAP in Tardigrada suggests that the pathway was present in the panarthropod LCA. Trunk, an ancient extracellular signalling molecule and a well-established paralog of the insect peptide prothoracicotropic hormone (PTTH), is present in the non-bilaterian ctenophore Mnemiopsis leidyi. This constitutes the first case of a ctenophore signalling peptide with homology to a neuropeptide.

scholarly journals Experimental evidence for yawn contagion in orangutans (Pongo pygmaeus)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Evy van Berlo ◽  
Alejandra P. Díaz-Loyo ◽  
Oscar E. Juárez-Mora ◽  
Mariska E. Kret ◽  
Jorg J. M. Massen
Keyword(s):  
Experimental Evidence ◽  
Common Ancestor ◽  
Great Apes ◽  
Pongo Pygmaeus ◽  
Last Common Ancestor ◽  
Contagious Yawning ◽  
Proximate Mechanism ◽  
Social Species ◽  
Ultimate Causation

AbstractYawning is highly contagious, yet both its proximate mechanism(s) and its ultimate causation remain poorly understood. Scholars have suggested a link between contagious yawning (CY) and sociality due to its appearance in mostly social species. Nevertheless, as findings are inconsistent, CY’s function and evolution remains heavily debated. One way to understand the evolution of CY is by studying it in hominids. Although CY has been found in chimpanzees and bonobos, but is absent in gorillas, data on orangutans are missing despite them being the least social hominid. Orangutans are thus interesting for understanding CY’s phylogeny. Here, we experimentally tested whether orangutans yawn contagiously in response to videos of conspecifics yawning. Furthermore, we investigated whether CY was affected by familiarity with the yawning individual (i.e. a familiar or unfamiliar conspecific and a 3D orangutan avatar). In 700 trials across 8 individuals, we found that orangutans are more likely to yawn in response to yawn videos compared to control videos of conspecifics, but not to yawn videos of the avatar. Interestingly, CY occurred regardless of whether a conspecific was familiar or unfamiliar. We conclude that CY was likely already present in the last common ancestor of humans and great apes, though more converging evidence is needed.

scholarly journals Recombinant transfer in the basic genome ofEscherichia coli

2015 ◽  
Vol 112 (29) ◽  
pp. 9070-9075 ◽  
Author(s):  
Purushottam D. Dixit ◽  
Tin Yau Pang ◽  
F. William Studier ◽  
Sergei Maslov
Keyword(s):  
Common Ancestor ◽  
Recipient Cell ◽  
Gene Clusters ◽  
Selective Advantage ◽  
Last Common Ancestor ◽  
Genome Sequences ◽  
Bacterial Genomes ◽  
Basic Genome ◽  
Single Base Pair ◽  
Generalized Transduction

An approximation to the ∼4-Mbp basic genome shared by 32 strains ofEscherichia colirepresenting six evolutionary groups has been derived and analyzed computationally. A multiple alignment of the 32 complete genome sequences was filtered to remove mobile elements and identify the most reliable ∼90% of the aligned length of each of the resulting 496 basic-genome pairs. Patterns of single base-pair mutations (SNPs) in aligned pairs distinguish clonally inherited regions from regions where either genome has acquired DNA fragments from diverged genomes by homologous recombination since their last common ancestor. Such recombinant transfer is pervasive across the basic genome, mostly between genomes in the same evolutionary group, and generates many unique mosaic patterns. The six least-diverged genome pairs have one or two recombinant transfers of length ∼40–115 kbp (and few if any other transfers), each containing one or more gene clusters known to confer strong selective advantage in some environments. Moderately diverged genome pairs (0.4–1% SNPs) show mosaic patterns of interspersed clonal and recombinant regions of varying lengths throughout the basic genome, whereas more highly diverged pairs within an evolutionary group or pairs between evolutionary groups having >1.3% SNPs have few clonal matches longer than a few kilobase pairs. Many recombinant transfers appear to incorporate fragments of the entering DNA produced by restriction systems of the recipient cell. A simple computational model can closely fit the data. Most recombinant transfers seem likely to be due to generalized transduction by coevolving populations of phages, which could efficiently distribute variability throughout bacterial genomes.

