Mitochondrial distribution and ATP levels in Chironomus salivary gland cells as related to growth, metabolic activity, and atmospheric oxygen tension

摘要: During larval development of the dipteran Chironomus tentans its salivary gland cells increase in volume and become highly polytenized. A part this growth process, from early second instar to late fourth instar, which represents a 130-fold cell volume, was investigated here found be accompanied by changes intracellular distribution mitochondria. In very young animals mitochondria were scattered throughout cytoplasm but with increasing size they became concentrated narrow basal zone between infoldings plasma membrane until at end essentially all them localized zone. ATP-ADP-AMP concentrations did not change increased during these developmental phases. However, inhibition total or, predominantly, secretory protein synthesis order decrease energy consumption resulted striking increases ATPADP ratios. Concomitantly distributed whole endoplasm number decreased. On other hand, when exposed low oxygen pressure, moved into Our observations support view that accumulation an adaptation optimize supply for ATP production. This arrangement is necessary becomes extreme or short, unless The results show are able shift their position apparently functionally meaningful way.