caa a22 4500 465826563 CHVBK 20180323112151.0 cr unu---uuuuu 170327e19900801xx s 000 0 eng 10.1007/BF00302593 doi (NATIONALLICENCE)springer-10.1007/BF00302593 Distinct effects of different low temperatures on the induction of NAD-sorbitol dehydrogenase activity in diapause eggs of the silkworm, Bombyx mori [Elektronische Daten] [Toshinobu Yaginuma, Michihiro Kobayashi, Okitsugu Yamashita] Summary: Diapause eggs of the silkworm, Bombyx mori, exposed to 5°C and 0.5°C from 2 or 30 days after oviposition, were examined for changes in contents of glycogen, sorbitol and glycerol. Cold acclimation did not alter the profile of accumulation of sorbitol from that in eggs kept continuously at 25°C. However, acclimation at 5°C resulted in conversion of sorbitol to glycogen, while acclimation at 0.5°C was not accompanied by the utilization of sorbitol. NAD-sorbitol dehydrogenase (NAD-SDH; EC 1.1.1.14) activity was examined in the cold-acclimated eggs. The activity was induced by acclimation at 5°C but not at 0.5°C. Incubation at 0.5°C suppressed any further increase in the activity that had been induced. Temperature-directed changes in NAD-SDH activity paralleled those in sorbitol content. Hatching of the diapause eggs was monitored after cold acclimation for various periods of time and subsequent transfer to 25°C. Incubation at 0.5°C was less effective than 5°C at breaking diapause. The time required for the eggs to hatch in synchrony after acclimation at 5°C coincided with that required for the induction of NAD-SDH activity. These results show that different effects result from acclimation at 5°C and near 0°C with respect to the control of NAD-SDH activity, that utilization of sorbitol is controlled by NAD-SDH activity, and that induction of this activity is temperature-dependent. Furthermore, induction of NAD-SDH activity is involved in the termination of diapause in B. mori. Springer-Verlag, 1996 NAD-sorbitol dehydrogenase nationallicence Bombyx mori nationallicence Embryonic diapause nationallicence Low temperatures nationallicence DH : diapause hormone nationallicence NAD : nicotinamide-adenine-dinucleotide nationallicence NAD-SDH : NAD-sorbitol-dehydrogenase nationallicence Yaginuma Toshinobu Laboratory of Sericultural Science, Faculty of Agriculture, Nagoya University, Chikusa, 464-01, Nagoya, Japan aut Kobayashi Michihiro Laboratory of Sericultural Science, Faculty of Agriculture, Nagoya University, Chikusa, 464-01, Nagoya, Japan aut Yamashita Okitsugu Laboratory of Sericultural Science, Faculty of Agriculture, Nagoya University, Chikusa, 464-01, Nagoya, Japan aut Journal of Comparative Physiology B Springer-Verlag 160/3(1990-08-01), 277-285 0174-1578 160:3<277 1990 160 360 https://doi.org/10.1007/BF00302593 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00302593 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yaginuma Toshinobu Laboratory of Sericultural Science, Faculty of Agriculture, Nagoya University, Chikusa, 464-01, Nagoya, Japan aut NATIONALLICENCE 700 1- Kobayashi Michihiro Laboratory of Sericultural Science, Faculty of Agriculture, Nagoya University, Chikusa, 464-01, Nagoya, Japan aut NATIONALLICENCE 700 1- Yamashita Okitsugu Laboratory of Sericultural Science, Faculty of Agriculture, Nagoya University, Chikusa, 464-01, Nagoya, Japan aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer-Verlag 160/3(1990-08-01), 277-285 0174-1578 160:3<277 1990 160 360 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer