scholarly journals Loss of plastid developmental genes coincides with a reversion to monoplastidy in hornworts

2022 ◽  
Author(s):  
Alexander Istvan MacLeod ◽  
Parth K Raval ◽  
Simon Stockhorst ◽  
Michael Knopp ◽  
Eftychios Frangedakis ◽  
...  
Keyword(s):  
Common Ancestor ◽  
Nuclear Division ◽  
Developmental Pathways ◽  
Ancestral State ◽  
Plastid Division ◽  
Plastid Development ◽  
State Reconstruction ◽  
Transcriptomic Data ◽  
The Common ◽  
Almost All

The first plastid evolved from an endosymbiotic cyanobacterium in the common ancestor of the Archaeplastida. The transformative steps from cyanobacterium to organelle included the transfer of control over developmental processes; a necessity for the host to orchestrate, for example, the fission of the organelle. The plastids of almost all embryophytes divide independent from nuclear division, leading to cells housing multiple plastids. Hornworts, however, are monoplastidic (or near-monoplastidic) and their photosynthetic organelles are a curious exception among embryophytes for reasons such as the occasional presence of pyrenoids. Here we screened genomic and transcriptomic data of eleven hornworts for components of plastid developmental pathways. We find intriguing differences among hornworts and specifically highlight that pathway components involved in regulating plastid development and biogenesis were differentially lost in this group of bryophytes. In combination with ancestral state reconstruction, our data suggest that hornworts have reverted back to a monoplastidic phenotype due to the combined loss of two plastid division-associated genes: ARC3 and FtsZ2.

scholarly journals Ancestral State Reconstruction of the Apoptosis Machinery in the Common Ancestor of Eukaryotes

2018 ◽  
Vol 8 (6) ◽  
pp. 2121-2134 ◽  
Author(s):  
Joanna Klim ◽  
Arkadiusz Gładki ◽  
Roza Kucharczyk ◽  
Urszula Zielenkiewicz ◽  
Szymon Kaczanowski
Keyword(s):  
Common Ancestor ◽  
Ancestral State Reconstruction ◽  
Ancestral State ◽  
State Reconstruction ◽  
The Common

scholarly journals A new lineage of mazaediate fungi in the Eurotiomycetes: Cryptocaliciomycetidae subclass. nov., based on the new species Cryptocalicium blascoi and the revision of the ascoma evolution

2021 ◽  
Vol 20 (7) ◽  
pp. 889-904
Author(s):  
M. Prieto ◽  
Javier Etayo ◽  
I. Olariaga
Keyword(s):  
New Species ◽  
Common Ancestor ◽  
External Surface ◽  
Evolutionary Relationships ◽  
New Order ◽  
Ancestral State ◽  
Multigene Phylogeny ◽  
State Reconstruction ◽  
Distinct Structure ◽  
Dark Violet

AbstractThe class Eurotiomycetes (Ascomycota, Pezizomycotina) comprises important fungi used for medical, agricultural, industrial and scientific purposes. Eurotiomycetes is a morphologically and ecologically diverse monophyletic group. Within the Eurotiomycetes, different ascoma morphologies are found including cleistothecia and perithecia but also apothecia or stromatic forms. Mazaediate representatives (with a distinct structure in which loose masses of ascospores accumulate to be passively disseminated) have evolved independently several times. Here we describe a new mazaediate species belonging to the Eurotiomycetes. The multigene phylogeny produced (7 gene regions: nuLSU, nuSSU, 5.8S nuITS, mtSSU, RPB1, RPB2 and MCM7) placed the new species in a lineage sister to Eurotiomycetidae. Based on the evolutionary relationships and morphology, a new subclass, a new order, family and genus are described to place the new species: Cryptocalicium blascoi. This calicioid species occurs on the inner side of loose bark strips of Cupressaceae (Cupressus, Juniperus). Morphologically, C. blascoi is characterized by having minute apothecioid stalked ascomata producing mazaedia, clavate bitunicate asci with hemiamyloid reaction, presence of hamathecium and an apothecial external surface with dark violet granules that becomes turquoise green in KOH. The ancestral state reconstruction analyses support a common ancestor with open ascomata for all deep nodes in Eurotiomycetes and the evolution of closed ascomata (cleistothecioid in Eurotiomycetidae and perithecioid in Chaetothyriomycetidae) from apothecioid ancestors. The appropriateness of the description of a new subclass for this fungus is also discussed.

scholarly journals Juvenile hormone III skipped bisepoxide is widespread in true bugs (Hemiptera: Heteroptera)

