scholarly journals Ambulacrarian insulin-related peptides and their putative receptors suggest how insulin and similar peptides may have evolved from Insulin-like Growth Factor

2021 ◽  
Author(s):  
Jan Adrianus Veenstra
Keyword(s):  
Receptor Tyrosine Kinase ◽  
Common Ancestor ◽  
Neuroendocrine Cells ◽  
Last Common Ancestor ◽  
Gene Duplications ◽  
Hormonal Signal ◽  
Intracellular Response ◽  
G Protein Coupled ◽  
The Brain ◽  
Insulin Like Growth Factors

Background: Insulin is evolutionarily related to the insulin-like growth factors (IGFs) and like the latter stimulates a receptor tyrosine kinase (RTK) that transfers the extracellular hormonal signal into an intracellular response. Other hormones related to insulin, such as relaxin, do not use an RTK, but a G-protein coupled receptor (GPCR). This is unusual since evolutionarily related hormones typically either use the same or paralogous receptors. In arthropods three different IGF-related peptides likely evolved from a gene triplication, as in several species genes coding these three peptides are located next to one another on the same chromosomal fragment. Of these three hormones one, an IGF-like hormone, acts through an RTK, while the other two use a GPCR. This suggests that the ancestral IGF-like peptide may have used both types of receptors. These arthropod insulin-like peptides have homologs in vertebrates, which suggests that the initial gene triplication was perhaps already present in the last common ancestor of deuterostomes and protostomes. It would be interesting to know whether this is indeed so and to establish how insulin and other insulin-like peptides might be related to this trio of IGF-related hormones. Methodology: Genes coding insulin and related peptides as well as their putative receptors were identified in genomes and transcriptomes from echinoderms and hemichordates. Results: A similar triplet of genes coding insulin-like peptides is also found in some hemichordates and echinoderms. Two of the three ambulacrarian peptides are orthologs of arthropod IGF and Drosophila insulin-like peptide 7 (dilp7), while the third one looks like an ortholog of the arthropod peptide gonadulin. In echinoderms two novel insulin-like peptides emerged, gonad stimulating substance (GSS) and multinsulin, likely from gene duplications of the IGF and dilp7-like genes respectively. However, no novel receptors for insulin-like peptides evolved. If IGF were to act through both a GPCR and an RTK it would suggest that GSS acts on only one of the two receptors, possibly the RTK. The evolution of GSS from IGF may represent a pattern, where IGF gene duplications lead to novel genes coding shorter peptides that have lost their ability to activate a GPCR. It is likely this is how insulin and the insect neuroendocrine insulin-like peptides evolved independently from IGF. Conclusion: The local gene triplication previously described from arthropods that yielded three genes coding IGF-related peptides was already present in the last common ancestor of protostomes and deuterostomes. It seems plausible that insulin and other insulin-like peptides, such as those produced by neuroendocrine cells in the brain of insects and echinoderm GSS evolved independently from IGF and thus are not true orthologs, but the result of convergent evolution.

scholarly journals Ambulacrarian insulin-related peptides and their putative receptors suggest how insulin and similar peptides may have evolved from insulin-like growth factor

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11799
Author(s):  
Jan A. Veenstra
Keyword(s):  
Common Ancestor ◽  
Amino Acid Sequences ◽  
Neuroendocrine Cells ◽  
Last Common Ancestor ◽  
Gene Duplications ◽  
The Third ◽  
Genes Encoding ◽  
Hormonal Signal ◽  
Intracellular Response ◽  
G Protein Coupled

