Update CHANGELOG

CHANGELOG.md

@@ -7,12 +7,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- `translate` functionality for `Haplotype`s ([#31](https://github.com/BioJulia/SequenceVariation.jl/pull/31))
+
 ## [0.2.0] - 2023-01-10
 
 ### Added
 
 - Tutorial-type documentation ([#28](https://github.com/BioJulia/SequenceVariation.jl/pull/28))
-- `Base.isless` implementation for `Edit` and `Variation` ([#31](https://github.com/BioJulia/SequenceVariation.jl/pull/31))
+- `Base.isless` implementation for `Edit` and `Variation` ([#32](https://github.com/BioJulia/SequenceVariation.jl/pull/32))
 
 ### Changed
 

docs/src/api.md

@@ -22,6 +22,7 @@ Haplotype
 reference(::Haplotype)
 variations
 reconstruct
+translate(::Haplotype{S,T}, ::PairwiseAlignment{S,S}) where {S,T}
 ```
 
 ## Variations
@@ -30,7 +31,7 @@ reconstruct
 Variation
 reference(::Variation)
 mutation
-translate
+translate(::Variation{S,T}, ::PairwiseAlignment{S,S}) where {S,T}
 refbases
 altbases
 ```

docs/src/haplotypes.md

@@ -38,3 +38,18 @@ human2 = reconstruct(bos_human_haplotype)
 human2 == bovine
 human2 == human
 ```
+
+## Reference switching
+
+All variations within a haplotype can be mapped to a new reference sequence
+given an alignment between the new and old references using the
+[`translate`](@ref translate(::Haplotype{S,T}, ::PairwiseAlignment{S,S}) where {S,T})
+function. This could be useful if variants were called against a reference
+sequence for the entire species, but need to be analyzed as variants of a
+subtype later.
+
+```@repl call_variants
+ovis_human_alignment =
+    PairwiseAlignment(AlignedSequence(human, Alignment("32M", 1, 1)), ovine)
+SequenceVariation.translate(bos_ovis_haplotype, ovis_human_alignment)
+```

docs/src/variations.md

@@ -54,13 +54,15 @@ variations(bos_human_haplotype)
 ## Reference switching
 
 An individual variation can be mapped to a new reference sequence given an
-alignment between the new and old references using the [`translate`](@ref).
+alignment between the new and old references using the
+[`translate`](@ref translate(::Variation{S,T}, ::PairwiseAlignment{S,S}) where {S,T})
+function.
 
