A median fin derived from the lateral plate mesoderm and the origin of paired fins

The development of paired appendages was a key innovation during evolution and facilitated the aquatic to terrestrial transition of vertebrates. Largely derived from the lateral plate mesoderm (LPM), one hypothesis for the evolution of paired fins invokes derivation from unpaired median fins via a pair of lateral fin folds located between pectoral and pelvic fin territories1. Whilst unpaired and paired fins exhibit similar structural and molecular characteristics, no definitive evidence exists for paired lateral fin folds in larvae or adults of any extant or extinct species. As unpaired fin core components are regarded as exclusively derived from paraxial mesoderm, any transition presumes both co-option of a fin developmental programme to the LPM and bilateral duplication2. Here, we identify that the larval zebrafish unpaired pre-anal fin fold (PAFF) is derived from the LPM and thus may represent a developmental intermediate between median and paired fins. We trace the contribution of LPM to the PAFF in both cyclostomes and gnathostomes, supporting the notion that this is an ancient trait of vertebrates. Finally, we observe that the PAFF can be bifurcated by increasing bone morphogenetic protein signalling, generating LPM-derived paired fin folds. Our work provides evidence that lateral fin folds may have existed as embryonic anlage for elaboration to paired fins

Partitioning the Heritability of Tourette Syndrome and Obsessive Compulsive Disorder Reveals Differences in Genetic Architecture

The direct estimation of heritability from genome-wide common variant data as implemented in the program Genome-wide Complex Trait Analysis (GCTA) has provided a means to quantify heritability attributable to all interrogated variants. We have quantified the variance in liability to disease explained

Gender differences in the healthy worker effect among synthetic vitreous fiber workers

The aim of this study was to determine whether the healthy worker effect and its component parts operate similarly for women and men. A cohort of workers from 14 synthetic vitreous fiber factories in seven countries, employed for at least 1 year between 1933 and 1977 and followed up to the early 1990s, included 375 deaths and 53,608 person-years among females and 2,568 deaths and 210,073 person-years among males. Standardized mortality ratios for all-cause and circulatory diseases were adjusted for country, age, calendar time, and gender. In addition, internal comparisons were adjusted for time since hire and employment status. The analyses addressed the following: 1) the healthy hire effect, 2) the time since hire effect, and 3) the healthy worker survivor effect. In this cohort, an overall healthy worker effect was not present in either gender. The healthy hire effect, based on standardized mortality ratios for years 1-4 since hire, was observed in males (standardized mortality ratio (SMR) = 0.8; 95% confidence interval (CI): 0.7, 1.0) but was less in females (SMR = 0.9; 95% CI: 0.5, 1.6). The relative risks increased slightly with time since hire in males but not in females. Higher mortality ratios were seen among those leaving employment than among those who remained actively employed; however, this effect was substantially greater for women (relative risk (RR) = 3.4; 95% CI: 1.8, 6.3) than men (RR = 1.8; 95% CI: 1.5, 2.1). The gender difference for active versus inactive status was stronger up to age 60 (men: RR = 1.7; 95% CI: 1.4, 2.0; women: RR = 3.6; 95% CI: 1.8, 7.1) than above that age. In conclusion, it appears that there is a stronger selection of healthy men than women into the workforce, while health-related selection out of the workforce is stronger for women than men

Extreme convergence in stick insect evolution: phylogenetic placement of the Lord Howe Island tree lobster

The ‘tree lobsters’ are an enigmatic group of robust, ground-dwelling stick insects (order Phasmatodea) from the subfamily Eurycanthinae, distributed in New Guinea, New Caledonia and associated islands. Its most famous member is the Lord Howe Island stick insect Dryococelus australis (Montrouzier), which was believed to have become extinct but was rediscovered in 2001 and is considered to be one of the rarest insects in the world. To resolve the evolutionary position of Dryococelus, we constructed a phylogeny from approximately 2.4 kb of mitochondrial and nuclear sequence data from representatives of all major phasmatodean lineages. Our data placed Dryococelus and the New Caledonian tree lobsters outside the New Guinean Eurycanthinae as members of an unrelated Australasian stick insect clade, the Lanceocercata. These results suggest a convergent origin of the ‘tree lobster’ body form. Our reanalysis of tree lobster characters provides additional support for our hypothesis of convergent evolution. We conclude that the phenotypic traits leading to the traditional classification are convergent adaptations to ground-living behaviour. Our molecular dating analyses indicate an ancient divergence (more than 22 Myr ago) between Dryococelus and its Australian relatives. Hence, Dryococelus represents a long-standing separate evolutionary lineage within the stick insects and must be regarded as a key taxon to protect with respect to phasmatodean diversity

Data from: Urbanization and anticoagulant poisons promote immune dysfunction in bobcats

Understanding how human activities influence immune response to environmental stressors can support biodiversity conservation across increasingly urbanizing landscapes. We studied a bobcat (Lynx rufus) population in urban southern California that experienced a rapid population decline from 2002–2005 due to notoedric mange. Because anticoagulant rodenticide (AR) exposure was an underlying complication in mange deaths, we aimed to understand sublethal contributions of urbanization and ARs on 65 biochemical markers of immune and organ function. Variance in immunological variables was primarily associated with AR exposure and secondarily with urbanization. Use of urban habitat and AR exposure has pervasive, complex and predictable effects on biochemical markers of immune and organ function in free-ranging bobcats that include impacts on neutrophil, lymphocyte and cytokine populations, total bilirubin and phosphorus. We find evidence of both inflammatory response and immune suppression associated with urban land use and rat poison exposure that could influence susceptibility to opportunistic infections. Consequently, AR exposure may influence mortality and has population-level effects, as previous work in the focal population has revealed substantial mortality caused by mange infection. The secondary effects of anticoagulant exposure may be a worldwide, largely unrecognized problem affecting a variety of vertebrate species in human-dominated environments