2021 ◽  
Vol 8 (2) ◽  
pp. 202242
Author(s):  
Keiji Matsumoto ◽  
Toyomi Kotaki ◽  
Hideharu Numata ◽  
Tetsuro Shinada ◽  
Shin G. Goto
Keyword(s):  
Juvenile Hormone ◽  
Common Ancestor ◽  
Ultra Performance Liquid Chromatography ◽  
Insect Development ◽  
Methyl Farnesoate ◽  
True Bugs ◽  
Focal Species ◽  
Chemically Modified ◽  
The Common ◽  
Almost All

Juvenile hormone (JH) plays important roles in almost every aspect of insect development and reproduction. JHs are a group of acyclic sesquiterpenoids, and their farnesol backbone has been chemically modified to generate a homologous series of hormones in some insect lineages. JH III (methyl farnesoate, 10,11-epoxide) is the most common JH in insects, but Lepidoptera (butterflies and moths) and ‘higher’ Diptera (suborder: Brachycera; flies) have developed their own unique JHs. Although JH was first proposed in the hemipteran suborder Heteroptera (true bugs), the chemical identity of the heteropteran JH was only recently determined. Furthermore, recent studies revealed the presence of a novel JH, JH III skipped bisepoxide (JHSB 3 ), in some heteropterans, but its taxonomic distribution remains largely unknown. In the present study, we investigated JHSB 3 production in 31 heteropteran species, covering almost all heteropteran lineages, through ultra-performance liquid chromatography coupled with tandem mass spectrometry. We found that all of the focal species produced JHSB 3 , indicating that JHSB 3 is widespread in heteropteran bugs and the evolutionary occurrence of JHSB 3 ascends to the common ancestor of Heteroptera.

scholarly journals Postcranial skeletal pneumaticity and air-sacs in the earliest pterosaurs

2009 ◽  
Vol 5 (4) ◽  
pp. 557-560 ◽  
Author(s):  
Richard J. Butler ◽  
Paul M. Barrett ◽  
David J. Gower
Keyword(s):  
Respiratory System ◽  
Common Ancestor ◽  
Late Triassic ◽  
Air Sacs ◽  
The Common ◽  
Respiratory Systems ◽  
Almost All

Patterns of postcranial skeletal pneumatization (PSP) indicate that pterosaurs possessed components of a bird-like respiratory system, including a series of ventilatory air-sacs. However, the presence of PSP in the oldest known pterosaurs has not been unambiguously demonstrated by previous studies. Here we provide the first unequivocal documentation of PSP in Late Triassic and earliest Jurassic pterosaurs. This demonstrates that PSP and, by inference, air-sacs were probably present in the common ancestor of almost all known pterosaurs, and has broader implications for the evolution of respiratory systems in bird-line archosaurs, including dinosaurs.

scholarly journals Giant GAL gene clusters for the melibiose-galactose pathway in Torulaspora

2020 ◽  
Author(s):  
Anjan Venkatesh ◽  
Anthony L. Murray ◽  
Aisling Y. Coughlan ◽  
Kenneth H. Wolfe
Keyword(s):  
Gene Cluster ◽  
Glucose Transporter ◽  
Common Ancestor ◽  
Yeast Species ◽  
Gene Clusters ◽  
Yeast Strains ◽  
The Common ◽  
Almost All ◽  
Horizontal Transfers ◽  
Catabolism Pathway

AbstractIn many yeast species the three genes at the center of the galactose catabolism pathway, GAL1, GAL10 and GAL7, are neighbors in the genome and form a metabolic gene cluster. We report here that some yeast strains in the genus Torulaspora have much larger GAL clusters that include genes for melibiase (MEL1), galactose permease (GAL2), glucose transporter (HGT1), phosphoglucomutase (PGM1), and the transcription factor GAL4, in addition to GAL1, GAL10, and GAL7. Together, these 8 genes encode almost all the steps in the pathway for catabolism of extracellular melibiose (a disaccharide of galactose and glucose). We show that a progenitor 5-gene cluster containing GAL 7-1-10-4-2 was likely present in the common ancestor of Torulaspora and Zygotorulaspora. It added PGM1 and MEL1 in the ancestor of most Torulaspora species. It underwent further expansion in the T. pretoriensis clade, involving the fusion of three progenitor clusters in tandem and the gain of HGT1. These giant GAL clusters are highly polymorphic in structure, and subject to horizontal transfers, pseudogenization and gene losses. We identify recent horizontal transfers of complete GAL clusters from T. franciscae into one strain of T. delbrueckii, and from a relative of T. maleeae into one strain of T. globosa. The variability and dynamic evolution of GAL clusters in Torulaspora indicates that there is strong natural selection on the GAL pathway in this genus.

