scholarly journals Mitochondria and hydrogenosomes are two forms of the same fundamental organelle

2003 ◽  
Vol 358 (1429) ◽  
pp. 191-203 ◽  
Author(s):  
Martin Embley ◽  
Mark van der Giezen ◽  
David S. Horner ◽  
Patricia L. Dyal ◽  
Peter Foster
Keyword(s):  
Early Stage ◽  
Phylogenetic Analyses ◽  
Eukaryotic Cell ◽  
Published Data ◽  
Ferredoxin Oxidoreductase ◽  
Cell Compartments ◽  
Microbial Eukaryotes ◽  
A Genome ◽  
Different Types ◽  
Pyruvate Ferredoxin Oxidoreductase

Published data suggest that hydrogenosomes, organelles found in diverse anaerobic eukaryotes that make energy and hydrogen, were once mitochondria. As hydrogenosomes generally lack a genome, the conversion is probably one way. The sources of the key hydrogenosomal enzymes, pyruvate : ferredoxin oxidoreductase (PFO) and hydrogenase, are not resolved by current phylogenetic analyses, but it is likely that both were present at an early stage of eukaryotic evolution. Once thought to be restricted to a few unusual anaerobic eukaryotes, the proteins are intimately integrated into the fabric of diverse eukaryotic cells, where they are targeted to different cell compartments, and not just hydrogenosomes. There is no evidence supporting the view that PFO and hydrogenase originated from the mitochondrial endosymbiont, as posited by the hydrogen hypothesis for eukaryogenesis. Other organelles derived from mitochondria have now been described in anaerobic and parasitic microbial eukaryotes, including species that were once thought to have diverged before the mitochondrial symbiosis. It thus seems possible that all eukaryotes may eventually be shown to contain an organelle of mitochondrial ancestry, to which different types of biochemistry can be targeted. It remains to be seen if, despite their obvious differences, this family of organelles shares a common function of importance for the eukaryotic cell, other than energy production, that might provide the underlying selection pressure for organelle retention.

scholarly journals Unequal contribution of two paralogous centromeric histones to function the cowpea centromere

2020 ◽  
Author(s):  
Takayoshi Ishii ◽  
Martina Juranić ◽  
Shamoni Maheshwari ◽  
Fernanda de Oliveira Bustamante ◽  
Maximilian Moritz Vogt ◽  
...  
Keyword(s):  
Genome Duplication ◽  
Early Stage ◽  
Generative Cell ◽  
Reproductive Development ◽  
Duplication Event ◽  
Genome Duplication Event ◽  
A Genome ◽  
Specific Manner ◽  
Different Types ◽  
Drought And Heat Stress

AbstractThe legume cowpea (Vigna unguiculata, 2n=2x=22) has significant tolerance to drought and heat stress. Here we analysed and manipulated cowpea centromere-specific histone H3 (CENH3) genes, aiming to establish a centromere-based doubled-haploid method for use in genetic improvement of this dryland crop in future. Cowpea encodes two functional CENH3 variants (CENH3.1 and CENH3.2) and two CENH3 pseudogenes. Phylogenetic analysis suggests that gene duplication of CENH3 occurred independently during the speciation of V. unguiculata and the related V. mungo without a genome duplication event. Both functional cowpea CENH3 variants are transcribed, and the corresponding proteins are intermingled in subdomains of different types of centromere sequences in a tissue-specific manner together with the outer kinetochore protein CENPC. CENH3.2 is removed from the generative cell of mature pollen, while CENH3.1 persists. Differences between both CENH3 paralogs are restricted to the N-terminus. The complete CRISPR/Cas9-based inactivation of CENH3.1 resulted in delayed vegetative growth and sterility, indicating that this variant is needed for plant development and reproduction. By contrast, CENH3.2 knockout individuals did not show obvious defects during vegetative and reproductive development, suggesting that the gene is an early stage of subfunctionalization or pseudogenization.One-sentence summaryThe two paralogous centromeric histones (CENH3) of cowpea contribute unequal to the function of the centromere.

