Department of Comparative Physiology, Uppsala University, Norbyvägen 18A, SE-752 36 Uppsala, Sweden.
Fish Shellfish Immunol. 2010 Apr;28(4):649-53. doi: 10.1016/j.fsi.2009.12.021. Epub 2010 Jan 7.
Crayfish do not have larval stage as other crustacean such as penaeid shrimp they spawn their eggs until hatching and what hatches out from the eggs are miniature crayfish known as juveniles. In order to address the question whether immune genes are initially expressed during the embryo development in the egg stage, the expression of some immune-related genes: prophenoloxidase (proPO), peroxinectin, hemocyanin, anti-lipopolysaccharide factor (ALF), plcrustin, astakine-1, 2 and transglutaminase (TGase) were determined in the middle phase of crayfish embryo development. Furthermore, immune challenge was used to determine the immune response of eggs by immersing them in a solution of the highly pathogenic bacterium Aeromonas hydrophila. Semi-quantitative RT-PCR analysis showed that all tested genes are present except proPO in this phase of crayfish embryo development and none of the genes tested changed their expression following immersion in A. hydrophila. The proPO transcript has been reported from hemocytes in crustaceans and it plays crucial roles in crustacean immune response. This may indicate that the development of immune-competent hemocytes in this stage of crayfish embryo is not completed and the egg shell as such plays an important role as a shield in protecting the embryo from bacteria and maybe also other pathogens.
淡水小龙虾没有像对虾那样的幼虫阶段，它们将卵产到孵化，从卵中孵化出来的是被称为幼体的微型小龙虾。为了解决免疫基因是否在卵期胚胎发育过程中最初表达的问题，研究了一些与免疫相关的基因的表达：酚氧化酶原（proPO）、过氧化物酶、血蓝蛋白、抗脂多糖因子（ALF）、plcrustin、astakine-1、2 和转谷氨酰胺酶（TGase）在小龙虾胚胎发育的中期。此外，通过将卵浸入高致病性细菌嗜水气单胞菌的溶液中，进行免疫挑战来确定卵的免疫反应。半定量 RT-PCR 分析表明，在这个阶段的小龙虾胚胎发育中，除了 proPO 之外，所有测试的基因都存在，并且在浸入 A. hydrophila 后，没有一个测试的基因改变了它们的表达。在甲壳动物的血细胞中已经报道了 proPO 转录本，它在甲壳动物的免疫反应中起着至关重要的作用。这可能表明，在这个小龙虾胚胎发育阶段，具有免疫能力的血细胞的发育尚未完成，卵壳作为一种保护胚胎免受细菌和其他病原体侵害的盾牌发挥着重要作用。
