scholarly journals Changes in the neuropeptide complement correlate with nervous system architectures in xenacoelomorphs

2018 ◽  
Author(s):  
Daniel Thiel ◽  
Mirita Franz-Wachtel ◽  
Felipe Aguilera ◽  
Andreas Hejnol

AbstractNeuropeptides are essential neurosecretory signaling molecules common in protostomes and deuterostomes (together Nephrozoa). Not much, however, is known about the neuropeptide complement of the sister group Xenacoelomorpha. This group is comprised of the three clades Xenoturbella, Nemertodermatida, and Acoela, which differ strongly in their nervous system anatomy. In order to reconstruct the ancestral bilaterian neuropeptide complement and gain insights into neuropeptide evolution within Xenacoelomorpha, we analyzed transcriptomes of 13 acoels, nemertodermatids, and Xenoturbella species. Together with motif searches, similarity searches, mass spectrometry and phylogenetic analyses of neuropeptide precursors and neuropeptide receptors, we reconstruct the xenacoelomorph neuropeptide complement. Our comparison of xenacoelomorph GPCRs with cnidarian and nephrozoan neuropeptide receptors shows that the neuropeptide signaling diversified into at least 20 ancestral peptidergic systems in the lineage to Bilateria. We find that Xenoturbella species possess many of the ancestral bilaterian peptidergic systems and only a few clade-specific neuropeptides. Nemertodermatids seem to have nearly the complete complement of ancestral bilaterian systems and several novel neuropeptides. Acoels show an extensive loss of conserved bilaterian systems, but gained the highest number of novel and group-specific neuropeptides. While it is difficult to correlate the emergence of the bilaterian neuropeptide complement with the evolution of centralized nervous systems, we find a correlation between nervous system novelties and the expansion of taxon-specific neuropeptides in Xenacoelomorpha.

2011 ◽  
Vol 57 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Ankur Abhishek ◽  
Anish Bavishi ◽  
Ashay Bavishi ◽  
Madhusudan Choudhary

Many studies have sought to determine the origin and evolution of mitochondria. Although the Alphaproteobacteria are thought to be the closest relatives of the mitochondrial progenitor, there is dispute as to what its particular sister group is. Some have argued that mitochondria originated from ancestors of the order Rickettsiales, or more specifically of the Rickettsiaceae family, while others believe that ancestors of the family Rhodospirillaceae are also equally likely the progenitors. To resolve some of these disputes, sequence similarity searches and phylogenetic analyses were performed against mitochondria-related proteins in Saccharomyces cerevisiae . The 86 common matches of 5 Alphaproteobacteria ( Rickettsia prowazekii , Rhodospirillum rubrum , R hodopseudomonas palustris , Rhodobacter sphaeroides , and Ochrobactrum anthropi ) to yeast mitochondrial proteins were distributed fairly evenly among the 5 species when sorted by highest identity or score. Moreover, exploratory phylogenetic analyses revealed that among these common matches, 44.19% (38) had branched most closely with O. anthropi, while only 34.88% (30) corresponded with Rickettsia prowazekii. More detailed phylogenetic analyses with additional Alphaproteobacteria and including genes from the mitochondria of Reclinomonas americana found matches of mitochondrial genes to those of members of the Rickettsiaceae, Anaplasmataceae, and Rhodospirillaceae families. The results support the idea that notable bacterial genome chimaerism has occurred en route to the formation of mitochondria.


2015 ◽  
Vol 370 (1684) ◽  
pp. 20150065 ◽  
Author(s):  
Iva Kelava ◽  
Fabian Rentzsch ◽  
Ulrich Technau

Cnidarians, the sister group to bilaterians, have a simple diffuse nervous system. This morphological simplicity and their phylogenetic position make them a crucial group in the study of the evolution of the nervous system. The development of their nervous systems is of particular interest, as by uncovering the genetic programme that underlies it, and comparing it with the bilaterian developmental programme, it is possible to make assumptions about the genes and processes involved in the development of ancestral nervous systems. Recent advances in sequencing methods, genetic interference techniques and transgenic technology have enabled us to get a first glimpse into the molecular network underlying the development of a cnidarian nervous system—in particular the nervous system of the anthozoan Nematostella vectensis . It appears that much of the genetic network of the nervous system development is partly conserved between cnidarians and bilaterians, with Wnt and bone morphogenetic protein (BMP) signalling, and Sox genes playing a crucial part in the differentiation of neurons. However, cnidarians possess some specific characteristics, and further studies are necessary to elucidate the full regulatory network. The work on cnidarian neurogenesis further accentuates the need to study non-model organisms in order to gain insights into processes that shaped present-day lineages during the course of evolution.


