123 research outputs found

    Trematominae and Artedidraconinae: contrasted mitogenome evolution for two Antarctic radiations

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    Cellular respiration has been widely studied in Antarctic teleost fishes because of their peculiar adaptations to an extreme environment. In parallel mitochondrial sequence markers have become highly popular for molecular systematics. However, there are few whole mitochondrial genome sequences published, and none available for some of the subfamilies. Here, we present two large mitogenome datasets including most species and multiple sequences for many species of two subfamilies, Trematominae and Artedidraconinae (Duhamel et al. 2014). These include two highly diverse but very different adaptative radiations, with contrasting divergence dates, morphological polymorphism, and habitat dominance. The sampling is based on a well identified, extensive collection resulting from the 2008 CEAMARC survey and the subsequent REVOLTA surveys in Terre Adélie (IPEV), already DNA barcoded and sequenced in previous studies. The mitogenome sequences for these two subfamilies differ in composition, gene order, and relative divergence of mitochondrial markers, with strong, taxon-specific biases like very high C contents in some regions. The gene order change provides a synapomorphy for the subfamily Trematominae and an interesting development in teleost mitogenomes. The complete Artedidraconinae mitogenomes provide a much higher amount of variable sites (approx*30), while previous sequence datasets were plagued by low informativeness (Lecointre et al. 2011). As already established on single mitochondrial genes, intraspecific variability is lower than interspecific variability within each subfamily, however interspecific variability in Artedidraconinae is lower or similar to intraspecific variability in Trematominae. This expanded dataset confirms the unusual evolution of the mitochondrial coded sequences involved in the cellular respiration in Antarctic Nototheniidae, as well as the usefulness of complete mitochondrial genomes for their systematics. The two level multiplexing (Timmermans et al. 2010) and next generation sequencing of long PCR amplicons (following Hinsinger et al. 2015) is efficient to obtain large mitogenomic datasets representative of both inter- and intraspecific variability, key to the understanding of mitochondrial evolution and a step closer to resolving the relationships among these taxa.RECTO (Refugia and Ecosystem Tolerance in the Southern Ocean, BR/154/A1/RECTO

    The interest of gait markers in the identification of subgroups among fibromyalgia patients

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    <p>Abstract</p> <p>Background</p> <p>Fibromyalgia (FM) is a heterogeneous syndrome and its classification into subgroups calls for broad-based discussion. FM subgrouping, which aims to adapt treatment according to different subgroups, relies in part, on psychological and cognitive dysfunctions. Since motor control of gait is closely related to cognitive function, we hypothesized that gait markers could be of interest in the identification of FM patients' subgroups. This controlled study aimed at characterizing gait disorders in FM, and subgrouping FM patients according to gait markers such as stride frequency (SF), stride regularity (SR), and cranio-caudal power (CCP) which measures kinesia.</p> <p>Methods</p> <p>A multicentre, observational open trial enrolled patients with primary FM (44.1 ± 8.1 y), and matched controls (44.1 ± 7.3 y). Outcome measurements and gait analyses were available for 52 pairs. A 3-step statistical analysis was carried out. A preliminary single blind analysis using k-means cluster was performed as an initial validation of gait markers. Then in order to quantify FM patients according to psychometric and gait variables an open descriptive analysis comparing patients and controls were made, and correlations between gait variables and main outcomes were calculated. Finally using cluster analysis, we described subgroups for each gait variable and looked for significant differences in self-reported assessments.</p> <p>Results</p> <p>SF was the most discriminating gait variable (73% of patients and controls). SF, SR, and CCP were different between patients and controls. There was a non-significant association between SF, FIQ and physical components from Short-Form 36 (p = 0.06). SR was correlated to FIQ (p = 0.01) and catastrophizing (p = 0.05) while CCP was correlated to pain (p = 0.01). The SF cluster identified 3 subgroups with a particular one characterized by normal SF, low pain, high activity and hyperkinesia. The SR cluster identified 2 distinct subgroups: the one with a reduced SR was distinguished by high FIQ, poor coping and altered affective status.</p> <p>Conclusion</p> <p>Gait analysis may provide additional information in the identification of subgroups among fibromyalgia patients. Gait analysis provided relevant information about physical and cognitive status, and pain behavior. Further studies are needed to better understand gait analysis implications in FM.</p

    LIPH Expression in Skin and Hair Follicles of Normal Coat and Rex Rabbits

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    Natural mutations in the LIPH gene were shown to be responsible for hair growth defects in humans and for the rex short hair phenotype in rabbits. In this species, we identified a single nucleotide deletion in LIPH (1362delA) introducing a stop codon in the C-terminal region of the protein. We investigated the expression of LIPH between normal coat and rex rabbits during critical fetal stages of hair follicle genesis, in adults and during hair follicle cycles. Transcripts were three times less expressed in both fetal and adult stages of the rex rabbits than in normal rabbits. In addition, the hair growth cycle phases affected the regulation of the transcription level in the normal and mutant phenotypes differently. LIPH mRNA and protein levels were higher in the outer root sheath (ORS) than in the inner root sheath (IRS), with a very weak signal in the IRS of rex rabbits. In vitro transfection shows that the mutant protein has a reduced lipase activity compared to the wild type form. Our results contribute to the characterization of the LIPH mode of action and confirm the crucial role of LIPH in hair production

    A Deletion in Exon 9 of the LIPH Gene Is Responsible for the Rex Hair Coat Phenotype in Rabbits (Oryctolagus cuniculus)

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    The fur of common rabbits is constituted of 3 types of hair differing in length and diameter while that of rex animals is essentially made up of amazingly soft down-hair. Rex short hair coat phenotypes in rabbits were shown to be controlled by three distinct loci. We focused on the “r1” mutation which segregates at a simple autosomal-recessive locus in our rabbit strains. A positional candidate gene approach was used to identify the rex gene and the corresponding mutation. The gene was primo-localized within a 40 cM region on rabbit chromosome 14 by genome scanning families of 187 rabbits in an experimental mating scheme. Then, fine mapping refined the region to 0.5 cM (Z = 78) by genotyping an additional 359 offspring for 94 microsatellites present or newly generated within the first defined interval. Comparative mapping pointed out a candidate gene in this 700 kb region, namely LIPH (Lipase Member H). In humans, several mutations in this major gene cause alopecia, hair loss phenotypes. The rabbit gene structure was established and a deletion of a single nucleotide was found in LIPH exon 9 of rex rabbits (1362delA). This mutation results in a frameshift and introduces a premature stop codon potentially shortening the protein by 19 amino acids. The association between this deletion and the rex phenotype was complete, as determined by its presence in our rabbit families and among a panel of 60 rex and its absence in all 60 non-rex rabbits. This strongly suggests that this deletion, in a homozygous state, is responsible for the rex phenotype in rabbits
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