Microchromosomes are common yet poorly understood components of many vertebrate genomes. Recent studies have revealed that microchromosomes contain a high density of genes and possess other distinct characteristics compared to macrochromosomes. Whether distinctive characteristics of microchromosomes extend to features of genome structure and organization, however, remains an open question. Here we analyze Hi-C sequencing data from multiple vertebrate lineages and show that microchromosomes exhibit consistently high degrees of interchromosomal interaction (particularly with other microchromosomes), appear to be co-localized to a common central nuclear territory, and are comprised of a higher proportion of open chromatin than macrochromosomes. These findings highlight an unappreciated level of diversity in vertebrate genome structure and function, and raise important questions regarding the evolutionary origins and ramifications of microchromosomes and the genes that they house.

中文翻译：

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微染色体表现出脊椎动物染色体结构和功能的独特特征，而对基因组进化的认识不足

微染色体是许多脊椎动物基因组的常见但了解甚少的组成部分。最近的研究表明，与大染色体相比，微染色体包含高密度的基因并具有其他独特的特征。然而，微染色体的独特特征是否扩展到基因组结构和组织的特征，仍然是一个悬而未决的问题。在这里，我们分析了来自多个脊椎动物谱系的Hi-C测序数据，结果表明，微染色体始终表现出高度的染色体间相互作用（尤其是与其他微染色体），似乎共定位于一个共同的中央核区域，并且所占比例较高开放染色质比大染色体 这些发现突显了脊椎动物基因组结构和功能的多样性水平未得到重视，