Temporal Control of Puffing Activity in Polytene Chromosomes
This extract was created in the absence of an abstract.
Excerpt
The genetic organization of individual bands of polytene chromosomes is an enigma. On the one hand, we have evidence (Rudkin, 1965; Daneholt and Edström, 1967; Mulder et al, 1968; see also Rasch et al., 1971) that an “average” band contains DNA equivalent to 40,000 or so nucleotide pairs. The range is perhaps between 3000 and 100,000 nucleotide pairs (Beermann, 1972). On the other hand, classical (e.g., Painter, 1934; Bridges, 1935, 1936; Mackensen, 1935; Muller and Prokofyeva, 1935) and more modern (e.g., Hochman, 1971; Lefevre, 1971; Lim et al., 1971; Judd et al., 1972; Rayle, 1972) evidence strongly suggests that one band (or band plus adjacent interband(s), if you will: Crick, 1971) corresponds to a unit of genetic function.
It is not our intention to discuss the many ideas now current to “explain” this paradox. Beermann (1972) has authoritatively reviewed much of the data on which they are based, and others...