Post-Tonsillectomy Hemorrhage Diagnosis and Management

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P34-P35 ◽  
Author(s):  
Michael S Morris
Keyword(s):  
Ct Angiography ◽  
Early Stage ◽  
Cardiopulmonary Arrest ◽  
Vascular Trauma ◽  
Post Mortem ◽  
Direct Examination ◽  
Operative Field ◽  
Different Types ◽  
Vascular Physiology ◽  
Vascular Spasm

Objective 1) Better recognize pathophysiology of postoperative tonsillectomy hemorrhage. 2) Be able to better differentiate the different types of post-tonsillectomy hemorrhage based upon understanding the vascular physiology and adjust management accordingly. Methods Post-tonsillectomy complications in children and adults were reviewed. 7 cases of hemorrhage, including 5 deaths, were carefully reviewed. Patients ranged between 2–40 years of age. This represents the largest series of post-tonsillectomy deaths reported to date. All postoperative deaths were due to bleeding and cardiopulmonary arrest. Post-mortem analysis was undertaken on those patients. CT angiography was reviewed in one surviving patient and the utility of this type of scanning is discussed. Results Post-tonsillectomy bleeding is one of the most worrisome otolaryngology concerns. Patients with bleeding on postoperative days 2–3 reported episodic bleeding stopping spontaneously. In these patients, the episode of unobserved bleeding signaled a vascular spasm with a likehood of recurrence. When the bleeding recurred it was massive and occured in a uncontrolled setting, leading to a poor outcome. Vascular trauma and spasm is likely. Conclusions Postoperative tonsillectomy bleeding is better managed by differentiating those patients with early stage bleeding on postoperative days 2–3. Direct examination of the operative field is imperative. Ancillary testing including CT angiograpy is helpful in the evaluation.

scholarly journals Pyruvate-Ferredoxin Oxidoreductase

1971 ◽  
Vol 246 (10) ◽  
pp. 3120-3125
Author(s):  
Kosaku Uyeda ◽  
Jesse C. Rabinowitz
Keyword(s):  
Ferredoxin Oxidoreductase ◽  
Pyruvate Ferredoxin Oxidoreductase

scholarly journals Genetic Diversity of Enteric Viruses in Children under Five Years Old in Gabon

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 545
Author(s):  
Gédéon Prince Manouana ◽  
Paul Alvyn Nguema-Moure ◽  
Mirabeau Mbong Ngwese ◽  
C.-Thomas Bock ◽  
Peter G. Kremsner ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Preventive Measures ◽  
Phylogenetic Analyses ◽  
Enteric Viruses ◽  
Study Cohort ◽  
Viral Agent ◽  
A Genome ◽  
Stool Samples ◽  
Pcr Techniques ◽  
High Diversity

Enteric viruses are the leading cause of diarrhea in children globally. Identifying viral agents and understanding their genetic diversity could help to develop effective preventive measures. This study aimed to determine the detection rate and genetic diversity of four enteric viruses in Gabonese children aged below five years. Stool samples from children <5 years with (n = 177) and without (n = 67) diarrhea were collected from April 2018 to November 2019. Norovirus, astrovirus, sapovirus, and aichivirus A were identified using PCR techniques followed by sequencing and phylogenetic analyses. At least one viral agent was identified in 23.2% and 14.9% of the symptomatic and asymptomatic participants, respectively. Norovirus (14.7%) and astrovirus (7.3%) were the most prevalent in children with diarrhea, whereas in the healthy group norovirus (9%) followed by the first reported aichivirus A in Gabon (6%) were predominant. The predominant norovirus genogroup was GII, consisting mostly of genotype GII.P31-GII.4 Sydney. Phylogenetic analysis of the 3CD region of the aichivirus A genome revealed the presence of two genotypes (A and C) in the study cohort. Astrovirus and sapovirus showed a high diversity, with five different astrovirus genotypes and four sapovirus genotypes, respectively. Our findings give new insights into the circulation and genetic diversity of enteric viruses in Gabonese children.

scholarly journals Nuclear Gene Dosage Effects Upon the Expression of Maize Mitochondrial Genes

Genetics ◽  
2001 ◽  
Vol 157 (4) ◽  
pp. 1711-1721
Author(s):  
Donald L Auger ◽  
Kathleen J Newton ◽  
James A Birchler
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Gene Dosage ◽  
Nuclear Gene ◽  
Eukaryotic Cell ◽  
Mitochondrial Genes ◽  
Northern Analysis ◽  
Α Subunit ◽  
Dosage Effects ◽  
A Genome

