scholarly journals Identification of Mobile Elements and Pseudogenes in the Shewanella oneidensis MR-1 Genome

2008 ◽  
Vol 74 (10) ◽  
pp. 3257-3265 ◽  
Author(s):  
Margaret F. Romine ◽  
Timothy S. Carlson ◽  
Angela D. Norbeck ◽  
Lee Ann McCue ◽  
Mary S. Lipton

ABSTRACT Shewanella oneidensis MR-1 is the first of 22 different Shewanella spp. whose genomes have been or are being sequenced and thus serves as the model organism for studying the functional repertoire of the Shewanella genus. The original MR-1 genome annotation revealed a large number of transposase genes and pseudogenes, indicating that many of the genome's functions may be decaying. Comparative analyses of the sequenced Shewanella strains suggest that 209 genes in MR-1 have in-frame stop codons, frameshifts, or interruptions and/or are truncated and that 65 of the original pseudogene predictions were erroneous. Among the decaying functions are that of one of three chemotaxis clusters, type I pilus production, starch utilization, and nitrite respiration. Many of the mutations could be attributed to members of 41 different types of insertion sequence (IS) elements and three types of miniature inverted-repeat transposable elements identified here for the first time. The high copy numbers of individual mobile elements (up to 71) are expected to promote large-scale genome recombination events, as evidenced by the displacement of the algA promoter. The ability of MR-1 to acquire foreign genes via reactions catalyzed by both the integron integrase and the ISSod25-encoded integrases is suggested by the presence of attC sites and genes whose sequences are characteristic of other species downstream of each site. This large number of mobile elements and multiple potential sites for integrase-mediated acquisition of foreign DNA indicate that the MR-1 genome is exceptionally dynamic, with many functions and regulatory control points in the process of decay or reinvention.

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1422
Author(s):  
Ousama Al Shanaa ◽  
Andrey Rumyantsev ◽  
Elena Sambuk ◽  
Marina Padkina

RNA aptamers are becoming increasingly attractive due to their superior properties. This review discusses the early stages of aptamer research, the main developments in this area, and the latest technologies being developed. The review also highlights the advantages of RNA aptamers in comparison to antibodies, considering the great potential of RNA aptamers and their applications in the near future. In addition, it is shown how RNA aptamers can form endless 3-D structures, giving rise to various structural and functional possibilities. Special attention is paid to the Mango, Spinach and Broccoli fluorescent RNA aptamers, and the advantages of split RNA aptamers are discussed. The review focuses on the importance of creating a platform for the synthesis of RNA nanoparticles in vivo and examines yeast, namely Saccharomyces cerevisiae, as a potential model organism for the production of RNA nanoparticles on a large scale.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Moritz Mercker ◽  
Philipp Schwemmer ◽  
Verena Peschko ◽  
Leonie Enners ◽  
Stefan Garthe

Abstract Background New wildlife telemetry and tracking technologies have become available in the last decade, leading to a large increase in the volume and resolution of animal tracking data. These technical developments have been accompanied by various statistical tools aimed at analysing the data obtained by these methods. Methods We used simulated habitat and tracking data to compare some of the different statistical methods frequently used to infer local resource selection and large-scale attraction/avoidance from tracking data. Notably, we compared spatial logistic regression models (SLRMs), spatio-temporal point process models (ST-PPMs), step selection models (SSMs), and integrated step selection models (iSSMs) and their interplay with habitat and animal movement properties in terms of statistical hypothesis testing. Results We demonstrated that only iSSMs and ST-PPMs showed nominal type I error rates in all studied cases, whereas SSMs may slightly and SLRMs may frequently and strongly exceed these levels. iSSMs appeared to have on average a more robust and higher statistical power than ST-PPMs. Conclusions Based on our results, we recommend the use of iSSMs to infer habitat selection or large-scale attraction/avoidance from animal tracking data. Further advantages over other approaches include short computation times, predictive capacity, and the possibility of deriving mechanistic movement models.