scholarly journals Molecular Evolutionary Analyses of Tooth Genes Support Sequential Loss of Enamel and Teeth in Baleen Whales (Mysticeti)

2021 ◽  
Author(s):  
JASON G RANDALL ◽  
John Gatesy ◽  
Mark Springer
Keyword(s):  
Common Ancestor ◽  
Single Step ◽  
Ancestral State ◽  
Protein Coding ◽  
Baleen Whales ◽  
Genome Data ◽  
Genomic Studies ◽  
The Common ◽  
Complete Protein ◽  
Inactivating Mutations

The loss of teeth and evolution of baleen racks in Mysticeti was a profound transformation that permitted baleen whales to radiate and diversify into a previously underutilized ecological niche of bulk filter-feeding on zooplankton and other small prey. Ancestral state reconstructions suggest that teeth were lost in the common ancestor of crown Mysticeti. Genomic studies provide some support for this hypothesis and suggest that the genetic toolkit for enamel production was inactivated in the common ancestor of living baleen whales. However, molecular studies to date have not provided direct evidence for the complete loss of teeth, including their dentin component, on the stem mysticete branch. Given these results, several questions remain unanswered: (1) Were teeth lost in a single step or did enamel loss precede dentin loss? (2) Was enamel lost early or late on the stem mysticete branch? (3) If enamel and dentin/tooth loss were decoupled in the ancestry of baleen whales, did dentin loss occur on the stem mysticete branch or independently in different crown mysticete lineages? To address these outstanding questions, we compiled and analyzed complete protein-coding sequences for nine tooth-related genes from cetaceans with available genome data. Seven of these genes are associated with enamel formation (ACP4, AMBN, AMELX, AMTN, ENAM, KLK4, MMP20) whereas two other genes are either dentin-specific (DSPP) or tooth-specific (ODAPH) but not enamel-specific. Molecular evolutionary analyses indicate that all seven enamel-specific genes have inactivating mutations that are scattered across branches of the mysticete tree. Three of the enamel genes (ACP4, KLK4, MMP20) have inactivating mutations that are shared by all mysticetes. The two genes that are dentin-specific (DSPP) or tooth-specific (ODAPH) do not have any inactivating mutations that are shared by all mysticetes, but there are shared mutations in Balaenidae as well as in Plicogulae (Neobalaenidae + Balaenopteroidea). These shared mutations suggest that teeth were lost at most two times. Shared inactivating mutations and dN/dS analyses, in combination with cetacean divergence times, were used to estimate inactivation times of genes and by proxy enamel and tooth phenotypes. The results of these analyses are most compatible with a two-step model for the loss of teeth in the ancestry of living baleen whales: enamel was lost very early on the stem Mysticeti branch followed by the independent loss of dentin (and teeth) in the common ancestors of Balaenidae and Plicogulae, respectively. These results imply that some stem mysticetes, and even early crown mysticetes, may have had vestigial teeth comprised of dentin with no enamel. Our results also demonstrate that all odontocete species (in our study) with absent or degenerative enamel have inactivating mutations in one or more of their enamel genes.

scholarly journals Bilaterally symmetric axes with rhizoids composed the rooting structure of the common ancestor of vascular plants

2017 ◽  
Vol 373 (1739) ◽  
pp. 20170042 ◽  
Author(s):  
Alexander J. Hetherington ◽  
Liam Dolan
Keyword(s):  
Vascular Plants ◽  
Common Ancestor ◽  
Terrestrial Ecosystem ◽  
Bilateral Symmetry ◽  
Land Plant ◽  
Land Plants ◽  
Free Living ◽  
Rhynie Chert ◽  
The Common ◽  
Almost All

There are two general types of rooting systems in extant land plants: gametophyte rhizoids and sporophyte root axes. These structures carry out the rooting function in the free-living stage of almost all land plant gametophytes and sporophytes, respectively. Extant vascular plants develop a dominant, free-living sporophyte on which roots form, with the exception of a small number of taxa that have secondarily lost roots. However, fossil evidence indicates that early vascular plants did not develop sporophyte roots. We propose that the common ancestor of vascular plants developed a unique rooting system—rhizoidal sporophyte axes. Here we present a synthesis and reinterpretation of the rootless sporophytes of Horneophyton lignieri , Aglaophyton majus , Rhynia gwynne-vaughanii and Nothia aphylla preserved in the Rhynie chert. We show that the sporophyte rooting structures of all four plants comprised regions of plagiotropic (horizontal) axes that developed unicellular rhizoids on their underside. These regions of axes with rhizoids developed bilateral symmetry making them distinct from the other regions which were radially symmetrical. We hypothesize that rhizoidal sporophyte axes constituted the rooting structures in the common ancestor of vascular plants because the phylogenetic positions of these plants span the origin of the vascular lineage. This article is part of a discussion meeting issue ‘The Rhynie cherts: our earliest terrestrial ecosystem revisited’.

