def extract_boundary_sequences(self):
read_pairs = self.get_read_pairs()
trimmed_read_pairs = self.trim_barcodes(read_pairs)
total_reads = 0
well_formed = 0
long_enough = 0
counters = {'positions': {orientation: Counter() for orientation in orientations},
'control_ids': Counter(),
'polyA_lengths': Counter(),
'left_ids': Counter(),
'right_ids': Counter(),
'joint_lengths': Counter(),
}
with open(self.file_names['five_prime_boundaries'], 'w') as fives_fh, \
open(self.file_names['three_prime_boundaries'], 'w') as threes_fh:
for R1, R2 in trimmed_read_pairs:
total_reads += 1
five_payload_read, three_payload_read = TIF_seq_structure.find_boundary_sequences(R1, R2, counters)
if five_payload_read and three_payload_read:
well_formed += 1
if len(five_payload_read.seq) >= self.min_payload_length and \
len(three_payload_read.seq) >= self.min_payload_length:
long_enough += 1
fives_fh.write(fastq.make_record(*five_payload_read))
threes_fh.write(fastq.make_record(*three_payload_read))
# Pop off of counters so that what is left at the end can be written
# directly to the id_counts file.
position_counts = counters.pop('positions')
for orientation in orientations:
key = '{0}_{1}'.format(orientation, 'positions')
array = counts_to_array(position_counts[orientation])
self.write_file(key, array)
polyA_lengths = counts_to_array(counters.pop('polyA_lengths'))
self.write_file('polyA_lengths', polyA_lengths)
joint_lengths = counts_to_array(counters.pop('joint_lengths'), dim=2)
self.write_file('joint_lengths', joint_lengths)
self.write_file('id_counts', counters)
self.summary.extend(
[('Total read pairs', total_reads),
('Well-formed', well_formed),
('Long enough', long_enough),
],
)
def zero_padded_array(self, counts):
array = utilities.counts_to_array(counts)
if len(array) < self.max_read_length + 1:
padded_array = np.zeros(self.max_read_length + 1, int)
padded_array[:len(array)] += array
else:
padded_array = array
return padded_array
def filter_mappings(self):
num_unmapped = 0
num_entirely_genomic = 0
num_nonunique = 0
num_unique = 0
nongenomic_lengths = Counter()
sam_file = pysam.Samfile(self.file_names['accepted_hits'])
region_fetcher = genomes.build_region_fetcher(self.file_names['genome'],
load_references=True,
sam_file=sam_file,
)
extended_sorter = sam.AlignmentSorter(sam_file.references,
sam_file.lengths,
self.file_names['extended'],
)
filtered_sorter = sam.AlignmentSorter(sam_file.references,
sam_file.lengths,
self.file_names['extended_filtered'],
)
extended_mappings = (trim.extend_polyA_end(mapping, region_fetcher) for mapping in sam_file)
mapping_groups = utilities.group_by(extended_mappings, lambda m: m.qname)
with extended_sorter, filtered_sorter:
for qname, group in mapping_groups:
for m in group:
extended_sorter.write(m)
min_nongenomic_length = min(trim.get_nongenomic_length(m) for m in group)
nongenomic_lengths[min_nongenomic_length] += 1
if min_nongenomic_length == 0:
num_entirely_genomic += 1
continue
nonunique = len(group) > 1 or any(m.mapq < 40 for m in group)
if nonunique:
num_nonunique += 1
continue
num_unique += 1
for m in group:
filtered_sorter.write(m)
self.summary.extend(
[('Mapped with no non-genomic A\'s', num_entirely_genomic),
('Nonunique', num_nonunique),
('Unique', num_unique),
],
)
nongenomic_lengths = utilities.counts_to_array(nongenomic_lengths)
self.write_file('nongenomic_lengths', nongenomic_lengths)
def extract_fragment_lengths(bam_file_name):
def concordantly_mapped(mapping):
return not mapping.mate_is_unmapped and \
not mapping.is_unmapped and \
mapping.rnext == mapping.tid and \
abs(mapping.tlen) < 10000
bam_fh = pysam.Samfile(bam_file_name)
TLENs = (abs(mapping.tlen) for mapping in bam_fh
if mapping.is_read1 and concordantly_mapped(mapping))
fragment_lengths = Counter(TLENs)
