genetic element
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Author(s):  
Amina Hashim ◽  
Mahmoud Elgamal ◽  
Shazeda H. Chowdhury ◽  
Fatima A. Hattab ◽  
Rafal Al-Shibly ◽  
...  

2021 ◽  
Vol 15 (12) ◽  
pp. 3299-3301
Author(s):  
Anam Iqbal ◽  
Usman Shahid Butt ◽  
Nasreen Akhtar ◽  
Riasat Ali ◽  
Tooba Ali ◽  
...  

Background: The human behavior is influenced by genetic as well as environment components. Likewise, the aggressive behavior having an intent of criminality is also governed by both environmental and genetic makeup. Aim: The genetic element has been explored by analyzing the microsatellite RS1 and RS3 of AVPRIA gene which showed strong variations in short tandem repeats (STRs) of convicted offenders when they were compared with normal population. Methods: Blood samples of 100 convicted offenders were taken and DNA was extracted using PCI protocol. The PCR was then carried out using primers and the products were send for gene sequencing. The results were compared with that of general population having no history of crime or psychological abnormality. Results: The microsatellite RS1 and RS3 of AVPRIA gene showed strong variations in short tandem repeats (STRs) of convicted offenders when they were compared with normal population. Keywords: AVPR1A, criminal intent, PCR


2021 ◽  
Author(s):  
Cai Ping Koh ◽  
Avinash Govind Bahirvani ◽  
Chelsia Qiuxia Wang ◽  
Tomomasa Yokomizo ◽  
Cherry Ee Lin Ng ◽  
...  

A cis-regulatory genetic element which targets gene expression to stem cells, termed stem cell enhancer, serves as a molecular handle for stem cell-specific genetic engineering. Here we show the generation and characterization of a tamoxifen-inducible CreERT2 transgenic (Tg) mouse employing previously identified hematopoietic stem cell (HSC) enhancer for Runx1, eR1 (+24m). Kinetic analysis of labeled cells after tamoxifen injection and transplantation assays revealed that eR1-driven CreERT2 activity marks dormant adult HSCs which slowly but steadily contribute to unperturbed hematopoiesis. Fetal and child HSCs which are uniformly or intermediately active were also efficiently targeted. Notably, a gene ablation at distinct developmental stages, enabled by this system, resulted in different phenotypes. Similarly, an oncogenic Kras induction at distinct ages caused different spectrums of malignant diseases. These results demonstrate that the eR1-CreERT2 Tg mouse serves as a powerful resource for the analyses of both normal and malignant HSCs at all developmental stages.


2021 ◽  
Vol 12 ◽  
Author(s):  
Luis Janssen ◽  
Felipe Marques de Almeida ◽  
Thais Amanda Silva Damasceno ◽  
Rodrigo de Paula Baptista ◽  
Georgios Joannis Pappas ◽  
...  

Antimicrobial resistance (AMR) is an increasing and urgent issue for human health worldwide, as it leads to the reduction of available antibiotics to treat bacterial infections, in turn increasing hospital stays and lethality. Therefore, the study and genomic surveillance of bacterial carriers of resistance in and outside of clinical settings is of utter importance. A colony of multidrug resistant (MDR) bacteria identified as Klebsiella spp., by 16S rDNA amplicon sequencing, has been isolated from an urban lake in Brazil, during a drug-degrading bacterial prospection. Genomic analyses revealed the bacteria as Klebsiella pneumoniae species. Furthermore, the in silico Multilocus Sequence Typing (MLST) identified the genome as a new sequence type, ST5236. The search for antimicrobial resistance genes (ARGs) detected the presence of genes against beta-lactams, fosfomycin, acriflavine and efflux pumps, as well as genes for heavy metal resistance. Of particular note, an extended-spectrum beta-lactamase gene (blaCTX-M-15) has been detected in close proximity to siphoviridae genes, while a carbapenemase gene (KPC-2) has been found in an extrachromosomal contig, within a novel non-Tn4401 genetic element (NTEKPC). An extrachromosomal contig found in the V3 isolate is identical to a contig of a K. pneumoniae isolate from a nearby hospital, which indicates a putative gene flow from the hospital network into Paranoá lake. The discovery of a MDR isolate in this lake is worrisome, as the region has recently undergone periods of water scarcity causing the lake, which receives treated wastewater effluent, and is already used for recreational purposes, to be used as an environmental buffer for drinking water reuse. Altogether, our results indicate an underrepresentation of environmental K. pneumoniae among available genomes, which may hamper the understanding of the population dynamics of the species in the environment and its consequences in the spread of ARGs and virulence genes.


2021 ◽  
Author(s):  
Cheryl Armstrong ◽  
Lijuang Zhou ◽  
Weiqi Luo ◽  
Ozgur Batuman ◽  
Olfemi Alabi ◽  
...  

Candidatus Liberibacter asiaticus (Las) is the prominent species of Liberibacter associated with huanglongbing, a devastating disease of citrus worldwide. In this study, we report the identification of a ~8.3 kb DNA region of the Las genome containing eight putative open reading frames (ORFs) flanked by two inverted repeats, which was not present in the Las str. psy62 genome. Comparisons with other genome sequences established this region as a unique genetic element associated with genome plasticity/instability. Primers specific for both the presence (Las wild-type) and absence (Las mutant) of this region were designed to study the population dynamics and host adaptation of the two strains. Las populations with and/or without the wild-type strain were detected and differentiated in >2,300 samples that included psyllids, periwinkle, and several species of citrus. In psyllids, although a mixed population of the wild-type and mutant was observed in most samples (88%), the wild-type Las was detected alone at a rate of 11%. In contrast, none of the infected citrus plants were positive for the wild-type alone, which harbored either the mutant strain alone (8%) or a mixed population of the mutant and wild-type (92%). Furthermore, the dynamics of these two major Las populations varied with different citrus hosts while an in-depth study on grapefruit that did not rapidly succumb to disease revealed that the population of mutant alone increased with time, indicating that the absence of this genetic element is associated with the fitness of Las in planta under the selection pressure of its host.