scholarly journals Open cup nests evolved from roofed nests in the early passerines

2017 ◽  
Vol 284 (1848) ◽  
pp. 20162708 ◽  
Author(s):  
J. Jordan Price ◽  
Simon C. Griffith
Keyword(s):  
Adaptive Radiation ◽  
Common Ancestor ◽  
Terrestrial Ecosystems ◽  
Ancestral State ◽  
Passerine Birds ◽  
Australian Continent ◽  
Nest Design ◽  
Relative Rarity ◽  
The Common ◽  
Order Passeriformes

The architectural diversity of nests in the passerine birds (order Passeriformes) is thought to have played an important role in the adaptive radiation of this group, which now comprises more than half of avian species and occupies nearly all terrestrial ecosystems. Here, we present an extensive survey and ancestral state reconstruction of nest design across the passerines, focusing on early Australian lineages and including members of nearly all passerine families worldwide. Most passerines build open cup-shaped nests, whereas a minority build more elaborate domed structures with roofs. We provide strong evidence that, despite their relative rarity today, domed nests were constructed by the common ancestor of all modern passerines. Open cup nests evolved from enclosed domes at least four times independently during early passerine evolution, at least three of which occurred on the Australian continent, yielding several primarily cup-nesting clades that are now widespread and numerically dominant among passerines. Our results show that the ubiquitous and relatively simple cup-shaped nests of many birds today evolved multiple times convergently, suggesting adaptive benefits over earlier roofed designs.

Fibrinolytic Activity of the Arterial Wall

1969 ◽  
Vol 21 (01) ◽  
pp. 001-011 ◽  
Author(s):  
K Onoyama ◽  
K Tanaka
Keyword(s):  
Carotid Artery ◽  
Fibrinolytic Activity ◽  
Arterial Wall ◽  
Aortic Wall ◽  
Internal Carotid ◽  
Atheromatous Plaque ◽  
Human Fibrinogen ◽  
The Media ◽  
The Common ◽  
Almost All

SummaryThe tissue fibrinolysis was studied in 550 specimens of 7 kinds of arteries from 80 fresh cadavers, using Astrup’s biochemical method and Todd’s histochemical method with human fibrinogen.In the microscopically normal aortic wall, almost all specimens had the fibrinolytic activity which was the strongest in the adventitia and the weakest in the media.The fibrinolytic activity seemed to be localized in the endothelium.The stronger activity lay in the adventitia of the aorta and the pulmonary artery and all layers of the cerebral artery.The activity of the intima and media of the macroscopically normal areas seemed to be stronger in the internal carotid artery than in the common carotid artery.Mean fibrinolytic activity of the macroscopically normal areas seemed to decrease with age in the intima and the media of the thoracic aorta and seemed to be low in the cases with a high atherosclerotic index.The fibrinolytic activities of all three layers of the fibrous thickened aorta seemed to decrease, and those of the media and the adventitia of the atheromatous plaque to increase.The fibrinolytic activity of the arterial wall might play some role in the progress of atherosclerosis.

The Possible Common Origin of tRNA and 5S rRNA

1983 ◽  
Vol 38 (5-6) ◽  
pp. 501-504 ◽  
Author(s):  
Mária Ujhelyi
Keyword(s):  
Common Ancestor ◽  
Common Origin ◽  
5S Rrna ◽  
Mitochondrial Trna ◽  
Trna Molecule ◽  
The Common

Seryl tRNA (anticodon GCU) from mammalian mito­chondria shows in comparison to other mitochondrial tRNAs additional special features differing from the generalized tRNA model. When arranged in the tradi­tional cloverleaf form, eight bases fall within the TΨC loop, and the entire dihydrouridine loop is lacking. This seryl tRNA molecule is therefore shorter than other tRNAs. It was originally thought to represent a mito­chondrial analogon of 5 S rRNA and its precise classifica­tion is still disputed. The present studies suggest that this mitochondrial tRNA represents a fossil molecule which is related to the common ancestor of the present tRNA and 5 S rRNA molecules.

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