Chronic calorie restriction (CR) improves cardiovascular function and several other physiological markers of healthspan. However, CR is impractical in non-obese older humans due to potential loss of lean mass and bone density, poor adherence, and risk of malnutrition. Time-restricted feeding (TRF), which limits the daily feeding period without requiring a reduction in calorie intake, may be a promising alternative healthspan-extending strategy for midlife and older adults; however, there is limited evidence for its feasibility and efficacy in humans. We conducted a randomized, controlled pilot study to assess the safety, tolerability, and overall feasibility of short-term TRF (eating <8 h day −1 for 6 weeks) without weight loss in healthy non-obese midlife and older adults, while gaining initial insight into potential efficacy for improving cardiovascular function and other indicators of healthspan. TRF was safe and well-tolerated, associated with excellent adherence and reduced hunger, and did not influence lean mass, bone density, or nutrient intake. Cardiovascular function was not enhanced by short-term TRF in this healthy cohort, but functional (endurance) capacity and glucose tolerance were modestly improved. These results provide a foundation for conducting larger clinical studies of TRF in midlife and older adults, including trials with a longer treatment duration.

Cardiovascular diseases (CVD) remain the leading cause of morbidity and mortality in both men and women in developed societies. Age is the greatest risk factor for CVD due largely to adverse changes to arteries that include stiffening of the large elastic arteries (aortic and carotid arteries) and endothelial dysfunction. Vascular ageing is driven by oxidative stress, which reduces nitric oxide (NO) bioavailability and stimulates changes in the extracellular matrix. In women, reductions in circulating oestrogens with menopause interact with ageing processes to induce vascular dysfunction. Regular aerobic exercise is the most evidence‐based strategy for reducing CVD risk with ageing in both men and women. Much of this cardiovascular‐protective effect of aerobic exercise is likely due to its vascular health‐enhancing influence. Large elastic artery stiffening with advancing age is attenuated in healthy adults engaged in aerobic exercise training, and aerobic exercise interventions improve arterial stiffness in previously sedentary middle‐aged and older men and postmenopausal women. Regular aerobic exercise also enhances endothelial function with ageing in men (by reducing oxidative stress and preserving NO bioavailability), but not consistently in oestrogen‐deficient postmenopausal women. In postmenopausal women, treatment with oestradiol appears to restore the ability of aerobic exercise to improve NO‐mediated endothelial function by reducing oxidative stress. Several research gaps exist in our understanding of potential sex differences in the vascular adaptations to regular aerobic exercise. More information is needed on the factors that are responsible for sex differences, including the role of circulating oestrogens in transducing the aerobic exercise training ‘stimulus’.

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The Pc locus of sorghum (Sorghum bicolor) determines dominant sensitivity to a host-selective toxin produced by the fungal pathogen Periconia circinata. The Pc region was cloned by a map-based approach and found to contain three tandemly repeated genes with the structures of nucleotide binding site–leucine-rich repeat (NBS–LRR) disease resistance genes. Thirteen independent Pc-to-pc mutations were analyzed, and each was found to remove all or part of the central gene of the threesome. Hence, this central gene is Pc. Most Pc-to-pc mutations were associated with unequal recombination. Eight recombination events were localized to different sites in a 560-bp region within the ∼3.7-kb NBS–LRR genes. Because any unequal recombination located within the flanking NBS–LRR genes would have removed Pc, the clustering of cross-over events within a 560-bp segment indicates that a site-directed recombination process exists that specifically targets unequal events to generate LRR diversity in NBS–LRR loci.