Improved resolution of recalcitrant nodes in the animal phylogeny through the analysis of genome gene content and morphology

2021 ◽  
Author(s):  
Ksenia Juravel ◽  
Luis Porras ◽  
Sebastian Hoehna ◽  
Davide Pisani ◽  
Gert Wörheide
Keyword(s):  
Common Ancestor ◽  
Sister Group ◽  
The Other ◽  
Gene Content ◽  
Statistical Hypothesis ◽  
Phylogenetic Position ◽  
Last Common Ancestor ◽  
Statistical Hypothesis Testing ◽  
Animal Phylogeny ◽  
Phylogenetic Hypotheses

An accurate phylogeny of animals is needed to clarify their evolution, ecology, and impact on shaping the biosphere. Although multi-gene alignments of up to several hundred thousand amino acids are nowadays routinely used to test hypotheses of animal relationships, some nodes towards the root of the animal phylogeny are proving hard to resolve. While the relationships of the non-bilaterian lineages, primarily sponges (Porifera) and comb jellies (Ctenophora), have received much attention since more than a decade, controversies about the phylogenetic position of the worm-like bilaterian lineage Xenacoelomorpha and the monophyly of the "Superphylum" Deuterostomia have more recently emerged. Here we independently analyse novel genome gene content and morphological datasets to assess patterns of phylogenetic congruence with previous amino-acid derived phylogenetic hypotheses. Using statistical hypothesis testing, we show that both our datasets very strongly support sponges as the sister group of all the other animals, Xenoacoelomorpha as the sister group of the other Bilateria, and largely support monophyletic Deuterostomia. Based on these results, we conclude that the last common animal ancestor may have been a simple, filter-feeding organism without a nervous system and muscles, while the last common ancestor of Bilateria might have been a small, acoelomate-like worm without a through gut.

Inductive patterning of the embryonic brain in Drosophila

Development ◽  
2002 ◽  
Vol 129 (9) ◽  
pp. 2121-2128
Author(s):  
Damon T. Page
Keyword(s):  
Brain Development ◽  
Common Ancestor ◽  
Last Common Ancestor ◽  
Embryonic Brain ◽  
Germ Layers ◽  
Brain Anomaly ◽  
Prechordal Plate ◽  
Foregut Endoderm ◽  
The Brain ◽  
Brain Patterning

In vertebrates (deuterostomes), brain patterning depends on signals from adjacent tissues. For example, holoprosencephaly, the most common brain anomaly in humans, results from defects in signaling between the embryonic prechordal plate (consisting of the dorsal foregut endoderm and mesoderm) and the brain. I have examined whether a similar mechanism of brain development occurs in the protostome Drosophila, and find that the foregut and mesoderm act to pattern the fly embryonic brain. When the foregut and mesoderm of Drosophila are ablated, brain patterning is disrupted. The loss of Hedgehog expressed in the foregut appears to mediate this effect, as it does in vertebrates. One mechanism whereby these defects occur is a disruption of normal apoptosis in the brain. These data argue that the last common ancestor of protostomes and deuterostomes had a prototype of the brains present in modern animals, and also suggest that the foregut and mesoderm contributed to the patterning of this ‘proto-brain’. They also argue that the foreguts of protostomes and deuterostomes, which have traditionally been assigned to different germ layers, are actually homologous.

Natural history of ABC systems: not only transporters

2011 ◽  
Vol 50 ◽  
pp. 19-42 ◽  
Author(s):  
Elie Dassa
Keyword(s):  
Common Ancestor ◽  
Three Dimensional ◽  
Last Common Ancestor ◽  
Abc Proteins ◽  
Hypothetical Scenario ◽  
History Of ◽  
Phylogenetic Perspective ◽  
Living Organisms

In recent years, our understanding of the functioning of ABC (ATP-binding cassette) systems has been boosted by the combination of biochemical and structural approaches. However, the origin and the distribution of ABC proteins among living organisms are difficult to understand in a phylogenetic perspective, because it is hard to discriminate orthology and paralogy, due to the existence of horizontal gene transfer. In this chapter, I present an update of the classification of ABC systems and discuss a hypothetical scenario of their evolution. The hypothetical presence of ABC ATPases in the last common ancestor of modern organisms is discussed, as well as the additional possibility that ABC systems might have been transmitted to eukaryotes, after the two endosymbiosis events that led to the constitution of eukaryotic organelles. I update the functional information of selected ABC systems and introduce new families of ABC proteins that have been included recently into this vast superfamily, thanks to the availability of high-resolution three-dimensional structures.

scholarly journals The rosetteless gene controls development in the choanoflagellate S. rosetta

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Tera C Levin ◽  
Allison J Greaney ◽  
Laura Wetzel ◽  
Nicole King
Keyword(s):  
Innate Immunity ◽  
Single Cell ◽  
Common Ancestor ◽  
Forward Genetics ◽  
Last Common Ancestor ◽  
Salpingoeca Rosetta

The origin of animal multicellularity may be reconstructed by comparing animals with one of their closest living relatives, the choanoflagellate Salpingoeca rosetta. Just as animals develop from a single cell–the zygote–multicellular rosettes of S. rosetta develop from a founding cell. To investigate rosette development, we established forward genetics in S. rosetta. We find that the rosette defect of one mutant, named Rosetteless, maps to a predicted C-type lectin, a class of signaling and adhesion genes required for the development and innate immunity in animals. Rosetteless protein is essential for rosette development and forms an extracellular layer that coats and connects the basal poles of each cell in rosettes. This study provides the first link between genotype and phenotype in choanoflagellates and raises the possibility that a protein with C-type lectin-like domains regulated development in the last common ancestor of choanoflagellates and animals.

