Era-like GTP protein gene expression in rice

The mutations are genetic changes in the genome sequences and have a significant role in biotechnology, genetics, and molecular biology even to find out the genome sequences of a cell DNA along with the viral RNA sequencing. The mutations are the alterations in DNA that may be natural or spontaneous and induced due to biochemical reactions or radiations which damage cell DNA. There is another cause of mutations which is known as transposons or jumping genes which can change their position in the genome during meiosis or DNA replication. The transposable elements can induce by self in the genome due to cellular and molecular mechanisms including hypermutation which caused the localization of transposable elements to move within the genome. The use of induced mutations for studying the mutagenesis in crop plants is very common as well as a promising method for screening crop plants with new and enhanced traits for the improvement of yield and production. The utilization of insertional mutations through transposons or jumping genes usually generates stable mutant alleles which are mostly tagged for the presence or absence of jumping genes or transposable elements. The transposable elements may be used for the identification of mutated genes in crop plants and even for the stable insertion of transposable elements in mutated crop plants. The guanine nucleotide-binding (GTP) proteins have an important role in inducing tolerance in rice plants to combat abiotic stress conditions.

The Evolutionary Volte-Face of Transposable Elements: From Harmful Jumping Genes to Major Drivers of Genetic Innovation

Transposable elements (TEs) are self-replicating DNA elements that constitute major fractions of eukaryote genomes. Their ability to transpose can modify the genome structure with potentially deleterious effects. To repress TE activity, host cells have developed numerous strategies, including epigenetic pathways, such as DNA methylation or histone modifications. Although TE neo-insertions are mostly deleterious or neutral, they can become advantageous for the host under specific circumstances. The phenomenon leading to the appropriation of TE-derived sequences by the host is known as TE exaptation or co-option. TE exaptation can be of different natures, through the production of coding or non-coding DNA sequences with ultimately an adaptive benefit for the host. In this review, we first give new insights into the silencing pathways controlling TE activity. We then discuss a model to explain how, under specific environmental conditions, TEs are unleashed, leading to a TE burst and neo-insertions, with potential benefits for the host. Finally, we review our current knowledge of coding and non-coding TE exaptation by providing several examples in various organisms and describing a method to identify TE co-option events.

The Central Importance of E. coli and λ‎ Phage in the New Molecular Biology

This chapter considers two of the most important legacies of the Lederbergs’ pioneering work: the discoveries of the model organisms that would dominate molecular biology, E. coli and λ‎ bacteriophage. The Lederbergs’ introduction of E. coli as a convenient model organism shifted the direction of molecular genetics. Barbara McClintock’s discovery of jumping genes remained unappreciated for decades, until the field of molecular biology caught up to validate her transposable elements in bacteria. The discovery of restriction enzymes—the molecular scissors for precisely cutting DNA at specific sites, a prerequisite for genetic recombination techniques—emphasized the versatility of bacteriophage λ‎ as a powerful experimental tool. The discovery of specialized transduction by Larry Morse and Esther Lederberg hinted at the mechanisms of “host restriction.” Werner Arber and Daisy Dussoix discovered restriction endonucleases by building upon Esther Lederberg’s research with λ‎ phage and the differences between E. coli B and K-12.

Characterization of Mariner transposons in seven species of Rhus gall aphids

Transposable elements (TEs), also known as jumping genes, are widely spread in the genomes of insects and play a considerable role in genomic evolution. Mariner/DD34D family belongs to class II transposable elements which is widely spread in the genomes of insects and have considerable role in genomic evolution. Mariner like elements (MLEs) were searched in the genomes of seven species of Rhus gall aphids belonging to six genera. In total, 121 MLEs were detected in the genomes of the seven investigated species of Rhus gall aphids, which showed a wide distribution in both close and distant related species. The sequences of MLEs ranged from 1 to 1.4 kb in length and the structural analysis of the MLEs showed that only five copies were potentially active with intact open reading frame (ORF) and terminal inverted repeats (TIRs). Phylogenetic analysis showed that all the 121 MLE sequences belonged to four subfamilies, i.e., Mauritiana, Drosophila, Vertumana and Irritans, among which Drosophila and Vertumana subfamilies were reported in aphids for the first time. Our present report revealed the diversity and distribution of MLEs in Rhus gall aphid genomes and expanded our understandings on the characterization of transposable elements in aphid genomes, which might be useful as genetic markers and tools and would play an important role in genomic evolution and adaptation of aphids.

