scholarly journals Separating the Wheat from the Chaff: RNA Editing and Selection of Translatable mRNA in Trypanosome Mitochondria

Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 105 ◽  
Author(s):  
Dmitri A. Maslov
Keyword(s):  
Rna Editing ◽  
Transcription Initiation ◽  
Mrna Processing ◽  
Selective Recognition ◽  
Reading Frame ◽  
Mitochondrial Ribosomes ◽  
The Subject ◽  
Translatable Mrna ◽  
A Minor ◽  
Selection Of

In the mitochondria of trypanosomes and related kinetoplastid protists, most mRNAs undergo a long and sophisticated maturation pathway before they can be productively translated by mitochondrial ribosomes. Some of the aspects of this pathway (identity of the promotors, transcription initiation, and termination signals) remain obscure, and some (post-transcriptional modification by U-insertion/deletion, RNA editing, 3′-end maturation) have been illuminated by research during the last decades. The RNA editing creates an open reading frame for a productive translation, but the fully edited mRNA often represents a minor fraction in the pool of pre-edited and partially edited precursors. Therefore, it has been expected that the final stages of the mRNA processing generate molecular hallmarks, which allow for the efficient and selective recognition of translation-competent templates. The general contours and several important details of this process have become known only recently and represent the subject of this review.

Expression of tissue-specific Ren-1 and Ren-2 genes of mice: comparative analysis of 5'-proximal flanking regions

1984 ◽  
Vol 4 (11) ◽  
pp. 2321-2331
Author(s):  
L J Field ◽  
W M Philbrick ◽  
P N Howles ◽  
D P Dickinson ◽  
R A McGowan ◽  
...  
Keyword(s):  
Structural Gene ◽  
Transcription Initiation ◽  
Submaxillary Gland ◽  
Inbred Strains ◽  
Initiation Site ◽  
Sequence Motifs ◽  
Specific Expression ◽  
Tissue Specific ◽  
Reading Frame ◽  
A Minor

All inbred strains of mice carry the Ren-1 structural gene, which encodes the renin-1 isozyme, the classical renin activity found in kidneys. In addition, some strains carry a second renin structural gene, Ren-2, which encodes the predominantly expressed submaxillary gland renin isozyme, renin-2. Ren-1 and Ren-2 exhibit markedly different patterns of tissue-specific expression. In an effort to understand the molecular basis for this differential expression, detailed analysis of the genomic sequences corresponding to the Ren-1 and Ren-2 genes, and the transcripts originating from these loci, was undertaken. Sequence analysis of regions proximal to the structural genes indicated the presence of eucaryotic consensus sequences for transcription. These sequence motifs were strongly conserved between Ren-1 and Ren-2. Approximately 150 bases upstream from the major transcription initiation site, significant differences between these genes were apparent, including the presence of a repetitive DNA element in the Ren-2 copy as well as other breaks in homology and sequence curiosities. Strong homology between Ren-1 and Ren-2 resumed at a point ca. 200 bases further upstream on Ren-1. S1 analysis of submaxillary gland and kidney RNA populations indicated that the majority of transcripts initiate at homologous positions on Ren-1 and Ren-2. On a per cell basis, the accumulation of Ren-1 transcripts in the kidney and Ren-2 transcripts in the submaxillary gland are probably equivalent. These results suggest that it is tissue-specific utilization of the homologous start sites that is critical to their differential patterns of expression. Models which can account for this observation are presented. Interestingly, we found a minor fraction of transcripts initiating 5' to the major transcription start site. These transcripts encoded an open reading frame which may add an additional 23 amino acids to the N-terminus of the renin precursor.

scholarly journals Structure and transcription of the Drosophila melanogaster vermilion gene and several mutant alleles

1990 ◽  
Vol 10 (4) ◽  
pp. 1423-1431
Author(s):  
L L Searles ◽  
R S Ruth ◽  
A M Pret ◽  
R A Fridell ◽  
A J Ali
Keyword(s):  
Drosophila Melanogaster ◽  
Transcription Initiation ◽  
Donor Site ◽  
Initiation Site ◽  
Splice Donor Site ◽  
Wild Type ◽  
Upstream Site ◽  
Reading Frame ◽  
Exon 1 ◽  
A Minor

