scholarly journals Whitefly genomes contain ribotoxin coding genes acquired from plants

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Walter J. Lapadula ◽  
María L. Mascotti ◽  
Maximiliano Juri Ayub

Abstract Ribosome inactivating proteins (RIPs) are RNA N-glycosidases that depurinate a specific adenine residue in the conserved sarcin/ricin loop of 28S rRNA. These enzymes are widely distributed among plants and bacteria. Previously, we have described for the first time RIP genes in mosquitoes belonging to the Culicidae family. We showed that these genes are derived from a single event of horizontal gene transfer (HGT) from a prokaryotic donor. Mosquito RIP genes are evolving under purifying selection, strongly suggesting that these toxins have acquired a functional role. In this work, we show the existence of two RIP encoding genes in the genome of the whitefly Bemisia tabaci, a hemiptera species belonging to the Aleyrodidae family distantly related to mosquitoes. Contamination artifacts were ruled out analyzing three independent B. tabaci genome databases. In contrast to mosquito RIPs, whitefly genes harbor introns and according to transcriptomic evidence are transcribed and spliced. Phylogeny and the taxonomic distribution strongly support that whitefly RIP genes are derived from an independent HGT event from a plant source. These results, along with our previous description of RIPs in Diptera, suggest that the acquired genes are functional in these insects and confer some fitness advantage.

2016 ◽  
Author(s):  
Walter J. Lapadula ◽  
Paula L. Marcet ◽  
María L. Mascotti ◽  
María V. Sánchez Puerta ◽  
Maximiliano Juri Ayub

AbstractRibosome inactivating proteins (RIPs) are RNA N-glycosidases that depurinate a specific adenine residue in the conserved sarcin/ricin loop of 28S rRNA. These enzymes are widely distributed among plants and their presence has also been confirmed in several bacterial species. Recently, we reported for the first time in silico evidence of RIP encoding genes in metazoans, in two closely related species of insects: Aedes aegypti and Culex quinquefasciatus. Here, we have experimentally confirmed the presence of these genes in mosquitoes and attempted to unveil their evolutionary history. A detailed study was conducted, including evaluation of taxonomic distribution, phylogenetic inferences and microsynteny analyses, indicating that the culicine RIP genes derived from a single Horizontal Gene Transfer (HGT) event, probably from a Cyanobacterial donor species. Moreover, evolutionary analyses show that, after transference, these genes evolved under purifying selection, strongly suggesting that they play functional roles in these organisms. In this work we confirm the presence of RIP genes in Culicinae species, and show solid evidence supporting the hypothesis that these genes are derived from a single prokaryotic transferred gene through HGT. In addition, clear evidence of purifying selection pressure has been recorded, supporting the hypothesis that these genes are functional within this subfamily.


2019 ◽  
Author(s):  
Walter J. Lapadula ◽  
María L. Mascotti ◽  
Maximiliano Juri Ayub

ABSTRACTRibosome inactivating proteins (RIPs) are RNA N-glycosidases that depurinate a specific adenine residue in the conserved sarcin/ricin loop of 28S rRNA. These enzymes are widely distributed among plants and bacteria. Recently, we have described RIP genes in mosquitoes belonging to the Culicinae subfamily (Aedini and Culicini tribes). We have also shown that these genes are derived from a single event of horizontal gene transfer (HGT) from a prokaryotic donor. In the present work, we show the existence of two RIP encoding genes in the genome of the whitefly Bemisia tabaci (a hemiptera species belonging to the Aleyrodidae family, distantly related to mosquitoes). Contamination artifacts were ruled out analyzing three independent Bemisia tabaci genome databases. In contrast to mosquitoes RIPs, the whitefly genes harbor introns and, according to transcriptomic evidence, are transcribed and spliced. Interestingly, phylogenetic inference combined with taxonomic distribution strongly supports that whitefly RIP genes are derived from an independent HGT event from a plant source. Our results suggest that RIP genes fill a functional niche in insects.


Author(s):  
Samuel Chef ◽  
Chung Tah Chua ◽  
Yu Wen Siah ◽  
Philippe Perdu ◽  
Chee Lip Gan ◽  
...  

