Following the chromosome path to the garden of the genome

• Published in: Annual review of cell and developmental biology Vol. 23; p. 1
• Main Author: Pardue, Mary-Lou
• Format: Journal Article
• Language: English
• Published: United States 01.01.2007
• Subjects: Animals; Chromosomes - genetics; Drosophila melanogaster - genetics; Genetics - history; Genome; History, 20th Century; History, 21st Century; United States; United States
• ISSN: 1081-0706
• DOI: 10.1146/annurev.cellbio.23.090506.123459

I have been fascinated by chromosomes for longer than I care to mention; their beautiful structure, cell-type-specific changes in morphology, and elegant movements delight me. Shortly before I began graduate study, the development of nucleic acid hybridization made it possible to compare two nucleic acids whether or not their sequences were known. From this stemmed a progression of development in tools and techniques that continues to enhance our understanding of how chromosomes function. As my PhD project I contributed to this progression by developing in situ hybridization, a technique for hybridization to nucleic acids within their cellular context. Early studies with this technique initiated several lines of research, two of which I describe here, that I have pursued to this day. First, analysis of RNA populations by hybridization to polytene chromosomes (a proto-microarray-type experiment) led us to characterize levels of regulation during heat shock beyond those recognizable by puffing studies. We found also that one still-undeciphered major heat shock puff encodes a novel set of RNAs for which we propose a regulatory role. Second, localization of various multicopy DNA sequences has suggested roles for them in chromosome structure: Most recently we have found that Drosophila telomeres consist of and are maintained by special non-LTR (long terminal repeat) retrotransposons.