2001 ◽  
Vol 2 (4) ◽  
pp. 243-251
Author(s):  
Jo Wixon

We bring you a report from the CSHL Genome Sequencing and Biology Meeting, which has a long and prestigious history. This year there were sessions on large-scale sequencing and analysis, polymorphisms (covering discovery and technologies and mapping and analysis), comparative genomics of mammalian and model organism genomes, functional genomics and bioinformatics.


2008 ◽  
Vol 233 (10) ◽  
pp. 1309-1314 ◽  
Author(s):  
A. V. Capuco ◽  
E. E. Connor ◽  
D. L. Wood

Thyroid hormones are galactopoietic and help to establish the mammary gland’s metabolic priority during lactation. Expression patterns for genes that can alter tissue sensitivity to thyroid hormones and thyroid hormone activity were evaluated in the mammary gland and liver of cows at 53, 35, 20, and 7 days before expected parturition, and 14 and 90 days into the subsequent lactation. Transcript abundance for the three isoforms of iodothyronine deiodinase, type I ( DIO1), type II ( DIO2) and type III ( DIO3), thyroid hormone receptors alpha1 ( TRα 1), alpha2 ( TRα 2) and beta1 ( TRβ 1), and retinoic acid receptors alpha ( RXRα) and gamma ( RXRγ), which act as coregulators of thyroid hormone receptor action, were evaluated by quantitative RT-PCR. The DIO3 is a 5-deiodinase that produces inactive iodothyronine metabolites, whereas DIO1 and DIO2 generate the active thyroid hormone, triiodothyronine, from the relatively inactive precursor, thyroxine. Low copy numbers of DIO3 transcripts were present in mammary gland and liver. DIO2 was the predominant isoform expressed in mammary gland and DIO1 was the predominant isoform expressed in liver. Quantity of DIO1 mRNA in liver tissues did not differ with physiological state, but tended to be lowest during lactation. Quantity of DIO2 mRNA in mammary gland increased during lactation ( P < 0.05), with copy numbers at 90 days of lactation 6-fold greater than at 35 and 20 days prepartum. When ratios of DIO2/DIO3 mRNA were evaluated, the increase was more pronounced (>100-fold). Quantity of TRβ 1 mRNA in mammary gland increased with onset of lactation, whereas TRα 1 and TRα 2 transcripts did not vary with physiological state. Conversely, quantity of RXRα mRNA decreased during late gestation to low levels during early lactation. Data suggest that increased expression of mammary TRβ 1 and DIO2, and decreased RXRα, provide a mechanism to increase thyroid hormone activity within the mammary gland during lactation.


Ethnomusic ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 142-177
Author(s):  
Jarema Pavliv ◽  

In the offered article, a comparative analysis of two performing versions of the wedding ceremonial dance “Hutsulka”, dominant in the Eastern Carpathians region of Ukraine has been made, with outstanding violinists-capellists, which, based on traditions and their own virtuoso style, developed this dance genre due to the accumulation of stable and mobile elements of melo-, rhythm- and form-making, as well as the establishment of aesthetics of regional styles. The material for the study was the audio version of the “Hutsulka” recorded on the basis of the performance of two violinists representing the region of Kosmach- Brusturiv villages tradition – Kyrylo Lyndiuk (“Vityshyn”, 1929–2003) (recorded by prof. Bogdan Lukaniuk in 1991) and Ivan Sokoliuk (born in 1944; Musician's own recording of 2017) – and transcribed by the author of the article. The performance of “Hutsulka” by each violinist is characteristic of common and distinctive features concerning the formation of the variative composition, the thematic material (respectively, 29 and 43 themes of kolomyika, kozachok and voloshka bases), tonality and rhythmic structuring, individual interpretation of ornamentation, which is collectively connected with artistic orientation on certain artistic and performing directions, presented by iconic musicians-predecessors. The formal features of the Hutsulka composition depends on scenery where it is performed (1); the tonality outline determined by established regional tradition (2), and rhythmic outline, by the overall style, varyation technics, updating and ornamentation of rhythmic formulas, characteristic of the personal manner and style of the performer (3). Ornamentation, as the essence of the performing style of any Hutsul musician, in K. “Vityshyn” is characterized by intense interweaving of short melismatic legal groups and non-legal figurations within melodic line and texture. I. Sokoliuk 166 enriches the linear movement with prolonged melismatic groups and rhythm- intonational and figurational turns that decorate it and amplify the expression of dance overall sonority. In performing aesthetics of K. Lyndiuk prevails an acute articulation of melodic expressiveness with accented and often pointed rhythmic patterns that provides representative-temperamental virtuosity. For strategic performance aesthetics of I. Sokoliuk, rich in virtuosic expressiveness, is characterized by choral and transparent ringing articulation in the context of “stratum”-development creation of the whole large-scale virtuoso composition. Each version reveals individual compositional, improvised, techno-performing, emotional as well as aesthetic mind of their creators. All these qualities, formed by both musicians in a single tradition and expressed in related kolomyika and kozachok-voloshka tunes, present the decision of developmental, composite, rhythmic, intonational, articulation, tempo and many other aspects of style, characteristic of folk violinists – soloists and capellists, inherent to each of them, in their performing manner, evident in “Hutsulka” rendering.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Guillaume Bordet ◽  
Niraj Lodhi ◽  
Danping Guo ◽  
Andrew Kossenkov ◽  
Alexei V. Tulin

