Negative feedback control of jasmonate signaling by an alternative splice variant of JAZ10

The plant hormone jasmonate (JA) activates gene expression by promoting ubiquitin-dependent degradation of JAZ transcriptional repressor proteins. A key feature of all JAZ proteins is the highly conserved Jas motif, which mediates both JAZ degradation and JAZ binding to the transcription factor MYC2. Rapid expression of JAZ genes in response to JA is thought to attenuate JA responses, but little is known about the mechanisms by which newly synthesized JAZ proteins exert repression in the presence of the hormone. Here, we show that desensitization to JA is mediated by an alternative splice variant (JAZ10.4) of JAZ10 that lacks the Jas motif. Unbiased protein-protein interaction screens identified three related bHLH transcription factors (MYC2, MYC3, and MYC4) and the co-repressor NINJA as JAZ10.4-binding partners. We show that the N-terminal region of JAZ10.4 contains a cryptic MYC2-binding site that resembles the Jas motif, and that the ZIM motif of JAZ10.4 functions as a transferable repressor domain whose activity is associated with recruitment of NINJA. Functional studies showed that expression of JAZ10.4 from the native JAZ10 promoter complemented the JA-hypersensitive phenotype of a jaz10 mutant. Moreover, treatment of these complemented lines with JA resulted in rapid accumulation of JAZ10.4 protein. Our results provide an explanation for how the unique domain architecture of JAZ10.4 links transcription factors to a co-repressor complex, and suggest how JA-induced transcription and alternative splicing of JAZ10 pre-mRNA creates a regulatory circuit to attenuate JA responses.Fil: Moreno, Javier Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina. Michigan State University; Estados UnidosFil: Shyu, Christine. Michigan State University; Estados UnidosFil: Campos, Marcelo L.. Michigan State University; Estados UnidosFil: Patel, Lalita C.. Michigan State University; Estados UnidosFil: Chung, Hoo Sun. Michigan State University; Estados UnidosFil: Yao, Jian. Michigan State University; Estados UnidosFil: He, Sheng Hang. Michigan State University; Estados UnidosFil: Howe, Gregg A.. Michigan State University; Estados Unido

Outcomes of breech birth by mode of delivery: a population linkage study

Background: Trial evidence supports a policy of caesarean section for singleton breech presentations at term but vaginal breech birth is considered a safe option for selected women. Aims: To provide recent Australian data on outcomes associated with intended mode of delivery for term breech singletons in women who meet conservative eligibility criteria for vaginal breech birth. Materials and Methods: Birth and hospital records from 2009 to 2012 in New South Wales were used to identify women with non-anomalous pregnancies who would be considered eligible for vaginal breech birth. Intended mode of delivery was inferred from labour onset and management. Results: Of 10,133 women with term breech singleton pregnancies, 5,197 (51.3%) were classified as eligible for vaginal breech delivery. Of these, 6.8% intended vaginal breech birth, 76.4% planned caesarean section, and intention could not be determined for 16.8%. Women intending vaginal delivery had higher rates of neonatal morbidity (6.0% vs. 2.1%), neonatal birth trauma (7.4% vs. 0.9%), Apgar <4 at 1 minute (10.5% vs. 1.1%), Apgar<7 at 5 minutes (4.3% vs. 0.5%), and NICU/SCN admissions (16.2% vs. 6.6%) than those planning caesarean section. Increased perinatal risks remained after adjustment for maternal characteristics. Severe maternal morbidity (1.4% vs. 0.7%) and postpartum readmission (4.6% vs. 4.0%) were higher in the intended vaginal compared to planned caesarean births but these differences were not statistically significant. Conclusions: In a population of women classified as being eligible for vaginal breech birth, intended vaginal delivery was associated with higher rates of neonatal morbidity than planned caesarean section.NHMRC, AR

Seasonal Changes in Methanogenesis and Methanogenic Community in Three Peatlands, New York State

Fluctuating environmental conditions can promote diversity and control dominance in community composition. In addition to seasonal temperature and moisture changes, seasonal supply of metabolic substrates selects populations temporally. Here we demonstrate cascading effects in the supply of metabolic substrates on methanogenesis and community composition of anaerobic methanogenic archaea in three contrasting peatlands in upstate New York. Fresh samples of peat soils, collected about every 3 months for 20 months and incubated at 22 ± 2°C regardless of the in situ temperature, exhibited potential rates of methane (CH4) production of 0.02–0.2 mmol L−1 day−1 [380–3800 nmol g−1 (dry) day−1). The addition of acetate stimulated rates of CH4 production in a fen peatland soil, whereas addition of hydrogen (H2), and simultaneous inhibition of H2-consuming acetogenic bacteria with rifampicin, stimulated CH4 production in two acidic bog soils, especially, in autumn and winter. The methanogenic community structure was characterized using T-RFLP analyses of SSU rRNA genes. The E2 group of methanogens (Methanoregulaceae) dominated in the two acidic bog peatlands with relatively greater abundance in winter. In the fen peatland, the E1 group (Methanoregulaceae) and members of the Methanosaetaceae were co-dominant, with E1 having a high relative abundance in spring. Change in relative abundance profiles among methanogenic groups in response to added metabolic substrates was as predicted. The acetate-amendment increased abundance of Methanosarcinaceae, and H2-amendment enhanced abundance of E2 group in all peat soils studied, respectively. Additionally, addition of acetate increased abundance of Methanosaetaceae only in the bog soils. Variation in the supply of metabolic substrates helps explain the moderate diversity of methanogens in peatlands