# Note that counts_to_array implicitly discards negative key values.
fragment_lengths = utilities.counts_to_array(fragment_lengths)
return fragment_lengths
def collapse_fragments(self):
get_position = annotation.make_convertor(self.MappingAnnotation,
self.PositionAnnotation,
)
get_fragment = annotation.make_convertor(self.MappingAnnotation,
self.FragmentAnnotation,
)
amplification_counts = Counter()
sq_lines = sam.get_sq_lines(self.merged_file_names['sorted_clean_sam'])
sam_lines = self.get_sorted_sam_lines()
with open(self.file_names['collapsed_sam'], 'w') as collapsed_fh, \
open(self.file_names['collisions'], 'w') as collisions_fh:
for sq_line in sq_lines:
collapsed_fh.write(sq_line)
position_groups = utilities.group_by(sam_lines, get_position)
for position_annotation, position_lines in position_groups:
fragment_counts = Counter()
position_count = len(position_lines)
fragment_groups = utilities.group_by(position_lines, get_fragment)
for fragment_annotation, fragment_lines in fragment_groups:
fragment_count = len(fragment_lines)
fragment_counts[fragment_count] += 1
amplification_counts['{},{}'.format(position_count, fragment_count)] += 1
collapsed_annotation = self.CollapsedAnnotation(count=fragment_count, **fragment_annotation)
new_line = sam.splice_in_name(fragment_lines[0], collapsed_annotation.identifier)
collapsed_fh.write(new_line)
fragment_counts = utilities.counts_to_array(fragment_counts)
if position_count > 100:
collisions_fh.write(position_annotation.identifier + '\n')
collisions_fh.write(','.join(map(str, fragment_counts)) + '\n')
sam.make_sorted_bam(self.file_names['collapsed_sam'],
self.file_names['collapsed_bam'],
)
self.write_file('amplification_counts', amplification_counts)
def trim_reads(self, read_pairs):
total_reads = 0
long_enough_reads = 0
trimmed_lengths = Counter()
barcodes = Counter()
for R1, R2 in read_pairs:
total_reads += 1
barcodes[R2.seq[:len(self.barcode)]] += 1
# R2 isn't expected to have adapters sequence because it will
# have to get through the A tail first.
position = adapters.find_adapter(self.adapter_in_R1, 3, R1.seq)
trimmed_lengths[position] += 1
if position < 12:
continue
long_enough_reads += 1
R1_slice = slice(None, position)
# position points to where the barcode starts in R1. The length
# of the trimmed R2 read should be equal to position.
R2_slice = slice(len(self.barcode), len(self.barcode) + position)
processed_R1 = fastq.Read(R1.name, R1.seq[R1_slice], R1.qual[R1_slice])
processed_R2 = fastq.Read(R2.name, R2.seq[R2_slice], R2.qual[R2_slice])
yield processed_R1, processed_R2
trimmed_lengths = utilities.counts_to_array(trimmed_lengths)
self.write_file('trimmed_lengths', trimmed_lengths)
self.write_file('barcodes', barcodes)
self.summary.extend(
[('Total read pairs', total_reads),
('Long enough', long_enough_reads),
]
)
def filter_mappings(self):
num_unmapped = 0
num_entirely_genomic = 0
num_nonunique = 0
num_unique = 0
nongenomic_lengths = Counter()
sam_file = pysam.Samfile(self.file_names['accepted_hits'])
