Human Satellite 1 (HSAT1) analysis provides novel evidence of pericentromeric transcription

Pericentromeric regions of human chromosomes are composed of tandem-repeated and highly organized sequences named satellite DNAs. Although being known for a long time as the most AT-rich fraction of the human genome, classical satellite HSAT1 has been disregarded in genomic and transcriptional studies, falling behind other human satellites in terms of knowledge. The path followed herein trails with HSAT1 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. HSAT1 was mapped in human chromosomes and applied in in situ transcriptional assays. Additionally, it was possible to observe the nuclear organization of HSAT1 transcripts and further characterize them by 3 RACE-Seq. Size-varying polyadenylated HSAT1 transcripts were detected, which possibly accounts for the intricate regulation of alternative polyadenylation. As far as we know, this work pioneers HSAT1 transcription studies. With the emergence of new human genome assemblies, acrocentric pericentromeres are becoming relevant characters in disease and other biological contexts. HSAT1 sequences and associated noncoding RNAs will most certainly prove significant in the future of HSAT research.