基因指纹图谱探索胚胎淋巴细胞克隆发生的规律  

Research the regularity of fetus lymphocyte repertoires ontogeny by gene fingerprinting map.

作　　者：刘继华[1] 朱平[1] 

机构地区：[1]北京大学第一医院,100034

出　　处：《中国优生与遗传杂志》2002年第3期1-3,共3页Chinese Journal of Birth Health & Heredity

基　　金：自然科学基金 (3 9970 3 5 4;3 99793 13 )资助

摘　　要：目的　通过人胚胎发生不同时期的IgH基因指纹图谱 ,观察执行免疫功能的B淋巴细胞克隆是如何发育起来的。方法　提取不同胎龄肝脏、脾脏、骨髓、胸腺标本的RNA ,根据不同淋巴细胞克隆具有不同的IgH基因重排的特点 ,用RT-PCR扩增IgHV1-V6基因 ,变性胶电泳获得人类胚胎B细胞克隆的表达谱系。结果　胎龄 11w大部分B细胞克隆已在肝脏出现 ,13w～ 14w达高峰后迁移至脾脏。脾脏的B细胞克隆于 14w出现 ,19w～ 2 0w达高峰。骨髓的B细胞克隆迟至 17w出现 ,2 5w出现全部表达谱系。有IgH基因家族标志的淋巴细胞克隆出现是有规律的 ,肝脏IgHV6是优势利用的家族 ,而IgHV3为脾脏优势表达的家族 ,骨髓更多利用的基因家族也是IgHV3。胎儿胸腺内也可以有B淋巴细胞克隆表达。结论　人类胚胎B细胞克隆谱系发育有明显规律。在不同脏器 ,具有不同的IgH基因家族标志的淋巴细胞可成为优势克隆 。Objective: How develop lymphocyte repertoires that execute immunology function in human fetus ontogeny by analysis with the immunoglobulin heavy chain (IgH) gene fingerprinting.Methods: Lymphocytes have characteristic clonal markers that formed by gene rearrangement of the immunoglobulin heavy chain (IgH). It can be used to constitute the IgH gene fingerprinting map of expressed B lymphocyte repertoires ontogeny in human fetus via RT-PCR and denaturing polyacromadime gel electrophoresis. The expressed repertoires were constituted by amplification of IgH V1～V6 genes. The mRNA used in RT-PCR was from liver, spleen, bone marrow and thymus of different fetal ages (11～32 week).Results: The expressed B lymphocyte repertoire was detectable in human fetal livers as early as the 11th week of gestation. The majority of the IgH-V families were expressed in livers of 13 and 14-week old fetus. From 15 weeks of gestation onwards,spleens begin to be the major site for B lymphocyte repertoire generation, where the expressed B lymphocyte repertoire occurred initially in 14 weeks of gestation and expressed fullest at 19 weeks of gestation. The level of expression of IgH V families was low in bone marrow until 25 weeks of gestation and gradually increased with the development of fetus. Non-random employment of IgH V families was exhibited and IgH V6, IgH V3 and IgH V3 were dominated in liver, spleen and bone marrow individually. In addition, expressed B lymphocyte repertoire could be detected in fetal thymus, especially early fetus.Conclusions: The development B lymphocyte repertoires in human fetus was regularity. Some lymphocyte clones can become preferential clones in different organs and can change during different fetus stage.

关 键 词：基因指纹图 胚胎 淋巴细胞克隆 

分 类 号：R394[医药卫生—医学遗传学]