Background Some insulin/IGF-related peptides (irps) stimulate a receptor tyrosine kinase (RTK) that transfers the extracellular hormonal signal into an intracellular response. Other irps, such as relaxin, do not use an RTK, but a G-protein coupled receptor (GPCR). This is unusual since evolutionarily related hormones typically either use the same or paralogous receptors. In arthropods three different irps, i.e. arthropod IGF, gonadulin and Drosophila insulin-like peptide 7 (dilp7), likely evolved from a gene triplication, as in several species genes encoding these three peptides are located next to one another on the same chromosomal fragment. These arthropod irps have homologs in vertebrates, suggesting that the initial gene triplication was perhaps already present in the last common ancestor of deuterostomes and protostomes. It would be interesting to know whether this is indeed so and how insulin might be related to this trio of irps. Methodology Genes encoding irps as well as their putative receptors were identified in genomes and transcriptomes from echinoderms and hemichordates. Results A similar triplet of genes coding for irps also occurs in some ambulacrarians. Two of these are orthologs of arthropod IGF and dilp7 and the third is likely a gonadulin ortholog. In echinoderms, two novel irps emerged, gonad stimulating substance (GSS) and multinsulin, likely from gene duplications of the IGF and dilp7-like genes respectively. The structures of GSS diverged considerably from IGF, which would suggest they use different receptors from IGF, but no novel irp receptors evolved. If IGF and GSS use different receptors, and the evolution of GSS from a gene duplication of IGF is not associated with the appearance of a novel receptor, while irps are known to use two different types of receptors, the ancestor of GSS and IGF might have acted on both types of receptors while one or both of its descendants act on only one. There are three ambulacrarian GPCRs that have amino acid sequences suggestive of being irp GPCRs, two of these are orthologs of the gonadulin and dilp7 receptors. This suggests that the third might be an IGF receptor, and that by deduction, GSS only acts on the RTK. The evolution of GSS from IGF may represent a pattern, where IGF gene duplications lead to novel genes coding for shorter peptides that activate an RTK. It is likely this is how insulin and the insect neuroendocrine irps evolved independently from IGF. Conclusion The local gene triplication described from arthropods that yielded three genes encoding irps was already present in the last common ancestor of protostomes and deuterostomes. It seems plausible that irps, such as those produced by neuroendocrine cells in the brain of insects and echinoderm GSS evolved independently from IGF and, thus, are not true orthologs, but the result of convergent evolution.

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.

scholarly journals The comparative neuroprimatology 2018 (CNP-2018) road map for research on How the Brain Got Language

2018 ◽  
Vol 19 (1-2) ◽  
pp. 370-387 ◽  
Author(s):  
Michael A. Arbib ◽  
Francisco Aboitiz ◽  
Judith M. Burkart ◽  
Michael Corballis ◽  
Gino Coudé ◽  
...  
Keyword(s):  
Comparative Study ◽  
Cultural Evolution ◽  
Common Ancestor ◽  
Great Apes ◽  
Last Common Ancestor ◽  
Road Map ◽  
The Rich ◽  
The Comparative Study ◽  
Brain Behavior ◽  
The Brain

Abstract We present a new road map for research on “How the Brain Got Language” that adopts an EvoDevoSocio perspective and highlights comparative neuroprimatology – the comparative study of brain, behavior and communication in extant monkeys and great apes – as providing a key grounding for hypotheses on the last common ancestor of humans and monkeys (LCA-m) and chimpanzees (LCA-c) and the processes which guided the evolution LCA-m → LCA-c → protohumans → H. sapiens. Such research constrains and is constrained by analysis of the subsequent, primarily cultural, evolution of H. sapiens which yielded cultures involving the rich use of language.

Computational challenges of evolving the language-ready brain

2018 ◽  
Vol 19 (1-2) ◽  
pp. 7-21 ◽  
Author(s):  
Michael A. Arbib
Keyword(s):  
Computational Modeling ◽  
Common Ancestor ◽  
Homo Sapiens ◽  
Mirror System ◽  
Last Common Ancestor ◽  
New Challenges ◽  
The Brain

Abstract Computational modeling of the macaque brain grounds hypotheses on the brain of LCA-m (the last common ancestor of monkey and human). Elaborations thereof provide a brain model for LCA-c (c for chimpanzee). The Mirror System Hypothesis charts further steps via imitation and pantomime to protosign and protolanguage on the path to a "language-ready brain" in Homo sapiens, with the path to speech being indirect. The material poses new challenges for both experimentation and modeling.

scholarly journals Carbonic Anhydrases: An Ancient Tool in Calcareous Sponge Biomineralization

2021 ◽  
Vol 12 ◽  
Author(s):  
Oliver Voigt ◽  
Benedetta Fradusco ◽  
Carolin Gut ◽  
Charalampos Kevrekidis ◽  
Sergio Vargas ◽  
...  
Keyword(s):  
Gene Family ◽  
Common Ancestor ◽  
Last Common Ancestor ◽  
Gene Duplications ◽  
Carbonic Anhydrases ◽  
Temporal Expression ◽  
Additional Species ◽  
Calcareous Sponges ◽  
Membrane Bound