AbstractPoly(ADP-ribose) polymerase 1 (PARP-1) is a nuclear enzyme involved in DNA repair and transcription regulation, among other processes. Malignant transformations, tumor progression, the onset of some neuropathies and other disorders have been linked to misregulation of PARP-1 activity. Despite intensive studies during the last few decades, the role of PARP-1 in transcription regulation is still not well understood. In this study, a transcriptomic analysis in Drosophila melanogaster third instar larvae was carried out. A total of 602 genes were identified, showing large-scale changes in their expression levels in the absence of PARP-1 in vivo. Among these genes, several functional gene groups were present, including transcription factors and cytochrome family members. The transcription levels of genes from the same functional group were affected by the absence of PARP-1 in a similar manner. In the absence of PARP-1, all misregulated genes coding for transcription factors were downregulated, whereas all genes coding for members of the cytochrome P450 family were upregulated. The cytochrome P450 proteins contain heme as a cofactor and are involved in oxidoreduction. Significant changes were also observed in the expression of several mobile elements in the absence of PARP-1, suggesting that PARP-1 may be involved in regulating the expression of mobile elements.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 32-32
Author(s):  
Juan P Steibel ◽  
Ignacio Aguilar

Abstract Genomic Best Linear Unbiased Prediction (GBLUP) is the method of choice for incorporating genomic information into the genetic evaluation of livestock species. Furthermore, single step GBLUP (ssGBLUP) is adopted by many breeders’ associations and private entities managing large scale breeding programs. While prediction of breeding values remains the primary use of genomic markers in animal breeding, a secondary interest focuses on performing genome-wide association studies (GWAS). The goal of GWAS is to uncover genomic regions that harbor variants that explain a large proportion of the phenotypic variance, and thus become candidates for discovering and studying causative variants. Several methods have been proposed and successfully applied for embedding GWAS into genomic prediction models. Most methods commonly avoid formal hypothesis testing and resort to estimation of SNP effects, relying on visual inspection of graphical outputs to determine candidate regions. However, with the advent of high throughput phenomics and transcriptomics, a more formal testing approach with automatic discovery thresholds is more appealing. In this work we present the methodological details of a method for performing formal hypothesis testing for GWAS in GBLUP models. First, we present the method and its equivalencies and differences with other GWAS methods. Moreover, we demonstrate through simulation analyses that the proposed method controls type I error rate at the nominal level. Second, we demonstrate two possible computational implementations based on mixed model equations for ssGBLUP and based on the generalized least square equations (GLS). We show that ssGBLUP can deal with datasets with extremely large number of animals and markers and with multiple traits. GLS implementations are well suited for dealing with smaller number of animals with tens of thousands of phenotypes. Third, we show several useful extensions, such as: testing multiple markers at once, testing pleiotropic effects and testing association of social genetic effects.