 ```@repl call_variants
 ovis_human_alignment =
     PairwiseAlignment(AlignedSequence(human, Alignment("32M", 1, 1)), ovine)
 human_variation = first(variations(bos_ovis_haplotype))
 reference(ans) == bovine
-SequenceVariation.translate(human_variation, ovis_human_haplotype)
+SequenceVariation.translate(human_variation, ovis_human_alignment)
 reference(ans) == bovine
 ```

src/Haplotype.jl

@@ -198,3 +198,23 @@ function reconstruct(h::Haplotype)
     end
     return seq
 end
+
+"""
+    translate(hap::Haplotype{S,T}, aln::PairwiseAlignment{S,S}) where {S,T}
+
+Convert the variations in `hap` to a new reference sequence based upon `aln`. The alignment
+rules follow the conventions of
+[`translate(::Variation, PairwiseAlignment)`](@ref translate(::Variation{S,T}, ::PairwiseAlignment{S,S}) where {S,T}).
+Indels at the beginning or end may not be preserved. Returns a new
+[`Haplotype`](@ref)
+"""
+function translate(hap::Haplotype{S,T}, aln::PairwiseAlignment{S,S}) where {S,T}
+    vars = variations(hap)
+    new_ref = BA.sequence(aln)
+    translated_vars = Variation{S,T}[]
+    for v in vars
+        new_v = translate(v, aln)
+        isnothing(new_v) || push!(translated_vars, new_v)
+    end
+    return Haplotype(new_ref, translated_vars)
+end

src/Variation.jl

@@ -138,7 +138,7 @@ function translate(var::Variation{S,T}, aln::PairwiseAlignment{S,S}) where {S,T}
     if iszero(pos)
         (s, r), _ = iterate(aln)
         (isgap(s) | isgap(r)) && return Inapplicable()
-        return Variation{S,T}(seq, Edit{S,T}(Insertion(var.edit.x), 0))
+        return Variation{S,T}(seq, Edit{S,T}(Insertion(kind.seq), 0))
     end
 
     (seqpos, op) = BA.ref2seq(aln, pos)
@@ -153,18 +153,19 @@ function translate(var::Variation{S,T}, aln::PairwiseAlignment{S,S}) where {S,T}
         # If it's a deletion, return nothing if the deleted part is already missing
         # from the new reference.
         (stop, op2) = BA.ref2seq(aln, pos + length(kind) - 1)
-        start = seqpos + op == BA.OP_DELETE
-        start < stop && return nothing
-        edit = Edit{S,T}(Deletion(stop - start + 1), start)
+        start = seqpos + (op == BA.OP_DELETE)
+        del_len = stop - start + 1
+        del_len > 0 || return nothing
+        edit = Edit{S,T}(Deletion(del_len), start)
         return Variation{S,T}(seq, edit, Unsafe())
     else
         # If it maps directly to a symbol, just insert
         if op in (BA.OP_MATCH, BA.OP_SEQ_MATCH, BA.OP_SEQ_MISMATCH)
             # This happens if there is already an insertion at the position
-            if pos != lastindex(ref) && first(ref2seq(aln, pos + 1)) != seqpos + 1
+            if pos != lastindex(ref) && first(BA.ref2seq(aln, pos + 1)) != seqpos + 1
                 return Inapplicable()
             else
-                edit = Edit{S,T}(Insertion(var.edit.x), seqpos)
+                edit = Edit{S,T}(Insertion(mutation(var).seq), seqpos)
                 return Variation{S,T}(seq, edit, Unsafe())
             end
             # Alternatively, it can map to a deletion. In that case, it become really

test/runtests.jl

@@ -24,16 +24,25 @@ TODO now:
 """
 
 using Aqua
-using BioAlignments
-using BioSequences
+using BioAlignments:
+    AffineGapScoreModel,
+    GlobalAlignment,
+    EDNAFULL,
+    pairalign,
+    Alignment,
+    AlignedSequence,
+    PairwiseAlignment
+using BioSequences: BioSequence, @dna_str, ungap!
+using BioSymbols: DNA_A
 using SequenceVariation
 using Test
 
-const DNA_MODEL = BioAlignments.AffineGapScoreModel(EDNAFULL; gap_open=-25, gap_extend=-2)
+const DNA_MODEL = AffineGapScoreModel(EDNAFULL; gap_open=-25, gap_extend=-2)
 
 align(a::BioSequence, b::BioSequence) = pairalign(GlobalAlignment(), a, b, DNA_MODEL).aln
 seq1 = ungap!(dna"--ATGCGTGTTAGCAAC--TTATCGCG")
 seq2 = ungap!(dna"TGATGCGTGT-AGCAACACTTATAGCG")
+seq3 = ungap!(dna"-GATGCGTGT-AGCAACACTTATCGC-")
 var = Haplotype(align(seq1, seq2))
 
 @testset "EditSorting" begin
@@ -60,6 +69,16 @@ end
     @test Variation(seq2, "A3T") < Variation(seq2, "T4A")
 end
 
+@testset "HaplotypeTranslation" begin
+    ref1 = seq2
+    ref2 = seq3
+    alt = seq1
+
+    @test all(
+        v -> v in Haplotype(align(alt, ref2)), variations(translate(var, align(ref2, ref1)))
+    )
+end
+
 @testset "VariationPosition" begin
     refseq = dna"ACAACTTTATCT"
     mutseq = dna"ACATCTTTATCT"
@@ -95,6 +114,49 @@ end
     @test first(variations(var)) == sub
 end
 
+@testset "VariationTranslation" begin
+    ref1 = seq2
+    ref2 = seq3
+    ref3 = copy(ref1)
+    ref3[1] = DNA_A
+    alt = seq1
+
+    ref2_on_ref1 = align(ref2, ref1)
+    alt_on_ref1 = align(alt, ref1)
+    ref1_on_alt = align(ref1, alt)
+    ref3_on_ref1 = align(ref3, ref1)
+
+    # Test insertion at position zero
+    @test translate(Variation(ref1, "0CAT"), ref2_on_ref1) ==
+        SequenceVariation.Inapplicable()
+    @test translate(Variation(ref1, "0CAT"), ref3_on_ref1) == Variation(ref3, "0CAT")
+
+    # Test substitution on deletion
+    @test isnothing(translate(Variation(ref1, "A17T"), ref1_on_alt))
+
+    # Test substitution to itself
+    @test isnothing(translate(Variation(ref1, "A23C"), ref2_on_ref1))
+
+    # Test simple substitution
+    @test translate(Variation(ref1, "T10A"), ref2_on_ref1) == Variation(ref2, "T9A")
+
+    # Test simple deletion
+    @test translate(Variation(ref1, "Δ17-18"), ref2_on_ref1) == Variation(ref2, "Δ16-17")
+
+    # Test deletion on deletion
+    @test isnothing(translate(Variation(ref1, "Δ17-17"), alt_on_ref1))
+
+    # Test simple insertion
+    @test translate(Variation(ref1, "6CAT"), ref2_on_ref1) == Variation(ref2, "5CAT")
+
+    # Test two insertions at the same position
+    @test translate(Variation(ref1, "10G"), alt_on_ref1) == SequenceVariation.Inapplicable()
+
+    # Test insertion on deletion
+    @test translate(Variation(ref1, "17CAT"), alt_on_ref1) ==
+        SequenceVariation.Inapplicable()
+end
+
 @testset "VariationBases" begin
     # Test substition bases
     @test refbases(Variation(dna"ATCGA", "C3G")) == dna"C"