Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: March 18, 2004
Publication Date: July 29, 2004
Citation: Connor, E.E., Capuco, A.V., Sonstegard, T.S. 2004. Use of serial analysis of gene expression (sage) for gene transcript profiling in lactating bovine mammary gland [abstract]. Journal of Animal Science Supplement. 82(Suppl. 1):131.
Serial analysis of gene expression (SAGE) methodology permits quantitative analysis of global gene expression in a given tissue and is useful for comparison of gene expression patterns across physiological states and identification of novel transcripts. At present, only three SAGE libraries have been produced in cattle from cultured kidney, cultured aorta and immature B cells, and are publicly available in the NCBI SAGEMap database (http://www.ncbi.nlm.nih.gov/SAGE/). Our interest is in characterizing gene expression in bovine mammary parenchyma during lactation; however, the disproportionate abundance of milk protein transcripts during this physiological stage hinders the use of microarrays for transcript profiling. To evaluate gene expression during early lactation, a SAGE library was produced from pooled RNA (n=3 multiparous Holstein cows) isolated from biopsied mammary parenchyma at approximately Day 7 of lactation. Preliminary sequencing of SAGE tags identified the greatest abundance of alpha-, beta- and kappa-casein, alpha-lactalbumin, beta-lactoglobulin and ribosomal protein transcripts, as expected. However, a number of tags corresponding to bovine expressed sequence tags and genes involved in metabolism, intracellular signaling and proteolysis were detected in lower abundance. Our results suggest that SAGE is a feasible approach to study gene expression in lactating mammary gland.