scholarly journals Geoffrey Burnstock. 10 May 1929—3 June 2020

2021 ◽  
Author(s):  
R. Alan North ◽  
Marcello Costa
Keyword(s):  
P2y Receptors ◽  
Autonomic Nerves ◽  
Purine Nucleotides ◽  
Biomedical Scientist ◽  
Signalling Molecule ◽  
University College London ◽  
University Colleges ◽  
The University ◽  
G Protein Coupled ◽  
Extracellular Signalling

Geoffrey Burnstock was a biomedical scientist who gained renown for his discovery that adenosine 5′-triphosphate (ATP) functions as an extracellular signalling molecule. Born in London and educated at King's and University colleges, he did postdoctoral work at Mill Hill and Oxford. He moved in 1959 to the Department of Zoology at the University of Melbourne because he sensed there a greater freedom to challenge established thinking in physiology. His group found that transmission from sympathetic and parasympathetic autonomic nerves to smooth muscle was in some places not mediated by the accepted chemical messengers (noradrenaline and acetylcholine). He amassed evidence that ATP was this non-adrenergic, non-cholinergic transmitter, using biochemical, histological and electrophysiological approaches: heretically, he styled this ‘purinergic transmission’. Geoff further upset dogma in the 1970s by proposing ‘co-transmission’ in which some nerves released ATP in addition to either noradrenaline or acetylcholine. He distinguished pharmacologically P1 receptors (activated best by adenosine and blocked by xanthines) and P2 receptors (activated best by purine nucleotides such as ATP) and he proposed in 1985 that the latter embraced P2X (ion channel) and P2Y (G protein-coupled) subtypes: about 10 years later these categories were substantiated by cDNA cloning. From 1975 until his retirement in 1997, Geoff was head of the Department of Anatomy and Embryology at University College London (UCL), which he developed energetically into a large and strong research department. Later, as head of the Autonomic Research Institute at the Royal Free (part of UCL), he continued to collaborate extensively, and founded several journals and international professional societies. He widely sought clinical benefit for his discoveries, and both P2X and P2Y receptors have been developed as the targets of useful therapeutics (gefapixant, clopidogrel). Geoff was proud of his modest, rather humble, background and eschewed formality. He may have smiled when his early discoveries were met with cynicism, even ridicule (‘pure-imagine’ transmission noted one amusing critic), but this just reinforced his resolve and encouraged his encyclopaedic oeuvre.

scholarly journals Body mass estimates of the earliest possible hominins and implications for the last common ancestor

2018 ◽  
Vol 122 ◽  
pp. 84-92 ◽  
Author(s):  
Mark Grabowski ◽  
Kevin G. Hatala ◽  
William L. Jungers
Keyword(s):  
Body Mass ◽  
Common Ancestor ◽  
Last Common Ancestor

scholarly journals Sawfly Genomes Reveal Evolutionary Acquisitions That Fostered the Mega-Radiation of Parasitoid and Eusocial Hymenoptera

2020 ◽  
Vol 12 (7) ◽  
pp. 1099-1188
Author(s):  
Jan Philip Oeyen ◽  
Patrice Baa-Puyoulet ◽  
Joshua B Benoit ◽  
Leo W Beukeboom ◽  
Erich Bornberg-Bauer ◽  
...  
Keyword(s):  
Species Richness ◽  
Transposable Element ◽  
Common Ancestor ◽  
Odorant Receptors ◽  
Last Common Ancestor ◽  
Gene Repertoire ◽  
Genome Sequences ◽  
Reliable Identification ◽  
Efficient Detection ◽  
Co2 Detection

Abstract The tremendous diversity of Hymenoptera is commonly attributed to the evolution of parasitoidism in the last common ancestor of parasitoid sawflies (Orussidae) and wasp-waisted Hymenoptera (Apocrita). However, Apocrita and Orussidae differ dramatically in their species richness, indicating that the diversification of Apocrita was promoted by additional traits. These traits have remained elusive due to a paucity of sawfly genome sequences, in particular those of parasitoid sawflies. Here, we present comparative analyses of draft genomes of the primarily phytophagous sawfly Athalia rosae and the parasitoid sawfly Orussus abietinus. Our analyses revealed that the ancestral hymenopteran genome exhibited traits that were previously considered unique to eusocial Apocrita (e.g., low transposable element content and activity) and a wider gene repertoire than previously thought (e.g., genes for CO2 detection). Moreover, we discovered that Apocrita evolved a significantly larger array of odorant receptors than sawflies, which could be relevant to the remarkable diversification of Apocrita by enabling efficient detection and reliable identification of hosts.

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