scholarly journals Shared Transcriptional Control and Disparate Gain and Loss of Aphid Parasitism Genes

2018 ◽  
Vol 10 (10) ◽  
pp. 2716-2733 ◽  
Author(s):  
Peter Thorpe ◽  
Carmen M Escudero-Martinez ◽  
Peter J A Cock ◽  
Sebastian Eves-van den Akker ◽  
Jorunn I B Bos
2018 ◽  
Author(s):  
Peter Thorpe ◽  
Carmen M. Escudero-Martinez ◽  
Peter J. A. Cock ◽  
D. Laetsch ◽  
Sebastian Eves-van den Akker ◽  
...  

AbstractBackgroundAphids are a diverse group of taxa that contain hundreds of agronomically important species, which vary in their host range and pathogenicity. However, the genome evolution underlying agriculturally important aphid traits is not well understood.ResultsWe generated highly-contiguous draft genome assemblies for two aphid species: the narrow host range Myzus cerasi, and the cereal specialist Rhopalosiphum padi. Using a de novo gene prediction pipeline on both these genome assemblies, and those of three related species (Acyrthosiphon pisum, D. noxia and M. persicae), we show that aphid genomes consistently encode similar gene numbers, and in the case of A. pisum, fewer and larger genes than previously reported. We compare gene content, gene duplication, synteny, horizontal gene transfer events, and putative effector repertoires between these five species to understand the genome evolution of globally important plant parasites.Aphid genomes show signs of relatively distant gene duplication, and substantial, relatively recent, gene birth, and are characterized by disparate gain and loss of genes acquired by horizontal gene transfer (HGT). Such HGT events account for approximately 1% of loci, and contribute to the protein-coding content of aphid species analysed. Putative effector repertoires, originating from duplicated loci, putative HGT events and other loci, have an unusual genomic organisation and evolutionary history. We identify a highly conserved effector-pair that is tightly genetically-linked in all aphid species. In R. padi, this effector pair is tightly transcriptionally-linked, and shares a transcriptional control mechanism with a subset of approximately 50 other putative effectors distributed across the genome.ConclusionsThis study extends our current knowledge on the evolution of aphid genomes and reveals evidence for a shared control mechanism, which underlies effector expression, and ultimately plant parasitism.


2006 ◽  
Vol 73 ◽  
pp. 85-96 ◽  
Author(s):  
Richard J. Reece ◽  
Laila Beynon ◽  
Stacey Holden ◽  
Amanda D. Hughes ◽  
Karine Rébora ◽  
...  

The recognition of changes in environmental conditions, and the ability to adapt to these changes, is essential for the viability of cells. There are numerous well characterized systems by which the presence or absence of an individual metabolite may be recognized by a cell. However, the recognition of a metabolite is just one step in a process that often results in changes in the expression of whole sets of genes required to respond to that metabolite. In higher eukaryotes, the signalling pathway between metabolite recognition and transcriptional control can be complex. Recent evidence from the relatively simple eukaryote yeast suggests that complex signalling pathways may be circumvented through the direct interaction between individual metabolites and regulators of RNA polymerase II-mediated transcription. Biochemical and structural analyses are beginning to unravel these elegant genetic control elements.


2019 ◽  
Author(s):  
Thi-An Vu ◽  
Ingrid Lema ◽  
Jerome Bouligand ◽  
Laetitia Martinerie ◽  
Marc Lombes ◽  
...  

Author(s):  
Tara A Shrout

Titin is the largest known protein in the human body, and forms the backbone of all striated muscle sarcomeres. The elastic nature of titin is an important component of muscle compliance and functionality. A significant amount of energy is expended to synthesize titin, thus we postulate that titin gene expression is under strict regulatory control in order to conserve cellular resources. In general, gene expression is mediated in part by post-transcriptional control elements located within the 5’ and 3’ untranslated regions (UTRs) of mature mRNA. The 3’UTR in particular contains structural features that affect binding capacity to other RNA components, such as MicroRNA, which control mRNA localization, translation, and degradation. The degree and significance of the regulatory effects mediated by two determined variants of titin’s 3’ UTR were evaluated in Neonatal Rat Ventricular Myocyte and Human Embryonic Kidney cell lines. Recombinant plasmids to transfect these cells lines were engineered by insertion of the variant titin 3’UTR 431- and 1047-base pairs sequences into luciferase reporter vectors. Expression due to an unaltered reporter vector served as the control. Quantitative changes in luciferase activity due to the recombinants proportionally represented the effect titin’s respective 3’UTR conferred on downstream post-transcriptional expression relative to the control. The effect due to titin’s shorter 3’UTR sequence was inconclusive; however, results illustrated that titin’s longer 3’UTR sequence caused a 35 percent decrease in protein expression. Secondary structural analysis of the two sequences revealed differential folding patterns that affect the stability and degree of MicroRNA-binding within titin’s variant 3’UTR sequences.


Sign in / Sign up

Export Citation Format

Share Document