| Citation | Distinguished for his outstandings and innovative research on the molecular biology and cytogenetics of chromosome organisation in higher eukaryotes. His earlier work on chromosome replication and meiotic recombination established the differing polarities of chromosomal duplication subunits and their role in restricting reunion, and experimentally confirmed the breakage and reunion of non-sister chromatids during crossing-over at the beginning of pachytene. More recently he has identified and purified six major satellite DNA species of Drosophila melanogaster, which accounts for almost all the highly repeated sequences of the genome, and has shown that all the satellites are related to each other in their basic repeats which are arranged in extremely long tandem arrays, and that their sequences are highly conserved. Moreover, by in situ hybridisation, he has, for the first time, mapped the various satellite DNA species in the heterochromatin of the four chromosomes; each satellite has few locations but occurs on more than one chromosome, each of which presents a unique pattern, while parallel arrays flank the nucleolus organising regions of the X and Y chromosomes. These findings are vital to any theory of the function of satellite DNA. Dr Peacock is currently extending his research to the closely related Drosophila simulans, which appears to have the same satellite DNA species as D.melanogaster but in different amounts, as well as to the chromosomes of plants. |