Abstract Each mitochondrion possesses a genome that encodes some of its own components. The nucleus encodes most of the mitochondrial proteins, including the polymerases and factors that regulate the expression of mitochondrial genes. Little is known about the number or location of these nuclear factors. B-A translocations were used to create dosage series for 14 different chromosome arms in maize plants with normal cytoplasm. The presence of one or more regulatory factors on a chromosome arm was indicated when variation of its dosage resulted in the alteration in the amount of a mitochondrial transcript. We used quantitative Northern analysis to assay the transcript levels of three mitochondrially encoded components of the cytochrome c oxidase complex (cox1, cox2, and cox3). Data for a nuclearly encoded component (cox5b) and for two mitochondrial genes that are unrelated to cytochrome c oxidase, ATP synthase α-subunit and 18S rRNA, were also determined. Two tissues, embryo and endosperm, were compared and most effects were found to be tissue specific. Significantly, the array of dosage effects upon mitochondrial genes was similar to what had been previously found for nuclear genes. These results support the concept that although mitochondrial genes are prokaryotic in origin, their regulation has been extensively integrated into the eukaryotic cell.

scholarly journals Identification of 35 C-Type Lectins in the Oriental Armyworm, Mythimna separata (Walker)

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 559
Author(s):  
Hao Li ◽  
Fang-Fang Liu ◽  
Li-Qing Fu ◽  
Ze Liu ◽  
Wen-Ting Zhang ◽  
...  
Keyword(s):  
Fat Body ◽  
Early Stage ◽  
Average Length ◽  
Phylogenetic Analyses ◽  
Endocrine System ◽  
Economic Loss ◽  
Mythimna Separata ◽  
Oriental Armyworm ◽  
Potential Ligand ◽  
Cellular Immune

Insect C-type lectins (CTLs) play vital roles in modulating humoral and cellular immune responses. The oriental armyworm, Mythimna separata (Walker) (Lepidoptera: Noctuidae) is a migratory pest that causes significant economic loss in agriculture. CTLs have not yet been systematically identified in M. separata. In this study, we first constructed a transcriptome of M. separata larvae, generating a total of 45,888 unigenes with an average length of 910 bp. Unigenes were functionally annotated in six databases: NR, GO, KEGG, Pfam, eggNOG, and Swiss-Prot. Unigenes were enriched in functional pathways, such as those of signal transduction, endocrine system, cellular community, and immune system. Thirty-five unigenes encoding C-type lectins were identified, including CTL-S1~CTL-S6 (single CRD) and IML-1~IML-29 (dual CRD). Phylogenetic analyses showed dramatic lineage-specific expansions of IMLs. Sequence alignment and structural modeling identified potential ligand-interacting residues. Real-time qPCR revealed that CTL-Ss mainly express in eggs and early stage larvae, while IMLs mainly express in mid-late-stage larvae, pupae, and adults. In naïve larvae, hemocytes, fat body, and epidermis are the major tissues that express CTLs. In larvae challenged by Escherichia coli, Staphylococcus aureus, or Beauveria bassiana, the expression of different CTLs was stimulated in hemocytes, fat body and midgut. The present study will help further explore functions of M. separata CTLs.

scholarly journals Presence of a Member of the Mitochondrial Carrier Family in Hydrogenosomes: Conservation of Membrane-Targeting Pathways between Hydrogenosomes and Mitochondria

2000 ◽  
Vol 20 (7) ◽  
pp. 2488-2497 ◽  
Author(s):  
Sabrina D. Dyall ◽  
Carla M. Koehler ◽  
Maria G. Delgadillo-Correa ◽  
Peter J. Bradley ◽  
Evelyn Plümper ◽  
...  
Keyword(s):  
Trichomonas Vaginalis ◽  
Protein Targeting ◽  
Phylogenetic Analyses ◽  
Eukaryotic Cell ◽  
Membrane Targeting ◽  
Carrier Proteins ◽  
Mitochondrial Carrier ◽  
Mitochondrial Carrier Family ◽  
Targeting Signal ◽  
Mitochondrial Carrier Proteins

ABSTRACT A number of microaerophilic eukaryotes lack mitochondria but possess another organelle involved in energy metabolism, the hydrogenosome. Limited phylogenetic analyses of nuclear genes support a common origin for these two organelles. We have identified a protein of the mitochondrial carrier family in the hydrogenosome ofTrichomonas vaginalis and have shown that this protein, Hmp31, is phylogenetically related to the mitochondrial ADP-ATP carrier (AAC). We demonstrate that the hydrogenosomal AAC can be targeted to the inner membrane of mitochondria isolated from Saccharomyces cerevisiae through the Tim9-Tim10 import pathway used for the assembly of mitochondrial carrier proteins. Conversely, yeast mitochondrial AAC can be targeted into the membranes of hydrogenosomes. The hydrogenosomal AAC contains a cleavable, N-terminal presequence; however, this sequence is not necessary for targeting the protein to the organelle. These data indicate that the membrane-targeting signal(s) for hydrogenosomal AAC is internal, similar to that found for mitochondrial carrier proteins. Our findings indicate that the membrane carriers and membrane protein-targeting machinery of hydrogenosomes and mitochondria have a common evolutionary origin. Together, they provide strong evidence that a single endosymbiont evolved into a progenitor organelle in early eukaryotic cells that ultimately give rise to these two distinct organelles and support the hydrogen hypothesis for the origin of the eukaryotic cell.