Contribution of Changing Risk Factors to the Trend in Breech Presentation at Term

Background: Recent population-wide changes in perinatal risk factors may affect rates of breech presentation at birth, and have implications for the provision of breech services and clinical training in breech management. Aims: To determine the trend in breech presentation at term and investigate whether changes in maternal and pregnancy characteristics explain the observed trend. Materials and Methods: All singleton term (≥37 week) births in New South Wales during 2002 – 2012 were identified through birth and associated hospital records. Annual rates of breech presentation were determined. Logistic regression modelling was used to predict expected rates of breech presentation over time and these were compared with observed rates. A priori predictors included maternal age, country of birth, parity, smoking during pregnancy, diabetes, pregnancy hypertension, placenta praevia, previous singleton term breech, previous caesarean section, infant sex, gestational age, birthweight, and congenital anomalies. Hospital and Medicare data were used to assess trends in external cephalic version. Results: Among 914,147 singleton term births, 3.1% were breech at delivery. Rates declined from 3.6% in 2002 to 2.7% in 2012 (test for trend p<0.001). Breech presentation was predicted to increase from 3.6% in 2002 to 4.3% in 2012 because of increased maternal age, nulliparity, maternal diabetes, history of breech presentation and previous caesarean section. Use of external cephalic version appears to have increased over time. Conclusions: Breech presentation at delivery has decreased in New South Wales. Increased use of external cephalic version likely accounts for this decline, as changes in risk factors do not.NHMRC, AR

Thiophen-basierte konjugierte acetylenische Polymere mit dualen aktiven Zentren für effiziente Cokatalysator-freie photoelektrochemische Wasserreduktion im alkalischen Medium

AbstractKonjugierte Polymere sind attraktive Materialien für die photoelektrochemische Wasserstoffentwicklungsreaktion (PEC‐HER) unter neutralen oder sauren Bedingungen. Jedoch zeigen sie im alkalischen Medium immer noch eine geringe PEC‐HER‐Leistung aufgrund des Fehlens von Wasserdissoziations‐Zentren. Hier zeigen wir, dass durch Anpassung des konjugierten acetylenischen Polymers (CAPs) von Poly(diethinylthieno[3,2‐b]thiophen) (pDET) zu Poly(2,6‐diethinylbenzo[1,2‐b:4,5‐b′]dithiophen (pBDT) und Poly(diethinyldithieno[3,2‐b:2′,3′‐d]thiophen) (pDTT) hocheffiziente aktive Wasserdissoziations‐Zentren in CAPs eingeführt werden können. Infolgedessen zeigen auf Cu‐Substrat gewachsene pDTT und pBDT Benchmark‐Photostromdichten von 170 μA cm−2 und 120 μA cm−2 (bei 0,3 V vs. RHE; pH 13), die 4,2‐ bzw. 3‐mal höher sind als die von pDET. DFT‐Rechnungen und elektrochemische Operando‐Resonanz‐Raman‐Spektroskopie zeigen, dass die elektronenangereicherten Cβ der äußeren Thiophenringe von pDTT die aktiven Zentren für die Wasserdissoziation sind, während die ‐C≡C‐Bindungen als aktive Zentren für die Wasserstoffentwicklung fungieren

Chemoprevention of nonmelanoma skin cancer: experience with a polyphenol from green tea.

