Reference : PhD Jocelyn Laporte
Congenital myopathies are severe genetic diseases that are characterized by muscle weakness at birth and the prevalence of specific histological abnormalities on muscle biopsy. These rare diseases are models to study the changes that occur with age, such as sarcopenia and the accumulation of skeletal muscle dysfunction. Several genes are already involved in myopathies; nevertheless, almost half of the patients have no known genetic defects, precluding genetic counseling and a better patient care. There is no specific therapy for these myopathies.
The PhD project aims to identify new myopathy genes by sequencing DNA and RNA from patients, to validate the impact of mutations on the function of the encoded proteins in cellular and potentially animal models, and to decipher the underlying disease mechanisms. The project is multidisciplinary and proposes to:
1- Identify mutations and new genes by DNA (exome, genome) and RNA sequencing of patients and relatives. Preliminary data on 1250 exomes are available and preliminary bioinformatic analyses suggest the presence of several new genes for myopathies.
2-Validate the impact of mutations on the function of the new involved genes on cells derived from patients or transfected with cDNA carrying the mutations identified, and on patient samples muscles by qPCR, western blotting, confocal imaging and immunolabeling.
3-Investigate the importance of these new genes in the muscle function and myopathies, and the pathological mechanisms leading to these diseases. Two animal models developed in the laboratory can be used: the zebrafish and mouse. We will express either mutated cDNA to study the dominant mutations or shRNA to reduce the expression of the genes identified in recessive forms. The impact of genes and mutations will be analyzed by measuring the movement and strength of animals, in vivo imaging, histological and molecular studies. This will help to understand the pathological mechanisms involved.
The success of this project will improve genetic counseling and support for patients, expand our understanding of muscle under normal and pathological conditions and identify new therapeutic targets for myopathies.
Date limite de candidature : 1 novembre 2018