Quantitative analysis of two-dimensional protein profiles of inbred lines of maize (Zea mays L.)

Two-dimensional electrophoresis and fluorography of [35S]methionine labeled maize germinated embryo proteins were performed at Cold Spring Harbor Laboratory. Fluorographs of 63 gels representing 37 inbred lines were subsequently scanned and spot-detected at Protein and DNA Imageware Systems (Huntington Station, NY). The digitized images were then matched with the aid of PDQUEST-II computer software. Over 1500 different protein spots were included in the resulting dataset. The optical density data were normalized to parts per million, then transformed to their natural logarithms. Analyses of variance were performed on each spot in order to select for further study those spots with most of their variation partitioned among inbred lines rather than within inbred lines. Using this method of spot selection, over 100 protein spots were included in the set of spots which display significant differences among inbred lines of maize.