caa a22 4500 465826431 CHVBK 20180323112150.0 cr unu---uuuuu 170327e19900401xx s 000 0 eng 10.1007/BF00258762 doi (NATIONALLICENCE)springer-10.1007/BF00258762 Hormonal control of hemolymph lipoprotein ice nucleators in overwintering freeze-susceptible larvae of the stag beetle Ceruchus piceus: adipokinetic hormone and juvenile hormone [Elektronische Daten] [Lei Xu, Lisa Neven, John Duman] Summary: Freeze-resistant overwintering larvae of the stag beetle Ceruchus piceus do not produce antifreezes in winter, but instead lower their supercooling points by seasonal removal of lipoprotein ice nucleators (LPINs) from the hemolymph. The normal lipid transport function of these lipoproteins becomes less essential during winter because of the low temperatures and the diapause state of the larvae. Adipokinetic hormone (AKH) and juvenile hormone (JH) were shown to be involved in the control of supercooling abilities and LPIN levels. Treatment of midwinter larvae with AKH resulted in an increase in ice nucleator activity within 2 h, associated with elevated levels of LPINs, as demonstrated by Western blots derived from native PAGE gels probed with polyclonal antibodies to the LPINs. AKH also stimulated the release of LPIN in vitro from cultured fat bodies. In contrast, JH treatments of larvae with high hemolymph ice nucleator contents (either autumn or spring larvae) caused a decrease in ice nucleator activity and supercooling points. However, Western blots showed increased LPIN levels in these JH treated larvae. Apparently, this JH-induced, inactive form of LPIN lacks some component(s) essential for ice nucleator activity. Springer-Verlag, 1990 Ice nucleator lipoprotein nationallicence Cold tolerance nationallicence Lipoprotein nationallicence Juvenile hormone nationallicence Adipokinetic hormone nationallicence AKH : Adipokinetic hormone nationallicence Apo-I : Apolipoprotein-I nationallicence Apo-II : Apolipoprotein-II nationallicence JH : Juvenile hormone nationallicence LPIN : Lipoprotein ice nucleator nationallicence PAGE : Polyacrylamide gel electrophoresis nationallicence SDS : Sodium dodecyl sulfate nationallicence SCP : Supercooling point nationallicence THP : Thermal hysteresis protein nationallicence HDLp : High density lipophorin nationallicence VHDLp : Very high density lipophorin nationallicence Xu Lei Department of Biological Science, University of Notre Dame, 46556, Notre Dame, IN, USA aut Neven Lisa Department of Biological Science, University of Notre Dame, 46556, Notre Dame, IN, USA aut Duman John Department of Biological Science, University of Notre Dame, 46556, Notre Dame, IN, USA aut Journal of Comparative Physiology B Springer-Verlag 160/1(1990-04-01), 51-59 0174-1578 160:1<51 1990 160 360 https://doi.org/10.1007/BF00258762 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00258762 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Xu Lei Department of Biological Science, University of Notre Dame, 46556, Notre Dame, IN, USA aut NATIONALLICENCE 700 1- Neven Lisa Department of Biological Science, University of Notre Dame, 46556, Notre Dame, IN, USA aut NATIONALLICENCE 700 1- Duman John Department of Biological Science, University of Notre Dame, 46556, Notre Dame, IN, USA aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer-Verlag 160/1(1990-04-01), 51-59 0174-1578 160:1<51 1990 160 360 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer