Change in nuclear potassium electrochemical activity and puffing of potassium-sensitive salivary chromosome regions during Chironomus development.
Changes in nuclear K+ electrochemical activity and total nuclear K+ content in salivary glands of Chironomus tentans were measured with ion-selective microelectrodes based on valinomycin and with flameless atomic absorption spectrometry, respectively. The K+ activity increased by a factor of 2.6 and the total K+, by a factor of 1.5 as oligopausing larvae developed into prepupae. The extent of decondensation (puffing) of K+-sensitive regions in the polytene chromosomes underwent a parallel increase during this developmental event. In vitro culture of glands from oligopausing larvae resulted in similar changes with respect to nuclear K+ activity and puffing.
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D002875:Chromosomes / Q000648:ultrastructure*; D004175:Diptera / Q000235:genetics* / Q000254:growth & development; D007814:Larva; D008675:Metamorphosis, Biological; D008839:Microelectrodes; D011188:Potassium / Q000378:metabolism*; D012469:Salivary Glands / Q000648:ultrastructure; D014158:Transcription, Genetic
D011188:Potassium