region_fetcher = genomes.build_region_fetcher(
self.file_names['genome'],
load_references=True,
sam_file=sam_file,
)
extended_sorter = sam.AlignmentSorter(
sam_file.references,
sam_file.lengths,
self.file_names['extended'],
)
filtered_sorter = sam.AlignmentSorter(
sam_file.references,
sam_file.lengths,
self.file_names['extended_filtered'],
)
extended_mappings = (trim.extend_polyA_end(mapping, region_fetcher)
for mapping in sam_file)
mapping_groups = utilities.group_by(extended_mappings,
lambda m: m.qname)
with extended_sorter, filtered_sorter:
for qname, group in mapping_groups:
for m in group:
extended_sorter.write(m)
min_nongenomic_length = min(
trim.get_nongenomic_length(m) for m in group)
nongenomic_lengths[min_nongenomic_length] += 1
if min_nongenomic_length == 0:
num_entirely_genomic += 1
continue
nonunique = len(group) > 1 or any(m.mapq < 40 for m in group)
if nonunique:
num_nonunique += 1
continue
num_unique += 1
for m in group:
filtered_sorter.write(m)
self.summary.extend([
('Mapped with no non-genomic A\'s', num_entirely_genomic),
('Nonunique', num_nonunique),
('Unique', num_unique),
], )
nongenomic_lengths = utilities.counts_to_array(nongenomic_lengths)
self.write_file('nongenomic_lengths', nongenomic_lengths)
def trim_reads(self, read_pairs):
total_reads = 0
long_enough_reads = 0
trimmed_lengths = Counter()
barcodes = Counter()
truncated_in_R1 = self.adapter_in_R1[1:]
truncated_in_R2 = self.adapter_in_R2[1:]
for R1, R2 in read_pairs:
total_reads += 1
barcodes[R2.seq[:len(self.barcode)]] += 1
# Check for weird thing where expected overhang base doesn't
# exist in primer dimers.
R1_dimer_distance = adapters.adapter_hamming_distance(
R1.seq,
truncated_in_R1,
len(R1.seq),
len(truncated_in_R1),
len(self.barcode),
)
R2_dimer_distance = adapters.adapter_hamming_distance(
R2.seq,
truncated_in_R2,
len(R2.seq),
len(truncated_in_R2),
len(self.barcode),
)
if R1_dimer_distance <= 3 and R2_dimer_distance <= 3:
position = len(self.barcode)
else:
position = adapters.consistent_paired_position(
R1.seq,
R2.seq,
self.adapter_in_R1,
self.adapter_in_R2,
19,
3,
)
if position != None:
trimmed_lengths[position] += 1
if position - len(self.barcode) < 12:
continue
else:
position = len(R1.seq)
long_enough_reads += 1
payload_slice = slice(len(self.barcode), position)
processed_R1 = fastq.Read(R1.name, R1.seq[payload_slice],
R1.qual[payload_slice])
processed_R2 = fastq.make_record(R2.name, R2.seq[payload_slice],
R2.qual[payload_slice])
yield processed_R1, processed_R2
trimmed_lengths = utilities.counts_to_array(trimmed_lengths)
self.write_file('trimmed_lengths', trimmed_lengths)
self.write_file('barcodes', barcodes)
self.summary.extend([
('Total read pairs', total_reads),
('Long enough', long_enough_reads),
])
def trim_reads(self, read_pairs):
total_reads = 0
long_enough_reads = 0
trimmed_lengths = Counter()
barcodes = Counter()
truncated_in_R1 = self.adapter_in_R1[1:]
truncated_in_R2 = self.adapter_in_R2[1:]
for R1, R2 in read_pairs:
total_reads += 1
barcodes[R2.seq[:len(self.barcode)]] += 1
# Check for weird thing where expected overhang base doesn't
# exist in primer dimers.
R1_dimer_distance = adapters.adapter_hamming_distance(R1.seq,
truncated_in_R1,
len(R1.seq),
len(truncated_in_R1),
len(self.barcode),
)
R2_dimer_distance = adapters.adapter_hamming_distance(R2.seq,
truncated_in_R2,
len(R2.seq),
len(truncated_in_R2),
len(self.barcode),
)
if R1_dimer_distance <= 3 and R2_dimer_distance <= 3:
position = len(self.barcode)
else:
position = adapters.consistent_paired_position(R1.seq,
R2.seq,
self.adapter_in_R1,
self.adapter_in_R2,
19,
3,
)
if position != None:
trimmed_lengths[position] += 1
if position - len(self.barcode) < 12:
continue
else:
position = len(R1.seq)
long_enough_reads += 1
payload_slice = slice(len(self.barcode), position)
processed_R1 = fastq.Read(R1.name, R1.seq[payload_slice], R1.qual[payload_slice])
processed_R2 = fastq.make_record(R2.name, R2.seq[payload_slice], R2.qual[payload_slice])
yield processed_R1, processed_R2
trimmed_lengths = utilities.counts_to_array(trimmed_lengths)
self.write_file('trimmed_lengths', trimmed_lengths)
self.write_file('barcodes', barcodes)
self.summary.extend(
[('Total read pairs', total_reads),
('Long enough', long_enough_reads),
]
)
def combine_mappings(self):
num_unmapped = 0
num_R1_unmapped = 0
num_R2_unmapped = 0
num_nonunique = 0
num_discordant = 0
num_disoriented = 0
num_concordant = 0
tlens = Counter()
R1_mappings = pysam.Samfile(self.file_names['R1_accepted_hits'])
R1_unmapped = pysam.Samfile(self.file_names['R1_unmapped'])
all_R1 = sam.merge_by_name(R1_mappings, R1_unmapped)
R1_grouped = utilities.group_by(all_R1, lambda m: m.qname)
R2_mappings = pysam.Samfile(self.file_names['R2_accepted_hits'])
R2_unmapped = pysam.Samfile(self.file_names['R2_unmapped'])
all_R2 = sam.merge_by_name(R2_mappings, R2_unmapped)
R2_grouped = utilities.group_by(all_R2, lambda m: m.qname)
group_pairs = izip(R1_grouped, R2_grouped)
alignment_sorter = sam.AlignmentSorter(R1_mappings.references,
R1_mappings.lengths,
self.file_names['combined'],
)
with alignment_sorter:
for (R1_qname, R1_group), (R2_qname, R2_group) in group_pairs:
#print R1_qname, R2_qname
if fastq.get_pair_name(R1_qname) != fastq.get_pair_name(R2_qname):
# Ensure that the iteration through pairs is in sync.
print R1_qname, R2_qname
raise ValueError
R1_unmapped = any(m.is_unmapped for m in R1_group)
R2_unmapped = any(m.is_unmapped for m in R2_group)
if R1_unmapped:
num_R1_unmapped += 1
if R2_unmapped:
num_R2_unmapped += 1
if R1_unmapped or R2_unmapped:
num_unmapped += 1
continue
R1_nonunique = len(R1_group) > 1 or any(m.mapq < 40 for m in R1_group)
R2_nonunique = len(R2_group) > 1 or any(m.mapq < 40 for m in R2_group)
if R1_nonunique or R2_nonunique:
num_nonunique += 1
continue
R1_m = R1_group.pop()
R2_m = R2_group.pop()
R1_strand = sam.get_strand(R1_m)
R2_strand = sam.get_strand(R2_m)
tlen = max(R1_m.aend, R2_m.aend) - min(R1_m.pos, R2_m.pos)
discordant = (R1_m.tid != R2_m.tid) or (R1_strand) == (R2_strand) or (tlen > 10000)
if discordant:
num_discordant += 1
continue
# Reminder: the protocol produces anti-sense reads.
if R1_strand == '-':
if R1_m.pos < R2_m.pos:
num_disoriented += 1
continue
elif R1_strand == '+':
if R2_m.pos < R1_m.pos:
num_disoriented += 1
continue
combined_read = paired_end.combine_paired_mappings(R1_m, R2_m)
tlens[tlen] += 1
if combined_read:
# Flip combined_read back to the sense strand.
if combined_read.is_reverse:
combined_read.is_reverse = False
else:
combined_read.is_reverse = True
trim.set_nongenomic_length(combined_read, 0)
alignment_sorter.write(combined_read)
num_concordant += 1
self.summary.extend(
[('Unmapped', num_unmapped),
('R1 unmapped', num_R1_unmapped),
('R2 unmapped', num_R2_unmapped),
('Nonunique', num_nonunique),
('Discordant', num_discordant),
('Unexpected orientation', num_disoriented),
('Concordant', num_concordant),
],
)
tlens = utilities.counts_to_array(tlens)
self.write_file('tlens', tlens)