The nucleotide sequence and intron-exon structure of the Drosophila melanogaster vermilion (v) gene have been determined. In addition, the sites of several mutations and the effects of these mutations on transcription have been examined. The major v mRNA is generated upon splicing six exons of lengths (5' to 3') 83, 161, 134, 607, 94, and 227 nucleotides (nt). A minor species of v mRNA is initiated at an upstream site and has a 5' exon of at least 152 nt which overlaps the region included in the 83-nt exon of the major v RNA. The three v mutations, v1, v2, and vk, which can be suppressed by mutations at suppressor of sable, su(s), are insertions of transposon 412 at the same position in exon 1, 36 nt downstream of the major transcription initiation site. Despite the 7.5-kilobase insertion in these v alleles, a reduced level of wild-type-sized mRNA accumulates in suppressed mutant strains. The structure and transcription of several unsuppressible v alleles have also been examined. The v36f mutation is a B104/roo insertion in intron 4 near the splice donor site. A mutant carrying this alteration accumulates a very low level of mRNA that is apparently polyadenylated at a site within the B104/roo transposon. The v48a mutation, which deletes approximately 200 nt of DNA, fuses portions of exons 3 and 4 without disruption of the translational reading frame. A smaller transcript accumulates at a wild-type level, and thus an altered, nonfunctional polypeptide is likely to be synthesized in strains carrying this mutation.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Expression of tissue-specific Ren-1 and Ren-2 genes of mice: comparative analysis of 5'-proximal flanking regions.

1984 ◽  
Vol 4 (11) ◽  
pp. 2321-2331 ◽  
Author(s):  
L J Field ◽  
W M Philbrick ◽  
P N Howles ◽  
D P Dickinson ◽  
R A McGowan ◽  
...  
Keyword(s):  
Structural Gene ◽  
Transcription Initiation ◽  
Submaxillary Gland ◽  
Inbred Strains ◽  
Initiation Site ◽  
Sequence Motifs ◽  
Specific Expression ◽  
Tissue Specific ◽  
Reading Frame ◽  
A Minor

All inbred strains of mice carry the Ren-1 structural gene, which encodes the renin-1 isozyme, the classical renin activity found in kidneys. In addition, some strains carry a second renin structural gene, Ren-2, which encodes the predominantly expressed submaxillary gland renin isozyme, renin-2. Ren-1 and Ren-2 exhibit markedly different patterns of tissue-specific expression. In an effort to understand the molecular basis for this differential expression, detailed analysis of the genomic sequences corresponding to the Ren-1 and Ren-2 genes, and the transcripts originating from these loci, was undertaken. Sequence analysis of regions proximal to the structural genes indicated the presence of eucaryotic consensus sequences for transcription. These sequence motifs were strongly conserved between Ren-1 and Ren-2. Approximately 150 bases upstream from the major transcription initiation site, significant differences between these genes were apparent, including the presence of a repetitive DNA element in the Ren-2 copy as well as other breaks in homology and sequence curiosities. Strong homology between Ren-1 and Ren-2 resumed at a point ca. 200 bases further upstream on Ren-1. S1 analysis of submaxillary gland and kidney RNA populations indicated that the majority of transcripts initiate at homologous positions on Ren-1 and Ren-2. On a per cell basis, the accumulation of Ren-1 transcripts in the kidney and Ren-2 transcripts in the submaxillary gland are probably equivalent. These results suggest that it is tissue-specific utilization of the homologous start sites that is critical to their differential patterns of expression. Models which can account for this observation are presented. Interestingly, we found a minor fraction of transcripts initiating 5' to the major transcription start site. These transcripts encoded an open reading frame which may add an additional 23 amino acids to the N-terminus of the renin precursor.

scholarly journals Structure and transcription of the Drosophila melanogaster vermilion gene and several mutant alleles.

1990 ◽  
Vol 10 (4) ◽  
pp. 1423-1431 ◽  
Author(s):  
L L Searles ◽  
R S Ruth ◽  
A M Pret ◽  
R A Fridell ◽  
A J Ali
Keyword(s):  
Drosophila Melanogaster ◽  
Transcription Initiation ◽  
Donor Site ◽  
Initiation Site ◽  
Splice Donor Site ◽  
Wild Type ◽  
Upstream Site ◽  
Reading Frame ◽  
Exon 1 ◽  
A Minor