2019 ◽  
Vol 44 (4) ◽  
pp. 930-942
Author(s):  
Geraldine A. Allen ◽  
Luc Brouillet ◽  
John C. Semple ◽  
Heidi J. Guest ◽  
Robert Underhill

Abstract—Doellingeria and Eucephalus form the earliest-diverging clade of the North American Astereae lineage. Phylogenetic analyses of both nuclear and plastid sequence data show that the Doellingeria-Eucephalus clade consists of two main subclades that differ from current circumscriptions of the two genera. Doellingeria is the sister group to E. elegans, and the Doellingeria + E. elegans subclade in turn is sister to the subclade containing all remaining species of Eucephalus. In the plastid phylogeny, the two subclades are deeply divergent, a pattern that is consistent with an ancient hybridization event involving ancestral species of the Doellingeria-Eucephalus clade and an ancestral taxon of a related North American or South American group. Divergence of the two Doellingeria-Eucephalus subclades may have occurred in association with northward migration from South American ancestors. We combine these two genera under the older of the two names, Doellingeria, and propose 12 new combinations (10 species and two varieties) for all species of Eucephalus.


1983 ◽  
Vol 96 (5) ◽  
pp. 1337-1354 ◽  
Author(s):  
P De Camilli ◽  
R Cameron ◽  
P Greengard

Synapsin I (formerly referred to as protein I) is the collective name for two almost identical phosphoproteins, synapsin Ia and synapsin Ib (protein Ia and protein Ib), present in the nervous system. Synapsin I has previously been shown by immunoperoxidase studies (De Camilli, P., T. Ueda, F. E. Bloom, E. Battenberg, and P. Greengard, 1979, Proc. Natl. Acad. Sci. USA, 76:5977-5981; Bloom, F. E., T. Ueda, E. Battenberg, and P. Greengard, 1979, Proc. Natl. Acad. Sci. USA 76:5982-5986) to be a neuron-specific protein, present in both the central and peripheral nervous systems and concentrated in the synaptic region of nerve cells. In those preliminary studies, the occurrence of synapsin I could be demonstrated in only a portion of synapses. We have now carried out a detailed examination of the distribution of synapsin I immunoreactivity in the central and peripheral nervous systems. In this study we have attempted to maximize the level of resolution of immunohistochemical light microscopy images in order to estimate the proportion of immunoreactive synapses and to establish their precise distribution. Optimal results were obtained by the use of immunofluorescence in semithin sections (approximately 1 micron) prepared from Epon-embedded nonosmicated tissues after the Epon had been removed. Our results confirm the previous observations on the specific localization of synapsin I in nerve cells and synapses. In addition, the results strongly suggest that, with a few possible exceptions involving highly specialized neurons, all synapses contain synapsin I. Finally, immunocytochemical experiments indicate that synapsin I appearance in the various regions of the developing nervous system correlates topographically and temporally with the appearance of synapses. In two accompanying papers (De Camilli, P., S. M. Harris, Jr., W. B. Huttner, and P. Greengard, and Huttner, W. B., W. Schiebler, P. Greengard, and P. De Camilli, 1983, J. Cell Biol. 96:1355-1373 and 1374-1388, respectively), evidence is presented that synapsin I is specifically associated with synaptic vesicles in nerve endings.


