PDF(Pubmed)
Abstract：
In dinoflagellates, a unique and extremely divergent genomic and nuclear organization has evolved. The highly unusual features of dinoflagellate nuclei and genomes include permanently condensed liquid crystalline chromosomes, primarily packaged by proteins other than histones, genes organized in very long unidirectional gene arrays, a general absence of transcriptional regulation, high abundance of the otherwise very rare DNA modification 5-hydroxymethyluracil (5-hmU), and many others. While most of these fascinating properties are originally identified in the 1970s and 1980s, they have not yet been investigated using modern genomic tools.
In this work, we address some of the outstanding questions regarding dinoflagellate genome organization by mapping the genome-wide distribution of 5-hmU (using both immunoprecipitation-based and basepair-resolution chemical mapping approaches) and of chromatin accessibility in the genome of the Symbiodiniaceae dinoflagellate Breviolum minutum. We find that the 5-hmU modification is preferentially enriched over certain classes of repetitive elements, often coincides with the boundaries between gene arrays, and is generally correlated with decreased chromatin accessibility, the latter otherwise being largely uniform along the genome. We discuss the potential roles of 5-hmU in the functional organization of dinoflagellate genomes and its relationship to the transcriptional landscape of gene arrays.
Our results provide the first window into the 5-hmU and chromatin accessibility landscapes in dinoflagellates.
In this work, we address some of the outstanding questions regarding dinoflagellate genome organization by mapping the genome-wide distribution of 5-hmU (using both immunoprecipitation-based and basepair-resolution chemical mapping approaches) and of chromatin accessibility in the genome of the Symbiodiniaceae dinoflagellate Breviolum minutum. We find that the 5-hmU modification is preferentially enriched over certain classes of repetitive elements, often coincides with the boundaries between gene arrays, and is generally correlated with decreased chromatin accessibility, the latter otherwise being largely uniform along the genome. We discuss the potential roles of 5-hmU in the functional organization of dinoflagellate genomes and its relationship to the transcriptional landscape of gene arrays.
Our results provide the first window into the 5-hmU and chromatin accessibility landscapes in dinoflagellates.
摘要：
背景：在鞭毛藻中，一个独特的和极其不同的基因组和核组织已经进化。鞭毛藻核和基因组的极不寻常特征包括永久凝聚的液晶染色体，主要由组蛋白以外的蛋白质包装，组织在很长的单向基因阵列中的基因，普遍缺乏转录调控，高丰度的原本非常罕见的DNA修饰5-羟甲基尿嘧啶（5-hmU），和许多其他人。虽然大多数这些迷人的属性最初是在20世纪70年代和80年代发现的，尚未使用现代基因组工具对它们进行研究。
结果：在这项工作中，我们通过作图5-hmU的全基因组分布(使用基于免疫沉淀和碱基对分辨率的化学作图方法)和共生鞭毛虫科鞭毛虫基因组中染色质的可及性,解决了有关鞭毛虫基因组组织的一些悬而未决的问题.我们发现，5-hmU修饰优先于某些类型的重复元素，通常与基因阵列之间的边界重合，通常与染色质可及性降低相关，否则，后者在基因组上基本上是一致的。我们讨论了5-hmU在鞭毛藻基因组功能组织中的潜在作用及其与基因阵列转录景观的关系。
结论：我们的结果为鞭毛藻的5-hmU和染色质可及性景观提供了第一个窗口。
结果：在这项工作中，我们通过作图5-hmU的全基因组分布(使用基于免疫沉淀和碱基对分辨率的化学作图方法)和共生鞭毛虫科鞭毛虫基因组中染色质的可及性,解决了有关鞭毛虫基因组组织的一些悬而未决的问题.我们发现，5-hmU修饰优先于某些类型的重复元素，通常与基因阵列之间的边界重合，通常与染色质可及性降低相关，否则，后者在基因组上基本上是一致的。我们讨论了5-hmU在鞭毛藻基因组功能组织中的潜在作用及其与基因阵列转录景观的关系。
结论：我们的结果为鞭毛藻的5-hmU和染色质可及性景观提供了第一个窗口。
