391 research outputs found

    Radiographic assessment of the skeletons of Dolly and other clones finds no abnormal osteoarthritis

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    Our recent report detailing the health status of cloned sheep concluded that the animals had aged normally. This is in stark contrast to reports on Dolly (first animal cloned from adult cells) whose diagnoses of osteoarthritis (OA) at 5½ years of age led to considerable scientific concern and media debate over the possibility of early-onset age-related diseases in cloned animals. Our study included four 8-year old ewes derived from the cell line that gave rise to Dolly, yet none of our aged sheep showed clinical signs of OA, and they had radiographic evidence of only mild or, in one case, moderate OA. Given that the only formal record of OA in Dolly is a brief mention of a single joint in a conference abstract, this led us to question whether the original concerns about Dolly’s OA were justified. As none of the original clinical or radiographic records were preserved, we undertook radiographic examination of the skeletons of Dolly and her contemporary clones. We report a prevalence and distribution of radiographic-OA similar to that observed in naturally conceived sheep, and our healthy aged cloned sheep. We conclude that the original concerns that cloning had caused early-onset OA in Dolly were unfounded

    The influence of textile materials on flame resistance ratings of professional uniforms

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    This study compares the flame speed of different textile materials employed in professional uniforms. Five different garments of aeronauts’ uniforms were analyzed (totaling 200 specimens submitted to flammability tests). Plain weaves and twill weaves composed by 100% CO; 100% PES; 67% PES/33% CO; 50% PES/50% WO; and 55% PES/45%WO were analyzed in the warp and filling directions. The flame speed of each material was determined, and differences in the flame propagation of the fabrics were identified. The lowest flame speed occurred for the material 50% PES/50% WO plain weave and weft direction (0.742 ± 0.140 m/s). The highest flame speed was 3.698 ± 1.806 cm/s for the material 67%PES/33%CO, plain weave and filling direction. Future experiments for reducing the fabric flammability of the uniforms could be related to more closed fabric constructions; mixtures with synthetic fibers to add functionality; changing the direction of the fabric; and changing the weight and torsion of its constituent yarns.São Paulo Research Foundation—FAPESP (“Fundação de Amparo à Pesquisa do Estado de São Paulo”) Grant Number 2016/01331-

    How consistent are the transcriptome changes associated with cold acclimation in two species of the Drosophila virilis group?

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    This work was financially support by a Marie Curie Initial Training Network grant, “Understanding the evolutionary origin of biological diversity” (ITN-2008–213780 SPECIATION), grants from the Academy of Finland to A.H. (project 132619) and M.K. (projects 268214 and 272927), a grant from NERC, UK to M.G.R. (grant NE/J020818/1), and NERC, UK PhD studentship to D.J.P. (NE/I528634/1).For many organisms the ability to cold acclimate with the onset of seasonal cold has major implications for their fitness. In insects, where this ability is widespread, the physiological changes associated with increased cold tolerance have been well studied. Despite this, little work has been done to trace changes in gene expression during cold acclimation that lead to an increase in cold tolerance. We used an RNA-Seq approach to investigate this in two species of the Drosophila virilis group. We found that the majority of genes that are differentially expressed during cold acclimation differ between the two species. Despite this, the biological processes associated with the differentially expressed genes were broadly similar in the two species. These included: metabolism, cell membrane composition, and circadian rhythms, which are largely consistent with previous work on cold acclimation/cold tolerance. In addition, we also found evidence of the involvement of the rhodopsin pathway in cold acclimation, a pathway that has been recently linked to thermotaxis. Interestingly, we found no evidence of differential expression of stress genes implying that long-term cold acclimation and short-term stress response may have a different physiological basis.PostprintPeer reviewe

    High genetic diversity at the extreme range edge: nucleotide variation at nuclear loci in Scots pine (Pinus sylvestris L.) in Scotland

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    Nucleotide polymorphism at 12 nuclear loci was studied in Scots pine populations across an environmental gradient in Scotland, to evaluate the impacts of demographic history and selection on genetic diversity. At eight loci, diversity patterns were compared between Scottish and continental European populations. At these loci, a similar level of diversity (θsil=~0.01) was found in Scottish vs mainland European populations, contrary to expectations for recent colonization, however, less rapid decay of linkage disequilibrium was observed in the former (ρ=0.0086±0.0009, ρ=0.0245±0.0022, respectively). Scottish populations also showed a deficit of rare nucleotide variants (multi-locus Tajima's D=0.316 vs D=−0.379) and differed significantly from mainland populations in allelic frequency and/or haplotype structure at several loci. Within Scotland, western populations showed slightly reduced nucleotide diversity (πtot=0.0068) compared with those from the south and east (0.0079 and 0.0083, respectively) and about three times higher recombination to diversity ratio (ρ/θ=0.71 vs 0.15 and 0.18, respectively). By comparison with results from coalescent simulations, the observed allelic frequency spectrum in the western populations was compatible with a relatively recent bottleneck (0.00175 × 4Ne generations) that reduced the population to about 2% of the present size. However, heterogeneity in the allelic frequency distribution among geographical regions in Scotland suggests that subsequent admixture of populations with different demographic histories may also have played a role

