We recently identified a line of transgenic mice that has a heritable form of polycystic disease (PKD) that closely resembles human infantile autosomal recessive PKD. The phenotype of the transgenic line arises from an insertional mutation caused by the integration of the transgene and is not related to expression of the transgene. In addition to closely mimicking human autosomal recessive PKD, this transgenic mutant line (Tg737) is unique in that we have been able to clone and characterize the DNA of the genetic locus. We expect to be able to directly analyze the mechanism by which a mutant gene participates in the development of PKD. Ultimately, DNA probes will be used to clone and map homologous genes in the human genome. Then, specific diagnostic tests could putatively be developed and genetic screening can be initiated. Different conventional therapies and newer methods of somatic cell gene therapy can be tested in the Tg737 mice.
The SPECIFIC AIMS are: 1. To characterize the phenotype of the Tg737 mouse including the clinical, pathologic, and clinicopathologic changes associated with the PKD in Tg737 mouse. We will document the nature and progression of the renal and hepatic lesions and correlate the changes with clinical pathologic data. We will also evaluate the role of other genetic traits on the expression of the polycystic disease. 2. To further characterize the structure and expression of the wild-type gene within the region corresponding to the mutant locus in the Tg737 line. We will thoroughly characterize the structure of the cDNA clones we have isolated utilizing restriction mapping and nucleotide sequence analysis procedures. We will also utilize antibodies and probes to examine the expression of the Tg737 protein and mRNA in normal and Tg737 mouse tissues during development and the course of the disease. 3. A minigene construct prepared from the cloned wild-type copy of the Tg737 gene will be used to generate additional lines of transgenic mice in an attempt to """"""""rescue"""""""" the phenotype in the mutant animals. 4. A full-length cDNA clone derived from the mouse Tg737 locus will be used as a probe to clone the homologous human gene, and then map it on the human genome.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK045633-02
Application #
3247129
Study Section
General Medicine B Study Section (GMB)
Project Start
1992-09-30
Project End
1995-09-29
Budget Start
1993-09-30
Budget End
1994-09-29
Support Year
2
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of Tennessee Knoxville
Department
Type
Schools of Veterinary Medicine
DUNS #
City
Knoxville
State
TN
Country
United States
Zip Code
37996
Yoder, B K; Richards, W G; Sommardahl, C et al. (1997) Differential rescue of the renal and hepatic disease in an autosomal recessive polycystic kidney disease mouse mutant. A new model to study the liver lesion. Am J Pathol 150:2231-41
Yoder, B K; Richards, W G; Sommardahl, C et al. (1996) Functional correction of renal defects in a mouse model for ARPKD through expression of the cloned wild-type Tg737 cDNA. Kidney Int 50:1240-8
Yoder, B K; Richards, W G; Sweeney, W E et al. (1995) Insertional mutagenesis and molecular analysis of a new gene associated with polycystic kidney disease. Proc Assoc Am Physicians 107:314-23
Moyer, J H; Lee-Tischler, M J; Kwon, H Y et al. (1994) Candidate gene associated with a mutation causing recessive polycystic kidney disease in mice. Science 264:1329-33