| Citation | Distinguished for his work on the sequences of nucleic acids and their biological implications. He contributed to the development of methods using 32P-labelling and two-dimensional fractionation techniques, which greatly accelerated the early RNA sequencing. He used these methods to determine the sequence of the 5S ribosomal RNA, at that time the largest nucleic acid to be sequenced. He used fingerprint analysis of messenger RNA to demonstrate that immunoglobulin V- and C-regions were not discontinuous at the messenger RNA level, and early analysis of messenger RNA to identify a precursor for light chain synthesis. Parallel studies on globin messenger RNA demonstrated important features of eucaryotic translation. More recently he has developed faster methods for RNA sequencing and has applied them to transfer RNAs and ovalbumin messenger RNA. He also studied the DNA sequence of the ovalbumin gene and its insertion sequences. He determined the nucleotide sequence of the multiple gene coding for the 5S RNA in Xenopus laevis and showed that the coding regions alternated with a repetitious region and a "pseudogene" that had a sequence homologous with part of the 5S region. |