Molecular Mechanisms underlying Allo-recoguition in Ascidians

血细胞的接触反应和配子的自交不育是海囊类全识别的典型例子。我们在罗瑞兹嗜盐菌中发现，这种接触反应伴随着酚氧化酶的突然耗氧。基于这一发现，我们开发了一种方法来量化接触反应，当血细胞是来自不同个体的混合卵子或毛囊细胞时，观察到类似的猝发。精液与卵黄被结合是海鞘异体识别的一个步骤。虽然H.roreizi是严格自我紧缩的，但自体和同源的Spem结合在卵黄的外套上。然而，自体精子完全不能阻止同种精子的受精，这表明结合自体精子对受精没有生理学意义。从罗氏绒毛中分离出一种70 kDa的高度疏水糖蛋白，作为精子受体进行了纯化。对该蛋白的N端二十肽和其他四个片段(共60个残基)进行了测序。为了回答自体不育是纯遗传的还是在一定程度上取决于发育过程中的一种克隆选择的问题，我们将8-CCL胚胎解剖成左右两半，形成嵌合体胚胎。没有这样的性成熟嵌合体。

The contact reaction of hemocytes and self-sterility of gametes are typical examples of all-recognition in the ascidians We have found in Halocymhia roreizi that the contact reaction is accompanied with a burst of oxygen consumption by phenol oxidase. Basing upon this finding, we developed a method to quantify the contact reaction Similar bursts were observed when hemocytes were mixed eggs or follicle cells from different individuals.Sperm binding to the vitelline coat is a step of allo- recognition in Ciona imtesinalis. Although H.roreizi is strictly self-stcrile, autologous as well as homologous spem bound to the vitelline coat. However, autologous sperm did not block fertilozation by homologous sperm at all, suggesting that binding of autologous sperm is phusiologically meaningless for fertilization. A highly hydrophobic glycoprotein of 70 kDa isolated from H.roretzi vitcllinc coats was purificd as a sperm-receptor. Thc N-terminal eicosapeptide and four other fragments (sixty residues in total)of this protein were sequenced.In order to answer a question whether self-sterility is purely genetic or it depends to some extent on a kind of clonal selection during devclopment, 8-ccll embryos of C.intestinalis were dissected into left and right halves to make chimeric chimeric embryos. No sexually matured chimeras were so for obtained.