Genetic analysis of a glomerulonephropathy segregating in a pedigree of French Mastiff.

in Proceedings of 32nd Annual Conference of the International Society of Animal Genetics (2010)

Evaluation biologique du stress oxydant : application en routine clinique.

in Nutritions & Endocrinologie (2009), HS Stress Oxydant

Patrocles: a database of polymorphic miR-mediated gene regulation in vertebrates

Scientific conference (2009, September 29)

Balancing selection of a frame-shift mutation in the MRC2 gene accounts for the outbreak of the Crooked Tail Syndrome in Belgian Blue Cattle.

in PLoS Genetics (2009), 5(9), 1000666

We herein describe the positional identification of a 2-bp deletion in the open reading frame of the MRC2 receptor causing the recessive Crooked Tail Syndrome in cattle. The resulting frame-shift reveals ... [more ▼]

We herein describe the positional identification of a 2-bp deletion in the open reading frame of the MRC2 receptor causing the recessive Crooked Tail Syndrome in cattle. The resulting frame-shift reveals a premature stop codon that causes nonsense-mediated decay of the mutant messenger RNA, and the virtual absence of functional Endo180 protein in affected animals. Cases exhibit skeletal anomalies thought to result from impaired extracellular matrix remodeling during ossification, and as of yet unexplained muscular symptoms. We demonstrate that carrier status is very significantly associated with desired characteristics in the general population, including enhanced muscular development, and that the resulting heterozygote advantage caused a selective sweep which explains the unexpectedly high frequency (25%) of carriers in the Belgian Blue Cattle Breed. [less ▲]

Patrocles: a database of polymorphic miRNA-mediated gene regulation

Poster (2008, July)

Highly effective SNP-based association mapping and management of recessive defects in livestock.

in Nature Genetics (2008), 40(4), 449-54

The widespread use of elite sires by means of artificial insemination in livestock breeding leads to the frequent emergence of recessive genetic defects, which cause significant economic and animal ... [more ▼]

The widespread use of elite sires by means of artificial insemination in livestock breeding leads to the frequent emergence of recessive genetic defects, which cause significant economic and animal welfare concerns. Here we show that the availability of genome-wide, high-density SNP panels, combined with the typical structure of livestock populations, markedly accelerates the positional identification of genes and mutations that cause inherited defects. We report the fine-scale mapping of five recessive disorders in cattle and the molecular basis for three of these: congenital muscular dystony (CMD) types 1 and 2 in Belgian Blue cattle and ichthyosis fetalis in Italian Chianina cattle. Identification of these causative mutations has an immediate translation into breeding practice, allowing marker assisted selection against the defects through avoidance of at-risk matings. [less ▲]

Compiling polymorphic miRNA-target interactions: the Patrocles database.

Poster (2007, November 12)

Using positional cloning, we have recently identified the mutation responsible for muscular phenotype of the Texel sheep. It is located in the 3’UTR of the GDF8 gene - a known developmental repressor of ... [more ▼]

Using positional cloning, we have recently identified the mutation responsible for muscular phenotype of the Texel sheep. It is located in the 3’UTR of the GDF8 gene - a known developmental repressor of muscle growth - and creates an illegitimate target site for miRNA expressed in the same tissue. This causes miRNA-mediated translation inhibition of mutant GDF8 transcripts which leads to muscle hypertrophy. We followed up on this finding by searching for common polymorphisms and mutations that affect either (i) RNAi silencing machinery components, (ii) miRNA precursors or (iii) target sites. These might likewise alter miRNA-target interaction and could be responsible for substantial differences in gene expression level. They have been compiled in a public database (“Patrocles”: www.patrocles.org), where they are classified in (i) DNA sequence polymorphisms (DSP) affecting the silencing machinery, (ii) DSP affecting miRNA structure or expression and (iii) DSP affecting miRNA target sites. DSP from the last category were organized in four classes: destroying a target site conserved between mammals (DC), destroying a non-conserved target site (DNC), creating a non-conserved target site (CNC), or shifting a target site (S). To aid in the identification of the most relevant DSP (such as those were a target site is created in an antitarget gene), we have quantified the level of coexpression for all miRNA-gene pairs. Analysis of the numbers of Patrocles-DSP as well as their allelic frequency distribution indicates that a substantial proportion of them undergo purifying selection. The signature of selection was most pronounced for the DC class but was significant for the DNC and CNC class as well, suggesting that a significant proportion of non-conserved targets is truly functional. The Patrocles database allowed for the selection of DSP that are likely to affect gene function and possibly disease susceptibility. The effect of these DSP is being studied both in vitro and in vivo. In conclusion, Patrocles-DSP could be widespread and underlie an appreciable amount of phenotypic variation, including common disease susceptibility. [less ▲]