Intercistronic heterogeneity of the 16S–23S rRNA spacer region among Pseudomonas strains isolated from subterranean seeds of hog peanut (Amphicarpa bracteata)

Microbiology ◽  
2009 ◽  
Vol 155 (8) ◽  
pp. 2630-2640 ◽  
Author(s):  
J. T. Tambong ◽  
R. Xu ◽  
E. S. P. Bromfield
Keyword(s):  
Root Zone ◽  
Phylogenetic Analyses ◽  
Melting Curve ◽  
Pcr Amplification ◽  
23S Rrna ◽  
Melting Curve Analysis ◽  
Its1 Region ◽  
A Genome ◽  
Pure Cultures ◽  
Intercalating Dye

Intercistronic heterogeneity of the 16S–23S rRNA internal transcribed spacer regions (ITS1) was investigated in 29 strains of fluorescent pseudomonads isolated from subterranean seeds of Amphicarpa bracteata (hog peanut). PCR amplification of the ITS1 region generated one or two products from the strains. Sequence analysis of the amplified fragments revealed an ITS1 fragment of about 517 bp that contained genes for tRNAIle and tRNAAla in all 29 strains; an additional smaller ITS1 of 279 bp without tRNA features was detected in 15 of the strains. The length difference appeared to be due to deletions of several nucleotide blocks between the 70 bp and 359 bp positions of the alignment. The end of the deletions in the variant ITS1 type coincided with the start of antiterminator box A, which is homologous to box A of other bacteria. Phylogenetic analyses using the neighbour-joining algorithm revealed two major phylogenetic clusters, one for each of the ITS1 types. Using a single specific primer set and the DNA-intercalating dye SYBR Green I for real-time PCR and melting-curve analysis produced highly informative curves with one or two recognizable melting peaks that readily distinguished between the two ITS1 types in pure cultures. The assay was used to confirm the presence of the variant ITS1 type in the Pseudomonas community in total DNA from root-zone soil and seed coats of hog peanut. Heterogeneity of the ITS1 region between species has potential for studying molecular systematics and population genetics of the genus Pseudomonas, but the presence of non-identical rRNA operons within a genome may pose problems.

scholarly journals Identification and characterization of Fep15, a new selenocysteine-containing member of the Sep15 protein family

2006 ◽  
Vol 394 (3) ◽  
pp. 575-579 ◽  
Author(s):  
Sergey V. Novoselov ◽  
Deame Hua ◽  
Alexey V. Lobanov ◽  
Vadim N. Gladyshev
Keyword(s):  
Mammalian Cells ◽  
Insertion Sequence ◽  
Phylogenetic Analyses ◽  
Dependent Manner ◽  
Putative Active Site ◽  
A Genome ◽  
Sequence Elements ◽  
Identification And Characterization ◽  
Insertion Sequence Elements

Sec (selenocysteine) is a rare amino acid in proteins. It is co-translationally inserted into proteins at UGA codons with the help of SECIS (Sec insertion sequence) elements. A full set of selenoproteins within a genome, known as the selenoproteome, is highly variable in different organisms. However, most of the known eukaryotic selenoproteins are represented in the mammalian selenoproteome. In addition, many of these selenoproteins have cysteine orthologues. Here, we describe a new selenoprotein, designated Fep15, which is distantly related to members of the 15 kDa selenoprotein (Sep15) family. Fep15 is absent in mammals, can be detected only in fish and is present in these organisms only in the selenoprotein form. In contrast with other members of the Sep15 family, which contain a putative active site composed of Sec and cysteine, Fep15 has only Sec. When transiently expressed in mammalian cells, Fep15 incorporated Sec in an SECIS- and SBP2 (SECIS-binding protein 2)-dependent manner and was targeted to the endoplasmic reticulum by its N-terminal signal peptide. Phylogenetic analyses of Sep15 family members suggest that Fep15 evolved by gene duplication.

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