59 research outputs found

    Phylogeny, genetic relationships and population structure of five Italian local chicken breeds

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    Number and population size of local chicken breeds in Italy is considered to be critical. Molecular data can be used to provide reliable insight into the diversity of chicken breeds. The first aim of this study was to investigate the maternal genetic origin of five Italian local chicken breeds (Ancona, Livorno, Modenese, Romagnola and Valdarnese bianca) based on mitochondrial DNA (mtDNA) information. Secondly, the extent of the genetic diversity, population structure and the genetic relationships among these chicken populations, by using 27 microsatellite markers, were assessed. To achieve these targets, a 506 bp fragment of the D-loop region was sequenced in 50 chickens of the five breeds. Eighteen variable sites were observed which defined 12 haplotypes. They were assigned to three clades and two maternal lineages. Results indicated that 90% of the haplotypes are related to clade E, which has been described to originate from the Indian subcontinent. For the microsatellite analysis, 137 individual blood samples from the five Italian breeds were included. A total of 147 alleles were detected at 27 microsatellite loci. The five Italian breeds showed a slightly higher degree of inbreeding (FIS=0.08) than the commercial populations that served as reference. Structure analysis showed a separation of the Italian breeds from the reference populations. A further sub-clustering allowed discriminating among the five different Italian breeds. This research provides insight into population structure, relatedness and variability of the five studied breeds

    Mitochondrial diversity of Yoruba and Fulani chickens: A biodiversity reservoir in Nigeria

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    Poultry are the most widely distributed type of livestock in Nigeria. Indigenous chickens are extremely common throughout the country. Indeed, approximately 83 million chickens are raised in extensive systems and 60 million in semi-intensive systems. To provide the first comprehensive overview of the maternal lineages in Southwest Nigeria, we analyzed 96 mitochondrial DNA control region sequences from 2 indigenous chicken ecotypes: Fulani and Yoruba. All samples belonged to the most frequent haplogroup (E) in Africa and Europe and showed noticeably low haplotype diversity. Although only 11 different haplotypes were detected, with 2 of them never found before in Nigeria, the presence of unique sequences among our indigenous samples testified to their status as an important genetic resource to be preserved. Furthermore, a total of 7,868 published sequences were included in the comparative analysis, which revealed an east-west geographic pattern of haplogroup distribution and led to the conclusion that the gene flow from Southeastern Asia mainly involved one mitochondrial clade. Moreover, owing to the extensive genetic intermixing among Nigerian chickens, conservation efforts are required to safeguard the extant mitochondrial variability in these indigenous ecotypes and establish future improvement and selection programs

    A comprehensive analysis of the genetic diversity and environmental adaptability in worldwide Merino and Merino-derived sheep breeds

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    BACKGROUND: To enhance and extend the knowledge about the global historical and phylogenetic relationships between Merino and Merino-derived breeds, 19 populations were genotyped with the OvineSNP50 BeadChip specifically for this study, while an additional 23 populations from the publicly available genotypes were retrieved. Three complementary statistical tests, Rsb (extended haplotype homozygosity between-populations), XP-EHH (cross-population extended haplotype homozygosity), and runs of homozygosity (ROH) islands were applied to identify genomic variants with potential impact on the adaptability of Merino genetic type in two contrasting climate zones. RESULTS: The results indicate that a large part of the Merino's genetic relatedness and admixture patterns are explained by their genetic background and/or geographic origin, followed by local admixture. Multi-dimensional scaling, Neighbor-Net, Admixture, and TREEMIX analyses consistently provided evidence of the role of Australian, Rambouillet and German strains in the extensive gene introgression into the other Merino and Merino-derived breeds. The close relationship between Iberian Merinos and other South-western European breeds is consistent with the Iberian origin of the Merino genetic type, with traces from previous contributions of other Mediterranean stocks. Using Rsb and XP-EHH approaches, signatures of selection were detected spanning four genomic regions located on Ovis aries chromosomes (OAR) 1, 6 and 16, whereas two genomic regions on OAR6, that partially overlapped with the previous ones, were highlighted by ROH islands. Overall, the three approaches identified 106 candidate genes putatively under selection. Among them, genes related to immune response were identified via the gene interaction network. In addition, several candidate genes were found, such as LEKR1, LCORL, GHR, RBPJ, BMPR1B, PPARGC1A, and PRKAA1, related to morphological, growth and reproductive traits, adaptive thermogenesis, and hypoxia responses. CONCLUSIONS: To the best of our knowledge, this is the first comprehensive dataset that includes most of the Merino and Merino-derived sheep breeds raised in different regions of the world. The results provide an in-depth picture of the genetic makeup of the current Merino and Merino-derived breeds, highlighting the possible selection pressures associated with the combined effect of anthropic and environmental factors. The study underlines the importance of Merino genetic types as invaluable resources of possible adaptive diversity in the context of the occurring climate changes

    Permanent Campaigning: A Meta-Analysis and Framework for Measurement

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    Permanent campaigning emerged as a concept in the 1970s in studies of US politics but is now recognized as a universal phenomenon. Despite its long history, there has been no attempt to build a holistic picture of the elements that constitute a permanent campaign. Generally, researchers focus on tactical elements, situating their use within an overall strategy, but there is a lack of a broader methodological framework for holistically measuring adherence to the permanent campaigning. This article presents results of a meta-analysis of relevant research to provide a framework to understand how permanent campaigning is practiced. Our study showed there were three reasonably discrete forms of campaigning activities that had been identified: those in which permanent campaign strategies are related to capacity building and strategy; a second, in which permanent campaigning relates to paid and owned media; and a third in which earned media is the main focus. In mapping these studies, we identify the common features of permanent campaigning, identifying strong and weak indicators and the extent these are employed by the government, parties, or elected representatives and within which political systems: parliamentarism or presidentialism. Our framework can be applied in future comparative research to understand trends in political communication

    ICT capital and labour productivity growth: A non-parametric analysis of 14 OECD countries

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    This paperusesanewsetofcountrydatafor14countries,membersoftheOECD,anda non-parametricapproachtoprovidenewevidenceontheimpactofInformationand CommunicationTechnology(ICT)onlabourproductivitygrowthbetween1995and 2005. Forthefirsttime,inthepresentpaperabootstrapapproachforthedecomposi- tion oflabourproductivitychange,proposedby Kumar andRussell(2002), isemployed. This approachpermitstoconductstatisticalinferenceontheparametersofinterest,and to analysetheeffectsofICTtechnologiesoncapitalaccumulation.Theresultsconfirm theroleofICTasageneralpurposetechnologythatneedsorganisationalandbusiness processchangestofullyexploititsgrowthopportunities.Thepaperalsofindsout,by applyinganon-parametrictest,thatICTtechnologiespositivelycontributetothe generationofconvergenceclubsintheevolutionoflabourproductivity.Finally,the empiricalevidenceofferssomebasicguidanceforfuturepolicyinterventionin supportingICTcapitalinvestments
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