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 an array comprising a plurality of capture probes affixed to the array, wherein a capture probe comprises: (i) a spatial barcode and (ii) a capture domain;
(b) contacting a plurality of first probes and second probes to a biological sample on the array, wherein the first probes and second probes target a plurality of nucleic acids in the biological sample,
wherein a first probe comprises a first sequence that is substantially complementary to a first target sequence of the target nucleic acid;
wherein a second probe comprises:
a second sequence that is substantially complementary to a second target sequence of the target nucleic acid;
a third sequence that is substantially complementary to a third target sequence of the target nucleic acid; and
wherein the first probe or the second probe comprises a capture probe capture domain that is complementary to all or a portion of the capture domain of the capture probes affixed to the array;
(c) hybridizing the first probe to the first sequence and the second probe to the second sequence and the third sequence;
(d) generating a ligation product by ligating the first probe and the second probe;
(e) hybridizing the ligation product to the capture domain of the capture probe; and
(f) determining (i) all or part of the sequence of the ligation product hybridized 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 second target sequence and the third target sequence are on different exons of the target nucleic acid.
3. The method of claim 1 , wherein the second target sequence and the third target sequence are located within the same exon of the target nucleic acid but are not adjacent on the target nucleic acid.
4. The method of claim 1 , wherein the second probe further comprises a linker sequence between the second sequence and the third sequence, wherein the linker sequence is about 1 nucleotide to about 100 nucleotides in length.
5. The method of claim 4 , wherein the linker sequence comprises a barcode sequence that serves as a proxy for identifying the target nucleic acid.
6. The method of claim 1 , wherein the first probe and the second probe are substantially complementary to adjacent sequences of the target nucleic acid.
7. The method of claim 1 , where the first probe and the second probe hybridize to sequences that are not adjacent to each other on the target nucleic acid.
8. The method of claim 7 , wherein the first probe is extended with a DNA polymerase, thereby (i) filling in a gap between the first probe and the second probe and (ii) generating an extended first probe.
9. 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.
10. 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.
11. The method of claim 1 , wherein the generating the ligation product comprises ligating the first probe to the second probe using enzymatic ligation or chemical ligation, wherein the enzymatic ligation utilizes a ligase.
12. The method of claim 11 , wherein the ligase is one or more of a T4 RNA ligase (Rnl2), a PBCV-1 ligase, a single stranded DNA ligase, or a T4 DNA ligase.
13. The method of claim 1 , wherein the first probe or the second probe further comprises a primer sequence.
14. The method of claim 1 , further comprising providing a capture probe capture domain blocking moiety that interacts with the capture probe capture domain sequence.
15. The method of claim 14 , further comprising releasing the capture probe capture domain blocking moiety from the capture probe capture domain sequence prior to step (e).
16. The method of claim 1 , wherein the first probe and/or the second probe is a DNA probe.
17. The method of claim 1 , wherein step (d) further comprises releasing the ligation product from the target nucleic acid, wherein releasing 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, or hematoxylin and 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 RNA.
24. The method of claim 23 , wherein the RNA is an mRNA.
25. The method of claim 1 , wherein the determining step (f) comprises amplifying all or part of the ligation product, thereby generating an amplified product, and wherein the amplified product comprises (i) all or part of the sequence of the ligation product, or a complement thereof, and (ii) the sequence of the spatial barcode, or a complement thereof.
26. The method of claim 1 , wherein the determining step (f) 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.
27. The method of claim 26 , wherein the sequencing comprises in situ sequencing, Sanger sequencing methods, and next-generation sequencing methods.
28. A kit for determining a location of a target nucleic acid in a biological sample, the kit comprising:
(a) an array comprising a plurality of capture probes affixed to the array, wherein a capture probe comprises a spatial barcode and a capture domain, wherein the spatial barcode comprises a sequence that provides a location of an analyte in a biological sample;
(b) a first probe and a second probe,
wherein the first probe comprises a first sequence that is substantially complementary to a first target sequence of the target nucleic acid,
wherein a second probe comprises:
a second sequence that is substantially complementary to a second target sequence of the target nucleic acid,
a third sequence that is substantially complementary to a third target sequence of the target nucleic acid, and
wherein the first probe or the second probe comprises a capture probe capture domain sequence that is complementary to all or a portion of the capture domain of the capture probes affixed to the array;
(c) an RNAse; and
(d) instructions for performing the method of claim 2 .
29. The kit of claim 28 , further comprising a ligase.
30. A kit for determining a location of a target nucleic acid in a biological sample, the kit comprising:
(a) an array comprising a plurality of capture probes affixed to the array, wherein a capture probe comprises a spatial barcode and a capture domain, wherein the spatial barcode comprises a sequence that provides a location of an analyte in a biological sample;
(b) a first probe and a second probe, wherein the first probe and the second probe each comprise one or more sequences that are substantially complementary to sequences of the analyte, and wherein one of the first probe or the second probe comprises a capture probe capture domain that is substantially complementary to the capture domain of the capture probe on the array; and
(c) instructions for performing a method for determining a location of the target nucleic acid in a biological sample, the method comprising:
(A) providing the array;
(B) contacting a plurality of first probes and second probes to a biological sample on the array;
(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) hybridizing the ligation product to the capture domain of the capture probe affixed on the array; and
(G) determining (i) all or part of the sequence of the ligation product hybridized 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.