Open Biology ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 210074
Author(s):  
Frances E. Clark ◽  
Takashi Akera

Female meiotic drive is the phenomenon where a selfish genetic element alters chromosome segregation during female meiosis to segregate to the egg and transmit to the next generation more frequently than Mendelian expectation. While several examples of female meiotic drive have been known for many decades, a molecular understanding of the underlying mechanisms has been elusive. Recent advances in this area in several model species prompts a comparative re-examination of these drive systems. In this review, we compare female meiotic drive of several animal and plant species, highlighting pertinent similarities.


2021 ◽  
Vol 70 (8) ◽  
Author(s):  
József Sóki ◽  
Anikó Keszőcze ◽  
István Nagy ◽  
Katalin Burián ◽  
Elisabeth Nagy

Introduction. There are several β-lactamase genes described for Bacteroide s strains, of which cepA and cfiA are specific for Bacteroides fragilis and define two genetic divisions. The expression and phenotypic effects of these genes are usually regulated by insertional activation. Hypotheses/Gap Statement. Information is lacking about how cepA is regulated for most of the B. fragilis strains and whether there could be a genetic element for it. Aim. We aimed to investigate the molecular background of ampicillin (and other β-lactam) resistance among Bacteroides strains as mediated mainly by cepA and also to find a genetic element for it as known for cfiA. Methodology. Various PCR methods were used for β-lactamase-resistance gene and insertion sequence (IS) element detection in 42 Bacteroides strains. β-Lactamase activity measurements and antimicrobial-susceptibility testing using agar dilution were also applied. Further molecular experiments involved sequencing, gene targeting, Southern blotting and bioinformatic analyses. Results. We found that high antibiotic resistance and β-lactamase levels are brought about by insertional activation of the cepA gene or by similar or dissimilar activation of cfxA or cfiA, or by the newly described pbbA genes. Non-activated cepA genes produced low levels of specific β-lactamase activities that did not correlate with ampicillin resistance. We found a genetic element for cepA and another region close to it that are characteristic for division I B. fragilis strains, which are replaced by other sequences in division II B. fragilis strains. Conclusion. cepA usually is not activated by IS elements and usually produces low β-lactamase activities that do not correlate with the ampicillin MICs; therefore, it probably involves some non-β-lactamase-mediated resistance mechanism(s). pbpA is a newly described, effective β-lactamase gene that is located on a plasmid, and cepA resides on a well-defined chromosomal segment that is mutually replaced in division II B. fragilis strains. This latter finding demonstrates the genetic dichotomy of cepA–cfiA in B. fragilis and requires further investigation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Clément Gilbert ◽  
Torstein Tengs

AbstractThe genetic element s2m has been acquired through horizontal transfer by many distantly related viruses, including the SARS-related coronaviruses. Here we show that s2m is evolutionarily conserved in these viruses. Though several lineages of severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) devoid of the element can be found, these variants seem to have been short lived, indicating that they were less evolutionary fit than their s2m-containing counterparts. On a species-level, however, there do not appear to be any losses and this pattern strongly suggests that the s2m element is essential to virus replication in SARS-CoV-2 and related viruses. Further experiments are needed to elucidate the function of s2m.


2021 ◽  
Vol 12 ◽  
Author(s):  
Nobuo Arai ◽  
Tsuyoshi Sekizuka ◽  
Yukino Tamamura-Andoh ◽  
Lisa Barco ◽  
Atsushi Hinenoya ◽  
...  

Salmonella enterica subsp. enterica serovar Typhimurium sequence type 34 (ST34) and its monophasic variant (Salmonella 4,[5],12:i:-) are among the most frequently isolated clones from both humans and animals worldwide. Our previous study demonstrated that Salmonella Typhimurium/4,[5],12:i:- strains isolated in Japan could be classified into nine clades and that clade 9 consisted of ST34 strains. In Japan, ST34/clade 9 was first found in the 1990s and has become predominant among food animals in recent years. In the present study, we analyzed the whole genome-based phylogenetic relationships and temporal information of 214 Salmonella Typhimurium/4,[5],12:i:- ST34/clade 9 strains isolated from 1998 to 2017 in Japan. The 214 strains were classified into two sublineages: the newly identified clade 9–2 diverged from clade 9 in the early 2000s and has predominated in recent years. Clonally expanding subclades in clades 9–1 or 9–2 lacked Gifsy-1 or HP1 prophages, respectively, and some strains in these subclades acquired plasmids encoding antimicrobial resistance genes. Additional genome reduction around the fljB gene encoding the phase 2-H antigen was generated by an IS26-mediated deletion adjacent to the transposon in clade 9–2. Although most of the clade 9 strains were isolated from cattle in Japan, the clonally expanding subclades in clade 9–2 (i.e., all and 24% strains of subclades 9–2a and 9–2b, respectively) were isolated from swine. The spread of clade 9 in recent years among food animals in Japan was responsible for the emergence of multiple host-adapted sublineages involving the clonally expanding subclades generated by mobile genetic element-mediated microevolution.


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