SciCombinator

Discover the most talked about and latest scientific content & concepts.

290

Kidney dysfunction in obesity may be independent of and may precede the development of hypertension and/or diabetes mellitus. We aimed to examine if abdominal obesity is associated with early markers of CKD in a young healthy population and whether these associations differ by race and/or ethnicity.

Concepts: Childhood obesity, Myocardial infarction, Nutrition, Metabolic syndrome, Obesity, Hypertension, Diabetes mellitus, Chronic kidney disease

76

The recent discovery of a plasmid-borne colistin resistance gene, mcr-1, heralds the emergence of truly pan-drug resistant bacteria (1).….

Concepts: Gene, Proteobacteria, DNA, Genome, Plasmid, Bacteria, Escherichia coli, Antibiotic resistance

57

Post-copulatory sexual selection (PSS), fuelled by female promiscuity, is credited with the rapid evolution of sperm quality traits across diverse taxa. Yet, our understanding of the adaptive significance of sperm ornaments and the cryptic female preferences driving their evolution is extremely limited. Here we review the evolutionary allometry of exaggerated sexual traits (for example, antlers, horns, tail feathers, mandibles and dewlaps), show that the giant sperm of some Drosophila species are possibly the most extreme ornaments in all of nature and demonstrate how their existence challenges theories explaining the intensity of sexual selection, mating-system evolution and the fundamental nature of sex differences. We also combine quantitative genetic analyses of interacting sex-specific traits in D. melanogaster with comparative analyses of the condition dependence of male and female reproductive potential across species with varying ornament size to reveal complex dynamics that may underlie sperm-length evolution. Our results suggest that producing few gigantic sperm evolved by (1) Fisherian runaway selection mediated by genetic correlations between sperm length, the female preference for long sperm and female mating frequency, and (2) longer sperm increasing the indirect benefits to females. Our results also suggest that the developmental integration of sperm quality and quantity renders post-copulatory sexual selection on ejaculates unlikely to treat male-male competition and female choice as discrete processes.

Concepts: Male, Evolution, Evolutionary psychology, Sexual dimorphism, Charles Darwin, Ronald Fisher, Sex, Sexual selection

57

An extensive infrastructure of neighborhood parks supports leisure time physical activity in most U.S. cities; yet, most Americans do not meet national guidelines for physical activity. Neighborhood parks have never been assessed nationally to identify their role in physical activity.

Concepts: D. W. Griffith, Oregon, Nationalism

54

The pottery vessels from the Mijiaya site reveal, to our knowledge, the first direct evidence of in situ beer making in China, based on the analyses of starch, phytolith, and chemical residues. Our data reveal a surprising beer recipe in which broomcorn millet (Panicum miliaceum), barley (Hordeum vulgare), Job’s tears (Coix lacryma-jobi), and tubers were fermented together. The results indicate that people in China established advanced beer-brewing technology by using specialized tools and creating favorable fermentation conditions around 5,000 y ago. Our findings imply that early beer making may have motivated the initial translocation of barley from the Western Eurasia into the Central Plain of China before the crop became a part of agricultural subsistence in the region 3,000 y later.

Concepts: Proso millet, Beer

54

Human activities have substantially changed the world’s oceans in recent decades, altering marine food webs, habitats and biogeochemical processes [1]. Cephalopods (squid, cuttlefish and octopuses) have a unique set of biological traits, including rapid growth, short lifespans and strong life-history plasticity, allowing them to adapt quickly to changing environmental conditions [2-4]. There has been growing speculation that cephalopod populations are proliferating in response to a changing environment, a perception fuelled by increasing trends in cephalopod fisheries catch [4,5]. To investigate long-term trends in cephalopod abundance, we assembled global time-series of cephalopod catch rates (catch per unit of fishing or sampling effort). We show that cephalopod populations have increased over the last six decades, a result that was remarkably consistent across a highly diverse set of cephalopod taxa. Positive trends were also evident for both fisheries-dependent and fisheries-independent time-series, suggesting that trends are not solely due to factors associated with developing fisheries. Our results suggest that large-scale, directional processes, common to a range of coastal and oceanic environments, are responsible. This study presents the first evidence that cephalopod populations have increased globally, indicating that these ecologically and commercially important invertebrates may have benefited from a changing ocean environment.