Abstract Today’s VLSI devices are neither designed nor manufactured for space applications in which single event effects (SEE) issues are common. In addition, very little information about the internal schematic and usually nothing about the layout or netlist is available. Thus, they are practically black boxes for satellite manufacturers. On the other hand, such devices are crucial in driving the performance of spacecraft, especially smaller satellites. The only way to efficiently manage SEE in VLSI devices is to localize sensitive areas of the die, analyze the regions of interest, study potential mitigation techniques, and evaluate their efficiency. For the first time, all these activities can be performed using the same tool with a single test setup that enables a very efficient iterative process that reduce the evaluation time from months to days. In this paper, we will present the integration of a pulsed laser for SEE study into a laser probing, laser stimulation, and emission microscope system. Use of this system will be demonstrated on a commercial 8 bit microcontroller.


2021 ◽  
Vol 9 (5) ◽  
pp. 951
Author(s):  
Hazrat Bilal ◽  
Gaojian Zhang ◽  
Tayyab Rehman ◽  
Jianxion Han ◽  
Sabir Khan ◽  
...  

The New Delhi Metallo-β-lactamase (NDM) is among the most threatening forms of carbapenemases produced by K. pneumoniae, well-known to cause severe worldwide infections. The molecular epidemiology of blaNDM-1-harboring K. pneumoniae is not well elucidated in Pakistan. Herein, we aim to determine the antibiotics-resistance profile, genes type, molecular type, and plasmid analysis of 125 clinically isolated K. pneumoniae strains from urine samples during July 2018 to January 2019 in Pakistan. A total of 34 (27.2%) K. pneumoniae isolates were carbapenemases producers, and 23 (18.4%) harbored the blaNDM-1 gene. The other carbapenemases encoding genes, i.e., blaIMP-1 (7.2%), blaVIM-1 (3.2%), and blaOXA-48 (2.4%) were also detected. The Multi Locus Sequence Typing (MLST) results revealed that all blaNDM-1-harboring isolates were ST11. The other sequence types detected were ST1, ST37, and ST105. The cluster analysis of Xbal Pulsed Field Gel Electrophoresis (PFGE) revealed variation amongst the clusters of the identical sequence type isolates. The blaNDM-1 gene in all of the isolates was located on a 45-kb IncX3 plasmid, successfully transconjugated. For the first time, blaNDM-1-bearing IncX3 plasmids were identified from Pakistan, and this might be a new primary vehicle for disseminating blaNDM-1 in Enterobacteriaceae as it has a high rate of transferability.


2014 ◽  
Author(s):  
Soni Deshwal ◽  
Eamonn Mallon

Bumblebees, amongst the most important of pollinators, are under enormous population pressures. One of these is disease. The bumblebee and its gut trypanosome Crithidia bombi are one of the fundamental models of ecological immunology. Although there is previous evidence of increased immune gene expression upon Crithidia infection, recent work has focussed on the bumblebee's gut microbiota. Here, by knocking down gene expression using RNAi, we show for the first time that antimicrobial peptides (AMPs) have a functional role in anti-Crithidia defense.


2018 ◽  
Vol 93 (05) ◽  
pp. 629-635
Author(s):  
F.B. Pereira ◽  
V.L. Ferreira ◽  
W.M. Tomas ◽  
C. Elisei ◽  
F. Paiva ◽  
...  

AbstractDiaphanocephalus galeatus collected from the small intestine of the lizard Dracaena paraguayensis in the Pantanal wetlands, State of Mato Grosso do Sul, Brazil, is redescribed. Genetic characterization and observations using scanning electron microscopy (SEM) were performed for the first time. The vouchers of D. galeatus and the type specimens of its congeners, deposited in the Coleção Helmintológica do Instituto Oswaldo Cruz (CHIOC), were consulted. Light and SEM observations revealed several undescribed features of D. galeatus, i.e. structure of the cephalic end and of the buccal capsule, position and morphology of deirids, presence of phasmids in females and presence of unpaired papilla on the membranous projection that covers the genital cone in males. After observation of the specimens deposited in the helminthological collection, D. jacuruxi is considered a synonym of D. galeatus, and D. diesingi, despite its incomplete description, is tentatively retained as valid due to the poor condition of the type material. The results also indicated low host specificity of D. galeatus, contradicting previous assertions. Genetic comparisons using patristic distances and phylogenetic trees generated from sequences of the 28S rRNA nuclear gene indicated that D. galeatus is closer to the taxa within Ancylostomatoidea and Strongyloidea than any lineage of Metastrongyloidea or Trichostrongyloidea. However, most of the nodal supports were low. Based on the genetic and morphological characterization, the validity of D. galeatus was confirmed. These data may serve for further comparative approaches for different populations of the parasite, from different hosts in different geographical areas, mitigating taxonomic confusions.