The nucleotide sequence and intron-exon structure of the Drosophila melanogaster vermilion (v) gene have been determined. In addition, the sites of several mutations and the effects of these mutations on transcription have been examined. The major v mRNA is generated upon splicing six exons of lengths (5' to 3') 83, 161, 134, 607, 94, and 227 nucleotides (nt). A minor species of v mRNA is initiated at an upstream site and has a 5' exon of at least 152 nt which overlaps the region included in the 83-nt exon of the major v RNA. The three v mutations, v1, v2, and vk, which can be suppressed by mutations at suppressor of sable, su(s), are insertions of transposon 412 at the same position in exon 1, 36 nt downstream of the major transcription initiation site. Despite the 7.5-kilobase insertion in these v alleles, a reduced level of wild-type-sized mRNA accumulates in suppressed mutant strains. The structure and transcription of several unsuppressible v alleles have also been examined. The v36f mutation is a B104/roo insertion in intron 4 near the splice donor site. A mutant carrying this alteration accumulates a very low level of mRNA that is apparently polyadenylated at a site within the B104/roo transposon. The v48a mutation, which deletes approximately 200 nt of DNA, fuses portions of exons 3 and 4 without disruption of the translational reading frame. A smaller transcript accumulates at a wild-type level, and thus an altered, nonfunctional polypeptide is likely to be synthesized in strains carrying this mutation.(ABSTRACT TRUNCATED AT 250 WORDS)

Thomas More’s Correspondence in a Spanish Ambiance

Moreana ◽  
2002 ◽  
Vol 39 (Number 149) (1) ◽  
pp. 41-60 ◽  
Author(s):  
Eugenio M. Olivares Merino
Keyword(s):  
The Subject ◽  
Selection Of

The recent reprinting of Álvaro de Silva’s 1998 edition of a selection of More’s letters prompts the author to examine the subject of Spanish translations of More, and of de Silva’s general commentary on More’s correspondence and on his relationship to other humanists. The author reflects on aspects of More’s personality as exposed in his letters and uses what he finds as a corrective to several biographical misconceptions. He points out the strengths and weaknesses of de Silva’s work and compares it with that of other translators, particularly Elizabeth Rogers, and notes the particularly Spanish quality of de Silva’s edition.

Tanks in the Spa Town. The New Book about the Events of the Year 1968 in Czechoslovakia

2019 ◽  
Vol 14 (1-2) ◽  
pp. 278-282
Author(s):  
Kirill A. Popov
Keyword(s):  
Fiftieth Anniversary ◽  
Warsaw Pact ◽  
Scientific Event ◽  
The Social ◽  
Prague Spring ◽  
The Subject ◽  
Scientific Terms ◽  
Selection Of ◽  
Regional Perspective ◽  
The Way

This review is devoted to the monograph by Jan Nedvěd “We do not decline our heads. The events of the year 1968 in Karlovy Vary”. The Karlovy Vary municipal museum coincided its publishing with the fiftieth anniversary of the Prague spring which, considering the way of the presentation, turned the book not only to scientific event but also to the social one. The book describes sociopolitical trends in the region before the year 1968, the development of the reformist movement, the invasion and advance of the armies of the Warsaw Pact countries, and finally the decline of the reformist mood and the beginning of the normalization. Working on his writing, the author deeply studied the materials of the local archive and gathered the unique selection of the photographs depicting the passage of the soviet army through the spa town and the protest actions of its inhabitants. In the meantime, Nedvěd takes undue freedom with scientific terms, and his selection of historiography raises questions. The author bases his research on the Czech papers and scarcely uses the books of Russian origin. He also did not study the subject of the participating of the GDR’s army in the operation Danube, although these troops were concentrated on the borders of Karlovy Vary region as well. Because of this decision, there are no materials from German archives or historiography in the monograph. In general, the work lacks the width of studying its subject, but it definitively accomplishes the task of depicting the Prague spring from the regional perspective.

scholarly journals Organelle Genetics in Plants

2021 ◽  
Vol 22 (4) ◽  
pp. 2104
Author(s):  
Pedro Robles ◽  
Víctor Quesada
Keyword(s):  
Rna Editing ◽  
Posttranscriptional Regulation ◽  
Genome Engineering ◽  
Plant Mitochondria ◽  
Plastid Dna ◽  
Chloroplast Genomes ◽  
Wide Range ◽  
Organelle Genetics ◽  
Selection Of

Eleven published articles (4 reviews, 7 research papers) are collected in the Special Issue entitled “Organelle Genetics in Plants.” This selection of papers covers a wide range of topics related to chloroplasts and plant mitochondria research: (i) organellar gene expression (OGE) and, more specifically, chloroplast RNA editing in soybean, mitochondria RNA editing, and intron splicing in soybean during nodulation, as well as the study of the roles of transcriptional and posttranscriptional regulation of OGE in plant adaptation to environmental stress; (ii) analysis of the nuclear integrants of mitochondrial DNA (NUMTs) or plastid DNA (NUPTs); (iii) sequencing and characterization of mitochondrial and chloroplast genomes; (iv) recent advances in plastid genome engineering. Here we summarize the main findings of these works, which represent the latest research on the genetics, genomics, and biotechnology of chloroplasts and mitochondria.

scholarly journals QTL Mapping for Gummy Stem Blight Resistance in Watermelon (Citrullus spp.)

