Chromosome Structure and Function e-bog

A Historical Perspective on the Study of Chromosome Structure and Function R. Appels Division of Plant Industry CSIRO P.O. Box 1600 A.C.T. AUSTRALIA "e;Modern physical science gives us no model to explain the re- duplication of the gene-string in each cell generation, or to ex- plain the production of effective quantities of specific enzymes or other agents by specific genes. The precise pairing and inter- change of segments by homologous gene-strings at meiosis also suggest novel physical properties of this form of matter"e;. Stadler (1954) The very strong influence of reductionism in the history of understanding chromosome structure and function is evident in the above quotation from Stadler's 1954 paper, "e;The gene"e;. Earlyob- servations on the constancy of the cytological appearance of chromo- somes and their regular behaviour in cell division led to specula- tion on their biological importance. As genetics became more refined in the early decades of the 20th century the genes-on-a- string model of chromosomes developed and greater emphasis was placed on the further dissection of these structures. As a result, in the 1980's the reductionist approach is reaching a crest as extensive regions of the genetic material are being sequenced.