scholarly journals A methylotrophic origin of methanogenesis and early divergence of anaerobic multicarbon alkane metabolism

2021 ◽  
Vol 7 (7) ◽  
pp. eabd7180 ◽  
Author(s):  
Yinzhao Wang ◽  
Gunter Wegener ◽  
Tom A. Williams ◽  
Ruize Xie ◽  
Jialin Hou ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Energy Conservation ◽  
Common Ancestor ◽  
Life Forms ◽  
Origin And Evolution ◽  
Climate Stability ◽  
The Common ◽  
Long Chain

Methanogens are considered as one of the earliest life forms on Earth, and together with anaerobic methane-oxidizing archaea, they have crucial effects on climate stability. Yet, the origin and evolution of anaerobic alkane metabolism in the domain Archaea remain controversial. Here, we show that methanogenesis was already present in the common ancestor of Euryarchaeota, TACK archaea, and Asgard archaea likely in the late Hadean or early Archean eon and that the ancestral methanogen was dependent on methylated compounds and hydrogen. Carbon dioxide–reducing methanogenesis developed later through the evolution of tetrahydromethanopterin S-methyltransferase, which linked methanogenesis to the Wood-Ljungdahl pathway for energy conservation. Multicarbon alkane metabolisms in Archaea also originated early, with genes coding for the activation of short- or even long-chain alkanes likely evolving from an ethane-metabolizing ancestor. These genes were likely horizontally transferred to multiple archaeal clades including Candidatus (Ca.) Bathyarchaeota, Ca. Helarchaeota, Ca. Hadesarchaeota, and the methanogenic Ca. Methanoliparia.

scholarly journals A methylotrophic origin of methanogenesis and early divergence of anaerobic multicarbon alkane metabolism

2021 ◽  
Vol 7 (27) ◽  
pp. eabj1453
Author(s):  
Yinzhao Wang ◽  
Gunter Wegener ◽  
Tom A. Williams ◽  
Ruize Xie ◽  
Jialin Hou ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Energy Conservation ◽  
Life Forms ◽  
Short Chain ◽  
Present Evidence ◽  
Origin And Evolution ◽  
Ancestral Form ◽  
Climate Stability ◽  
Long Chain

Methanogens are considered as one of the earliest life forms on Earth, and together with anaerobic methane-oxidizing archaea, they have crucial effects on climate stability. However, the origin and evolution of anaerobic alkane metabolism in the domain Archaea remain controversial. Here, we present evidence that methylotrophic methanogenesis was the ancestral form of this metabolism. Carbon dioxide–reducing methanogenesis developed later through the evolution of tetrahydromethanopterin S-methyltransferase, which linked methanogenesis to the Wood-Ljungdahl pathway for energy conservation. Anaerobic multicarbon alkane metabolisms in Archaea also originated early, with genes coding for the activation of short-chain or even long-chain alkanes likely evolving from an ethane-metabolizing ancestor. These genes were likely horizontally transferred to multiple archaeal clades including Candidatus (Ca.) Bathyarchaeia, Ca. Lokiarchaeia, Ca. Hadarchaeia, and the methanogenic Ca. Methanoliparia.

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.

scholarly journals Role of the Digestive Gland in Ink Production in Four Species of Sea Hares: An Ultrastructural Comparison

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Jeffrey S. Prince ◽  
Paul Micah Johnson
Keyword(s):  
Digestive Gland ◽  
Common Ancestor ◽  
Aplysia Californica ◽  
Digestive Cell ◽  
Digestive Cells ◽  
Sea Hare ◽  
Red Algal ◽  
The Common ◽  
Algal Chloroplast

