Class: Google::Apis::GenomicsV1::Read
- Inherits:
-
Object
- Object
- Google::Apis::GenomicsV1::Read
- Includes:
- Core::Hashable, Core::JsonObjectSupport
- Defined in:
- generated/google/apis/genomics_v1/classes.rb,
generated/google/apis/genomics_v1/representations.rb,
generated/google/apis/genomics_v1/representations.rb
Overview
A read alignment describes a linear alignment of a string of DNA to a reference sequence, in addition to metadata about the fragment (the molecule of DNA sequenced) and the read (the bases which were read by the sequencer). A read is equivalent to a line in a SAM file. A read belongs to exactly one read group and exactly one read group set.
Reverse-stranded reads
Mapped reads (reads having a non-null alignment
) can be aligned to either
the forward or the reverse strand of their associated reference. Strandedness
of a mapped read is encoded by alignment.position.reverseStrand
.
If we consider the reference to be a forward-stranded coordinate space of
[0, reference.length)
with 0
as the left-most position and
reference.length
as the right-most position, reads are always aligned left
to right. That is, alignment.position.position
always refers to the
left-most reference coordinate and alignment.cigar
describes the alignment
of this read to the reference from left to right. All per-base fields such as
alignedSequence
and alignedQuality
share this same left-to-right
orientation; this is true of reads which are aligned to either strand. For
reverse-stranded reads, this means that alignedSequence
is the reverse
complement of the bases that were originally reported by the sequencing
machine.
Generating a reference-aligned sequence string
When interacting with mapped reads, it's often useful to produce a string
representing the local alignment of the read to reference. The following
pseudocode demonstrates one way of doing this:
out = ""
offset = 0
for c in read.alignment.cigar
switch c.operation
case "ALIGNMENT_MATCH", "SEQUENCE_MATCH", "SEQUENCE_MISMATCH":
out += read.alignedSequence[offset:offset+c.operationLength]
offset += c.operationLength
break
case "CLIP_SOFT", "INSERT":
offset += c.operationLength
break
case "PAD":
out += repeat("*", c.operationLength)
break
case "DELETE":
out += repeat("-", c.operationLength)
break
case "SKIP":
out += repeat(" ", c.operationLength)
break
case "CLIP_HARD":
break
return out
Converting to SAM's CIGAR string
The following pseudocode generates a SAM CIGAR string from the
cigar
field. Note that this is a lossy conversion
(cigar.referenceSequence
is lost).
cigarMap =
"ALIGNMENT_MATCH": "M",
"INSERT": "I",
"DELETE": "D",
"SKIP": "N",
"CLIP_SOFT": "S",
"CLIP_HARD": "H",
"PAD": "P",
"SEQUENCE_MATCH": "=",
"SEQUENCE_MISMATCH": "X",
cigarStr = ""
for c in read.alignment.cigar
cigarStr += c.operationLength + cigarMap[c.operation]
return cigarStr
Instance Attribute Summary collapse
-
#aligned_quality ⇒ Array<Fixnum>
The quality of the read sequence contained in this alignment record (equivalent to QUAL in SAM).
-
#aligned_sequence ⇒ String
The bases of the read sequence contained in this alignment record, without CIGAR operations applied (equivalent to SEQ in SAM).
-
#alignment ⇒ Google::Apis::GenomicsV1::LinearAlignment
A linear alignment can be represented by one CIGAR string.
-
#duplicate_fragment ⇒ Boolean
(also: #duplicate_fragment?)
The fragment is a PCR or optical duplicate (SAM flag 0x400).
-
#failed_vendor_quality_checks ⇒ Boolean
(also: #failed_vendor_quality_checks?)
Whether this read did not pass filters, such as platform or vendor quality controls (SAM flag 0x200).
-
#fragment_length ⇒ Fixnum
The observed length of the fragment, equivalent to TLEN in SAM.
-
#fragment_name ⇒ String
The fragment name.
-
#id ⇒ String
The server-generated read ID, unique across all reads.
-
#info ⇒ Hash<String,Array<Object>>
A map of additional read alignment information.
-
#next_mate_position ⇒ Google::Apis::GenomicsV1::Position
An abstraction for referring to a genomic position, in relation to some already known reference.
