Linkage of two pseudogenes from V kappa 1 and V kappa 9 murine immunoglobulin families.
Linkage of two pseudogenes from V kappa 1 and V kappa 9 murine immunoglobulin families.
复制标题
来自 V kappa 1 和 V kappa 9 鼠免疫球蛋白家族的两个假基因的连锁。
DOI：
10.1016/0161-5890(92)90015-p
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发表时间：
1992
影响因子：
3.6
通讯作者：
Gearhart,PJ
中科院分区：
文献类型：
--
作者：
Lawler,AM;Umar,A;Gearhart,PJ
作为小鼠Vκ基因座分子分析的第一步，用代表10个Vκ家族的探针筛选BALB/cJ小鼠肝脏DNA的粘粒文库。在从初始筛选中分离的8个互补序列中，5个含有与探针杂交的单个限制性片段。两个互补序列含有两个与同一探针Vκ4杂交的片段，表明某些Vκ4基因片段是连锁的。一个粘粒含有两个属于不同家族的基因，Vκ1和Vκ9。这两个基因片段彼此位于12 kb以内，并且处于相同的转录方向。来自Vκ1和Vκ9家族的基因片段的连锁与该基因座的遗传图谱一致，并首次提供了来自不同家族的两个基因在小鼠κ基因座中紧密连锁的物理证据。序列分析表明，这两个基因都是假基因：Vκ B1.7基因片段有8个突变，包括终止密码子、插入和缺失，Vκ B9B.8基因片段有2个突变，即插入和改变的RNA剪接位点。这两个基因都有可能根据它们的七聚体-九聚体基序的序列进行重排。假基因的鉴定提出了一个问题，即在小鼠生殖细胞库中存在多少非功能性基因。
As an initial step towards the molecular analysis of the murine Vκlocus, a cosmid library from BALB/cJ mouse liver DNA was screened with probes representing 10 Vκfamilies. Of eight cosmids that were isolated from the initial screen, five contained a single restriction fragment that hybridized to the probes. Two cosmids contained two fragments that hybridized to the same probe, Vκ4, indicating that some Vκ4 gene segments are linked. One cosmid had two genes that belonged to different families, Vκ1 and Vκ9. The two gene segments were located within 12 kb of each other and lay in the same transcriptional orientation. Linkage of gene segments from the Vκ1 and Vκ9 families is consistent with a genetic map of the locus, and provides physical evidence for the first time that two genes from different families are closely linked in the murine κ locus. Sequence analysis revealed that both genes are pseudogenes: the VκΨ 1.7 gene segment has eight mutations, including termination codons, insertions, and deletions, and the VκΨ 9B.8 gene segment has two mutations of an insertion and altered RNA splice site. Both genes have the potential to rearrange based on the sequence of their heptamer-nonamer motifs. The identification of pseudogenes raises the question of how many nonfunctional genes are present in the murine germline repertoire.