Studies on Hemolymph Ice Nucleator Involved in Insect Cold Tolerance

冰成核菌在高于正常结冰温度的条件下形成冰，已经成为从大气科学到农业（由冰成核细菌造成的作物损害）到低温保存等广泛科学学科的重要研究课题。我们已经研究了具有冰核活性的血液蛋白的生物学和生物化学，这是某些昆虫在体液冻结中存活能力的重要组成部分。据推测，在组织形成冰之前，成核器会在血液中形成冰，从而促进细胞内过冷状态的形成，并防止细胞内冰晶的形成。本项目继续这些研究，并特别关注由耐冻的trivittata鹤蝇幼虫产生的脂蛋白。主要的研究工作集中在是什么使这种脂蛋白成为冰核。脂蛋白是非常有趣的，因为在组成上与细菌冰核有某些相似之处，而细菌冰核会对某些农作物造成严重的与冷冻有关的损害。总的来说，这些结果应该增加我们对昆虫抗寒性和抗冻性调控的理解。

Ice nucleators, which initiate ice formation at temperatures above those at which ice formation would normally occur, have become important research topics in a wide range of scientific disciplines ranging from atmospheric science to agriculture (crop damage resulting from ice nucleating bacteria) to cryopreservation. We have studied the biology and biochemistry of blood proteins with ice nucleator activity that are important components of the ability of certain insects to survive the freezing of their body fluids. It has been postulated that the nucleators cause ice formation in the blood prior to ice formation in the tissue thereby facilitating formation of a supercooled state within the cells and a prevention of ice crystal formation in the cells. This project continues those studies and is particularly concerned with blood lipoproteins produced by freeze tolerant larvae of the cranefly Tipula trivittata. The major research effort focuses on what makes this lipoprotein an ice nucleator. The lipoprotein is quite interesting because of certain similarities in composition with the bacterial ice nucleator which is involved in serious freeze related damage to certain agricultural crops. Overall, the results should increase our understanding of the regulation of cold-hardiness and freeze tolerance in insects.