-
#number_reads ⇒ Fixnum
The number of reads in the fragment (extension to SAM flag 0x1).
-
#proper_placement ⇒ Boolean
(also: #proper_placement?)
The orientation and the distance between reads from the fragment are consistent with the sequencing protocol (SAM flag 0x2).
-
#read_group_id ⇒ String
The ID of the read group this read belongs to.
-
#read_group_set_id ⇒ String
The ID of the read group set this read belongs to.
-
#read_number ⇒ Fixnum
The read number in sequencing.
-
#secondary_alignment ⇒ Boolean
(also: #secondary_alignment?)
Whether this alignment is secondary.
-
#supplementary_alignment ⇒ Boolean
(also: #supplementary_alignment?)
Whether this alignment is supplementary.
Instance Method Summary collapse
-
#initialize(**args) ⇒ Read
constructor
A new instance of Read.
-
#update!(**args) ⇒ Object
Update properties of this object.
Methods included from Core::JsonObjectSupport
Methods included from Core::Hashable
Constructor Details
#initialize(**args) ⇒ Read
Returns a new instance of Read
1979 1980 1981 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1979 def initialize(**args) update!(**args) end |
Instance Attribute Details
#aligned_quality ⇒ Array<Fixnum>
The quality of the read sequence contained in this alignment record
(equivalent to QUAL in SAM).
alignedSequence
and alignedQuality
may be shorter than the full read
sequence and quality. This will occur if the alignment is part of a
chimeric alignment, or if the read was trimmed. When this occurs, the CIGAR
for this read will begin/end with a hard clip operator that will indicate
the length of the excised sequence.
Corresponds to the JSON property alignedQuality
1858 1859 1860 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1858 def aligned_quality @aligned_quality end |
#aligned_sequence ⇒ String
The bases of the read sequence contained in this alignment record,
without CIGAR operations applied (equivalent to SEQ in SAM).
alignedSequence
and alignedQuality
may be
shorter than the full read sequence and quality. This will occur if the
alignment is part of a chimeric alignment, or if the read was trimmed. When
this occurs, the CIGAR for this read will begin/end with a hard clip
operator that will indicate the length of the excised sequence.
Corresponds to the JSON property alignedSequence
1869 1870 1871 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1869 def aligned_sequence @aligned_sequence end |
#alignment ⇒ Google::Apis::GenomicsV1::LinearAlignment
A linear alignment can be represented by one CIGAR string. Describes the
mapped position and local alignment of the read to the reference.
Corresponds to the JSON property alignment
1875 1876 1877 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1875 def alignment @alignment end |
#duplicate_fragment ⇒ Boolean Also known as: duplicate_fragment?
The fragment is a PCR or optical duplicate (SAM flag 0x400).
Corresponds to the JSON property duplicateFragment
1880 1881 1882 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1880 def duplicate_fragment @duplicate_fragment end |
#failed_vendor_quality_checks ⇒ Boolean Also known as: failed_vendor_quality_checks?
Whether this read did not pass filters, such as platform or vendor quality
controls (SAM flag 0x200).
Corresponds to the JSON property failedVendorQualityChecks
1887 1888 1889 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1887 def failed_vendor_quality_checks @failed_vendor_quality_checks end |
#fragment_length ⇒ Fixnum
The observed length of the fragment, equivalent to TLEN in SAM.
Corresponds to the JSON property fragmentLength
1893 1894 1895 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1893 def fragment_length @fragment_length end |
#fragment_name ⇒ String
The fragment name. Equivalent to QNAME (query template name) in SAM.
Corresponds to the JSON property fragmentName
1898 1899 1900 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1898 def fragment_name @fragment_name end |
#id ⇒ String
The server-generated read ID, unique across all reads. This is different
from the fragmentName
.
Corresponds to the JSON property id
1904 1905 1906 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1904 def id @id end |
#info ⇒ Hash<String,Array<Object>>
A map of additional read alignment information. This must be of the form
mapinfo
1910 1911 1912 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1910 def info @info end |
#next_mate_position ⇒ Google::Apis::GenomicsV1::Position
An abstraction for referring to a genomic position, in relation to some
already known reference. For now, represents a genomic position as a
reference name, a base number on that reference (0-based), and a
determination of forward or reverse strand.