2002 ◽  
Vol 13 (2) ◽  
pp. 698-710 ◽  
Author(s):  
Sylvie Ozon ◽  
Antoine Guichet ◽  
Olivier Gavet ◽  
Siegfried Roth ◽  
André Sobel

Stathmin is a ubiquitous regulatory phosphoprotein, the generic element of a family of neural phosphoproteins in vertebrates that possess the capacity to bind tubulin and interfere with microtubule dynamics. Although stathmin and the other proteins of the family have been associated with numerous cell regulations, their biological roles remain elusive, as in particular inactivation of the stathmin gene in the mouse resulted in no clear deleterious phenotype. We identified stathmin phosphoproteins inDrosophila, encoded by a unique gene sharing the intron/exon structure of the vertebrate stathmin andstathmin family genes. They interfere with microtubule assembly in vitro, and in vivo when expressed in HeLa cells. Drosophila stathmin expression is regulated during embryogenesis: it is high in the migrating germ cells and in the central and peripheral nervous systems, a pattern resembling that of mammalian stathmin. Furthermore, RNA interference inactivation ofDrosophila stathmin expression resulted in germ cell migration arrest at stage 14. It also induced important anomalies in nervous system development, such as loss of commissures and longitudinal connectives in the ventral cord, or abnormal chordotonal neuron organization. In conclusion, a single Drosophilagene encodes phosphoproteins homologous to the entire vertebrate stathmin family. We demonstrate for the first time their direct involvement in major biological processes such as development of the reproductive and nervous systems.


2012 ◽  
Vol 25 (6) ◽  
pp. 418 ◽  
Author(s):  
Roy E. Halling ◽  
Mitchell Nuhn ◽  
Todd Osmundson ◽  
Nigel Fechner ◽  
James M. Trappe ◽  
...  

Harrya is described as a new genus of Boletaceae to accommodate Boletus chromapes, a pink-capped bolete with a finely scabrous stipe adorned with pink scabers, a chrome yellow base and a reddish-brown spore deposit. Phylogenetic analyses of large-subunit rDNA and translation elongation factor 1α confirmed Harrya as a unique generic lineage with two species, one of which is newly described (H. atriceps). Some Chinese taxa were recently placed in a separate genus, Zangia, supported by both morphology and molecular data. Multiple accessions from Queensland, Australia, support the synonymy of at least three species in a separate Australian clade in the new genus, Australopilus. The truffle-like Royoungia is also supported as a separate lineage in this clade of boletes. Even though it lacks stipe characters, it possesses the deep, bright yellow to orange pigments in the peridium. Additional collections from Zambia and Thailand represent independent lineages of uncertain phylogenetic placement in the Chromapes complex, but sampling is insufficient for formal description of new species. Specimens from Java referable to Tylopilus pernanus appear to be a sister group of the Harrya lineage.


Zootaxa ◽  
2017 ◽  
Vol 4254 (5) ◽  
pp. 537 ◽  
Author(s):  
CHIA-HSUAN WEI ◽  
SHEN-HORN YEN

The Epicopeiidae is a small geometroid family distributed in the East Palaearctic and Oriental regions. It exhibits high morphological diversity in body size and wing shape, while their wing patterns involve in various complex mimicry rings. In the present study, we attempted to describe a new genus, and a new species from Vietnam, with comments on two assumed congeneric novel species from China and India. To address its phylogenetic affinity, we reconstructed the phylogeny of the family by using sequence data of COI, EF-1α, and 28S gene regions obtained from seven genera of Epicopeiidae with Pseudobiston pinratanai as the outgroup. We also compared the morphology of the new taxon to other epicopeiid genera to affirm its taxonomic status. The results suggest that the undescribed taxon deserve a new genus, namely Mimaporia gen. n. The species from Vietnam, Mimaporia hmong sp. n., is described as new to science. Under different tree building strategies, the new genus is the sister group of either Chatamla Moore, 1881 or Parabraxas Leech, 1897. The morphological evidence, which was not included in phylogenetic analyses, however, suggests its potential affinity with Burmeia Minet, 2003. This study also provides the first, although preliminary, molecular phylogeny of the family on which the revised systematics and interpretation of character evolution can be based. 


2019 ◽  
Author(s):  
Cristina Merla ◽  
Carla Rodrigues ◽  
Virginie Passet ◽  
Marta Corbella ◽  
Harry A. Thorpe ◽  
...  

