Identification Of Transposons Research Articles

The first discovery of Tc1 transposons in yeast.

Identification of transposons without close homologs is still a difficult task. IS630/Tc1/mariner transposons, classified into a superfamily, are probably the most widespread DNA transposons in nature. Tc1/mariner transposons have been discovered in animals, plants, and filamentous fungi, however, not in yeast. In the present study, we report the discovery of two intact Tc1 transposons in yeast and filamentous fungi, respectively. The first one, named Tc1-OP1 (DD40E), represents Tc1 transposons in Ogataea parapolymorpha. The second one, named Tc1-MP1 (DD34E), represents Tc1 transposons in the Rhizopodaceae and Mucoraceae families. As a homolog of Tc1-OP1 and Tc1-MP1, IS630-AB1 (DD34E) was discovered as an IS630 transposon in Acinetobacter spp. Tc1-OP1 is not only the first reported Tc1 transposon in yeast, but also the first reported nonclassical Tc1 transposon. Tc1-OP1 is the largest of IS630/Tc1/mariner transposons reported to date and significantly different from others. Notably, Tc1-OP1 encodes a serine-rich domain and a transposase, extending the current knowledge of Tc1 transposons. The phylogenetic relationships of Tc1-OP1, Tc1-MP1 and IS630-AB1 indicated that these transposons had evolved from a common ancestor. Tc1-OP1, Tc1-MP1 and IS630-AB1 can be used as reference sequences to facilitate the identification of IS630/Tc1/mariner transposons. More Tc1/mariner transposons will be identified in yeast, following our discovery.

Application of Whole-Genome Sequencing to Transposon Mutants of Salmonella Heidelberg.

Transposons are elements widely dispersed among organisms which are able to move and replicate fragments of genomes. The extensive variability in transposons present in most organisms requires extensive identification and interpretation of the resulting transposon mutants after transposon mutagenesis. However, much of this is reliant on utilizing randomness characteristics of transposon to identify essential genes for the organism of interest. Integration of the transposon mutant approach with commercialized next-generation sequencing (NGS) technology has helped to advance transposon identification by sequencing millions of reads generated from a single run on an NGS platform. Transposon sequencing is defined as a gene sequencing methodology that allows for the identification of nonessential genes and the determination of gene function using a random transposon insertional mutagenesis followed by massively parallel sequencing. The detailed protocol will be outlined in this chapter. The genomic DNA integrated with the transposons is sequenced using an NGS platform in order to determine the location of each mutation.

Identification of transposons near predicted lncRNA and mRNA pools of Prunus mume using an integrative transposable element database constructed from Rosaceae plant genomes.

This study focused on the construction of a database of transposable elements (TEs) from Rosaceae plants, the third most economically important plant family in temperate regions, and its transcriptomics applications. The evolutionary effects of TEs on gene regulation have been explored, and TE insertions can be the molecular bases of changes in gene structure and function. However, a specific Rosaceae plant TE database (RPTEdb) is lacking. The genomes of several Rosaceae plants have been sequenced, providing the opportunity to mine TE data at a whole-genome level. Therefore, we constructed the RPTEdb, a collective and comprehensive database of 19,596 annotated TEs in the genomes of Rosaceae plants using previously described identification and annotation methods and published genome sequences. The user-friendly web-based database provides access to research tools through hyperlinks, including Browse, TE tree, tools, JBrowse, and search sections, and through the inputting of sequences on the main webpage. Next, we performed one advanced application in which TEs near predicted long non-coding RNA (lncRNA) and mRNA domains within white and red petal-tissue transcriptomes of Prunus mume 'Fuban Tiaozhi' were identified, revealing 16 TEs that overlapped or were near 16 differentially expressed lncRNA domains, and 54 TEs that overlapped or were near 54 differentially expressed mRNA domains, and the TEs' possible functions were also discussed. We believe that the RPTEdb will contribute to the understanding of TE roles in the structural, functional and evolutionary dynamics of Rosaceae plant genomes.

Phage Genome Annotation Using the RAST Pipeline.

Phages are complex biomolecular machineries that have to survive in a bacterial world. Phage genomes show many adaptations to their lifestyle such as shorter genes, reduced capacity for redundant DNA sequences, and the inclusion of tRNAs in their genomes. In addition, phages are not free-living, they require a host for replication and survival. These unique adaptations provide challenges for the bioinformatics analysis of phage genomes. In particular, ORF calling, genome annotation, noncoding RNA (ncRNA) identification, and the identification of transposons and insertions are all complicated in phage genome analysis. We provide a road map through the phage genome annotation pipeline, and discuss the challenges and solutions for phage genome annotation as we have implemented in the rapid annotation using subsystems (RAST) pipeline.

Identification of transposons, retroelements, and a gene family predominantly expressed in floral tissues in chromosome 3DS of the hexaploid wheat progenitor Aegilops tauschii

A multigene family expressed during early floral development was identified on the short arm of wheat chromosome 3D in the region of the Ph2 locus, a locus controlling homoeologous chromosome pairing in allohexaploid wheat. Physical, genetic and molecular characterisation of the Wheat Meiosis 1 (WM1) gene family identified seven members that localised within a region of 173-kb. WM1 gene family members were sequenced and they encode mainly type Ia plasma membrane-anchored leucine rich repeat-like receptor proteins. In situ expression profiling suggests the gene family is predominantly expressed in floral tissue. In addition to the WM1 gene family, a number of other genes, gene fragments and pseudogenes were identified. It has been predicted that there is approximately one gene every 19-kb and that this region of the wheat genome contains 23 repetitive elements including BARE-1 and Wis2-1 like sequences. Nearly 50% of the repetitive elements identified were similar to known transposons from the CACTA superfamily. Ty1-copia, Ty3-gypsy and Athila LTR retroelements were also prevalent within the region. The WM1 gene cluster is present on 3DS and on barley 3HS but missing from the A and B genomes of hexaploid wheat. This suggests either recent generation of the cluster or specific deletion of the cluster during wheat polyploidisation. The evolutionary significance of the cluster, its possible roles in disease response or floral and early meiotic development and its location at or near the Ph2 locus are discussed.