The ultrastructure of the digestive gland of several sea hare species that produce different colored ink (Aplysia californicaproduces purple ink,A. julianawhite ink,A. parvulaboth white and purple ink, whileDolabrifera dolabriferaproduces no ink at all) was compared to determine the digestive gland’s role in the diet-derived ink production process. Rhodoplast digestive cells and their digestive vacuoles, the site of digestion of red algal chloroplast (i.e., rhodoplast) inA. californica, were present and had a similar ultrastructure in all four species. Rhodoplast digestive cell vacuoles either contained a whole rhodoplast or fragments of one or were empty. These results suggest that the inability to produce colored ink in some sea hare species is not due to either an absence of appropriate digestive machinery, that is, rhodoplast digestive cells, or an apparent failure of rhodoplast digestive cells to function. These results also propose that the digestive gland structure described herein occurred early in sea hare evolution, at least in the common ancestor to the generaAplysiaandDolabrifera. Our data, however, do not support the hypothesis that the loss of purple inking is a synapomorphy of the white-ink-producing subgenusAplysia.

Relative Reactivity Trends OP High Temperature Superconductor Phases

1992 ◽  
Vol 275 ◽  
Author(s):  
David R. Riley ◽  
Ji-Ping Zhou ◽  
A. Manthiram ◽  
John T. McDevitt
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
High Temperature ◽  
High Temperature Superconductor ◽  
Relative Reactivity ◽  
Complete Understanding ◽  
High Tc ◽  
X Ray ◽  
The Common ◽  
Scanning Electron

ABSTRACTMany of the high temperature superconductor phases degrade rapidly when in the presence of water, acids, carbon dioxide or carbon monoxide. In order to foster more rapid developments in the area of high-Tc research, it will be necessary to acquire a more complete understanding of the surface chemistry of these superconducting materials. In this paper, the relative reactivity of the common cuprate phases toward water is reported. X-ray powder diffraction and scanning electron microscopy measurements are utilized here to establish the reactivity trends.

scholarly journals Sexual reproduction and genetic exchange in parasitic protists

Parasitology ◽  
2014 ◽  
Vol 142 (S1) ◽  
pp. S120-S127 ◽  
Author(s):  
GARETH D. WEEDALL ◽  
NEIL HALL
Keyword(s):  
Life Cycle ◽  
Genome Sequencing ◽  
Common Ancestor ◽  
Life Cycles ◽  
Animal Disease ◽  
Eukaryotic Evolution ◽  
Sequencing Technology ◽  
Parasite Reproduction ◽  
The Common ◽  
Higher Eukaryotes

SUMMARYA key part of the life cycle of an organism is reproduction. For a number of important protist parasites that cause human and animal disease, their sexuality has been a topic of debate for many years. Traditionally, protists were considered to be primitive relatives of the ‘higher’ eukaryotes, which may have diverged prior to the evolution of sex and to reproduce by binary fission. More recent views of eukaryotic evolution suggest that sex, and meiosis, evolved early, possibly in the common ancestor of all eukaryotes. However, detecting sex in these parasites is not straightforward. Recent advances, particularly in genome sequencing technology, have allowed new insights into parasite reproduction. Here, we review the evidence on reproduction in parasitic protists. We discuss protist reproduction in the light of parasitic life cycles and routes of transmission among hosts.

Whole-genome analysis-based phylogeographic investigation of Streptococcus pneumoniae serotype 19A sequence type 320 isolates in Japan.

2021 ◽  
Author(s):  
Satoshi Nakano ◽  
Takao Fujisawa ◽  
Bin Chang ◽  
Yutaka Ito ◽  
Hideki Akeda ◽  
...  
Keyword(s):  
Common Ancestor ◽  
Sampling Bias ◽  
Health Concern ◽  
Recent Common Ancestor ◽  
Whole Genome ◽  
Whole Genome Analysis ◽  
Identification Rate ◽  
Most Recent Common Ancestor ◽  
The Common ◽  
The U.S