Corresponds to the JSON property nextMatePosition
1918 1919 1920 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1918 def next_mate_position @next_mate_position end |
#number_reads ⇒ Fixnum
The number of reads in the fragment (extension to SAM flag 0x1).
Corresponds to the JSON property numberReads
1923 1924 1925 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1923 def number_reads @number_reads end |
#proper_placement ⇒ Boolean Also known as: proper_placement?
The orientation and the distance between reads from the fragment are
consistent with the sequencing protocol (SAM flag 0x2).
Corresponds to the JSON property properPlacement
1929 1930 1931 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1929 def proper_placement @proper_placement end |
#read_group_id ⇒ String
The ID of the read group this read belongs to. A read belongs to exactly
one read group. This is a server-generated ID which is distinct from SAM's
RG tag (for that value, see
ReadGroup.name).
Corresponds to the JSON property readGroupId
1938 1939 1940 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1938 def read_group_id @read_group_id end |
#read_group_set_id ⇒ String
The ID of the read group set this read belongs to. A read belongs to
exactly one read group set.
Corresponds to the JSON property readGroupSetId
1944 1945 1946 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1944 def read_group_set_id @read_group_set_id end |
#read_number ⇒ Fixnum
The read number in sequencing. 0-based and less than numberReads. This
field replaces SAM flag 0x40 and 0x80.
Corresponds to the JSON property readNumber
1950 1951 1952 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1950 def read_number @read_number end |
#secondary_alignment ⇒ Boolean Also known as: secondary_alignment?
Whether this alignment is secondary. Equivalent to SAM flag 0x100.
A secondary alignment represents an alternative to the primary alignment
for this read. Aligners may return secondary alignments if a read can map
ambiguously to multiple coordinates in the genome. By convention, each read
has one and only one alignment where both secondaryAlignment
and supplementaryAlignment
are false.
Corresponds to the JSON property secondaryAlignment
1960 1961 1962 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1960 def secondary_alignment @secondary_alignment end |
#supplementary_alignment ⇒ Boolean Also known as: supplementary_alignment?
Whether this alignment is supplementary. Equivalent to SAM flag 0x800.
Supplementary alignments are used in the representation of a chimeric
alignment. In a chimeric alignment, a read is split into multiple
linear alignments that map to different reference contigs. The first
linear alignment in the read will be designated as the representative
alignment; the remaining linear alignments will be designated as
supplementary alignments. These alignments may have different mapping
quality scores. In each linear alignment in a chimeric alignment, the read
will be hard clipped. The alignedSequence
and
alignedQuality
fields in the alignment record will only
represent the bases for its respective linear alignment.
Corresponds to the JSON property supplementaryAlignment
1976 1977 1978 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1976 def supplementary_alignment @supplementary_alignment end |
Instance Method Details
#update!(**args) ⇒ Object
Update properties of this object
1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 |
# File 'generated/google/apis/genomics_v1/classes.rb', line 1984 def update!(**args) @aligned_quality = args[:aligned_quality] if args.key?(:aligned_quality) @aligned_sequence = args[:aligned_sequence] if args.key?(:aligned_sequence) @alignment = args[:alignment] if args.key?(:alignment) @duplicate_fragment = args[:duplicate_fragment] if args.key?(:duplicate_fragment) @failed_vendor_quality_checks = args[:failed_vendor_quality_checks] if args.key?(:failed_vendor_quality_checks) @fragment_length = args[:fragment_length] if args.key?(:fragment_length) @fragment_name = args[:fragment_name] if args.key?(:fragment_name) @id = args[:id] if args.key?(:id) @info = args[:info] if args.key?(:info) @next_mate_position = args[:next_mate_position] if args.key?(:next_mate_position) @number_reads = args[:number_reads] if args.key?(:number_reads) @proper_placement = args[:proper_placement] if args.key?(:proper_placement) @read_group_id = args[:read_group_id] if args.key?(:read_group_id) @read_group_set_id = args[:read_group_set_id] if args.key?(:read_group_set_id) @read_number = args[:read_number] if args.key?(:read_number) @secondary_alignment = args[:secondary_alignment] if args.key?(:secondary_alignment) @supplementary_alignment = args[:supplementary_alignment] if args.key?(:supplementary_alignment) end |