J genes for heavy chain immunoglobulins of mouse

A 15,8-kilobase pair fragment of BALB/c mouse liver DNA, cloned in the Charon 4A lambda phage vector system, was shown to contain the mu heavy chain constant region (CHmu) gene for the mouse immunoglobulin M. In addition, this fragment of DNA contains at least two J genes, used to code for the carboxyl terminal portion of heavy chain variable regions. These genes are located in genomic DNA about eight kilobase pairs to the 5' side of the CHmu gene. The complete nucleotide sequence of a 1120-base pair stretch of DNA that includes the two J genes has been determined.     

Structure of the hinge region of the mu heavy chain of human IgM immunoglobulins

The amino acid sequence around the central disulfide bridge linking the mu heavy chains of the human immunoglobulin M monomer is unlike that in immunoglobulin G. This hinge area contains one of the five oligosaccharides of the mu chain, is low in proline, and is the site of tryptic cleavage to yield Fabmicro and Fcmicro fragments.     

Immunoglobulin M heavy chain disease: intracellular origin of the mu chain fragment

Cells obtained from a patient with mu heavy chain disease synthesize a mu heavy chain fragment with a molecular weight of 55,000. The fragment is detected intracellularly after short labeling times and then is assembled inside the cell and secreted as a disulfide-linked polymer.     

Somatic mutation in genes for the variable portion of the immunoglobulin heavy chain

The size of the gene pool potentially encoding antibodies to p-azophenyl arsonate has been examined. A heavy chain-specific full-length complementary DNA clone has been constructed with the use of messenger RNA from a hybridoma that produces antibodies to the arsonate hapten and bears nearly a full complement of the determinants comprising the cross-reactive idiotype (CRI). The sequences of both the complementary DNA clone and the corresponding immunoglobulin heavy chain have been independently determined. A probe for the variable region gene was prepared from the original heavy chain complementary DNA clone and used to analyze, by Southern filter hybridization, genomic DNA from both A/J (CRI positive) and BALB/c (CRI negative) mice. Approximately 20 to 25 restriction fragments containing "germline" variable region gene segments were detected in both strains, and many are shared by both, Since 35 CRI-positive heavy chains have been partially sequenced thus far and 31 are different, the results of the hybridization analysis suggest that somatic mutation events involving the variable region gene segments of the heavy chain play a role in the origin of the amino acid sequence diversity seen in this system.     

Human immunoglobulin D: genomic sequence of the delta heavy chain

The DNA coding for the human immunoglobulin D(IgD) heavy chain (delta, delta) has been sequenced including the membrane and secreted termini. Human delta, like that of the mouse, has a separate exon for the carboxyl terminus of the secreted form. This feature of human and mouse IgD distinguishes it from all other immunoglobulins regardless of species or class. The human gene is different from that of the mouse; it has three, rather than two, constant region domains; and its lengthy hinge is encoded by two exons rather than one. Except for the third constant region, the human and mouse genes are only distantly related.     

罗非鱼免疫球蛋白（IgM）重链基因全长cDNA序列分析

从已经构建的罗非鱼白细胞cDNA文库中测定获得罗非鱼免疫球蛋白（IgM）重链的eDNA序列,全长1885bp,有一个完整ORF阅读框长1770bp,5’UTR为29bp,3’-UTR为86bp,编码588个氨基酸。罗非鱼与大黄鱼、斜带石斑鱼、南极鳕鱼、乌鳢、鳜鱼、伯氏豚[鱼叚]虎鱼、牙鲆、花狼鱼、硬头鳟的IgM重链氨基酸序列有较高的同源性,最高达到69％,表明已经获得罗非鱼IgM重链基因;对所得氨基酸进行二级结构预测发现,罗非鱼IgM重链基因全长cDNA序列所编码的氨基酸分子量为41453．94Da。该试验结果为罗非鱼IgM重链基因功能的实验性鉴定工作奠定了基础。     

Polymorphism of heavy-chain genes in immunoglobulins of wild mice

The serums of 123 wild mice from six different geographic locations in the United States contain five of the six known heavy-chain antigenic determinants that have been identified in immunoglobulin of inbred laboratory strains of mice. On the basis of the distribution of determinants in inbred strains,44 of the mice were judged to be heterozygotes of various combinations and two had combinations of determinants that were unusual and could only have occurred in laboratory inbred mice by recombination.     

