Texas A&M University (University)
Active Grant No: 779:
Characterization of the Canine Y Chromosome: Identifying Genes that Cause Male Infertility
Affenpinscher Club of America, American Cavalier King Charles Spaniel Club
Charitable Trust, Bernese Mountain Dog Club of America, Bulldog Club of America
Charitable Health Fund, Inc., Collie Health Foundation, Field Spaniel Society of
America, French Bulldog Club of America, Golden Retriever Foundation, Greyhound
Club of America, Health & Rescue Foundation of the Petit Basset Griffon Vendeen
Club of America, Italian Greyhound Club of America, Labrador Retriever Club,
Leonberger Health Foundation, Miniature Pinscher Club of America, Inc., National
Amateur Retriever Club, Pug Dog Club of America, Inc., Rhodesian Ridgeback Club
of the United States, Seminole Kennel Club, United States Kerry Blue Terrier
Club, Inc., Westie Foundation of America, Inc., Yorkshire Terrier Club of
America Foundation, Inc.
Researcher(s): William J. Murphy, PhD
Breed(s): All (non-specified)
Studies of the human and mouse Y chromosomes have shown that they contain many testis specific genes that, when defective, cause infertility and spermatogenesis defects. The causes of male infertility in dogs are not well known. Though much is now known about genes on the dog autosomes and X chromosome, owing to the canine genome sequence, virtually nothing is known about the canine Y chromosome and the genes it harbors. This study will exhaustively characterize the gene content of the dog Y chromosome by sequencing from a cDNA selection library that is enriched for Y chromosome gene transcripts. This procedure will isolate the majority of canine Y chromosome genes and the DNA fragments they reside on, which will be mapped in the dog genome. The copy number and expression profile of these genes will be determined in a broad range of tissues to discern which genes have testis-specific expression patterns, and may therefore be good candidates for abnormal spermatogenesis. The identification of testes-specific Y chromosome genes will provide gene targets for future development of molecular diagnostic assays that examine the influence of these genes on canine male infertility.
The causes of male infertility in dogs are not well known. Though much is now known about genes on the dog autosomes and X chromosome, owing to the canine genome sequence, virtually nothing is known about the canine Y chromosome and the genes it harbors. Studies of the human and mouse Y chromosomes have shown that they contain many testis-specific genes that when defective cause infertility and spermatogenesis defects. This study aims to characterize the gene content of the dog Y chromosome by sequencing from a cDNA selection library that is enriched for Y chromosome gene transcripts, and mapping these in the canine genome. We have identified gene sequences from twelve canine Y chromosome genes, and have also characterized seven new canine-specific genes. Determining the copy number and function of these novel genes are of primary importance, as they are primary infertility candidate genes. We are currently assembling a physical map in collaboration with the Washington University Genome Center, as a prerequisite to eventually obtain the sequence of the dog Y chromosome. Future experiments will examine the expression profile of the genes identified thus far to determine which are testis-specific, and therefore serve as good candidate genes that when ablated or deleted lead to abnormal spermatogenesis in infertile dogs.