Methods for spatial analysis using RNA-templated ligation
Provided herein are methods of detecting an analyte of interest to interrogate spatial gene expression in a sample using RNA-templated ligation.
1. A method for determining a location of a target nucleic acid in a biological sample comprising:
(a) providing the biological sample placed on a first substrate;
(b) contacting a plurality of first probes and second probes to the biological sample, wherein the plurality of first probes and second probes target a plurality of nucleic acids in the biological sample, wherein a first probe and a second probe of the plurality comprise sequences that are substantially complementary to sequences that are not adjacent to each other on the target nucleic acid, and wherein the second probe comprises a capture probe capture domain sequence that is complementary to all or a portion of a capture domain of a capture probe;
(c) hybridizing the first probe and the second probe to the target nucleic acid;
(d) generating a ligation product by ligating the first probe and the second probe;
(e) releasing the ligation product from the target nucleic acid;
(f) hybridizing the ligation product to the capture domain of the capture probe affixed on an array, wherein the capture probe further comprises a spatial barcode; and
(g) determining (i) all or part of the sequence of the ligation product bound to the capture domain, or a complement thereof, and (ii) the sequence of the spatial barcode, or a complement thereof, and using the determined sequences of (i) and (ii) to determine the location of the target nucleic acid in the biological sample.
2. The method of claim 1 , wherein the first probe is extended, thereby (i) filling in a gap between the first probe and the second probe and (ii) generating an extended first probe.
3. The method of claim 2 , wherein the first probe is extended via a Mu polymerase, a DNA polymerase, an RNA polymerase, a reverse transcriptase, a VENT polymerase, or a Taq polymerase.
4. The method of claim 2 , wherein the first probe is extended via a DNA polymerase.
5. The method of claim 2 , wherein generating the ligation product comprises ligating the extended first probe to the second probe using chemical ligation.
6. The method of claim 2 , wherein generating the ligation product comprises ligating the extended first probe to the second probe using a ligase selected from a T4 RNA ligase (Rnl2), a PBCV-1 ligase, a single stranded DNA ligase, or a T4 DNA ligase.
7. The method of claim 1 , wherein the first probe and the second probe hybridize to sequences that are at least 5, at least 10, at least 15, or at least 20 nucleotides apart.
8. The method of claim 1 , wherein the determining further comprises identifying presence or absence of one or more of a splice variant, an intron/exon junction, an insertion or deletion, a genetic variant, or a single nucleotide polymorphism.
9. The method of claim 1 , wherein the array is on the first substrate.
10. The method of claim 1 , wherein the array is on a second substrate.
11. The method of claim 10 , wherein the first substrate is aligned with the second substrate, such that at least a portion of the biological sample is aligned with at least a portion of the array.
12. The method of claim 1 , wherein the first probe, the second probe, or both the first probe and the second probe comprises a primer sequence.
13. The method of claim 1 , wherein the second probe comprises the capture probe capture domain sequence and the first probe comprises a primer sequence.
14. The method of claim 1 , wherein the first probe and/or the second probe is a DNA probe.
15. The method of claim 1 , wherein the contacting the first probe and the second probe with the biological sample comprises contacting the biological sample with 5000 or more probe pairs comprising the first probe and the second probe.
16. The method of claim 1 , wherein the contacting the first probe and the second probe with the biological sample comprises contacting the biological sample with 100 or more probe pairs comprising the first probe and the second probe.
17. The method of claim 1 , wherein releasing the ligation product comprises contacting the biological sample with an endoribonuclease.
18. The method of claim 17 , wherein the endoribonuclease is an RNase H enzyme.
19. The method of claim 1 , wherein the biological sample is a formalin-fixed, paraffin-embedded tissue sample, a fresh tissue sample, or a frozen tissue sample.
20. The method of claim 1 , wherein the biological sample is a formalin-fixed, paraffin-embedded tissue sample.
21. The method of claim 1 , wherein the biological sample was previously stained using immunofluorescence, immunohistochemistry, hematoxylin, or eosin.
22. The method of claim 1 , further comprising contacting the biological sample with a permeabilization agent, wherein the permeabilization agent comprises proteinase K or pepsin.
23. The method of claim 1 , wherein the target nucleic acid comprises mRNA.
24. The method of claim 1 , wherein the determining step comprises sequencing (i) all or a part of the sequence of the ligation product, or a complement thereof, and (ii) the sequence of the spatial barcode, or a complement thereof.
25. A composition comprising:
(a) a biological sample placed on a first substrate, wherein the biological sample comprises a target nucleic acid; and
(b) an array comprising a plurality of capture probes, wherein a capture probe of the plurality of capture probes comprises (i) a spatial barcode comprising a sequence that provides a location of the target nucleic acid and (ii) a capture domain;
(c) a ligation product comprising a first probe and a second probe, wherein the first probe and the second probe each comprise a sequence that is substantially complementary to sequences that are not adjacent to each other on the target nucleic acid, and wherein one of the first probe or the second probe comprises a capture probe capture domain that is hybridized to the capture domain of the capture probe; and
(d) a polymerase.
26. The composition of claim 25 , wherein the polymerase is selected from a Mu polymerase, a DNA polymerase, an RNA polymerase, a reverse transcriptase, a VENT polymerase, or a Taq polymerase.
27. The composition of claim 25 , wherein the polymerase is a DNA polymerase.
28. The composition of claim 25 , wherein the array is on a second substrate.
29. The composition of claim 28 , wherein the first substrate is aligned with the second substrate, such that at least a portion of the biological sample is aligned with at least a portion of the array.
30. The composition of claim 28 , further comprising 100 or more probe pairs, wherein a probe pair of the 100 or more probe pairs comprises the first probe and the second probe that are ligated together, thereby generating a ligation product, and wherein the ligation product is hybridized to the capture domain of the capture probe on the second substrate.