Variation and homology in the mu and gamma heavy chains of human immunoglobulins

Sequence analysis of an 1gM immunoglobulin shows that the variable regions of hunman micro and gamma1 heavy chainis may have twice as much homology as their constant regions and that evolutionary divergence of micro and gamma1 heavy chain genes occurred not long after the separation of heavy and light chain genes.     

西伯利亚鲟免疫球蛋白M重链区mRNA的组织分布和细菌感染后的表达

根据GenBank登录的西伯利亚鲟Acipernser baerii免疫球蛋白M重链区mRNA(IgHM mRNA)设计引物,进行SYBR green实时定量。结果表明:鲟的脑、鳃、性腺、心脏、后肠、肝脏、肌肉、脾脏8种组织中,IgHM mRNA在脾脏中表达最高,在肝脏和心脏中表达较少,在脑、鳃、性腺、后肠、肌肉5种组织中几乎不表达;在水温22.6²4.5℃时,按100 g体质量注射0.1 mL菌液,给体质量为(260.2±37.8)g的西伯利亚鲟注射浓度为2.0×107CFU/mL的维氏气单胞菌Aeromonas veronii,注射后40 h鱼开始死亡,62 h后停止死亡,注射后直至62 h时,处理组脾脏IgHM mRNA表达量一直处于对照组水平,93 h时处理组脾脏IgHM mRNA显著升高(P<0.05),为93 h对照组含量的3.7倍,说明机体已经开始特异性免疫应答。     

Macroglobulin structure: homology of mu and gamma heavy chains of human immunoglobulins

The amino acid sequence of fragments obtained by cyanogen bromide cleavage of the mu-chain of a human gammaM-globulin is homologous to the NH(2)-terminal sequences of the gamma-chain of human and rabbit gammaG-globulins and is related to that of human light chains. This supports the hypothesis that light and heavy chains evolved from a common ancestral gene.     

白来航鸡MHC-I重链基因克隆与序列分析

参照GenBank发表的鸡MHC-Ⅰ重链(BF2)基因序列,设计并合成1对引物,无菌采取纯系来航SPF鸡抗凝静脉血,直接提取总RNA,采用RT-PCR技术,PCR扩增BF2基因,并进行克隆和序列测定。测序结果表明,获得了来航鸡BF2基因,其大小为1 035 bp,包含一个完整阅读框,共编码345个氨基酸。与GenBank上鸡BF2基因序列进行比较,其核苷酸同源性在93.0%~97.6%之间,氨基酸同源性在83.2%~97.1%之间。来航鸡与人和其他种动物的MHC-Ⅰ重链基因核苷酸同源性在12.9%~83.6%之间。     

Human X chromosome carries quantitative genes for immunoglobulin M

Concentrations of immunoglobulin M in serum were one-third higher in females than in males in the Black and White populations of Virginia. In family studies, a much closer correlation was shown between boys and their mothers than between boys and their fathers. The immunoglobulin M concentrations in girls were more closely correlated with those of their fathers than with those of their mothers. The higher mean values for IgM in females and the relative magnitudes of the correlation coefficients between parents and offspring support the hypothesis that the X chromosome of man carries genes with an effect on IgM concentration. These patterns were not demonstrated for immunoglobulins A or G.     

