Human Satellite 1A analysis provides evidence of pericentromeric transcription

BackgroundPericentromeric regions of human chromosomes are composed of tandem-repeated and highly organized sequences named satellite DNAs. Human classical satellite DNAs are classified into three families named HSat1, HSat2, and HSat3, which have historically posed a challenge for the assembly of the human reference genome where they are misrepresented due to their repetitive nature. Although being known for a long time as the most AT-rich fraction of the human genome, classical satellite HSat1A has been disregarded in genomic and transcriptional studies, falling behind other human satellites in terms of functional knowledge. Here, we aim to characterize and provide an understanding on the biological relevance of HSat1A.ResultsThe path followed herein trails with HSat1A isolation and cloning, followed by in silico analysis. Monomer copy number and expression data was obtained in a wide variety of human cell lines, with greatly varying profiles in tumoral/non-tumoral samples. HSat1A was mapped in human chromosomes and applied in in situ transcriptional assays. Additionally, it was possible to observe the nuclear organization of HSat1A transcripts and further characterize them by 3 ' RACE-Seq. Size-varying polyadenylated HSat1A transcripts were detected, which possibly accounts for the intricate regulation of alternative polyadenylation.ConclusionAs far as we know, this work pioneers HSat1A transcription studies. With the emergence of new human genome assemblies, acrocentric pericentromeres are becoming relevant characters in disease and other biological contexts. HSat1A sequences and associated noncoding RNAs will most certainly prove significant in the future of HSat research.

Automated summary

This study aims to characterize and understand the biological relevance of HSat1A. Through in vitro isolation, gene cloning, and in vivo transcription analysis, the mapping and function of HSat1A in human chromosomes were identified. It was found that the polyadenylation status of HSat1A transcripts varies, suggesting a potential role in alternative polyadenylation regulation. This research is significant for understanding the transcriptional mechanism of HSat1A and its involvement in disease development.