Investigation of Gene Expression in the Kidney of an MYH9-Related Disease Zebrafish Model
Mentor 1
Jennifer Gutzman
Start Date
29-4-2022 11:00 AM
Description
MYH9-Related Disease encompasses five different diseases: May-Hegglin anomaly, Sebastian, Fetchner, and Epstein syndromes; and non-syndromic deafness DFNA17. These diseases present with a variety of conditions including thrombocytopenia, leukocyte inclusions, renal disease, cataracts, and hearing loss. Each disorder is due to mutations in the MYH9 gene, which codes for non-muscle myosin IIA (NMIIA). NMIIA is an intracellular motor protein important for cell division, cell migration, and cell shape changes during embryogenesis. Although we know mutations in MYH9 cause these diseases, we do not know the mechanisms underlying the development of disease. Using CRISPR we generated a zebrafish myh9b mutant, myh9b is the zebrafish MYH9 homolog. Studying these mutants has enabled us to examine early developmental defects due to the loss of NMIIA protein. Using these mutants, we discovered an embryonic phenotype consistent with kidney failure that appears between 48 and 72 hours post fertilization (hpf). However, this phenotype quickly reverses between 96 hpf and 5 days post fertilization. As a first step towards understanding the role of myh9b in kidney development, we examined gene expression patterning in the developing pronephros. We hypothesized, based on the reversal, that the expression patterns for the genes cdh17 and wt1b would be normal in our myh9b mutants. cdh17 encodes for cadherin 17 and is expressed in the pronephric ducts and duct progenitors. wt1b encodes for a zinc-finger transcription factor and is expressed in the pronephric glomeruli. Using in situ hybridization, we found that there were no obvious differences in gene expression between wild-type and the myh9b mutant zebrafish at the time points investigated. These data suggest that kidney pattering is not compromised in myh9b mutants leading to the hypothesis that the kidney defect is due to abnormal glomerular filtration. Future experiments will examine glomerular filtration rate and ultra-structure of the glomeruli during development.
Investigation of Gene Expression in the Kidney of an MYH9-Related Disease Zebrafish Model
MYH9-Related Disease encompasses five different diseases: May-Hegglin anomaly, Sebastian, Fetchner, and Epstein syndromes; and non-syndromic deafness DFNA17. These diseases present with a variety of conditions including thrombocytopenia, leukocyte inclusions, renal disease, cataracts, and hearing loss. Each disorder is due to mutations in the MYH9 gene, which codes for non-muscle myosin IIA (NMIIA). NMIIA is an intracellular motor protein important for cell division, cell migration, and cell shape changes during embryogenesis. Although we know mutations in MYH9 cause these diseases, we do not know the mechanisms underlying the development of disease. Using CRISPR we generated a zebrafish myh9b mutant, myh9b is the zebrafish MYH9 homolog. Studying these mutants has enabled us to examine early developmental defects due to the loss of NMIIA protein. Using these mutants, we discovered an embryonic phenotype consistent with kidney failure that appears between 48 and 72 hours post fertilization (hpf). However, this phenotype quickly reverses between 96 hpf and 5 days post fertilization. As a first step towards understanding the role of myh9b in kidney development, we examined gene expression patterning in the developing pronephros. We hypothesized, based on the reversal, that the expression patterns for the genes cdh17 and wt1b would be normal in our myh9b mutants. cdh17 encodes for cadherin 17 and is expressed in the pronephric ducts and duct progenitors. wt1b encodes for a zinc-finger transcription factor and is expressed in the pronephric glomeruli. Using in situ hybridization, we found that there were no obvious differences in gene expression between wild-type and the myh9b mutant zebrafish at the time points investigated. These data suggest that kidney pattering is not compromised in myh9b mutants leading to the hypothesis that the kidney defect is due to abnormal glomerular filtration. Future experiments will examine glomerular filtration rate and ultra-structure of the glomeruli during development.