Enzymes of the α-carbonic anhydrase gene family (CAs) are essential for the deposition of calcium carbonate biominerals. In calcareous sponges (phylum Porifera, class Calcarea), specific CAs are involved in the formation of calcite spicules, a unique trait and synapomorphy of this class. However, detailed studies on the CA repertoire of calcareous sponges exist for only two species of one of the two Calcarea subclasses, the Calcaronea. The CA repertoire of the second subclass, the Calcinea, has not been investigated so far, leaving a considerable gap in our knowledge about this gene family in Calcarea. Here, using transcriptomic analysis, phylogenetics, and in situ hybridization, we study the CA repertoire of four additional species of calcareous sponges, including three from the previously unsampled subclass Calcinea. Our data indicate that the last common ancestor of Calcarea had four ancestral CAs with defined subcellular localizations and functions (mitochondrial/cytosolic, membrane-bound, and secreted non-catalytic). The evolution of membrane-bound and secreted CAs involved gene duplications and losses, whereas mitochondrial/cytosolic and non-catalytic CAs are evidently orthologous genes. Mitochondrial/cytosolic CAs are biomineralization-specific genes recruited for biomineralization in the last common ancestor of calcareous sponges. The spatial–temporal expression of these CAs differs between species, which may reflect differences between subclasses or be related to the secondary thickening of spicules during biomineralization that does not occur in all species. With this study, we extend the understanding of the role and the evolution of a key biomineralization gene in calcareous sponges.

The cranial structure of the Triconodonts

1963 ◽  
Vol 246 (727) ◽  
pp. 83-103 ◽  
Keyword(s):  
Common Ancestor ◽  
British Museum ◽  
Lateral Wall ◽  
Upper Jurassic ◽  
Last Common Ancestor ◽  
Lateral Boundary ◽  
Cranial Cavity ◽  
Chemical Methods ◽  
Mesozoic Mammals ◽  
The Brain

This paper is a study of the structure of the braincase in two closely related Mesozoic mammals: Triconodon mordax and Trioracodon ferox . They belong to the order Triconodonta, subfamily Triconodontinae, and are from the English Upper Jurassic (Purbeck). One specimen of each species was available showing cranial structure, both from the collection in the British Museum. By chemical methods, both petrosals and the sphenoid of the specimen of Triconodon and both petrosals of the specimen of Trioracodon were prepared. The material shows that the Triconodonta had a braincase of an essentially reptilian pattern. There was a persistent cavum epiptericum lying outside the ossified lateral wall (formed by the petrosal) of the braincase. The alisphenoid, forming the lateral boundary of the cavum epiptericum, formed no part of the braincase wall in this region. This was also true of the Rhaetic Morganucodon , and may have been true of all pre-Cretaceous mammals. In basic construction the braincase of these mammals differs from that of an advanced therapsid only in the narrower cavum epiptericum in the former. This difference is due to the relatively larger size of the brain in the mammal. To convert a braincase constructed in this way into that of a modern mammal either the alisphenoid would have to be lost—leading to the condition found in the monotremes—or the lateral wall of the neurocranum would have to fail to ossify—thus incorporating the cavum epiptericum in the cranial cavity in the manner typical of marsupials and placentals. Although on these grounds alone the monotreme stock need not have separated from that which gave rise to the marsupials and placentals until early in the Cretaceous, other considerations suggest that the last common ancestor lived in Triassic times at the reptilian grade of organization. There seems, however, less reason than formerly to consider Morganucodon an ancestral monotreme. Finally, a reconsideration of all the evidence shows that there was no acceleration of evolutionary rates at the time the Mammalia came into existence.

scholarly journals Family of neural wiring receptors in bilaterians defined by phylogenetic, biochemical, and structural evidence

2019 ◽  
Vol 116 (20) ◽  
pp. 9837-9842 ◽  
Author(s):  
Shouqiang Cheng ◽  
Yeonwoo Park ◽  
Justyna D. Kurleto ◽  
Mili Jeon ◽  
Kai Zinn ◽  
...  
Keyword(s):  
Neural Development ◽  
Surface Proteins ◽  
Axonal Guidance ◽  
Last Common Ancestor ◽  
Gene Duplications ◽  
Synaptic Targeting ◽  
Surface Receptors ◽  
Structural Relationships ◽  
Synapse Targeting ◽  
The Brain

