Assignment of Rfp-Y to the chicken major histocompatibility complex NOR microchromosome and evidence for high-frequency recombination associated with the nucleolar organizer region
Assignment of Rfp-Y to the chicken major histocompatibility complex NOR microchromosome and evidence for high-frequency recombination associated with the nucleolar organizer region
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DOI：
10.1073/pnas.93.9.3958
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发表时间：
1996-04-30
影响因子：
11.1
通讯作者：
Bloom, SE
中科院分区：
文献类型：
--
作者：
Miller, MM;Goto, RM;Bloom, SE
Rfp-Y 是鸡基因组中的第二个区域，含有主要组织相容性复合体 (MHC) I 类和 II 类基因。 Rfp-Y 的单倍型独立于 B 系统的单倍型分类，B 系统的单倍型已知具有 MHC 功能，位于 16 号染色体（微染色体）上，在鸡基因组中具有单个核仁组织区 (NOR)。与参考群体的连锁作图未能揭示 Rfp-Y 的位置，导致 Rfp-Y 在包含超过 400 个标记的图中未连锁。在对 16 号染色体三体鸡的研究中，当注意到与 Rfp-Y 相关的限制性片段的强度随着 16 号染色体拷贝数的增加而增加时，Rfp-Y 的可能位置变得明显。当发现 16 号染色体三体体个体传递三种 Rfp-Y 单倍型时，获得了 Rfp-Y 可能位于 16 号染色体上的进一步证据。最后，将鸡 R-IHC 基因（包含 MHC II 类基因和两个 rRNA 基因）分子图谱的粘粒簇 LII 映射到 Rfp-Y，验证了 Rfp-Y 与 MHC/NOR 微染色体的分配。现在可以用 Rfp-Y 绘制鸡 16 号染色体的一部分的遗传图谱，其中包含两个 MHC I 类和三个 MHC II 类基因，通过包含 NOR 的区域与 B 系统分开，并表现出高频重组。
Rfp-Y is a second region in the genome of the chicken containing major histocompatibility complex (MHC) class I and II genes. Haplotypes of Rfp-Y assort independently from haplotypes of the B system, a region known to function as a MHC and to be located on chromosome 16 (a microchromosome) with the single nucleolar organizer region (NOR) in the chicken genome. Linkage mapping with reference populations failed to reveal the location of Rfp-Y, leaving Rfp-Y unlinked in a map containing >400 markers. A possible location of Rfp-Y became apparent in studies of chickens trisomic for chromosome 16 when it was noted that the intensity of restriction fragments associated with Rfp-Y increased with increasing copy number of chromosome 16. Further evidence that Rfp-Y might be located on chromosome 16 was obtained when individuals trisomic for chromosome 16 were found to transmit three Rfp-Y haplotypes. Finally, mapping of cosmid cluster LII of the molecular map of chicken R-IHC genes (containing a MHC class II gene and two rRNA genes) to Rfp-Y validated the assignment of Rfp-Y to the MHC/NOR microchromosome. A genetic map can now be drawn for a portion of chicken chromosome 16 with Rfp-Y, encompassing two MHC class I and three MHC class II genes, separated from the B system by a region containing the NOR and exhibiting highly frequent recombination.