| 11. |
- Börjesson, Vanja, et al.
(författare)
-
TC-hunter: identification of the insertion site of a transgenic gene within the host genome
- 2022
-
Ingår i: Bmc Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 23:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Transgenic animal models are crucial for the study of gene function and disease, and are widely utilized in basic biological research, agriculture and pharma industries. Since the current methods for generating transgenic animals result in the random integration of the transgene under study, the phenotype may be compromised due to disruption of known genes or regulatory regions. Unfortunately, most of the tools that predict transgene insertion sites from high-throughput data are not publicly available or not properly maintained. Results: We implemented TC-hunter, Transgene-Construct hunter, an open tool that identifies transgene insertion sites and provides simple reports and visualization aids. It relies on common tools used in the analysis of high-throughput data and makes use of chimeric reads and discordant read pairs to identify and support the transgenic insertion site. To demonstrate its applicability, we applied TC-hunter to four transgenic mice samples harboring the human PPM1D gene, a model used in the study of malignant tumor development. We identified the transgenic insertion site in each sample and experimentally validated them with Touchdown-polymerase chain reaction followed by Sanger sequencing. Conclusions: TC-hunter is an accessible bioinformatics tool that can automatically identify transgene insertion sites from DNA sequencing data with high sensitivity (98%) and precision (92.45%). TC-hunter is a valuable tool that can aid in evaluating any potential phenotypic complications due to the random integration of the transgene and can be accessed at https://github.com/bcfgothenburg/SSF.
|
|
| 12. |
- Carlsten, Jonas O P, et al.
(författare)
-
Loss of the Mediator subunit Med20 affects transcription of tRNA and other non-coding RNA genes in fission yeast
- 2016
-
Ingår i: Biochimica Et Biophysica Acta-Gene Regulatory Mechanisms. - : Elsevier BV. - 1874-9399. ; 1859:2, s. 339-347
-
Tidskriftsartikel (refereegranskat)abstract
- Mediator is a co-regulator of RNA polymerase II (Pol II), transducing signals from regulatory elements and transcription factors to the general transcription machinery at the promoter. We here demonstrate that Med20 influences ribosomal protein expression in fission yeast. In addition, loss of Med20 leads to an accumulation of aberrant, readthrough tRNA transcripts. These transcripts are polyadenylated and targeted for degradation by the exosome. Similarly, other non-coding RNA molecules, such as snRNA, snoRNA and rRNA, are also enriched in the polyadenylate preparations in the absence of Med20. We suggest that fission yeast Mediator takes part in a regulatory pathway that affects Pol III-dependent transcripts.
|
|
| 13. |
- Carlsten, Jonas O P, et al.
(författare)
-
Mediator Promotes CENP-A Incorporation at Fission Yeast Centromeres
- 2012
-
Ingår i: Molecular and Cellular Biology. - : Informa UK Limited. - 0270-7306 .- 1098-5549. ; 32:19, s. 4035-4043
-
Tidskriftsartikel (refereegranskat)abstract
- At Schizosaccharomyces pombe centromeres, heterochromatin formation is required for de novo incorporation of the histone H3 variant CENP-A(Cnp1), which in turn directs kinetochore assembly and ultimately chromosome segregation during mitosis. Noncoding RNAs (ncRNAs) transcribed by RNA polymerase II (Pol II) directs heterochromatin formation through not only the RNA interference (RNAi) machinery but also RNAi-independent RNA processing factors. Control of centromeric ncRNA transcription is therefore a key factor for proper centromere function. We here demonstrate that Mediator directs ncRNA transcription and regulates centromeric heterochromatin formation in fission yeast. Mediator colocalizes with Pol II at centromeres, and loss of the Mediator subunit Med20 causes a dramatic increase in pericentromeric transcription and desilencing of the core centromere. As a consequence, heterochromatin formation is impaired via both the RNAi-dependent and -independent pathways, resulting in loss of CENP-A(Cnp1) from the core centromere, a defect in kinetochore function, and a severe chromosome segregation defect. Interestingly, the increased centromeric transcription observed in med20 Delta cells appears to directly block CENP-A(Cnp1) incorporation since inhibition of Pol II transcription can suppress the observed phenotypes. Our data thus identify Mediator as a crucial regulator of ncRNA transcription at fission yeast centromeres and add another crucial layer of regulation to centromere function.
|
|
| 14. |
|
|
| 15. |
|
|
| 16. |
- Davila Lopez, Marcela, et al.
(författare)
-
Computational screen for spliceosomal RNA genes aids in defining the phylogenetic distribution of the major and minor spliceosomal components
- 2008
-
Ingår i: RNA Society Meeting 2008.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- An essential step of gene expression is the removal of non-coding sequences (introns) from the pre-mRNA and the ligation of coding sequences (exons) to form the mature RNA (mRNA). It is known that the pre-mRNA splicing occurs by two sequential trans-esterification reactions and is catalyzed by a multicomponent complex, the spliceosome. Its assembly involves five small nuclear ribonucleoprotein particles (snRNPs) as well as an array of protein factors, which are determined by the class of intron to be spliced1. To date, two intron classes are known, U2- and U12-type introns. The U2-dependent spliceosome (panel a) is formed by the interaction of the U1, U2, U4/U6 and U5 snRNPs and numerous non-snRNP proteins with the pre-mRNA. The U12-dependent spliceosome (also referred to as the minor spliceosome, panel b), in contrast, consists of the U11, U12, U4atac/U6atac and U5 snRNPs with an unknown number of non-snRNP proteins. Thus, of the main spliceosomal subunits, only the U5 snRNA is common to both spliceosomes2.
|
|
| 17. |
- Davila Lopez, Marcela, et al.
