The DNA nucleotide base sequence of a chloroplast gene will be used to interpret phylogenetic relationships among the subclasses of the Liliopsida (i.e., the monocots). This gene encodes the large subunit of ribulose 1,5-bisphosphate carboxylase (rbcL), part of the most abundant, and arguably, the most important protein on earth. Dr. Michael Clegg, Professor of Genetics at the University of California, Riverside, has agreed to sponsor this fellowship proposal. The rbcL gene is a particularly appropriate choice because it is ubiquitous among photoautotrophs, because it exhibits sufficient divergence for use in broad phylogenetic investigations, and because a data base of rbcL nucleotide sequences already exists which will be used in conjunction with sequence data. Contemporary sequencing technology permits the analysis of many species in a short period of time by one investigator, especially in a laboratory in which sequence analysis is conducted routinely, such as that of Dr. Clegg. Total cellular DNA will be extracted, the rbcL gene will be amplified in the polymerase chain reaction, and the nucleotide sequence will be determined by standard techniques. Sequence data will be analyzed to construct statistically supported dendrograms, It is anticipated that this research will require two years of work and support: 14-16 months will be spent procuring plant materials and determining rbcL gene sequences, and the remaining time will be devoted to analysis of the data and phylogenetic interpretation.
