Wharton D A, Judge K F, Worland M R
Department of Zoology, University of Otago, Dunedin, New Zealand.
J Comp Physiol B. 2000 Jun;170(4):321-7. doi: 10.1007/s003600000106.
Panagrolaimus davidi is a freeze-tolerant Antarctic nematode which survives extensive intracellular freezing. This paper describes the development of culture techniques which provide clean samples, with a high degree of freeze tolerance and in sufficient quantities for the analysis of potential cryoprotectants. Cultures grown at 20 degrees C survived a short-term freezing stress but survival declined with the time spent frozen. Acclimation of cultures at 5 degrees C enhanced the long-term survival of freezing. Starvation, however, reduced the nematode's ability to survive short-term freezing. The principal cryoprotectants detected by gas chromatography were trehalose and glycerol. The levels of trehalose, but not those of glycerol, increased significantly after acclimation. Trehalose may stabilise membranes and protect them against the dehydrating effects of the osmotic stresses resulting from freeze concentration effects but other factors, such as recrystallisation inhibition, may be involved in long-term survival.
大卫帕纳格罗线虫是一种耐冻的南极线虫，能在广泛的细胞内结冰情况下存活。本文描述了培养技术的发展，这些技术能提供干净的样本，具有高度的耐冻性且数量足够用于分析潜在的抗冻剂。在20摄氏度下培养的线虫能经受短期冷冻胁迫，但随着冷冻时间的延长，存活率下降。在5摄氏度下驯化培养物可提高冷冻后的长期存活率。然而，饥饿会降低线虫短期冷冻的存活能力。通过气相色谱法检测到的主要抗冻剂是海藻糖和甘油。驯化后海藻糖的含量显著增加，而甘油的含量没有。海藻糖可能会稳定细胞膜并保护它们免受冷冻浓缩效应导致的渗透胁迫脱水作用的影响，但其他因素，如抑制重结晶，可能与长期存活有关。