Concepts: Natural environment, Environmental science, Cuttlefish, Mollusca, Octopus, Ocean, Cephalopod

40

Bright-red colors in vertebrates are commonly involved in sexual, social, and interspecific signaling [1-8] and are largely produced by ketocarotenoid pigments. In land birds, ketocarotenoids such as astaxanthin are usually metabolically derived via ketolation of dietary yellow carotenoids [9, 10]. However, the molecular basis of this gene-environment mechanism has remained obscure. Here we use the yellowbeak mutation in the zebra finch (Taeniopygia guttata) to investigate the genetic basis of red coloration. Wild-type ketocarotenoids were absent in the beak and tarsus of yellowbeak birds. The yellowbeak mutation mapped to chromosome 8, close to a cluster of cytochrome P450 loci (CYP2J2-like) that are candidates for carotenoid ketolases. The wild-type zebra finch genome was found to have three intact genes in this cluster: CYP2J19A, CYP2J19B, and CYP2J40. In yellowbeak, there are multiple mutations: loss of a complete CYP2J19 gene, a modified remaining CYP2J19 gene (CYP2J19(yb)), and a non-synonymous SNP in CYP2J40. In wild-type birds, CYP2J19 loci are expressed in ketocarotenoid-containing tissues: CYP2J19A only in the retina and CYP2J19B in the beak and tarsus and to a variable extent in the retina. In contrast, expression of CYP2J19(yb) is barely detectable in the beak of yellowbeak birds. CYP2J40 has broad tissue expression and shows no differences between wild-type and yellowbeak. Our results indicate that CYP2J19 genes are strong candidates for the carotenoid ketolase and imply that ketolation occurs in the integument in zebra finches. Since cytochrome P450 enzymes include key detoxification enzymes, our results raise the intriguing possibility that red coloration may be an honest signal of detoxification ability.

Concepts: Gene expression, Chromosome, Zebra Finch, Evolution, Genetics, DNA, Gene, Cytochrome P450

40

UV-induced DNA damage, a major risk factor for skin cancers, is primarily repaired by nucleotide excision repair (NER). UV radiation resistance-associated gene (UVRAG) is a tumor suppressor involved in autophagy. It was initially isolated as a cDNA partially complementing UV sensitivity in xeroderma pigmentosum (XP), but this was not explored further. Here we show that UVRAG plays an integral role in UV-induced DNA damage repair. It localizes to photolesions and associates with DDB1 to promote the assembly and activity of the DDB2-DDB1-Cul4A-Roc1 (CRL4(DDB2)) ubiquitin ligase complex, leading to efficient XPC recruitment and global genomic NER. UVRAG depletion decreased substrate handover to XPC and conferred UV-damage hypersensitivity. We confirmed the importance of UVRAG for UV-damage tolerance using a Drosophila model. Furthermore, increased UV-signature mutations in melanoma correlate with reduced expression of UVRAG. Our results identify UVRAG as a regulator of CRL4(DDB2)-mediated NER and suggest that its expression levels may influence melanoma predisposition.

Concepts: Ultraviolet, Gene expression, Gene, Mutation, Xeroderma pigmentosum, Cancer, DNA, DNA repair

31

This study assessed changes in levels of ever use, perceptions of harm from e-cigarettes and sociodemographic correlates of use among European Union (EU) adults during 2012-2014, as well as determinants of current use in 2014.

Concepts: Treaty of Lisbon, Poland, Member State of the European Union, Malta, Slovakia, European Union, United Kingdom

30

Men have a shorter life expectancy compared with women but the underlying factor(s) are not clear. Late-onset, sporadic Alzheimer disease (AD) is a common and lethal neurodegenerative disorder and many germline inherited variants have been found to influence the risk of developing AD. Our previous results show that a fundamentally different genetic variant, i.e., lifetime-acquired loss of chromosome Y (LOY) in blood cells, is associated with all-cause mortality and an increased risk of non-hematological tumors and that LOY could be induced by tobacco smoking. We tested here a hypothesis that men with LOY are more susceptible to AD and show that LOY is associated with AD in three independent studies of different types. In a case-control study, males with AD diagnosis had higher degree of LOY mosaicism (adjusted odds ratio = 2.80, p = 0.0184, AD events = 606). Furthermore, in two prospective studies, men with LOY at blood sampling had greater risk for incident AD diagnosis during follow-up time (hazard ratio [HR] = 6.80, 95% confidence interval [95% CI] = 2.16-21.43, AD events = 140, p = 0.0011). Thus, LOY in blood is associated with risks of both AD and cancer, suggesting a role of LOY in blood cells on disease processes in other tissues, possibly via defective immunosurveillance. As a male-specific risk factor, LOY might explain why males on average live shorter lives than females.

Concepts: Tobacco smoking, Study design, Medical statistics, Neurodegenerative disorders, Odds ratio, Risk, Cancer, Epidemiology