Muscle gene expression of lambs with maternal callipyge allele

Lambs that inherit a callipyge allele from their dam have an up-regulation of maternally imprinted transcripts near the callipyge mutation but do not exhibit muscle hypertrophy. It is not clear what effects these maternally expressed transcripts have in the muscle or how the inheritance of a maternal callipyge allele prevents the expression of the callipyge phenotype which is seen paternal heterozygotes only. This experiment utilized bovine gene expression arrays to profile the gene expression of the semimembranosus muscle of 30 day old half-sibling lambs of all four possible genotypes with respect to the callipyge allele (+/+, C/+, +/C, and C/C). Keywords: allele effect 10 lambs were used for this study. N=3 biological reps for C/C genotype, N=3 biological reps for Cmat/+ genotype, N=2 biological reps for +/Cpat genotype, and N=2 biological reps for +/+ genotype. Pairwise contrasts were performed to analyze the presence of a maternally inherited callipyge allele and the effect on a homozygous animal (+/C vs CC; +/+ vs C/+; and C/+ vs C/C). These data make up two experiments. [1] The maternal allele (4 genotype) experiment compares all four possible genotypes of a particular allele at one age and one tissue (30 days semimembranosus). [2] The paternal allele (2 genotype) experiment compares only the NC and the NN genotypes in one tissue (SM) across 4 ages (10, 20, 30, and 80 days). Images were interpreted with Microarray Suite version 5.0 (MAS5.0) in GCOS with no scaling or normalization (i.e., Samples GSM298143-GSM298164). Images were also interpreted by RMA using Bioconductor package of R (i.e., Samples GSM298165-GSM298186).