Genome-wide SNP scan of pooled DNA reveals nonsense mutation in FGF20 in the Scaleless line of featherless chickens

<p>Abstract</p> <p>Background</p> <p>Scaleless (<it>sc/sc</it>) chickens carry a single recessive mutation that causes a lack of almost all body feathers, as well as foot scales and spurs, due to a failure of skin patterning during embryogenesis. This spontaneous mutant line, first described in the 1950s, has been used extensively to explore the tissue interactions involved in ectodermal appendage formation in embryonic skin. Moreover, the trait is potentially useful in tropical agriculture due to the ability of featherless chickens to tolerate heat, which is at present a major constraint to efficient poultry meat production in hot climates. In the interests of enhancing our understanding of feather placode development, and to provide the poultry industry with a strategy to breed heat-tolerant meat-type chickens (broilers), we mapped and identified the <it>sc</it> mutation.</p> <p>Results</p> <p>Through a cost-effective and labour-efficient SNP array mapping approach using DNA from <it>sc/sc</it> and <it>sc/+</it> blood sample pools, we map the <it>sc</it> trait to chromosome 4 and show that a nonsense mutation in <it>FGF20</it> is completely associated with the <it>sc/sc</it> phenotype. This mutation, common to all <it>sc/sc</it> individuals and absent from wild type, is predicted to lead to loss of a highly conserved region of the FGF20 protein important for FGF signalling. <it>In situ</it> hybridisation and quantitative RT-PCR studies reveal that <it>FGF20</it> is epidermally expressed during the early stages of feather placode patterning. In addition, we describe a dCAPS genotyping assay based on the mutation, developed to facilitate discrimination between wild type and <it>sc</it> alleles.</p> <p>Conclusions</p> <p>This work represents the first loss of function genetic evidence supporting a role for FGF ligand signalling in feather development, and suggests FGF20 as a novel central player in the development of vertebrate skin appendages, including hair follicles and exocrine glands. In addition, this is to our knowledge the first report describing the use of the chicken SNP array to map genes based on genotyping of DNA samples from pooled whole blood. The identification of the <it>sc</it> mutation has important implications for the future breeding of this potentially useful trait for the poultry industry, and our genotyping assay can facilitate its rapid introgression into production lines.</p

Safety improvements by eliminating hazardous combinations

In this paper we suggest the hazardous combinations method to facilitate safety improvements in technical and technological systems by eliminating combinations of major risk factors. The method is capable to significantly improve the safety level in systems as compared to a common situation when only the root causes of accidents were analysed (usually with unsatisfactory results), or where the usual procedures proved to be ineffective due to organisational, technological or financial constraints. In many cases the management decides to implement costly safety measures which have eventually only a minor effect, if at all, on preventing severe accidents. By focusing on prevention of not all recognised primary risk factors but only their hazardous combinations, both human lives and significant financial resources may be saved. Santrauka Straipsnyje siūlomas pavojingųjų derinių metodas, kuris padeda pagerinti techninių ir technologinių sistemų saugą, šalinant didžiausios rizikos veiksnių derinius. Jis gali būti taikomas, kai visuotinai paplitusi priežasčių analizė neduoda teigiamų rezultatų arba kai įprastines procedūros nėra efektyvios dėl organizacinių, technologinių arba finansinių apribojimų. Daugeliu atvejų diegiamos brangios saugos priemones, kurios duoda nedideli efekta, galbūt užkardo stambias avarijas. Sutelkiant demesi ne i visus imanomus rizikos veiksnius, bet tik į jų pavojinguosius derinius, gali būti išgelbėtos ir žmonių gyvybės, ir sutaupyta lėšų. First Published Online: 21 Oct 2010 Reikšminiai žodžiai: saugos gerinimas, rizikos veiksniai, avarijos, priežastys, pavojingieji derinia

Measuring and ranking of economic, environmental and social efficiency of countries

Purpose – The purpose of this paper is to measure and rank nation-states' governance effectiveness and quality on a quantifying scientific basis, by means of data envelopment analysis. Design/methodology/approach – The principles are first analyzed from a theoretical and normative standpoint, linking to earlier literature. One dimension of the approach is adding the equality in income distribution as an output. Another dimension boils down to environmental performance. Findings – The addition of the Gini index affects the ranking of the developing countries in a more significant manner. Similar results are obtained when the authors add the environmental performance as an input. Another interesting result suggests that conventional ranking methods (i.e gross domestic product per capita or human development index) could be used for representing the country's efficiency only for developed countries. Research limitations/implications – Future research may be aimed at applying the developed methodology to more countries, both developed and developing, as well as considering inclusion of additional ranking parameters. Practical implications – The obtained procedure may be regarded as a comprehensive, holistic, mostly objective, and quantifiable method of ranking countries according to their governmental performance accomplishments. The addition of the Gini index and the environmental performance influences the ranking and is a significant improvement as compared to contemporary procedures. Originality/value – The innovation in this paper is that the authors suggest to measure efficiency of countries not only by their income, but also, looking on wider aspects of efficiency as equity and environmental performance.Countries, Governance, Gross domestic product

Autosomal-Recessive Hypophosphatemic Rickets Is Associated with an Inactivation Mutation in the ENPP1 Gene

Human disorders of phosphate (Pi) handling and hypophosphatemic rickets have been shown to result from mutations in PHEX, FGF23, and DMP1, presenting as X-linked recessive, autosomal-dominant, and autosomal-recessive patterns, respectively. We present the identification of an inactivating mutation in the ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) gene causing autosomal-recessive hypophosphatemic rickets (ARHR) with phosphaturia by positional cloning. ENPP1 generates inorganic pyrophosphate (PPi), an essential physiologic inhibitor of calcification, and previously described inactivating mutations in this gene were shown to cause aberrant ectopic calcification disorders, whereas no aberrant calcifications were present in our patients. Our surprising result suggests a different pathway involved in the generation of ARHR and possible additional functions for ENPP1