2020 ◽  
Vol 35 (3) ◽  
pp. 455-460 ◽  
Author(s):  
Eduardo Bolea-Fernandez ◽  
Ana Rua-Ibarz ◽  
Milica Velimirovic ◽  
Kristof Tirez ◽  
Frank Vanhaecke

The occurrence of microplastics (MPs) in the environment is a matter of increasing concern. In this work, it has been shown for the first time that ICP-MS operated in single-event mode can be used for the characterization of MPs relying on their C content.


Nematology ◽  
2017 ◽  
Vol 19 (3) ◽  
pp. 333-350 ◽  
Author(s):  
Shigeyuki Sekimoto ◽  
Taketo Uehara ◽  
Takayuki Mizukubo

The Korean cyst nematode, Heterodera koreana, was recorded for the first time from Japan and characterised morphologically, morphometrically and molecularly. In total, 41 populations were detected from soil samples collected from the rhizosphere of four bamboo species in Japan: 31 populations from moso bamboo (Phyllostachys edulis), seven from madake (P. bambusoides), two from henon bamboo (P. nigra var. henonis) and one from fish pole bamboo (P. aurea). The morphology and morphometrics of the Japanese population were in agreement with those of the original description of H. koreana from South Korea and other subsequent descriptions from China and Iran, with the exception of some minor differences. The results of the phylogenetic analyses of the D2-D3 expansion segments of 28S rRNA gene and ITS rRNA gene sequences confirmed the species identification and phylogenetic relationship of H. koreana with other Heterodera species. The COI mtDNA gene sequences were obtained for the first time for H. koreana. Three COI haplotypes found in Japanese H. koreana populations showed a characteristic geographical distribution in Japan.


Author(s):  
D. G. Walker ◽  
T. S. Fisher ◽  
A. M. Al-badri ◽  
R. D. Schrimpf

Single-event burnout (SEB) is a catastrophic failure mechanism in power diodes that is initiated by the passage of a heavy ion through a diode in a current-blocking state. In this work, the physical mechanism responsible for device failure during SEB is investigated using transient, coupled electro-thermal, device simulations. For the first time, the effects of a thermal feedback mechanism have been examined and deemed crucial to predicting possible failure in power diodes. Results indicate that device failure is predicted for large blocking voltage near breakdown with a linear energy transfer (LET) of 30MeV/mg/cm2 only when thermal effects are included. However, without inclusion of the thermal model, no device failure is predicted. These results correspond to experimental observations better than any previous work.


2016 ◽  
Vol 91 (6) ◽  
pp. 739-751 ◽  
Author(s):  
F.B. Pereira ◽  
J.L. Luque

AbstractMolecular and morphological characterization of two species of Cucullanidae from freshwater fish in Brazil are provided, one of which represented an undescribed taxon. Cucullanus opisthoporus n. sp. was collected in Cichla melaniae from River Xingu, State of Pará, and in C. pinima from River Jamarí, State of Rondônia. Nematodes referable to Cucullanus grandistomis were collected in Oxydoras niger from River Xingu. The new species has an appendage in the tail tip, ventrally covered by small spines, which is an exclusive feature of Cucullanus tucunarensis. However, C. tucunarensis differs from C. opisthoporus n. sp. based upon the relative position of deirids and the excretory pore, which are more posterior from the oesophageal end in the new species. Observations of C. tucunarensis type specimens also revealed features that were wrongly or not reported in the original description. Type specimens of C. grandistomis were observed, although they were poorly preserved. After evaluation of newly collected specimens of C. grandistomis, features unreported in the original description were observed for the first time, including the presence of an intestinal caecum. Thus, C. grandistomis was transferred to Dichelyne. Sequences of the 18S and 28S rRNA genes revealed high genetic similarity between the specimens of C. opisthoporus n. sp. from the two different hosts as well as their genetic distance from Dichelyne grandistomis n. comb. Phylogenetic reconstructions using representatives of Cucullanidae suggested the artificiality of the current morphological system adopted to separate the genera, since most genera were not monophyletic, although the availability of genetic data is still fragmented.


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