    Serum organochlorines and urinary porphyrin pattern in a population highly exposed to hexachlorobenzene

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    BACKGROUND: Porphyria cutanea tarda (PCT) is caused by hexachlorobenzene (HCB) in several species of laboratory mammals, but the human evidence is contradictory. In a study among adults of a population highly exposed to HCB (Flix, Catalonia, Spain), the prevalence of PCT was not increased. We aimed at analysing the association of individual urinary porphyrins with the serum concentrations of HCB and other organochlorine compounds in this highly exposed population. METHODS: A cross-sectional study on total porphyrins was carried out in 1994 on 604 inhabitants of the general population of Flix, older than 14 years. Of them, 241 subjects (comprising a random sample and the subgroup with the highest exposure) were included for the present study. The porphyrin profile was determined by high-pressure liquid chromatography. Serum concentrations of HCB, as well as common organochlorine compounds, were determined by gas chromatography coupled to electron capture detection. RESULTS: Coproporphyrin I (CPI) and coproporphyrin III (CPIII) were the major porphyrins excreted, while uroporphyrins I and III were only detected in 2% and 36% of the subjects respectively, and heptaporphyrins I and III in 1% and 6%, respectively. CPI and CPIII decreased with increasing HCB concentrations (p < 0.05). This negative association was not explained by age, alcohol, smoking, or other organochlorine compounds. No association was found between uroporphyrin I and III excretion, nor heptaporphyrin excretion, and HCB. CPIII increased with smoking (p < 0.05). CONCLUSION: HCB exposure in this highly exposed population did not increase urinary concentrations of individual porphyrins

    A revised evolutionary history of the CYP1A subfamily : gene duplication, gene conversion, and positive selection

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    Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Journal of Molecular Evolution 62 (2006): 708-717, doi:10.1007/s00239-005-0134-z.Members of cytochrome P450 subfamily 1A (CYP1As) are involved in detoxification and bioactivation of common environmental pollutants. Understanding the functional evolution of these genes is essential to predicting and interpreting species differences in sensitivity to toxicity by such chemicals. The CYP1A gene subfamily comprises a single ancestral representative in most fish species and two paralogs in higher vertebrates, including birds and mammals. Phylogenetic analysis of complete coding sequences suggests that mammalian and bird paralog pairs (CYP1A1/2 and CYP1A4/5, respectively) are the result of independent gene duplication events. However, comparison of vertebrate genome sequences revealed that CYP1A genes lie within an extended region of conserved fine-scale synteny, suggesting that avian and mammalian CYP1A paralogs share a common genomic history. Algorithms designed to detect recombination between nucleotide sequences indicate that gene conversion has homogenized most of the length of the chicken CYP1A genes, as well as the 5’ end of mammalian CYP1As. Together, these data indicate that avian and mammalian CYP1A paralog pairs resulted from a single gene duplication event and that extensive gene conversion is responsible for the exceptionally high degree of sequence similarity between CYP1A4 and CYP1A5. Elevated non-synonymous/synonymous substitution ratios within a putatively unconverted stretch of ~250 bp suggests that positive selection may have reduced the effective rate of gene conversion in this region, which contains two substrate recognition sites. This work significantly alters our understanding of functional evolution in the CYP1A subfamily, suggesting that gene conversion and positive selection have been the dominant processes of sequence evolution.Funding for this work was provided by the NIH Superfund Basic Research Program at Boston University (5-P42-ES-07381) and by the Woods Hole Oceanographic Institution

    Healthy ageing of cloned sheep

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    The health of cloned animals generated by somatic-cell nuclear transfer (SCNT) has been of concern since its inception; however, there are no detailed assessments of late-onset, non-communicable diseases. Here we report that SCNT has no obvious detrimental longterm health effects in a cohort of 13 cloned sheep. We perform musculoskeletal assessments, metabolic tests and blood pressure measurements in 13 aged (7–9 years old) cloned sheep, including four derived from the cell line that gave rise to Dolly. We also perform radiological examinations of all main joints, including the knees, the joint most affected by osteoarthritis in Dolly, and compare all health parameters to groups of 5- and 6-year-old sheep, and published reference ranges. Despite their advanced age, these clones are euglycaemic, insulin sensitive and normotensive. Importantly, we observe no clinical signs of degenerative joint disease apart from mild, or in one case moderate, osteoarthritis in some animals. Our study is the first to assess the long-term health outcomes of SCNT in large animals
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