Nonmelanoma skin cancer is extremely common and is increasing in incidence. It would be very useful to have forms of therapy that would prevent precancerous changes from going on to form cancer, or to reverse the precancerous changes. Epidemiologic evidence in humans, in vitro studies on human cells, and clinical experiments in animals have identified polyphenol compounds found in tea to be possibly useful in reducing the incidence of various cancers, including skin cancer. To examine the potential for a polyphenol from green tea, epigallocatechin gallate, to act as a chemopreventive agent for nonmelanoma skin cancer, a randomized, double-blind, placebo-controlled phase II clinical trial of topical epigallocatechin gallate in the prevention of nonmelanoma skin cancer was performed

Structural characterization of gas-phase cysteine and cysteine methyl ester complexes with zinc and cadmium dications by infrared multiple photon dissociation spectroscopy

Contains fulltext : 149638.pdf (publisher's version ) (Closed access

Persisting Viral Sequences Shape Microbial CRISPR-based Immunity

Well-studied innate immune systems exist throughout bacteria and archaea, but a more recently discovered genomic locus may offer prokaryotes surprising immunological adaptability. Mediated by a cassette-like genomic locus termed Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), the microbial adaptive immune system differs from its eukaryotic immune analogues by incorporating new immunities unidirectionally. CRISPR thus stores genomically recoverable timelines of virus-host coevolution in natural organisms refractory to laboratory cultivation. Here we combined a population genetic mathematical model of CRISPR-virus coevolution with six years of metagenomic sequencing to link the recoverable genomic dynamics of CRISPR loci to the unknown population dynamics of virus and host in natural communities. Metagenomic reconstructions in an acid-mine drainage system document CRISPR loci conserving ancestral immune elements to the base-pair across thousands of microbial generations. This ‘trailer-end conservation’ occurs despite rapid viral mutation and despite rapid prokaryotic genomic deletion. The trailer-ends of many reconstructed CRISPR loci are also largely identical across a population. ‘Trailer-end clonality’ occurs despite predictions of host immunological diversity due to negative frequency dependent selection (kill the winner dynamics). Statistical clustering and model simulations explain this lack of diversity by capturing rapid selective sweeps by highly immune CRISPR lineages. Potentially explaining ‘trailer-end conservation,’ we record the first example of a viral bloom overwhelming a CRISPR system. The polyclonal viruses bloom even though they share sequences previously targeted by host CRISPR loci. Simulations show how increasing random genomic deletions in CRISPR loci purges immunological controls on long-lived viral sequences, allowing polyclonal viruses to bloom and depressing host fitness. Our results thus link documented patterns of genomic conservation in CRISPR loci to an evolutionary advantage against persistent viruses. By maintaining old immunities, selection may be tuning CRISPR-mediated immunity against viruses reemerging from lysogeny or migration

Clades of huge phages from across Earth's ecosystems.

Bacteriophages typically have small genomes1 and depend on their bacterial hosts for replication2. Here we sequenced DNA from diverse ecosystems and found hundreds of phage genomes with lengths of more than 200&nbsp;kilobases (kb), including a genome of 735&nbsp;kb, which is-to our knowledge-the largest phage genome to be described to date. Thirty-five genomes were manually curated to completion (circular and no gaps). Expanded genetic repertoires include diverse and previously undescribed CRISPR-Cas systems, transfer RNAs (tRNAs), tRNA synthetases, tRNA-modification enzymes, translation-initiation and elongation factors, and ribosomal proteins. The CRISPR-Cas systems of phages have the capacity to silence host transcription factors and translational genes, potentially as part of a larger interaction network that intercepts translation to redirect biosynthesis to phage-encoded functions. In addition, some phages may repurpose bacterial CRISPR-Cas systems to eliminate competing phages. We phylogenetically define the major clades of huge phages from human and other animal microbiomes, as well as from oceans, lakes, sediments, soils and the built environment. We conclude that the large gene inventories of huge phages reflect a conserved biological strategy, and that the phages are distributed across a broad bacterial host range and across Earth's ecosystems

Thiophene-Based Conjugated Acetylenic Polymers with Dual Active Sites for Efficient Co-Catalyst-Free Photoelectrochemical Water Reduction in Alkaline Medium

Although being attractive materials for photoelectrochemical hydrogen evolution reaction (PEC HER) under neutral or acidic conditions, conjugated polymers still show poor PEC HER performance in alkaline medium due to the lack of water dissociation sites. Herein, we demonstrate that tailoring the polymer skeleton from poly(diethynylthieno[3,2-b]thiophene) (pDET) to poly(2,6-diethynylbenzo[1,2-b:4,5-b′]dithiophene (pBDT) and poly(diethynyldithieno[3,2-b:2′,3′-d]thiophene) (pDTT) in conjugated acetylenic polymers (CAPs) introduces highly efficient active sites for water dissociation. As a result, pDTT and pBDT, grown on Cu substrate, demonstrate benchmark photocurrent densities of 170 μA cm−2 and 120 μA cm−2 (at 0.3 V vs. RHE; pH 13), which are 4.2 and 3 times higher than that of pDET, respectively. Moreover, by combining DFT calculations and electrochemical operando resonance Raman spectroscopy, we propose that the electron-enriched Cβ of the outer thiophene rings of pDTT are the water dissociation active sites, while the −C≡C− bonds function as the active sites for hydrogen evolution. © 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH Gmb