A happy accident: a novel turfgrass reference genome.

Poa pratensis, commonly known as Kentucky bluegrass, is a popular cool-season grass species used as turf in lawns and recreation areas globally. Despite its substantial economic value, a reference genome had not previously been assembled due to the genome's relatively large size and biological complexity that includes apomixis, polyploidy, and interspecific hybridization. We report here a fortuitous de novo assembly and annotation of a P. pratensis genome. Instead of sequencing the genome of a C4 grass, we accidentally sampled and sequenced tissue from a weedy P. pratensis whose stolon was intertwined with that of the C4 grass. The draft assembly consists of 6.09 Gbp with an N50 scaffold length of 65.1 Mbp, and a total of 118 scaffolds, generated using PacBio long reads and Bionano optical map technology. We annotated 256K gene models and found 58% of the genome to be composed of transposable elements. To demonstrate the applicability of the reference genome, we evaluated population structure and estimated genetic diversity in P. pratensis collected from three North American prairies, two in Manitoba, Canada and one in Colorado, USA. Our results support previous studies that found high genetic diversity and population structure within the species. The reference genome and annotation will be an important resource for turfgrass breeding and study of bluegrasses.

Genome sequencing reveals evidence of adaptive variation in the genus Zea.

Maize is a globally valuable commodity and one of the most extensively studied genetic model organisms. However, we know surprisingly little about the extent and potential utility of the genetic variation found in wild relatives of maize. Here, we characterize a high-density genomic variation map from 744 genomes encompassing maize and all wild taxa of the genus Zea, identifying over 70 million single-nucleotide polymorphisms. The variation map reveals evidence of selection within taxa displaying novel adaptations. We focus on adaptive alleles in highland teosinte and temperate maize, highlighting the key role of flowering-time-related pathways in their adaptation. To show the utility of variants in these data, we generate mutant alleles for two flowering-time candidate genes. This work provides an extensive sampling of the genetic diversity of Zea, resolving questions on evolution and identifying adaptive variants for direct use in modern breeding.

Dietary substitutions for refined carbohydrate that show promise for reducing risk of type 2 diabetes in men and women.

Both genetics and lifestyle contribute to type 2 diabetes (T2D), a condition of elevated circulating glucose induced by a collection of metabolic defects including peripheral insulin resistance, elevated hepatic glucose output, and impaired pancreatic insulin secretion. Because the prevalence of T2D and its modifiable risk factors (overweight/obesity, dyslipidemia, hypertension, and physical inactivity) have been increasing in recent decades, there has been growing interest in lifestyle interventions that target T2D management and prevention. Although it is increasingly recognized that lifestyle interventions aimed at encouraging physical activity and reducing body weight can improve insulin sensitivity, nutritional contributions to T2D risk reduction are less clear. Evidence from prospective cohort and randomized controlled trials suggests that diets rich in refined dietary carbohydrate [particularly those with a high glycemic index (GI)] may elevate T2D risk; however, the appropriate combination of macronutrients to optimize metabolic health has not been fully described. To date, the collective evidence suggests that diets rich in low-GI carbohydrates, cereal fiber, resistant starch, fat from vegetable sources (unsaturated fat), and lean sources of protein should be emphasized, whereas refined sugars and grains (high-GI carbohydrates) are to be avoided in order to lower risk of T2D and its related risk factors and comorbidities.

Addition of omega-3 carboxylic acids to statin therapy in patients with persistent hypertriglyceridemia.

The incidence of hypertriglyceridemia has grown alongside that of obesity. Statin therapy has been widely recommended for the treatment of dyslipidemias. Omega-3 (OM3) fatty acid concentrates are commonly prescribed concurrently with statins in patients with persistent hypertriglyceridemia for additional lowering of triglyceride and non-HDL cholesterol. The bioavailability of currently available OM3 ethyl ester drugs is limited by their need for hydrolysis by pancreatic lipases, largely stimulated by dietary fat, prior to intestinal absorption. This review will discuss the chemistry, pharmacokinetics and clinical efficacy of a novel OM3 carboxylic acid drug that provides polyunsaturated docosahexaenoic and eicosapentaenoic acids in the free fatty acid form, which is readily absorbed by the intestine. This drug was approved in May 2014 as an adjunct to diet to reduce triglyceride levels in adults with severe (≥500 mg/dl) hypertriglyceridemia.

Impact of multiple prenatal risk factors on newborn iron status at delivery.

BACKGROUND: Maternal anemia and several complications of pregnancy can affect fetal iron acquisition. AIM: Because it is unknown whether the effects of demographic and maternal risk factors (RF) are summative, we examined cord iron status in newborns with multiple RF for acquiring iron deficiency. METHODS: Cord blood indices from healthy control newborns with and without RF for newborn or infant iron deficiency were studied. RESULTS: Newborns with greater RF had poorer erythrocyte and storage iron status. Poorest status was seen if mothers with comorbid obesity and diabetes delivered large-for-gestation newborns. Findings highlight the importance of identifying RF.

Recruiting Latina families in a study of infant iron deficiency: a description of barriers, study adjustments and review of the literature.

BACKGROUND: Maternal minority status is a risk factor for iron deficiency in infancy and pregnancy. Because language and cultural differences may limit research participation, a prospective study examining iron deficiency included maternal minority status as an inclusionary criterion. Cognizant of potential barriers to recruitment, goals were to quantify eligible Latina enrollees and refusals, examine participation barriers, and devise possible solutions. METHODS: Mothers and their full-term newborns were eligible if the women were anemic, diabetic during pregnancy, of minority and/or lower socioeconomic status, and/or delivered an infant outside the average weight range for gestational age. Self-reported ethnicity and reasons for participation refusal were documented. RESULTS: During the first 18 months, 255 mothers and their infants were enrolled. Based on inclusionary criteria and the percentage of minority women admitted to the birthing center in a year, we anticipated 25% minority enrollees, with 16.3% Latina. Although 27% minority enrollment was obtained, only 8% were Latina (P < 0.01). System barriers, researcher perception barriers, and participant perception barriers were encountered. Over the next 8 months, addressing these recruitment barriers improved Latina enrollment. CONCLUSION: Enrollment barriers are significant hurdles to overcome, but with increased understanding and effort, more successful inclusion of Latina families can be achieved.