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Horticulturae ◽  
2021 ◽  
Vol 7 (9) ◽  
pp. 327
Author(s):  
Eugenio Butelli ◽  
Katharina Bulling ◽  
Lionel Hill ◽  
Cathie Martin

The range of colours of many flowers and fruits is largely due to variations in the types of anthocyanins produced. The degree of hydroxylation on the B-ring affects the hue of these pigments, causing a shift from the orange end of the visible spectrum to the blue end. Besides colour, this modification can also affect other properties of anthocyanins, including the ability to protect the plant against different stresses or, when included in the human diet, to provide benefits for disease prevention. The level of hydroxylation of the B-ring is determined by the activity of two key hydroxylases, F3′H and F3′5′H, and by the substrate preference of DFR, an enzyme acting downstream in the biosynthetic pathway. We show that, in tomato, a strategy based on fruit-specific engineering of three regulatory genes (AmDel, AmRos1, AtMYB12) and a single biosynthetic gene (AmDFR), together with the availability of a specific mutation (f3′5′h), results in the generation of three different varieties producing high levels of anthocyanins with different levels of hydroxylation. These tomatoes show distinctive colours and mimic the classes of anthocyanins found in natural berries, thus providing unique near-isogenic material for different studies.


2021 ◽  
Author(s):  
Zahra Hasan ◽  
Uzma Bashir Aamir ◽  
Asghar Nasir ◽  
Akbar Kanji ◽  
Azra Samreen ◽  
...  

Abstract We investigated the presence of SARS-CoV-2 variants of concern (VoC) in Karachi, Pakistan between April and July 2021 in specimens received at the Aga Khan University Clinical Laboratories. VoC were identified using a PCR based approach targeting lineage specific mutation. Of the 710 clinical isolates tested, 63% were VoC comprising; 36% alpha, 37% beta, 7% gamma and 21% delta variants. Alpha variants remained the majority whilst, delta strains increased to 43% of cases in July. Thirty-six per cent of all cases were admitted COVID-19 in-patient samples. Of the in-patient cases, 41% were alpha, 28% were beta, 8% were gamma and 24% were delta variants. Overall, we report an increase of delta variants in Karachi over the past two months which is concordant with the currently observed exacerbation in COVID-19 morbidity and mortality.


2021 ◽  
Vol 141 (5) ◽  
pp. S27
Author(s):  
D. Yamada ◽  
S. Vu ◽  
X. Wu ◽  
Z. Shi ◽  
M. Huynh ◽  
...  
Keyword(s):  

Author(s):  
Natalie A Lamb ◽  
Jonathan E Bard ◽  
Michael J Buck ◽  
Jennifer A Surtees

Abstract Distinct mutation signatures arise from environmental exposures and/or from defects in metabolic pathways that promote genome stability. The presence of a particular mutation signature can therefore predict the underlying mechanism of mutagenesis. These insults to the genome often alter dNTP pools, which itself impacts replication fidelity. Therefore, the impact of altered dNTP pools should be considered when making mechanistic predictions based on mutation signatures. We developed a targeted deep-sequencing approach on the CAN1 gene in Saccharomyces cerevisiae to define information-rich mutational profiles associated with distinct rnr1 backgrounds. Mutations in the activity and selectivity sites of rnr1 lead to elevated and/or unbalanced dNTP levels, which compromises replication fidelity and increases mutation rates. The mutation spectra of rnr1Y285F and rnr1Y285A alleles were characterized previously; our analysis was consistent with this prior work but the sequencing depth achieved in our study allowed a significantly more robust and nuanced computational analysis of the variants observed, generating profiles that integrated information about mutation spectra, position effects, and sequence context. This approach revealed previously unidentified, genotype-specific mutation profiles in the presence of even modest changes in dNTP pools. Furthermore, we identified broader sequence contexts and nucleotide motifs that influenced variant profiles in different rnr1 backgrounds, which allowed specific mechanistic predictions about the impact of altered dNTP pools on replication fidelity.


2021 ◽  
Author(s):  
Paolo Gaibani ◽  
Donatella Lombardo ◽  
Linda Bussini ◽  
Federica Bovo ◽  
Maddalena Giannella ◽  
...  

Abstract We aimed to investigate the incidence of meropenem/vaborbactam-resistance among KPC-producing Klebsiella pneumoniae (KPC-Kp) bloodstream infection in a large Italian hospital. Meropenem/vaborbactam-resistance was found in 8% (n = 5) KPC-Kp, while 5% (n = 3) strains exhibited cross-resistance to ceftazidime/avibactam. Genomic analysis revealed that meropenem/vaborbactam-resistance was associated to non-functional OmpK35 and OmpK36 porins and no specific mutation was associated to cross-resistance. No specific antimicrobial treatment was related to favorable clinical outcome, while cross-resistance was not associated to higher clinical and/or microbiological failures. Our study indicated that resistance to meropenem/vaborbactam was due to porins deficiency and is associated to reduced susceptibility both to ceftazidime/avibactam and carbapenems.


2021 ◽  
Vol 16 (2) ◽  
pp. 309-323
Author(s):  
Hisamitsu Hayashi ◽  
Shuhei Osaka ◽  
Kokoro Sakabe ◽  
Aiko Fukami ◽  
Eriko Kishimoto ◽  
...  

eNeuro ◽  
2020 ◽  
Vol 7 (6) ◽  
pp. ENEURO.0284-20.2020
Author(s):  
Swarna Pandian ◽  
Jian-Ping Zhao ◽  
Yasunobu Murata ◽  
Fernando J. Bustos ◽  
Cansu Tunca ◽  
...  

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