Polymorphic miRNA-mediated gene regulation: contribution to phenotypic variation and disease.

in Current opinion in genetics & development (2007), 17(3), 166-76

The expression of at least a third of mammalian genes is post-transcriptionally fine-tuned by approximately 1000 microRNAs (miRNAs), assisted by the RNA silencing machinery, comprising tens of components ... [more ▼]

The expression of at least a third of mammalian genes is post-transcriptionally fine-tuned by approximately 1000 microRNAs (miRNAs), assisted by the RNA silencing machinery, comprising tens of components. Polymorphisms and mutations in the corresponding sequence space (machinery, miRNA precursors and target sites) are likely to make a significant contribution to phenotypic variation, including disease susceptibility. Here we review basic miRNA biology in animals, survey the available evidence for DNA sequence polymorphisms affecting miRNA-mediated gene regulation and thus phenotype, and discuss their possible importance in the determination of complex traits. [less ▲]

Polymorphic miRNA-target interactions : A Novel Source of Phenotypic Variation

in Cold Spring Harbor Symposia on Quantitative Biology (2006, June), 71

Studying the muscular hypertrophy of Texel sheep by forward genetics, we have identified an A-to-G transition in the 3'UTRof the GDF8 gene that reveals an illegitimate target site for microRNAs miR-1 and ... [more ▼]

Studying the muscular hypertrophy of Texel sheep by forward genetics, we have identified an A-to-G transition in the 3'UTRof the GDF8 gene that reveals an illegitimate target site for microRNAs miR-1 and miR-206 that are highly expressed in skeletal muscle. This causes the down-regulation of this muscle-specific chalone and hence contributes to the muscular hypertrophyof Texel sheep. We demonstrate that polymorphisms which alter the content of putative miRNA target sites are commonin human and mice, and provide evidence that both conserved and nonconserved target sites are selectively constrained. Wespeculate that these polymorphisms might be important mediators of phenotypic variation including disease. To facilitatestudies along those lines, we have constructed a database (www.patrocles.org) listing putative polymorphic microRNA–targetinteractions. [less ▲]

A mutation creating a potential illegitimate microRNA target site in the myostatin gene affects muscularity in sheep.

in Nature Genetics (2006), 38(7), 813-8

Texel sheep are renowned for their exceptional meatiness. To identify the genes underlying this economically important feature, we performed a whole-genome scan in a Romanov x Texel F2 population. We ... [more ▼]

Texel sheep are renowned for their exceptional meatiness. To identify the genes underlying this economically important feature, we performed a whole-genome scan in a Romanov x Texel F2 population. We mapped a quantitative trait locus with a major effect on muscle mass to chromosome 2 and subsequently fine-mapped it to a chromosome interval encompassing the myostatin (GDF8) gene. We herein demonstrate that the GDF8 allele of Texel sheep is characterized by a G to A transition in the 3' UTR that creates a target site for mir1 and mir206, microRNAs (miRNAs) that are highly expressed in skeletal muscle. This causes translational inhibition of the myostatin gene and hence contributes to the muscular hypertrophy of Texel sheep. Analysis of SNP databases for humans and mice demonstrates that mutations creating or destroying putative miRNA target sites are abundant and might be important effectors of phenotypic variation. [less ▲]