A Classical Revival: Human Satellite DNAs Enter The Genomics Era

Abstract

The classical human satellite DNAs, also referred to as human satellites 1, 2 and 3 (HSat1, HSat2, HSat3, collectively HSat1-3) constitute the largest individual arrays of tandemly repeated DNA sequences in the genome. Even though they were among the first human DNA sequences to be isolated and characterized at the dawn of molecular biology, HSat1-3 have been left behind in the genomics era and remain among the most enigmatic sequences in the human genome. Although HSat1-3 total roughly 3% of the genome on average, they were almost entirely missing from the human genome reference assembly for 20 years. Recently, the Telomere-to-Telomere Consortium produced the first truly complete assembly of a human genome, including the enormous HSat1-3 arrays, opening them up for a new wave of discovery. Towards this end, here, I provide an account of the history and current understanding of HSat1-3 genomics, evolution, and roles in disease.

HSF1-Activated Non-Coding Stress Response: Satellite lncRNAs and Beyond, an Emerging Story with a Complex Scenario

“…The majority of them contain, as a major component, a single family of simple repeated satellite (SAT) sequences formed by the classical satellites I, II and III. Of these, SATIII are characterized by the high frequency of the sat3 motif [19][20][21] (also see Table 2, associated references [20][21][22][23][24][25][26][27][28][29]). More recent sequencing analysis of human satellite regions led to a more refined identification of chromosome-specific satellite 2 and 3 motifs with the identification of 10 subfamilies, each displaying specific chromosome-specific distributions [27].…”