Horizontal transfer and southern migration: the tale of Hydrophiinae′s marine journey.

Transposable elements (TEs), also known as jumping genes, are sequences able to move or copy themselves within a genome. As TEs move throughout genomes they can be exapted as coding and regulatory elements, or can promote genetic rearrangement. In so doing TEs act as a source of genetic novelty, hence understanding TE evolution within lineages is key in understanding adaptation to their environment. Studies into the TE content of lineages of mammals such as bats have uncovered horizontal transposon transfer (HTT) into these lineages, with squamates often also containing the same TEs. Despite the repeated finding of HTT into squamates, little comparative research has examined the evolution of TEs within squamates. The few broad scale studies in Squamata which have been conducted found both the diversity and total number of TEs differs significantly across the entire order. Here we examine a diverse family of Australo-Melanesian snakes (Hydrophiinae) to examine if this pattern of variable TE content and activity holds true on a smaller scale. Hydrophiinae diverged from Asian elapids ~15-25 Mya and have since rapidly diversified into 6 amphibious, ~60 marine and ~100 terrestrial species which fill a broad range of ecological niches. We find TE diversity and expansion differs between hydrophiines and their Asian relatives and identify multiple HTTs into Hydrophiinae, including three transferred into the ancestral hydrophiine likely from marine species. These HTT events provide the first tangible evidence that Hydrophiinae reached Australia from Asia via a marine route.

Characterization of Mariner transposons in Rhus gall aphids (Hemiptera: Aphididae: Eriosomatinae)

Background: Transposable elements (TEs), also known as jumping genes, are widely spread in the genomes of insects and play a considerable role in genomic evolution. Mariner family belongs to class II transposable elements, were searched in the genomes of seven species of Rhus gall aphids belonging to six genera. Mariner-like elements were characterized for the first time in Rhus gall aphids and classified in to respective subfamilies.Results: In total, one hundred twenty-one MLEs were detected in the genomes of the seven investigated species of Rhus gall aphids, which showed a wide distribution of MLEs in both close and distant related species. The sequences of MLEs ranged from 1kb to 1.4kb in length and the structural analysis of the MLEs showed that only five copies were potentially active with intact open reading frame (ORF) while the remaining were classified as inactive MLEs according to absence of single intact ORF or terminal inverted repeats (TIRs). Based on the MLEs in Rhus gall aphids as well as the well characterized MLEs in other organisms from GenBank, the phylogenetic analysis showed that all the one hundred twenty-one MLE sequences belonged to four subfamilies, i.e., thirty from Maurutiana subfamily, twenty-six from Drosophila subfamily, thirty-three from Vertumana subfamily and thirty-two from Irritans subfamily, among which Drosophila and Vertumana subfamilies were reported in aphids for the first time. Moreover, the phylogenetic relationship suggested possible horizontal transfer events of MLEs between aphids and other insects.Conclusion: Our present report revealed the diversity and distribution of MLEs in Rhus gall aphid genomes sequenced by shotgun genome skimming method. This study further expanded our understandings on the characterization of transposable elements in aphid genomes, which might be useful as genetic markers and tools and would play an important role in genomic evolution and adaptation of aphids.

JUMP AROUND, JUMP AROUND: TRANSPOSABLE ELEMENT ACTIVATION IN NEURODEGENERATIVE TAUOPATHY

Transposable elements, or “jumping genes,” constitute ~45% of the human genome. We have identified transposable element activation as a key mediator of neurodegeneration in tauopathies, a group of disorders that are pathologically defined by deposits of tau protein in the brain. Cellular defenses that limit transposable element mobilization include 1) formation of silencing heterochromatin and 2) generation of piwi-interacting RNAs (piRNAs) that clear transposable element transcripts. Using genetic approaches in Drosophila models of tauopathy, we find evidence for a causal relationship between tau-induced heterochromatin decondensation and piRNA depletion, transposable element mobilization, and neurodegeneration. 3TC, an FDA-approved inhibitor of reverse transcriptase, suppresses transposable element mobilization and neuronal death in tau transgenic Drosophila. We detect a significant increase in transcripts of the human endogenous retrovirus class of transposable elements in postmortem human Alzheimer’s disease brains. Our data identify transposable element activation as a conserved, pharmacologically targetable driver of neurodegeneration in tauopathy.