Antigenic determinants common to human immunoglobulins G and M: importance of conformational antigens

Antiserums produced against certain isolated human myeloma IgGglobulins and absorbed in order to show only individual antigenic specificity crossreact with certain Waldenstrom IgM-globulins. Some of the common antigenic determinants revealed by these cross-reactions depend on the tertiary and quaternary structure of the IgG and IgM molecules and are independent of their K and L light-chain antigenic types.     

Natural human antibodies to gram-negative bacteria: immunoglobulins G, A, and M

Significant amounts of immunoglobulins G and M, and a small amount of natural antibodies reactive with Neisseria gonorrhoeae and Escherichia coli, have been detected in human adult serums by imnmunofluorescent techniques. Umbilical cord serums also contained substantial immunoglobulin-G antibody but little or no M or A. These findings challenge the concept that natural antibodies reactive with Gram-negative bacteria are primarily of the immunoglobulin-M class.     

Interactions of immunoglobulins G and M in the detection of the mammalian C-type virus cross-reactive antigen

The mammalian C-type tumor viruses share an antigenic determinant, gs-3, located on the major internal polypeptide of the virion. Detection of this determined in gel diffusion assays by antiserums prepared in rats by immunization with rat tumor homogenates carrying murine virus and serums prepared in a rabbit by immunization with purified murine gs antigen depended on antibodies present in the fractions containing immunoglobulins M and G. The immunoglobulin G fraction by itself precipitated only the homologous murine antigen. Neither fraction alone precipitated heterologous (cat, rat, or hamster) antigen (definition of the gs-3 reaction), while a mixture of the two fractions did. The gs-3 reaction was eliminated by treatment of the serums with beta-mercaptoethanol, also indicating a requirement for immunoglobulin M antibodies.     

甘蓝型油菜细胞质雄性不育恢复基因的分子标记及定位

以甘蓝型油菜恢复系CP015和不育系77A构建的F2群体为供试材料,运用RAPD,SSR和AFLP 3种标记技术,对甘蓝型油菜恢复基因进行分子标记和图谱定位。在260条RAPD引物、185对SSR引物、58对AFLP引物中,在两亲本间筛选多态性高的RAPD引物121条,SSR引物128对,AFLP引物组合26对,进一步通过BSA法筛选,获得了与甘蓝型油菜恢复基因Rf连锁的1个RAPD标记S1009-750和1个AFLP标记E5M11-150,标记与基因Rf之间的遗传距离分别为4.9cM和8.6cM。     

Nlrp基因家族部分免疫相关基因在小鼠上的表达

利用RT-PCR研究Nlrp基因家族中与免疫有关的基因在小鼠中的表达.结果表明,Nlrp10在桑椹胚和囊胚中微量表达,而Nlrp1a、Nlrp1b、Nlrp1c、Nlrp3、Nlrp6和Nlrp12在小鼠附植前胚胎中都不表达;这7个与免疫有关的基因在4周龄小鼠体内不同组织中表达水平有差异,但都在脾脏和肝脏中表达;Nlrp基因家族中与免疫相关基因在小鼠细胞中的表达各不相同,但在卵母细胞中都不表达.结论:Nlrp1a、Nlrp1b、Nlrp1c、Nlrp3、Nlrp6、Nlrp10和Nlrp12与小鼠的先天免疫有关,在小鼠中的不同表达预示着这些基因在先天免疫系统中具有不同功能.     

天蓝色链霉菌M145中bldA依赖性突变的遗传定位与分析

bldA编码天蓝色链霉菌中识别UUA密码的tRNA,大部分菌株的生长不需要bldA功能。M145菌株发生了突变,使bldA成为必需基因。本研究以M145和1258等菌株为亲本,通过3轮杂交筛选构建了菌株LY3,作为遗传定位bldA依赖性(bldA-dependent,bad)突变的亲本之一。用LY3与1258杂交,筛选了217个重组子并鉴定其基因型。对217个重组子的基因型进行遗传分析,将bad突变定位于天蓝色链霉菌染色体SCO3934与SCO4659基因之间的758 kb区域。