AbstractKlebsiella oxytoca causes opportunistic human infections and post-antibiotic haemorrhagic diarrhoea. This Enterobacteriaceae species is genetically heterogeneous and is currently subdivided into seven phylogroups (Ko1 to Ko4, Ko6 to Ko8). Here we investigated the taxonomic status of phylogroups Ko3 and Ko4. Genomic sequence-based phylogenetic analyses demonstrate that Ko3 and Ko4 formed well-defined sequence clusters related to, but distinct from, Klebsiella michiganensis (Ko1), Klebsiella oxytoca (Ko2), K. huaxiensis (Ko8) and K. grimontii (Ko6). The average nucleotide identity of Ko3 and Ko4 were 90.7% with K. huaxiensis and 95.5% with K. grimontii, respectively. In addition, three strains of K. huaxiensis, a species so far described based on a single strain from a urinary tract infection patient in China, were isolated from cattle and human faeces. Biochemical and MALDI-ToF mass spectrometry analysis allowed differentiating Ko3, Ko4 and Ko8 from the other K. oxytoca species. Based on these results, we propose the names Klebsiella spallanzanii for the Ko3 phylogroup, with SPARK_775_C1T (CIP 111695T, DSM 109531T) as type strain, and Klebsiella pasteurii for Ko4, with SPARK_836_C1T (CIP 111696T, DSM 109530T) as type strain. Strains of K. spallanzanii were isolated from human urine, cow faeces and farm surfaces, while strains of K. pasteurii were found in faecal carriage from humans, cows and turtles.Accession numbersThe nucleotide sequences generated in this study were deposited in ENA and are available through the INSDC databases under accession numbers MN091365 (SB6411T = SPARK775C1T), MN091366 (SB6412 T = SPARK836C1T) and MN104661 to MN104677 (16S rRNA), MN076606 to MN076643 (gyrA and rpoB), and MN030558 to MN030567 (blaOXY). Complete genomic sequences were submitted to European Nucleotide Archive under the BioProject number PRJEB15325.AbbreviationsANI, average nucleotide identity; HCCA, a-cyano-4-hydroxycinnamic acid; isDDH, in silico DNA-DNA hybridization; SCAI, Simmons citrate agar with inositol; MALDI57 ToF MS: Matrix-assisted laser desorption/ionization time of flight mass spectrometry


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7853 ◽  
Author(s):  
Yuchen Yan ◽  
Gengyun Niu ◽  
Yaoyao Zhang ◽  
Qianying Ren ◽  
Shiyu Du ◽  
...  

Labriocimbex sinicus Yan & Wei gen. et sp. nov. of Cimbicidae is described. The new genus is similar to Praia Andre and Trichiosoma Leach. A key to extant Holarctic genera of Cimbicinae is provided. To identify the phylogenetic placement of Cimbicidae, the mitochondrial genome of L. sinicus was annotated and characterized using high-throughput sequencing data. The complete mitochondrial genome of L. sinicus was obtained with a length of 15,405 bp (GenBank: MH136623; SRA: SRR8270383) and a typical set of 37 genes (22 tRNAs, 13 PCGs, and two rRNAs). The results demonstrated that all PCGs were initiated by ATN codon, and ended with TAA or T stop codons. The study reveals that all tRNA genes have a typical clover-leaf secondary structure, except for trnS1. Remarkably, the secondary structures of the rrnS and rrnL of L. sinicus were much different from those of Corynis lateralis. Phylogenetic analyses verified the monophyly and positions of the three Cimbicidae species within the superfamily Tenthredinoidea and demonstrated a relationship as (Tenthredinidae + Cimbicidae) + (Argidae + Pergidae) with strong nodal supports. Furthermore, we found that the generic relationships of Cimbicidae revealed by the phylogenetic analyses based on COI genes agree quite closely with the systematic arrangement of the genera based on the morphological characters. Phylogenetic tree based on two methods shows that L. sinicus is the sister group of Praia with high support values. We suggest that Labriocimbex belongs to the tribe Trichiosomini of Cimbicinae based on adult morphology and molecular data. Besides, we suggest to promote the subgenus Asitrichiosoma to be a valid genus.


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