2019 ◽  
Author(s):  
Alvin Vista

Cheating detection is an important issue in standardized testing, especially in large-scale settings. Statistical approaches are often computationally intensive and require specialised software to conduct. We present a two-stage approach that quickly filters suspected groups using statistical testing on an IRT-based answer-copying index. We also present an approach to mitigate data contamination and improve the performance of the index. The computation of the index was implemented through a modified version of an open source R package, thus enabling wider access to the method. Using data from PIRLS 2011 (N=64,232) we conduct a simulation to demonstrate our approach. Type I error was well-controlled and no control group was falsely flagged for cheating, while 16 (combined n=12,569) of the 18 (combined n=14,149) simulated groups were detected. Implications for system-level cheating detection and further improvements of the approach were discussed.


2021 ◽  
Author(s):  
Negar Memarian ◽  
Matthew Jessulat ◽  
Javad Alirezaie ◽  
Nadereh Mir-Rashed ◽  
Jianhua Xu ◽  
...  

Background Numerous functional genomics approaches have been developed to study the model organism yeast, Saccharomyces cerevisiae, with the aim of systematically understanding the biology of the cell. Some of these techniques are based on yeast growth differences under different conditions, such as those generated by gene mutations, chemicals or both. Manual inspection of the yeast colonies that are grown under different conditions is often used as a method to detect such growth differences. Results Here, we developed a computerized image analysis system called Growth Detector (GD), to automatically acquire quantitative and comparative information for yeast colony growth. GD offers great convenience and accuracy over the currently used manual growth measurement method. It distinguishes true yeast colonies in a digital image and provides an accurate coordinate oriented map of the colony areas. Some post-processing calculations are also conducted. Using GD, we successfully detected a genetic linkage between the molecular activity of the plant-derived antifungal compound berberine and gene expression components, among other cellular processes. A novel association for the yeast mek1 gene with DNA damage repair was also identified by GD and confirmed by a plasmid repair assay. The results demonstrate the usefulness of GD for yeast functional genomics research. Conclusion GD offers significant improvement over the manual inspection method to detect relative yeast colony size differences. The speed and accuracy associated with GD makes it an ideal choice for large-scale functional genomics investigations.


2020 ◽  
Author(s):  
Miguel Araujo-Voces ◽  
Victor Quesada

Abstract Background Through its ability to open pores in cell membranes, perforin-1 plays a key role in the immune system. Consistent with this role, the gene encoding perforin shows hallmarks of complex evolutionary events, including amplification and pseudogenization, in multiple species. A large proportion of these events occurred in phyla for which scarce genomic data were available. However, recent large-scale genomics projects have added a wealth of information on those phyla. Using this input, we annotated perforin-1 homologs in more than eighty species including mammals, reptiles, birds, amphibians and fishes. Results We have annotated more than 400 perforin genes in all groups studied. Most mammalian species only have one perforin locus, which may contain a related pseudogene. However, we found four independent small expansions in unrelated members of this class. We could reconstruct the full-length coding sequences of only a few avian perforin genes, although we found incomplete and truncated forms of these gene in other birds. In the rest of reptilia, perforin-like genes can be found in at least three different loci containing up to twelve copies. Notably, mammals, non-avian reptiles, amphibians, and possibly teleosts share at least one perforin-1 locus as assessed by flanking genes. Finally, fish genomes contain multiple perforin loci with varying copy numbers and diverse exon/intron patterns. We have also found evidence for shorter genes with high similarity to the C2 domain of perforin in several teleosts. A preliminary analysis suggests that these genes arose at least twice during evolution from perforin-1 homologs. Conclusions The assisted annotation of new genomic assemblies shows complex patterns of birth-and-death events in the evolution of perforin. These events include duplication/pseudogenization in mammals, multiple amplifications and losses in reptiles and fishes and at least one case of partial duplication with a novel start codon in fishes.


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