Methods and systems for nucleic acid preparation and chromatin analysis
The present disclosure provides methods and systems for nucleic acid preparation and/or analysis. Nucleic acids may be derived from one or more cells. Nucleic acid preparation may comprise generating nucleic acid molecules of varying lengths. Nucleic acid analysis may comprise identifying nucleic acid sequence information with nucleosome position information.
1. A method for nucleic acid preparation or analysis comprising:
(a) providing a mixture comprising:
(i) a plurality of template deoxyribonucleic acid (DNA) molecules, wherein at least a portion of said plurality of template DNA molecules is in the form of native, intact chromatin comprising one or more nucleosomes;
(ii) a plurality of transposase molecules; and
(iii) a plurality of first nucleic acid molecules each comprising a promoter region and a first sequencing adaptor region;
(b) subjecting said mixture to conditions sufficient to cause transposition of at least some of said plurality of first nucleic acid molecules into said template DNA molecules with the aid of a transposon-nucleic acid complex generated from at least a subset of said plurality of transposase molecules and said plurality of first nucleic acid molecules, to yield a plurality of DNA molecules comprising said promoter region and said first sequencing adaptor region;
(c) generating a plurality of ribonucleic acid (RNA) molecules of varying lengths comprising sequences that correspond to said first sequencing adaptor region using said promoter region; and
(d) reverse transcribing said plurality of RNA molecules using a plurality of template switching oligonucleotides, each comprising a second sequencing adapter region, to generate a plurality of single-stranded DNA molecules comprising said first sequencing adapter region and said second sequencing adapter region, thereby preserving a plurality of nucleosome positioning information from said intact chromatin.
2. The method of claim 1 , further comprising generating from said plurality of single-stranded DNA molecules a plurality of double-stranded DNA molecules.
3. The method of claim 2 , further comprising subjecting said plurality of double-stranded DNA molecules, or a derivative thereof, to sequencing to yield sequences of said plurality of template DNA molecules.
4. The method of claim 3 , wherein said sequences identify one or more positions of said one or more nucleosomes within said native, intact chromatin.
5. The method of claim 1 , wherein said method is performed in a partition.
6. The method of claim 5 , wherein said partition comprises a droplet.
7. The method of claim 1 , wherein said first sequencing adaptor region and said second sequencing adaptor region are attached to different ends of each of said plurality of single-stranded DNA molecules.
8. The method of claim 1 , wherein at least one of said plurality of first nucleic acid molecules further comprises a molecular barcode.
9. The method of claim 1 , wherein at least one of said plurality of template switching oligonucleotides further comprises a molecular barcode.
10. The method of claim 1 , wherein, in (c), said plurality of RNA molecules is generated by in vitro transcription.
11. The method of claim 10 , wherein said in vitro transcription is performed using a polymerase selected from the group consisting of: T7, T3, SP6, and combinations thereof.
12. The method of claim 1 , wherein, in (d), said reverse transcription is performed using a Moloney murine leukemia virus reverse transcriptase, or a functional variant thereof.
13. The method of claim 1 , wherein said first sequencing adaptor region comprises a P5 sequencing adaptor.
14. The method of claim 1 , wherein said second sequencing adaptor region comprises a P7 sequencing adaptor.
15. The method of claim 1 , wherein said transposon-nucleic acid complex comprises two transposase molecules and two transposon molecules.
16. The method of claim 1 , wherein each of said plurality of first nucleic acid molecules comprises a transposon end sequence.
17. The method of claim 16 , wherein said transposon end sequence is a Tn5 or modified Tn5 transposon end sequence.
18. The method of claim 16 , wherein said transposon end sequence comprises a mosaic end sequence.
19. The method of claim 1 , wherein the plurality of template DNA molecules are derived from a single cell.
20. The method of claim 1 , 5 - 9 , 10 , 15 , 17 , 18 or 19 , wherein said RNA molecules of varying lengths correspond to the plurality of nucleosome positioning information from said intact chromatin.