After the introduction of the seven-valent pneumococcal conjugate vaccine, the global spread of multidrug resistant serotype 19A-ST320 strains became a public health concern. In Japan, the main genotype of serotype 19A was ST3111, and the identification rate of ST320 was low. Although the isolates were sporadically detected in both adults and children, their origin remains unknown. Thus, by combining pneumococcal isolates collected in three nationwide pneumococcal surveillance studies conducted in Japan between 2008 and 2020, we analyzed 56 serotype 19A-ST320 isolates along with 931 global isolates, using whole-genome sequencing to uncover the transmission route of the globally distributed clone in Japan. The clone was frequently detected in Okinawa Prefecture, where the U.S. returned to Japan in 1972. Phylogenetic analysis demonstrated that the isolates from Japan were genetically related to those from the U.S.; therefore, the common ancestor may have originated in the U.S. In addition, Bayesian analysis suggested that the time to the most recent common ancestor of the isolates form Japan and the U.S. was approximately the 1990s to 2000, suggesting the possibility that the common ancestor could have already spread in the U.S. before the Taiwan 19F-14 isolate was first identified in a Taiwanese hospital in 1997. The phylogeographical analysis supported the transmission of the clone from the U.S. to Japan, but the analysis could be influenced by sampling bias. These results suggested the possibility that the serotype 19A-ST320 clone had already spread in the U.S. before being imported into Japan.

scholarly journals Climatic effects on rapid chemical and physical denudation rates measured with cosmogenic nuclides in the Ōhau catchment, New Zealand

2021 ◽  
Author(s):  
◽  
Maia Bellingham
Keyword(s):  
Carbon Dioxide ◽  
New Zealand ◽  
Chemical Weathering ◽  
Southern Alps ◽  
Grain Sizes ◽  
Denudation Rates ◽  
Climate Stability ◽  
Mountain Landscapes ◽  
Carbon Dioxide Cycling

<p>Understanding how active mountain landscapes contribute to carbon dioxide cycling and influences on long-term climate stability requires measurement of weathering fluxes from these landscapes. The few measured chemical weathering rates in the Southern Alps are an order of magnitude greater than in the rest of the world. Rapid tectonic uplift coupled with extreme orographic precipitation is driving exceptionally fast chemical and physical denudation. These rates suggest that weathering in landscapes such as the Southern Alps could play a significant role in carbon dioxide cycling. However, the relative importance of climate and tectonics driving these fast rates remains poorly understood.   To address this gap, in situ ¹⁰Be derived catchment-averaged denudation rates were measured in the Ōhau catchment, Canterbury, New Zealand. Denudation rates in the Dobson Valley within the Ōhau catchment, varied from 474 – 7,570 m Myr⁻¹, aside from one sub-catchment in the upper Dobson Valley that had a denudation rate of 12,142 m Myr⁻¹. The Dobson and Hopkins Rivers had denudation rates of 1,660 and 4,400 m Myr⁻¹ respectively, in these catchments. Dobson Valley denudation rates show a moderate correlation with mean annual precipitation (R²=0.459). This correlation supports a similar trend identified at local and regional scales, and at high rates of precipitation this may be an important driver of erosion and weathering.   Sampling of four grain sizes (0.125 to > 8 mm) at one site in the Dobson Valley resulted in variability in ¹⁰Be concentrations up to a factor of 2.5, which may be a result of each grain size recording different erosional processes. These observations demonstrate the importance of assessing potential variability and the need to sample consistent grain sizes across catchments.   Chemical depletion fractions measured within soil pits in the upper Dobson Valley indicate chemical weathering contributes 30% of total denudation, and that physical erosion is driving rapid total denudation. Chemical weathering appears to surpass any proposed weathering speed limit and suggests total weathering may not be limited by weathering kinetics. This research adds to the paucity of research in New Zealand, and for the first time presents ¹⁰Be derived denudation rates from the eastern Southern Alps, with estimates of the long-term weathering flux. High weathering fluxes in the Southern Alps uphold the hypothesis that mountain landscapes play an important role in carbon dioxide cycling and long-term climate stability.</p>

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