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 500
Author(s):  
Eun Su Lee ◽  
Do-Sun Kim ◽  
Sang Gyu Kim ◽  
Yun-Chan Huh ◽  
Chang-Gi Back ◽  
...  
Keyword(s):  
Chromosome 8 ◽  
Chromosome 6 ◽  
Potential Candidate ◽  
Stem Blight ◽  
Gummy Stem Blight ◽  
F2 Population ◽  
Leaf Lesion ◽  
Phenotypic Variations ◽  
A Minor ◽  
Selection Of

Watermelon (Citrulluslanatus) is an economically important fruit crop worldwide. Gummy stem blight (GSB) is one of the most damaging diseases encountered during watermelon cultivation. In the present study, we identified quantitative trait loci (QTLs) associated with GSB resistance in an F2 population derived from a cross between maternal-susceptible line ‘920533’ (C. lanatus) and the paternal-resistant line ‘PI 189225’ (C. amarus). The resistance of 178 F2 plants was assessed by two different evaluation methods, including leaf lesion (LL) and stem blight (SB). To analyze the QTLs associated with GSB resistance, a linkage map was constructed covering a total genetic distance of 1070.2 cM. QTL analysis detected three QTLs associated with GSB resistance on chromosome 8 and 6. Among them, two QTLs, qLL8.1 and qSB8.1 on chromosome 8 identified as major QTLs, explaining 10.5 and 10.0% of the phenotypic variations localizing at same area and sharing the same top markers for both LL and SB traits, respectively. A minor QTL, qSB6.1, explains 9.7% of phenotypic variations detected on chromosome 6 only for the SB trait. High-throughput markers were developed and validated for the selection of resistant QTLs using watermelon accessions, and commercial cultivars. Four potential candidate genes were predicted associated with GSB resistance based on the physical location of flanking markers on chromosome 8. These findings will be helpful for the development of watermelon cultivars resistant to GSB.

Determination of integral indicators characterizing the possibility of accommodating the evacuated population in the territory of the Republic of Kazakhstan

2020 ◽  
pp. 154851292097028
Author(s):  
Yernar Zh Akimbayev ◽  
Zhumabek Kh Akhmetov ◽  
Murat S Kuanyshbaev ◽  
Arman T Abdykalykov ◽  
Rashid V Ibrayev
Keyword(s):  
Statistical Data ◽  
Armed Conflicts ◽  
Security Issues ◽  
Inaccurate Information ◽  
The Subject ◽  
The Republic ◽  
The Impact ◽  
Integrated Indicators ◽  
Selection Of

Studying the historical facts of past wars and armed conflicts and natural and man-made emergencies, today in the Republic of Kazakhstan one of the most important security issues is the preparation and organization of the evacuation of the population from possible dangerous zones, taking into account the emergence of new threats to the country’s security. The paper presents an algorithm for constructing universal scales of the distribution function of opportunities by types of support and rebuilding them into subject scales using display functions. The purpose of the paper is to determine the integral indicators characterizing the possibility of accommodation of the evacuated population and the impact on resources during relocation. On the subject scales of cities and districts of the region, indicators of the possibility of relocation of a certain amount of the evacuated population by types of support and indicators characterizing the impact on the district’s resources during resettlement of a certain amount of the evacuated population are determined. It was concluded that the use of integrated indicators allows the selection of areas to accommodate the evacuated population without the use of statistical data, in conditions of incomplete and inaccurate information. The presented method does not replace traditional methods based on classical methods of territory assessment by the level of life sustenance, but also allows their reasonable combination with the experience of specialists in this field, taking into account the incompleteness, uncertainty, and inconsistency of the initial data of the study area, which does not allow the application of existing methods.

Singular agreement in there-existentials

2012 ◽  
Vol 33 (1) ◽  
pp. 53-68 ◽  
Author(s):  
Peter Collins
Keyword(s):  
Indirect Evidence ◽  
World Englishes ◽  
Relative Influence ◽  
Evolutionary Status ◽  
The Subject ◽  
Characteristic Style ◽  
Selection Of

The phenomenon of “singular agreement” (“SA”) in there-existentials — the combination of a plural post-verbal notional subject and a singular verb — has been the subject of a number of studies which have confirmed its covariation with a range of social, stylistic and grammatical factors. Whereas the focus of most such studies has been on the relative influence of these factors, that of the present study is on the nature and frequency of SA across (a selection of eight) World Englishes. Beginning with the assumption, for which there is indirect evidence in the literature, that SA is on the rise in contemporary English, an attempt is made to relate the degree of advancement of the eight varieties to their evolutionary status and characteristic style orientations.

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