BackgroundCultivated peanut (Arachis hypogaea) is an allotetraploid species whose ancestral genomes are most likely derived from the A-genome species, A. duranensis, and the B-genome species, A. ipaensis. The very recent (several millennia) evolutionary origin of A. hypogaea has imposed a bottleneck for allelic and phenotypic diversity within the cultigen. However, wild diploid relatives are a rich source of alleles that could be used for crop improvement and their simpler genomes can be more easily analyzed while providing insight into the structure of the allotetraploid peanut genome. The objective of this research was to establish a high-density genetic map of the diploid species A. duranensis based on de novo generated EST databases. Arachis duranensis was chosen for mapping because it is the A-genome progenitor of cultivated peanut and also in order to circumvent the confounding effects of gene duplication associated with allopolyploidy in A. hypogaea.ResultsMore than one million expressed sequence tag (EST) sequences generated from normalized cDNA libraries of A. duranensis were assembled into 81,116 unique transcripts. Mining this dataset, 1236 EST-SNP markers were developed between two A. duranensis accessions, PI 475887 and Grif 15036. An additional 300 SNP markers also were developed from genomic sequences representing conserved legume orthologs. Of the 1536 SNP markers, 1054 were placed on a genetic map. In addition, 598 EST-SSR markers identified in A. hypogaea assemblies were included in the map along with 37 disease resistance gene candidate (RGC) and 35 other previously published markers. In total, 1724 markers spanning 1081.3 cM over 10 linkage groups were mapped. Gene sequences that provided mapped markers were annotated using similarity searches in three different databases, and gene ontology descriptions were determined using the Medicago Gene Atlas and TAIR databases. Synteny analysis between A. duranensis, Medicago and Glycine revealed significant stretches of conserved gene clusters spread across the peanut genome. A higher level of colinearity was detected between A. duranensis and Glycine than with Medicago.ConclusionsThe first high-density, gene-based linkage map for A. duranensis was generated that can serve as a reference map for both wild and cultivated Arachis species. The markers developed here are valuable resources for the peanut, and more broadly, to the legume research community. The A-genome map will have utility for fine mapping in other peanut species and has already had application for mapping a nematode resistance gene that was introgressed into A. hypogaea from A. cardenasii.

Kompetitive allele-specific polymerase chain reaction (KASP) assays have emerged as cost-effective marker assays especially for molecular breeding applications. Therefore, a set of 96 informative single nucleotide polymorphisms (SNPs) was used to develop KASP assays in groundnut or peanut (Arachis spp.). Developed assays were designated as groundnut KASP assay markers (GKAMs) and screened on 94 genotypes (validation set) that included parental lines of 27 mapping populations, seven synthetic autotetraploid and amphidiploid lines, and 19 wild species accessions. As a result, 90 GKAMs could be validated and 73 GKAMs showed polymorphism in the validation set. Validated GKAMs were screened on 280 diverse genotypes of the reference set for estimating diversity features and elucidating genetic relationships. Cluster analysis of marker allelic data grouped accessions according to their genome type, subspecies, and botanical variety. The subspecies Arachis hypogaea L. subsp. fastigiata Waldron and A. hypogaea subsp. hypogaea formed distinct cluster; however, some overlaps were found indicating their frequent intercrossing during the course of evolution. The wild species, having diploid genomes, were grouped into a single cluster. The average polymorphism information content value for polymorphic GKAMs was 0.32 in the validation set and 0.31 in the reference set. These validated and highly informative GKAMs may be useful for genetics and breeding applications in Arachis species.

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Amphizoic small amoebic protozoa are capable of existing both in 'free-living' and in 'parasitic' form depending on the actual conditions. Two genera (Naegleria and Acanthamoeba) have become recognised as opportunist human parasites. Since the first description in 1965 of a lethal case of primary amoebic meningoencephalitis (PAM) caused by Naegleria, many more (mostly lethal) cases have been reported, while granulomatous amoebic encephalitis (GAE), as well as eye (keratinitis, conjunctivitis, etc.), ear, nose, skin and internal organ infections caused by Acanthamoeba have also occurred in rapidly increasing numbers. Both pathogenic and non-pathogenic species of Naegleria and Acanthamoeba are found worldwide in water, soil and dust, where they provide a potential source of infection. Successful differential diagnosis and appropriate (specific) therapy depends on precise laboratory identification of the 'free-living' amoebae. In most cases, isolation from the environment can be achieved, but identification and differentiation of the pathogenic and non-pathogenic strains is not easy. The methods presently available do not fulfil completely the requirements for specificity, sensitivity and reliability. Morphological criteria are inadequate, while thermophilic character, pH dependency and even virulence in infected mice, are not unambiguous features of pathogenicity of the different strains. More promising are molecular methods, such as restriction endonuclease digestion of whole-cell DNA or mitochondria1 DNA, as well as iso-enzyme profile analysis after iso-electric focusing and staining for acid phosphatase and propionyl esterase activity. Use of appropriate monoclonal antibodies has also yielded promising results in the differentiation of human pathogenic and non-pathogenic strains. However, quicker, simpler, more specific and reliable methods are still highly desirable. The significance of endosymbiosis (especially with Legionella strains) is not well understood. The results of a systematic survey in Hungary for the isolation and identification of 'free-living' amoebae, including an investigation of the Hungarian amoebic fauna, the isolation of possibly pathogenic Naegleria strains and of some Acanthamoeba strains from eye diseases, as well as the finding of a case of endosymbiosis, are also reported here.