The broad adoption of transgenic crops has revolutionized agriculture. However, resistance to insecticidal proteins by agricultural pests poses a continuous challenge to maintaining crop productivity ...and new proteins are urgently needed to replace those utilized for existing transgenic traits. We identified an insecticidal membrane attack complex/perforin (MACPF) protein, Mpf2Ba1, with strong activity against the devastating coleopteran pest western corn rootworm (WCR) and a novel site of action. Using an integrative structural biology approach, we determined monomeric, pre-pore and pore structures, revealing changes between structural states at high resolution. We discovered an assembly inhibition mechanism, a molecular switch that activates pre-pore oligomerization upon gut fluid incubation and solved the highest resolution MACPF pore structure to-date. Our findings demonstrate not only the utility of Mpf2Ba1 in the development of biotechnology solutions for protecting maize from WCR to promote food security, but also uncover previously unknown mechanistic principles of bacterial MACPF assembly.
Display omitted
•AfIP-1A/1B act as a binary insecticidal protein against western corn rootworm.•AfIP-1A, but not AfIP-1B exhibits specific binding directly to WCR midgut tissue.•AfIP-1A is essential ...to enable specific binding of AfIP-1B.•AfIP-1A/1B exhibits pore formation in artificial lipid bilayers.•Binding of AfIP-1A/1B was reduced in midgut tissue from Cry34Ab1/Cry35Ab1-resistant WCR.
AfIP-1A/1B is a two-component insecticidal protein identified from the soil bacterium Alcaligenes faecalis that has high activity against western corn rootworm (WCR; Diabrotica virgifera virgifera LeConte). Previous results revealed that AfIP-1A/1B is cross-resistant to the binary protein from Bacillus thuringiensis (Bt), Cry34Ab1/Cry35Ab1 (also known as Gpp34Ab1/Tpp35Ab1; Crickmore et al., 2020), which was attributed to shared binding sites in WCR gut tissue (Yalpani et al., 2017). To better understand the interaction of AfIP-1A/1B with its receptor, we have systematically evaluated the binding of these proteins with WCR brush border membrane vesicles (BBMVs). Our findings show that AfIP-1A binds directly to BBMVs, while AfIP-1B does not; AfIP-1B binding only occurred in the presence of AfIP-1A which was accompanied by the presence of stable, high molecular weight oligomers of AfIP-1B observed on denaturing protein gels. Additionally, we show that AfIP-1A/1B forms pores in artificial lipid membranes. Finally, binding of AfIP-1A/1B was found to be reduced in BBMVs from Cry34Ab1/Cry35Ab1-resistant WCR where Cry34Ab1/Cry35Ab1 binding was also reduced. The reduced binding of both proteins is consistent with recognition of a shared receptor that has been altered in the resistant strain. The coordination of AfIP-1B binding by AfIP-1A, the similar structures between AfIP-1A and Cry34Ab1, along with their shared binding sites and cross-resistance, suggest a similar role for AfIP1A and Cry34Ab1 in receptor recognition and docking site for their cognate partners, AfIP-1B and Cry35Ab1, respectively.
Mature composts and their water-based extracts, known as aerated compost teas (ACTs), are biofertilizers that share bioactive effects like soil restoration and plant health promotion, widely used for ...sustainable agriculture. Bioactive effects of compost and ACTs could be associated with their physicochemical and biological characteristics, like carbon/nitrogen (C/N) ratio and microbiota structure respectively. In our study, we elaborated ACTs using mature homemade compost, wheat bran, and grass clippings, following the C/N ratio criteria. Irrigation of tomato plantlets with ACT whose C/N ratio was close to the expected C/N ratio for mature compost evidenced plant growth promotion. Exploring the bacterial microbiota of elaborated ACTs and origin compost revealed significant structural differences, including phyla involved in N mineralization and free-living N-fixing bacteria. Therefore, ACTs harbor diverse bacterial microbiota involved in the N cycle, which would enrich plant and soil bacterial communities at the taxonomic and functional levels. Furthermore, ACTs are considered a part of agroecological and circular economy approaches.
