Major histocompatibility complex-encoded class I molecules are absent in immunologically competent Xenopus before metamorphosis.
Major histocompatibility complex-encoded class I molecules are absent in immunologically competent Xenopus before metamorphosis.
复制标题
在变态之前，具有免疫活性的非洲爪蟾中不存在主要的组织相容性复合体编码的 I 类分子。
作者：
M. Flajnik;J. Kaufman;E. Hsu;M. Manes;R. Parisot;L. Du Pasquier
I类和II类主要组织相容性复合体（MHC）编码的抗原的表达已被检查在爪蛙，爪蟾的发展的各个阶段。通过与来自放射性标记的脾和胸腺裂解物的同种抗血清或异种抗血清的免疫沉淀，以及通过混合淋巴细胞反应分析，确定在整个个体发育中表达相同的II类分子。与此相反，荧光冷冻切片的蝌蚪和免疫沉淀，I类分子没有检测到蝌蚪，但出现在所有组织中的高潮变态。通过化学处理长期保持为蝌蚪的动物确实表达I类抗原;因此，它们的表达可以独立于变态时发生的其他生物化学和形态学变化。免疫荧光法检测到一个其他未表征的MHC-连接同种异体抗原对蝌蚪胸腺上皮细胞从胸腺分化的最早阶段。
The expression of class I and class II major histocompatibility complex (MHC)-encoded antigens has been examined at various stages of the development of the clawed frog, Xenopus. By immunoprecipitation with alloantisera or xenoantisera from radio-labeled spleen and thymus lysates, and by mixed lymphocyte reaction analysis, it was determined that the same class II molecules are expressed throughout ontogeny. In contrast, by fluorescence on frozen sections of tadpoles and by immunoprecipitation, the class I molecule is not detected in tadpoles, but appears on all tissues at the climax of metamorphosis. Animals maintained as tadpoles for long periods of time by chemical treatment do express class I antigens; thus, their expression can be independent of other biochemical and morphological changes that occur at metamorphosis. Immunofluorescence detects an otherwise uncharacterized MHC-linked alloantigen on tadpole thymic epithelium from the earliest stages of thymus differentiation.