The evolution of complex nervous systems was accompanied by the expansion of numerous protein families, including cell-adhesion molecules, surface receptors, and their ligands. These proteins mediate axonal guidance, synapse targeting, and other neuronal wiring-related functions. Recently, 32 interacting cell surface proteins belonging to two newly defined families of the Ig superfamily (IgSF) in fruit flies were discovered to label different subsets of neurons in the brain and ventral nerve cord. They have been shown to be involved in synaptic targeting and morphogenesis, retrograde signaling, and neuronal survival. Here, we show that these proteins, Dprs and DIPs, are members of a widely distributed family of two- and three-Ig domain molecules with neuronal wiring functions, which we refer to as Wirins. Beginning from a single ancestral Wirin gene in the last common ancestor of Bilateria, numerous gene duplications produced the heterophilic Dprs and DIPs in protostomes, along with two other subfamilies that diversified independently across protostome phyla. In deuterostomes, the ancestral Wirin evolved into the IgLON subfamily of neuronal receptors. We show that IgLONs interact with each other and that their complexes can be broken by mutations designed using homology models based on Dpr and DIP structures. The nematode orthologs ZIG-8 and RIG-5 also form heterophilic and homophilic complexes, and crystal structures reveal numerous apparently ancestral features shared with Dpr-DIP complexes. The evolutionary, biochemical, and structural relationships we demonstrate here provide insights into neural development and the rise of the metazoan nervous system.

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 Molecular mechanisms of metabotropic GABAB receptor function

2021 ◽  
Vol 7 (22) ◽  
pp. eabg3362
Author(s):  
Hamidreza Shaye ◽  
Benjamin Stauch ◽  
Cornelius Gati ◽  
Vadim Cherezov
Keyword(s):  
G Protein ◽  
Molecular Mechanisms ◽  
Gabab Receptor ◽  
Neurological Diseases ◽  
Activation Mechanism ◽  
Allosteric Modulators ◽  
Inhibitory Neurotransmitter ◽  
Therapeutic Drugs ◽  
G Protein Coupled ◽  
The Brain

Metabotropic γ-aminobutyric acid G protein–coupled receptors (GABAB) represent one of the two main types of inhibitory neurotransmitter receptors in the brain. These receptors act both pre- and postsynaptically by modulating the transmission of neuronal signals and are involved in a range of neurological diseases, from alcohol addiction to epilepsy. A series of recent cryo-EM studies revealed critical details of the activation mechanism of GABAB. Structures are now available for the receptor bound to ligands with different modes of action, including antagonists, agonists, and positive allosteric modulators, and captured in different conformational states from the inactive apo to the fully active state bound to a G protein. These discoveries provide comprehensive insights into the activation of the GABAB receptor, which not only broaden our understanding of its structure, pharmacology, and physiological effects but also will ultimately facilitate the discovery of new therapeutic drugs and neuromodulators.

scholarly journals Potential for imaging the high-affinity state of the 5-HT1B receptor: a comparison of three PET radioligands with differing intrinsic activity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anton Lindberg ◽  
Ryosuke Arakawa ◽  
Tsuyoshi Nogami ◽  
Sangram Nag ◽  
Magnus Schou ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Specific Binding ◽  
Occipital Cortex ◽  
Intrinsic Activity ◽  
High Affinity ◽  
G Protein Coupled ◽  
Dose Dependent ◽  
The Brain ◽  
Agonist Affinity States ◽  
Different Doses

Abstract Background Over the last decade, a few radioligands have been developed for PET imaging of brain 5-HT1B receptors. The 5-HT1B receptor is a G-protein-coupled receptor (GPCR) that exists in two different agonist affinity states. An agonist ligand is expected to be more sensitive towards competition from another agonist, such as endogenous 5-HT, than an antagonist ligand. It is of interest to know whether the intrinsic activity of a PET radioligand for the 5-HT1B receptor impacts on its ability to detect changes in endogenous synaptic 5-HT density. Three high-affinity 11C-labeled 5-HT1B PET radioligands with differing intrinsic activity were applied to PET measurements in cynomolgus monkey to evaluate their sensitivity to be displaced within the brain by endogenous 5-HT. For these experiments, fenfluramine was pre-administered at two different doses (1.0 and 5.0 mg/kg, i.v.) to induce synaptic 5-HT release. Results A dose-dependent response to fenfluramine was detected for all three radioligands. At the highest dose of fenfluramine (5.0 mg/kg, i.v.), reductions in specific binding in the occipital cortex increased with radioligand agonist efficacy, reaching 61% for [11C]3. The most antagonistic radioligand showed the lowest reduction in specific binding. Conclusions Three 5-HT1B PET radioligands were identified with differing intrinsic activity that could be used in imaging high- and low-affinity states of 5-HT1B receptors using PET. From this limited study, radioligand sensitivity to endogenous 5-HT appears to depend on agonist efficacy. More extensive studies are required to substantiate this suggestion.

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