Although typically thought of as a beloved companion or indispensable aide, the domestic dog (Canis lupus familiaris) has emerged as an excellent model for the study of human hereditary diseases. Many hereditary diseases of the dog have nearly identical clinical presentations as those of the human and are, most often, caused by mutations in the same genes. One such disease is hereditary nephropathy; an inherited glomerular disease in the domestic dog that is similar to Alport syndrome of the human. Both diseases are caused by mutations in the type IV collagens genes, and the disease has nearly identical pathology and clinical presentations in the dog and human. By studying this disease in the dog, our laboratory hopes to increase understanding of the disease so that information that can be applied to both the human and the dog. Reported here is 1) the development of a genomic based test to determine genotypes of mixed breed dogs in a colony presenting with X-linked hereditary nephropathy, 2) the determination of patterns of X-chromosome inactivation in normal dogs and dogs that are carriers of Xlinked hereditary nephropathy, 3) the design of a synthetic COL4A5 cDNA to be used for gene therapy treatment of dogs with X-linked hereditary nephropathy, 4) the investigation of type IV collagen gene expression changes in normal dogs and those affected with X-linked and autosomal recessive hereditary nephropathy, and 5) the discovery of the mutation causative for autosomal recessive hereditary nephropathy in the English Cocker Spaniel. Utilization of the colony of dogs affected with X-linked hereditary nephropathy (for which the causative mutation was previously identified) allowed for comparisons of type IV collagen gene expression to English Cocker Spaniels with autosomal recessive hereditary nephropathy. These data were critical to identification of the gene harboring the causative mutation for autosomal recessive hereditary nephropathy. Sequencing was performed to identify the mutation. With the ability to test for carriers of this disease, it is our hope that breeders will use it to to maintain the desired traits in the ECS while simultaneously eliminating the production of affected offspring.

Although typically thought of as a beloved companion or indispensable aide, the domestic dog (Canis lupus familiaris) has emerged as an excellent model for the study of human hereditary diseases. Many hereditary diseases of the dog have nearly identical clinical presentations as those of the human and are, most often, caused by mutations in the same genes. One such disease is hereditary nephropathy; an inherited glomerular disease in the domestic dog that is similar to Alport syndrome of the human. Both diseases are caused by mutations in the type IV collagens genes, and the disease has nearly identical pathology and clinical presentations in the dog and human. By studying this disease in the dog, our laboratory hopes to increase understanding of the disease so that information that can be applied to both the human and the dog. Reported here is 1) the development of a genomic based test to determine genotypes of mixed breed dogs in a colony presenting with X-linked hereditary nephropathy, 2) the determination of patterns of X-chromosome inactivation in normal dogs and dogs that are carriers of X-linked hereditary nephropathy, 3) the design of a synthetic COL4A5 cDNA to be used for gene therapy treatment of dogs with X-linked hereditary nephropathy, 4) the investigation of type IV collagen gene expression changes in normal dogs and those affected with X-linked and autosomal recessive hereditary nephropathy, and 5) the discovery of the mutation causative for autosomal recessive hereditary nephropathy in the English Cocker Spaniel. Utilization of the colony of dogs affected with X-linked hereditary nephropathy (for which the causative mutation was previously identified) allowed for comparisons of type IV collagen gene expression to English Cocker Spaniels with autosomal recessive hereditary nephropathy. These data were critical to identification of the gene harboring the causative mutation for autosomal recessive hereditary nephropathy. Sequencing was performed to identify the mutation. With the ability to test for carriers of this disease, it is our hope that breeders will use it to to maintain the desired traits in the ECS while simultaneously eliminating the production of affected offspring.

The domestic dog, Canis familiaris, has over 450 naturally occurring inherited diseases. Over half of these diseases are clinically similar to human diseases making the dog an excellent model in which to study human hereditary diseases. Alport syndrome (AS), a group of heterogeneous, hereditary renal diseases, is one example of such a human disease. The disease is transmitted in three fashions: X-linked, autosomal recessive, and autosomal dominant. AS is caused by mutations in COL4α3, COL4α4 or COL4α5, all members of the type IV collagen family. The proteins products of these genes along with those of the other type IV collagen family members (COL4α1, COL4α2, and COL4α6) are structural components of basement membranes throughout the body. This dissertation describes the measurement of mRNA transcripts in two canine models of AS: a mixed breed model of X-linked AS (XLAS) and the English Cocker Spaniel (ECS) model of autosomal recessive AS (ARAS). The work done revealed a decrease in COL4α4 transcripts. The similarity between the decrease of COL4α5 in the XLAS model and that for COL4α4 in the ARAS model lead to the investigation of COL4α4 as the gene harboring the mutation causative for ARAS in the ECS. Upon sequencing COL4α4, the causative mutation was determined to be an A to T transversion in exon 3. To provide an in vitro model to study type IV collagens, a protocol was designed and experimentally validated to isolate and culture canine Sertoli cells. Canine testes cells were isolated and cultured. Cells were verified as Sertoli cells through positive identification of both SOX9 and Clusterin B proteins, along with sequence verification of SOX9 transcripts. This in vitro model provides a tool to further study the type IV collagens. Overall, the research described herein lead to the identification of the mutation causative for ARAS in the ECS. With this knowledge a genetic test was developed to test for the disease. This research also provided valuable information about the transcript levels of type IV collagens in two models of AS, and provided a novel model in which to study the type IV collagens further.

The domestic dog, Canis familiaris, has over 450 naturally occurring inherited diseases. Over half of these diseases are clinically similar to human diseases making the dog an excellent model in which to study human hereditary diseases. Alport syndrome (AS), a group of heterogeneous, hereditary renal diseases, is one example of such a human disease. The disease is transmitted in three fashions: X-linked, autosomal recessive, and autosomal dominant. AS is caused by mutations in COL4α3, COL4α4 or COL4α5, all members of the type IV collagen family. The proteins products of these genes along with those of the other type IV collagen family members (COL4α1, COL4α2, and COL4α6) are structural components of basement membranes throughout the body. This dissertation describes the measurement of mRNA transcripts in two canine models of AS: a mixed breed model of X-linked AS (XLAS) and the English Cocker Spaniel (ECS) model of autosomal recessive AS (ARAS). The work done revealed a decrease in COL4α4 transcripts. The similarity between the decrease of COL4α5 in the XLAS model and that for COL4α4 in the ARAS model lead to the investigation of COL4α4 as the gene harboring the mutation causative for ARAS in the ECS. Upon sequencing COL4α4, the causative mutation was determined to be an A to T transversion in exon 3. To provide an in vitro model to study type IV collagens, a protocol was designed and experimentally validated to isolate and culture canine Sertoli cells. Canine testes cells were isolated and cultured. Cells were verified as Sertoli cells through positive identification of both SOX9 and Clusterin B proteins, along with sequence verification of SOX9 transcripts. This in vitro model provides a tool to further study the type IV collagens. Overall, the research described herein lead to the identification of the mutation causative for ARAS in the ECS. With this knowledge a genetic test was developed to test for the disease. This research also provided valuable information about the transcript levels of type IV collagens in two models of AS, and provided a novel model in which to study the type IV collagens further.