In this section:
DNA and RNA Analysis
Analysis of the genetic determinants of livestock production traits now relies heavily upon the immense research capabilities embodied in Molecular Biology. These entail elucidation of the DNA sequences that comprise the genes themselves and detailed examination of the function of genes (gene expression) and their products, in the tissues and cell types where they are active. In the Molecular Biology Laboratory at Roseworthy, recombinant DNA technology is in everyday use in the identification and isolation of genomic DNA sequences of genes expressed in a range of ovine and bovine tissue types, and specifically ovine wool follicle and bovine muscle tissue. Sequences which represent the messenger RNA copies from expressed genes, cDNA sequences, are also routinely isolated. Genes and such cDNA clones isolated include those encoding both structural proteins (eg. wool fibre keratin proteins) and regulatory proteins (eg. myostatin and myoD from bovine muscle). Using methods such as the Southern transfer hybridisation protocol and Polymerase Chain Reaction (PCR) we are also able to analyse the genetic complement of individual animals. Methods including the northern transfer hybridisation protocol, Reverse transcription - Polymerase Chain Reaction (RT-PCR) and RNA in situ hybridisation allow us to determine tissue-specific sites of gene expression and to quantitate levels of gene expression.
Most recently, gene expression profiling has been undertaken using real-time PCR (quantitative or qPCR) and a very efficient and cost effective protocol has been developed, based upon the technology and automation offered by the Rotorgene machine and CAS Liquid handling station (Corbett Instruments). Construction of genes with appropriate processing signals for expression in cell culture or as transgenes in mice and sheep is routine in the laboratory.
For further information, please contact :
Dr. C. Simon Bawden
Molecular Biology Group
SARDI Livestock and Farming Systems
