Description of Imasa heleensis , gen. nov., sp. nov. (Imasidae, fam. nov.), a Deep‐Branching Marine Malawimonad and Possible Key Taxon in Understanding Early Eukaryotic Evolution

2020 ◽  
Author(s):  
Aaron A. Heiss ◽  
Sally D. Warring ◽  
Kaleigh Lukacs ◽  
John Favate ◽  
Ashley Yang ◽  
...  
Keyword(s):  
Eukaryotic Evolution

Horizontal gene transfer in eukaryotic evolution

2008 ◽  
Vol 9 (8) ◽  
pp. 605-618 ◽  
Author(s):  
Patrick J. Keeling ◽  
Jeffrey D. Palmer
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Eukaryotic Evolution

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.

Origin and Early Evolution of the Eukaryotic Cell

2021 ◽  
Vol 75 (1) ◽  
Author(s):  
Toni Gabaldón
Keyword(s):  
Current Knowledge ◽  
Eukaryotic Cell ◽  
Early Evolution ◽  
Annual Review ◽  
Publication Date ◽  
Eukaryotic Evolution ◽  
Life Itself ◽  
Metabolic Interactions ◽  
Phylogenomic Analyses ◽  
Origin Of Eukaryotes

The origin of eukaryotes has been defined as the major evolutionary transition since the origin of life itself. Most hallmark traits of eukaryotes, such as their intricate intracellular organization, can be traced back to a putative common ancestor that predated the broad diversity of extant eukaryotes. However, little is known about the nature and relative order of events that occurred in the path from preexisting prokaryotes to this already sophisticated ancestor. The origin of mitochondria from the endosymbiosis of an alphaproteobacterium is one of the few robustly established events to which most hypotheses on the origin of eukaryotes are anchored, but the debate is still open regarding the time of this acquisition, the nature of the host, and the ecological and metabolic interactions between the symbiotic partners. After the acquisition of mitochondria, eukaryotes underwent a fast radiation into several major clades whose phylogenetic relationships have been largely elusive. Recent progress in the comparative analyses of a growing number of genomes is shedding light on the early events of eukaryotic evolution as well as on the root and branching patterns of the tree of eukaryotes. Here I discuss current knowledge and debates on the origin and early evolution of eukaryotes. I focus particularly on how phylogenomic analyses have challenged some of the early assumptions about eukaryotic evolution, including the widespread idea that mitochondrial symbiosis in an archaeal host was the earliest event in eukaryogenesis. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Prediction of horizontal gene transfers in eukaryotes: approaches and challenges

2009 ◽  
Vol 37 (4) ◽  
pp. 792-795 ◽  
Author(s):  
John W. Whitaker ◽  
Glenn A. McConkey ◽  
David R. Westhead
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Present Review ◽  
Bacterial Evolution ◽  
Eukaryotic Evolution ◽  
Metabolic Evolution ◽  
Eukaryotic Genomes

HGT (horizontal gene transfer) is recognized as an important force in bacterial evolution. Now that many eukaryotic genomes have been sequenced, it has become possible to carry out studies of HGT in eukaryotes. The present review compares the different approaches that exist for identifying HGT genes and assess them in the context of studying eukaryotic evolution. The metabolic evolution resource metaTIGER is then described, with discussion of its application in identification of HGT in eukaryotes.

scholarly journals The Mouse Polyubiquitin Gene Ubb Is Essential for Meiotic Progression

2007 ◽  
Vol 28 (3) ◽  
pp. 1136-1146 ◽  
Author(s):  
Kwon-Yul Ryu ◽  
Shamim A. Sinnar ◽  
Laura G. Reinholdt ◽  
Sergio Vaccari ◽  
Susan Hall ◽  
...  
Keyword(s):  
Germ Cells ◽  
Striking Similarity ◽  
Eukaryotic Evolution ◽  
Targeted Disruption ◽  
Male And Female ◽  
Meiotic Progression ◽  
Polyubiquitin Gene ◽  
Polyubiquitin Genes ◽  
Meiosis I

ABSTRACT Ubiquitin is encoded in mice by two polyubiquitin genes, Ubb and Ubc, that are considered to be stress inducible and two constitutively expressed monoubiquitin (Uba) genes. Here we report that targeted disruption of Ubb results in male and female infertility due to failure of germ cells to progress through meiosis I and hypogonadism. In the absence of Ubb, spermatocytes and oocytes arrest during meiotic prophase, before metaphase of the first meiotic division. Although cellular ubiquitin levels are believed to be maintained by a combination of functional redundancy among the four ubiquitin genes, stress inducibility of the two polyubiquitin genes, and ubiquitin recycling by proteasome-associated isopeptidases, our results indicate that ubiquitin is required for and consumed during meiotic progression. The striking similarity of the meiotic phenotype in Ubb −/− germ cells to the sporulation defect in fission yeast (Schizosaccharomyces pombe) lacking a polyubiquitin gene suggests that a meiotic role of the polyubiquitin gene has been conserved throughout eukaryotic evolution.

scholarly journals Eukaryotic Evolution: Getting to the Root of the Problem

2002 ◽  
Vol 12 (20) ◽  
pp. R691-R693 ◽  
Author(s):  
Alastair G.B Simpson ◽  
Andrew J Roger
Keyword(s):  
Eukaryotic Evolution
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