The major horse satellite DNA family is associated with centromere competence.
The major horse satellite DNA family is associated with centromere competence.
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DOI：
10.1186/s13039-016-0242-z
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发表时间：
2016
影响因子：
1.3
通讯作者：
Giulotto E
中科院分区：
文献类型：
--
作者：
Cerutti F;Gamba R;Mazzagatti A;Piras FM;Cappelletti E;Belloni E;Nergadze SG;Raimondi E;Giulotto E
着丝粒是细胞分裂过程中染色体正确分离所需的特殊位点。大多数真核着丝粒的DNA由串联重复序列（卫星DNA）的扩展阵列组成。在马的研究中，我们先前发现，尽管11号染色体的着丝粒完全没有串联重复序列，但所有其他着丝粒都以卫星DNA的存在为特征。从马属4个种中分离出3条马卫星DNA序列（37cen、2P1和EC137），并对其染色体定位进行了分析。在这里提出的工作中，使用ChIP-seq方法，我们表明，在马，37厘米卫星结合CENP-A，着丝粒特异性组蛋白h3变体。由CENP-A结合的37厘米序列富含gc，具有221个bp单位，以头到尾的方式组织。通过槽印迹实验证实了CENP-A与37cen的物理相互作用。对拉伸的染色体和染色质纤维的免疫- fish研究表明，卫星DNA拉伸的延伸是可变的，与CENP-A结合结构域的组织无关。最后，我们证明了着丝粒卫星37cen具有转录活性。我们的数据为马着丝粒的组织提供了新的见解。虽然三个不同的卫星DNA家族在细胞遗传学上位于着丝粒，但只有37cen家族与着丝粒功能有关。此外，与其他物种相似，CENP-A结合结构域的大小是可变的。我们观察到的37厘米卫星的转录能力为着丝粒功能可能需要着丝粒转录本的假设提供了新的证据。本文的在线版本（doi:10.1186/s13039-016-0242-z）包含补充材料，仅供授权用户使用。
The centromere is the specialized locus required for correct chromosome segregation during cell division. The DNA of most eukaryotic centromeres is composed of extended arrays of tandem repeats (satellite DNA). In the horse, we previously showed that, although the centromere of chromosome 11 is completely devoid of tandem repeat arrays, all other centromeres are characterized by the presence of satellite DNA. We isolated three horse satellite DNA sequences (37cen, 2P1 and EC137) and described their chromosomal localization in four species of the genus Equus. In the work presented here, using the ChIP-seq methodology, we showed that, in the horse, the 37cen satellite binds CENP-A, the centromere-specific histone-H3 variant. The 37cen sequence bound by CENP-A is GC-rich with 221 bp units organized in a head-to-tail fashion. The physical interaction of CENP-A with 37cen was confirmed through slot blot experiments. Immuno-FISH on stretched chromosomes and chromatin fibres demonstrated that the extension of satellite DNA stretches is variable and is not related to the organization of CENP-A binding domains. Finally, we proved that the centromeric satellite 37cen is transcriptionally active. Our data offer new insights into the organization of horse centromeres. Although three different satellite DNA families are cytogenetically located at centromeres, only the 37cen family is associated to the centromeric function. Moreover, similarly to other species, CENP-A binding domains are variable in size. The transcriptional competence of the 37cen satellite that we observed adds new evidence to the hypothesis that centromeric transcripts may be required for centromere function. The online version of this article (doi:10.1186/s13039-016-0242-z) contains supplementary material, which is available to authorized users.