(författare)
-
Conserved and variable domains of RNase MRP RNA
- 2009
-
Ingår i: RNA Biology. - 1547-6286. ; 6:3, s. 208-221
-
Tidskriftsartikel (refereegranskat)abstract
- Ribonuclease MRP is a eukaryotic ribonucleoprotein complex consisting of one RNA molecule and 7-10 protein subunits. One important function of MRP is to catalyze an endonucleolytic cleavage during processing of rRNA precursors. RNase MRP is evolutionary related to RNase P which is critical for tRNA processing. A large number of MRP RNA sequences that now are available have been used to identify conserved primary and secondary structure features of the molecule. MRP RNA has structural features in common with P RNA such as a conserved catalytic core, but it also has unique features and is characterized by a domain highly variable between species. Information regarding primary and secondary structure features is of interest not only in basic studies of the function of MRP RNA, but also because mutations in the RNA give rise to human genetic diseases such as cartilage-hair hypoplasia.
|
|
| 18. |
- Davila Lopez, Marcela, et al.
(författare)
-
Early evolution of histone mRNA 3' end processing.
- 2008
-
Ingår i: RNA. - : Cold Spring Harbor Laboratory. - 1355-8382 .- 1469-9001. ; 14:1, s. 1-10
-
Tidskriftsartikel (refereegranskat)abstract
- The replication-dependent histone mRNAs in metazoa are not polyadenylated, in contrast to the bulk of mRNA. Instead, they contain an RNA stem-loop (SL) structure close to the 3' end of the mature RNA, and this 3' end is generated by cleavage using a machinery involving the U7 snRNP and protein factors such as the stem-loop binding protein (SLBP). This machinery of 3' end processing is related to that of polyadenylation as protein components are shared between the systems. It is commonly believed that histone 3' end processing is restricted to metazoa and green algae. In contrast, polyadenylation is ubiquitous in Eukarya. However, using computational approaches, we have now identified components of histone 3' end processing in a number of protozoa. Thus, the histone mRNA stem-loop structure as well as the SLBP protein are present in many different protozoa, including Dictyostelium, alveolates, Trypanosoma, and Trichomonas. These results show that the histone 3' end processing machinery is more ancient than previously anticipated and can be traced to the root of the eukaryotic phylogenetic tree. We also identified histone mRNAs from both metazoa and protozoa that are polyadenylated but also contain the signals characteristic of histone 3' end processing. These results provide further evidence that some histone genes are regulated at the level of 3' end processing to produce either polyadenylated RNAs or RNAs with the 3' end characteristic of replication-dependent histone mRNAs.
|
|
| 19. |
- Davila Lopez, Marcela, et al.
(författare)
-
eGOB: eukaryotic Gene Order Browser.
- 2011
-
Ingår i: Bioinformatics (Oxford, England). - : Oxford University Press (OUP). - 1367-4811 .- 1460-2059 .- 1367-4803. ; 27:8, s. 1150-1
-
Tidskriftsartikel (refereegranskat)abstract
- A large number of genomes have been sequenced, allowing a range of comparative studies. Here, we present the eukaryotic Gene Order Browser with information on the order of protein and non-coding RNA (ncRNA) genes of 74 different eukaryotic species. The browser is able to display a gene of interest together with its genomic context in all species where that gene is present. Thereby, questions related to the evolution of gene organization and non-random gene order may be examined. The browser also provides access to data collected on pairs of adjacent genes that are evolutionarily conserved. AVAILABILITY: eGOB as well as underlying data are freely available at http://egob.biomedicine.gu.se SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online. CONTACT: tore.samuelsson@medkem.gu.se.
|
|
| 20. |
- Davila Lopez, Marcela
(författare)
-
Evolution of protein and non-coding RNA genes studied with comparative genomics
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The identification of protein and non-coding RNA (ncRNA) genes is one important step in the analysis of a genome. This thesis focuses on the identification and analysis of proteins and ncRNAs homologues by exploiting a variety of computational methods in order to reach conclusions as to their structure, function, evolution and regulation. This work is composed of two different parts. One deals with computational prediction of protein and ncRNA homologues from different ribonucleoprotein (RNP) complexes and the other addresses problems related to non-random gene order in eukaryotes. In the first part RNPs that were previously not well explored with respect to their phylogenetic distribution were examined. Thus, homology-based methods were employed to analyze the RNP complexes of RNase P, RNase MRP and the spliceosome as well as RNPs and RNA structures involved in the 3' end processing of histone mRNAs. We identified a large number of previously unrecognized homologues that improved our understanding of the evolution of the different RNPs. For example, homology relationships of the RNases P and MRP proteins were identified providing further evidence of homology between the human and the yeast RNPs. We presented evidence that the histone 3’ end processing machinery is more ancient than previously anticipated and can be traced to the root of the eukaryotic phylogenetic tree. We presented a detailed map of the distribution of the spliceosomal U12-type RNA genes, supporting an early origin of the minor spliceosome and pointing to a number of occasions where it was lost during evolution. In the second part we generated gene order maps to show the localization of both protein and ncRNA genes in a wide range of eukaryotic organisms. Non-random gene order was then examined to identify the most important determinants of gene order conservation. One important conclusion was that gene pairs that are evolutionarily conserved and that are divergently transcribed are much more likely to be related by function as compared to poorly conserved gene pairs. The genes of such pairs are likely to be related also in terms of transcriptional control. Moreover, we presented the eukaryotic Gene Order Browser (eGOB), where data related to this project is available and where researchers can visualize and compare the evolution of gene organization in different organisms. In addition, the browser may be used to identify pairs of adjacent genes that are evolutionarily conserved and likely to be transcriptionally linked. eGOB is available at http://egob.bioimedicine.gu.se.
|
|