Fishes are relevant indicators of reefs’ conservation status due to the wide variety of functions they perform in the ecosystem. Natural and anthropogenic-induced threats are causing declines in ...biomass and diversity locally, with immediate effects on trophic structure and ecosystem function. This study evaluated the spatial variation of species richness and the alpha and beta functional diversity of fish assemblages across the Mexican Tropical Pacific (MTP). Visual fish censuses were performed in nine localities between 2012 and 2020. The results showed that species richness and functional diversity of the reef-associated fish assemblage vary at different spatial scales (local and regional), with the highest variability on the local scale. The functional richness and functional divergence presented high values in most localities. On their part, functional beta diversity among regions was low, with almost no functional turnover, while higher trait turnover was observed among localities. This study complements taxonomic diversity metrics by identifying differences due to local conditions, with human intervention as a critical factor. Therefore, it provides information tools that can help improve the management of marine communities subjected to distinct types and degrees of intervention in the MTP.
Summary
The coleopteran insect western corn rootworm (WCR, Diabrotica virgifera virgifera) is an economically important pest in North America and Europe. Transgenic corn plants producing Bacillus ...thuringiensis (Bt) insecticidal proteins have been useful against this devastating pest, but evolution of resistance has reduced their efficacy. Here, we report the discovery of a novel insecticidal protein, PIP‐47Aa, from an isolate of Pseudomonas mosselii. PIP‐47Aa sequence shows no shared motifs, domains or signatures with other known proteins. Recombinant PIP‐47Aa kills WCR, two other corn rootworm pests (Diabrotica barberi and Diabrotica undecimpunctata howardi) and two other beetle species (Diabrotica speciosa and Phyllotreta cruciferae), but it was not toxic to the spotted lady beetle (Coleomegilla maculata) or seven species of Lepidoptera and Hemiptera. Transgenic corn plants expressing PIP‐47Aa show significant protection from root damage by WCR. PIP‐47Aa kills a WCR strain resistant to mCry3A and does not share rootworm midgut binding sites with mCry3A or AfIP‐1A/1B from Alcaligenes that acts like Cry34Ab1/Cry35Ab1. Our results indicate that PIP‐47Aa is a novel insecticidal protein for controlling the corn rootworm pests.
Crops expressing Bacillus thuringiensis (Bt)-derived insecticidal protein genes have been commercially available for over 15 years and are providing significant value to growers. However, there ...remains the need for alternative insecticidal actives due to emerging insect resistance to certain Bt proteins. A screen of bacterial strains led to the discovery of a two-component insecticidal protein named AfIP-1A/1B from an Alcaligenes faecalis strain. This protein shows selectivity against coleopteran insects including western corn rootworm (WCR). Transgenic maize plants expressing AfIP-1A/1B demonstrate strong protection from rootworm injury. Surprisingly, although little sequence similarity exists to known insecticidal proteins, efficacy tests using WCR populations resistant to two different Cry proteins show that AfIP-1A/1B and mCry3A differ in their mode of action while AfIP-1A/1B and the binary Cry34Ab1/Cry35Ab1 protein share a similar mode. These findings are supported by results of competitive binding assays and the similarity of the x-ray structure of AfIP-1A to Cry34Ab1. Our work indicates that insecticidal proteins obtained from a non-Bt bacterial source can be useful for developing genetically modified crops and can function similarly to familiar proteins from Bt.
In this study, we report an experience of 59 natural-cycle IVF combined with in vitro oocyte maturation (IVF/M) cycles in patients with PCOS requiring IVF recruited based on limitations to afford a ...conventional IVF treatment in a 9-years period. Results of IVF/M were compared with 164 cycles of IVF in PCOS patients.
In IVF/M cycles only hCG priming was used before oocyte recovery, with in vitro maturation of immature oocytes in a commercial medium. In conventional IVF group, recombinant FSH (rFSH) and GnRH agonist/antagonist for ovarian stimulation were used. In both groups, fertilization was achieved by intracytoplasmic sperm injection (ICSI) of mature oocytes and fresh embryos transferred at day 2 or day 3.
