The immunoglobulin heavy chain locus of the duck - Genomic organization and expression of D, J, and C region genes
The immunoglobulin heavy chain locus of the duck - Genomic organization and expression of D, J, and C region genes
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DOI：
10.1074/jbc.m106221200
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发表时间：
2001-12-14
影响因子：
4.8
通讯作者：
Warr, GW
中科院分区：
文献类型：
--
作者：
Lundqvist, ML;Middleton, DL;Warr, GW
鸭IgH基因座从上游的近端多样性（D）段下游的恒定基因簇的区域已被克隆和定位。48，796个碱基对的序列重叠群确定了基因的组织是D-J（H）-mu-alpha-upper。没有证据表明δ基因的功能同源物（或残基）被发现。α基因是反向转录方向;类转换为伊加表达，因此需要反转类似于27-β-淀粉酶对区域，包括μ和α基因。鸭α和μ的分泌形式各自由4个恒定区外显子编码，并且α和tx的膜受体形式的疏水C-末端区域分别由一个和两个跨膜外显子编码。通过与鸡S mu和S uppergene序列比较，确定了鸭mu和uppergene的推定开关（S）区域，并通过与小鼠S α比较，确定了鸭α的推定开关（S）区域。鸭IgH基因座是丰富的复杂的可变数目的串联重复序列，占据了类似的60%的测序区域，并发生在IgH基因座比在其他测序区域的鸭基因组中的频率要高得多。
The region of the duck IgH locus extending from upstream of the proximal diversity (D) segment to downstream of the constant gene cluster has been cloned and mapped. A sequence contig of 48,796 base pairs established that the organization of the genes is D-J(H)-mu-alpha-upsilon. No evidence for a functional homologue (or remnant) of a delta gene was found. The a gene is in inverted transcriptional orientation; class switch to IgA expression thus requires inversion of the similar to 27-kilobase pair region that includes both mu and alpha genes. The secreted forms of duck alpha and mu are each encoded by 4 constant region exons, and the hydrophobic C-terminal regions of the membrane receptor forms of a and tx are encoded by one and two transmembrane exons, respectively. Putative switch (S) regions were identified for duck mu and upsilon by comparison with chicken S mu and S upsilon sequences and for duck alpha by comparison with mouse S alpha. The duck IgH locus is rich in complex variable number tandem repeats, which occupy similar to 60% of the sequenced region, and occur at a much higher frequency in the IgH locus than in other sequenced regions of the duck genome.