Genaktivitäten in den Riesenchromosomen von Chironomus tentans und ihre Beziehungen zur Entwicklung

摘要: 1. Alterations in the pattern of puffs salivary gland chromosomes indicate changes gene activities. The relationships between such alterations activity patterns and behaviour single activities on one side developmental processes fourth stage larvae Chironomus tentans other are subject this paper. 2. Before beginning pupal moult there exists a constant loci which form cells. This potentially active is identical all larvae. However, actually puffed given moment, varies from larva to larva. While some always occur every larva, others found only infrequently. puffing frequency each locus may be altered experimentally but it same young old if they live under conditions. It concluded that with low frequencies periods alternate those inactivity These independant any processes. Puffing these genes not specific for development. 3. In course moulting most development, decreases. prepupae few were at all. Thus, hardly by decreasing puff frequency. suggested reduction part metabolism related breakdown glands end prepupal phase. 4. In studying size was used as further measure activity. Homologous often vary different indicates lesser degree than leads disappearance puff. 5. Puffs I-17-B I-19-A present during whole last stage; sometimes small, large. time after reach their maximal size. At phase regress. number behaving manner I-19-A, become more moulting, though relatively small. 6. Puffs I-18-C IV-2-B either inactive or slightly before initiation moult. After its experimental induction (Clever 1961 a) activated within less hour influenced concentration hormone injected. In normal development appearance first known sign moulting. increases reaches maximum towards end. Puff also very much later I-18-C, although earlier puffs. Its gradually middle phase. Towards regresses. both interpreted controlled titer ecdysone haemolymph. As an explanation difference assumed have reaction thresholds phase. 7. Puffs sections I-1-A, I-14-B, II-14-A III-9-B older prepupae. Their strongly correlated certain stages process may, thus, serve markers subdividing sequence induction. 8. The studied article confirms conclusions about role physiology drawn experiments serves basis discussing regulatory mechanisms Our former hypothesis (and IV-2-B) directly ecdysone, now supplemented suggestion acts like effector substances genetic protein synthesis bacteria.