Normal mammalian development requires both parental genomes to be correctly expressed and transmitted to offspring. In general, both genomes are expressed equally from the homologous chromosomes inherited from the parents. However, a subset of genes known as imprinted genes is expressed from one of the parental alleles while the other parental allele is silent. This phenomenon is known as genomic imprinting. Although imprinted genes play critical roles in survival, growth, and development, there have been no attempts to characterize their genomic architecture (total number, distribution, and function) in the bovine genome. Indeed, the number of known imprinted genes in cattle is less than 20 compared to over 130 in the mouse.
There is an increasing body of knowledge on the roles of imprinted genes in livestock production. For example, in a recent genome scan, Imumorin et al. (2011) detected quantitative trait loci (QTL) with parent-of-origin effects on growth and carcass traits in the Angus x Brahman cattle crossbred. A single nucleotide polymorphism (SNP) in IGF2 was found to be associated with an increase in rib eye area and percentage of grade fat (Goodall and Schmutz, 2007). Magee et al. (2010) reported that SNPs in the bovine imprinted genes CALCR, GRB10, PEG3, RASGRF1, ZIM2 and ZNF215 displayed associations with milk production, health, body condition, reproduction, carcass traits, and calf mortality. Recent data by our lab shows that imprinted genes play crucial roles in embryonic survival and development in cattle. A survey of imprinted genes revealed that differential expression of imprinted genes is associated with the developmental status and quality of the embryo (Huang et al., 2010; Driver et al., 2013). Furthermore, these studies demonstrate the importance of imprinted genes in survival and production traits in cattle and the need of the identification of additional imprinted genes.
The ultimate goal of this project is create a web atlas of imprinted genes that can be used by the community for the investigation of the roles of imprinted genes and epigenetics in health and production traits. We hope that you benefit from this web site and that you share your information with the community.