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Bacillus thuringiensis (Bt) has been successfully used commercially for more than 60 years for biocontrol of insect pests. Since 1996, transgenic plants expressing Bt crystal (Cry) proteins have been used commercially to provide protection against insects that predate on corn and cotton. More recently, Bt Cry proteins that target nematodes have been discovered. One of these, Cry14Ab, has been expressed in transgenic soybean plants and found to provide significant protection against the soybean cyst nematode, Heterodera glycines. However, to date there has been no description of high-level resistance to any Cry14A family protein in nematodes. Here, we describe forward genetic screens to identify such mutants using the nematode Caenorhabditis elegans. Although non-conditional screens failed to identify highly resistant C. elegans, a conditional (temperature-sensitive) genetic screen identified one mutant, bre-6(ye123) (for Bt protein resistant), highly resistant to both Cry14Aa and Cry14Ab. The mutant comes at a high fitness cost, showing significant delays in growth and development and reduced fecundity. bre-6(ye123) hermaphrodites are only weakly resistant to copper intoxication, indicating that the mutant is not highly resistant to all insults. Backcrossing—whole genome sequencing was used to identify the gene mutated in ye123 as the nuclear hormone receptor nhr-31. RNAi, DNA rescue, and CRISPR analyses confirm that resistance to Cry14Aa intoxication in bre-6(ye123) is due to mutation of nhr-31 and was renamed nhr-31(ye123). As predicted for a mutation in this gene, nhr-31(ye123) animals showed significantly reduced expression of most of the subunits of the C. elegans vacuolar ATPase (vATPase). Mutants in the vATPase subunits unc-32 and vha-7 also show resistance to Cry14Aa and/or Cry14Ab. These data demonstrate that nhr-31 and the vATPase play a significant role in the intoxication of C. elegans by Cry14A family proteins, that reduction in vATPase levels result in high resistance to Cry14A family proteins, and that such resistance comes at a high fitness cost. Based on the relative difficulty of finding resistant mutants and the fitness cost associated with the vATPase pathway, our data suggest that transgenic Cry14Ab plants may hold up well to resistance by nematode parasites. Author summary: The bacterium Bacillus thuringiensis (Bt) is the most common biologically-produced insecticide used in agriculture. The main insect-killing components of Bt are crystal (Cry) proteins. Cry proteins that kill nematode (roundworm) pests have also been identified. One of these, Cry14Ab, is being developed to control plant-parasitic nematodes, which are highly-damaging pests of agriculture. Thus, understanding how nematodes become resistance to Cry14Ab is important. Using the free-living nematode Caenorhabditis elegans, we discovered a single mutant strain highly resistant to Cry14A family proteins. This mutant was rare and has compromised health in the absence of Cry protein (i.e., it grows slowly and has low brood size). We identified the gene altered in this mutant as nhr-31, a gene that is involved in making a large cellular protein machine that pumps protons across membranes. We found that reduction of function of other components of this proton-pumping machine also result in resistance to Cry14A family proteins. Taken together, our data suggest that a major pathway involved in resistance to Cry14A family proteins is reduction of function of a large cellular proton pump machine that comes at a high fitness cost to nematodes. [ABSTRACT FROM AUTHOR]

Celiac disease (CeD) is a common autoimmune condition, with a prevalence of ~1%. Currently, a gluten-free diet (GFD) is the only treatment option. Due to fortification rules excluding gluten-free products in the United States of America (U.S.A.), understanding the nutritional adequacy of a GFD is important for promoting optimal health among those with CeD. Cross-sectional examination of multiple 24 h dietary recalls from a study sample of 50 adults and 30 teens with CeD was used to determine nutritional adequacy and excesses according to U.S.A. recommendations. The results were compared with those of 15,777 adults and 2296 teens from a nationally representative sample not reporting CeD, the National Health and Nutrition Examination Survey (NHANES) 2009–2014. Compared with NHANES, our study population was more at risk of low folate and carbohydrate (adults) consumption, and of excessive niacin and vitamin A (teens), as well as saturated and total fat consumption (adults). Overall, though, compared with NHANES, our study participants had similar nutrient concerns but fewer nutritional imbalances, with some notable exceptions. In addition to maintaining a GFD, individuals with CeD should be counseled to maintain a balanced diet and to pay attention to nutrient-dense foods. Special attention should be given to teens in providing dietary counseling to potentially mitigate the risk of future morbidity. [ABSTRACT FROM AUTHOR]

Describing risk factors and outcomes in kidney transplant recipients with oxalate nephropathy (ON) may help elucidate the pathogenesis and guide treatment strategies. We used a large single‐center database to identify patients with ON and categorized them into delayed graft function with ON (DGF‐ON) and late ON. Incidence density sampling was used to select controls. A total of 37 ON cases were diagnosed between 1/2011 and 1/2021. DGF‐ON (n = 13) was diagnosed in 1.05% of the DGF population. Pancreatic atrophy on imaging (36.4% vs. 2.9%, p = 0.002) and gastric bypass history (7.7% vs. 0%; p = 0.06) were more common in DGF‐ON than with controls with DGF requiring biopsy but without evidence of ON. DGF‐ON was not associated with worse graft survival (p = 0.98) or death‐censored graft survival (p = 0.48). Late ON (n = 24) was diagnosed after a mean of 78.2 months. Late ON patients were older (mean age 55.1 vs. 48.4 years; p = 0.02), more likely to be women (61.7% vs. 37.5%; p = 0.03), have gastric bypass history (8.3% vs. 0.8%; p = 0.02) and pancreatic atrophy on imaging (38.9% vs. 13.3%; p = 0.02). Late ON was associated with an increased risk of graft failure (HR 2.0; p = 0.07) and death‐censored graft loss (HR 2.5; p = 0.10). We describe two phenotypes of ON after kidney transplantation: DGF‐ON and late ON. Our study is the first to our knowledge to evaluate DGF‐ON with DGF controls without ON. Although limited by small sample size, DGF‐ON was not associated with adverse outcomes when compared with controls. Late ON predicted worse allograft outcomes. [ABSTRACT FROM AUTHOR]

To demonstrate the prevalence of maternal mosaic monosomy X (MMXO) in a cohort of pregnant women in Vietnam. All 105,594 singleton pregnant women undergoing noninvasive prenatal screening (NIPS) between January 2019 and February 2021 in Vietnam were analyzed by measuring discordance between size- and count-based z-scores for chromosome X (ChrX) to identify suspected cases of MMXO and validated by fluorescence in situ hybridization (FISH) on maternal blood. We identified 295 (0.279%) suspected MMXO cases. After FISH analysis, MMXO was confirmed in 125 cases (42.37%), revealing the MMXO prevalence of 0.118% (95% CI: 0.097–0.139%) in this cohort. We found a relatively high prevalence of MMXO in Vietnamese pregnant women and demonstrated a strong influence of MMXO on the ChrX z-score using a count-based method, resulting in false positives. The size-based method is not sensitive to MMXO and therefore achieves higher PPV. [ABSTRACT FROM AUTHOR]