In all IVF/M cycles oocytes and transferable quality embryos were obtained, only in 6 IVF/M cycles mature oocytes were obtained at oocyte capture day. Clinical pregnancy rate per cycle was 39.0% vs 53.6% (p = 0.0682) and delivery rate per cycle was 30.5% vs 42.6% (p = 0.1209) in IVF/M and conventional IVF respectively. Patients with ovarian hyperstimulation syndrome (OHSS) were 0% in IVF/M vs 6.7% in conventional IVF (p = 0.0399).
Our experience in a private clinic in Mexico suggests that IVF/M can be a useful initial strategy to treat PCOS patients requiring IVF with comparable delivery rates to conventional IVF and a decreased risk of ovary hyperstimulation. IVF/M may be indicated to patients with limited resources paying without insurance for their infertility treatment.
Dynamic infrared thermography (DIRT) has been used for the preoperative mapping of cutaneous perforators. This technique has shown a positive correlation with intraoperative findings. Our aim was to ...evaluate the accuracy of perforator mapping with DIRT and augmented reality using a portable projector. For this purpose, three volunteers had both of their anterolateral thighs assessed for the presence and location of cutaneous perforators using DIRT. The obtained image of these “hotspots” was projected back onto the thigh and the presence of Doppler signals within a 10-cm diameter from the midpoint between the lateral patella and the anterior superior iliac spine was assessed using a handheld Doppler device. Hotspots were identified in all six anterolateral thighs and were successfully projected onto the skin. The median number of perforators identified within the area of interest was 5 (range, 3–8) and the median time needed to identify them was 3.5 minutes (range, 3.3–4.0 minutes). Every hotspot was correlated to a Doppler sound signal. In conclusion, augmented reality can be a reliable method for transferring the location of perforators identified by DIRT onto the thigh, facilitating its assessment and yielding a reliable map of potential perforators for flap raising.
Maritime activity has diverse environmental consequences impacts in port areas, especially for air quality, and the post-COVID-19 cruise tourism market's potential to recover and grow is causing new ...environmental concerns in expanding port cities. This research proposes an empirical and modelling approach for the evaluation of cruise ships' influence on air quality concerning NO2 and SO2 in the city of La Paz (Mexico) using indirect measurements. EPA emission factors and the AERMOD modelling system coupled to WRF were used to model dispersions, while street-level mobile monitoring data of air quality from two days of 2018 were used and processed using a radial base function interpolator. The local differential Moran's Index was estimated at the intersection level using both datasets and a co-location clustering analysis was performed to address spatial constancy and to identify the pollution levels. The modelled results showed that cruise ships' impact on air quality had maximum values of 13.66 μg/m3 for NO2 and 15.71 μg/m3 for SO2, while background concentrations of 8.80 for NOx and 0.05 for SOx (μg/m3) were found by analysing the LISA index values for intersections not influenced by port pollution. This paper brings insights to the use of hybrid methodologies as an approach to studying the influence of multiple-source pollutants on air quality in contexts totally devoid of environmental data.
Display omitted
•Cruise ship's impact on air quality modelling (AERMOD-WRF).•The spatial pattern of pollutant concentration using low-cost analysers.•Differential Moran's I Index with local indicators of spatial association (DiLISA).•The influence of multiple-source pollutants on air quality was elucidated using a hybrid methodology.
We researched how the transition to remote learning during the COVID-19 pandemic affected the development of mathematical thinking and reading comprehension skills of high school students based on ...the analysis of the results of a standardized test for higher education admission. The total number of participants was N = 17,942, out of which N1 = 10,611 were pre-pandemic applicants and N2 = 7,331 were post-pandemic applicants. The pre-pandemic group took into consideration the exam results from September 2016 to June 2020. The post-pandemic group took into consideration the exam results from September 2020 up to May 2023. We conclude that emergency remote teaching decreased the average mathematical competence of incoming university students by 12.8%. Similarly, emergency remote teaching decreased the average reading achievement of students entering university by 8%. Therefore, the impact of emergency remote teaching was greater on mathematics skills than on reading achievements.
PDF
