def plot_GC(handle, outname):
pp = PdfPages(outname)
parsed_handle = [record for record in SeqIO.parse(handle, "fasta")]
for i in range(0, len(parsed_handle)):
gc_skew = GC_skew(parsed_handle[i].seq)
cumulated_skew = np.cumsum(gc_skew)
pylab.plot(cumulated_skew)
pylab.plot(gc_skew)
pylab.title("contig %s" % (str(parsed_handle[i].id)))
pylab.savefig(pp, format='pdf')
pylab.close()
all_seq = ''
for record in parsed_handle:
all_seq += record.seq
gc_skew = GC_skew(all_seq)
cumulated_skew = np.cumsum(gc_skew)
pylab.plot(cumulated_skew)
pylab.plot(gc_skew)
pylab.title("concatenated contigs")
pylab.savefig(pp, format='pdf')
pp.close()
def gc_skew_window(genome, window=1000):
interval = [x for x in range(int(len(genome.seq) / window) + 1)]
result_dict = dict()
for i in interval[:-1]:
gc_skew = GC_skew(genome.seq[interval[i] * window:interval[i + 1] *
window])[0]
gc_skew_cell = {
i: {
"chr": genome.id,
"start": interval[i] * window + 1,
"end": interval[i + 1] * window,
"GC_skew": gc_skew
}
}
result_dict.update(gc_skew_cell)
gc_skew = GC_skew(genome.seq[interval[-1] * window:len(genome.seq)])[0]
gc_skew_cell = {
interval[-1]: {
"chr": genome.id,
"start": interval[-1] * 100 + 1,
"end": len(genome.seq),
"GC_skew": gc_skew
}
}
result_dict.update(gc_skew_cell)
return DataFrame.from_dict(result_dict, "index")
def calculate_GCskew(entries):
name, sequences = list(zip(*entries))
total_seq = ''.join(sequences)
L = len(total_seq)
window = L // len(sequences)
gc_skew_values = GC_skew(total_seq, window=window)
return pd.Series(gc_skew_values[:len(sequences)], name='gc_skew')
def skew(file_name, file_type):
file_path = os.path.join(os.path.abspath(os.path.dirname(__file__)), "Files", file_name + "." + file_type)
skew_val = [0]
positions = [0]
for rec in SeqIO.parse(file_path, file_type):
skew_data = GC_skew(rec.seq, 1)
for i in range(0, len(rec.seq)):
positions.append(i)
skew_val.append(skew_val[len(skew_val) - 1] + int(skew_data[i]))
x = positions
y = skew_val
return x, y
def mk_gc_skewset(data, outpath, window):
"""calculates the GC skew in a window and writes in a file that circos accepts to plot"""
skew_file = open(outpath + '/gc_skew.txt', 'w')
cg = 0
for contig in data:
cg += 1
pos = 0
interval = window
gc_skew = GC_skew(data[contig], window=window)
for point in gc_skew:
skew_file.write('cg{} {} {} {}\n'.format(cg, pos, interval, point))
pos = interval + 1
interval += window
return outpath + '/gc_skew.txt'
def find_ori_ter(gb):
"""Find positions of origin and terminus of replication in a genome,
using the cumulative GC skew method.
Args:
gb (Bio.SeqRecord.SeqRecord): GenBank annotation.
Returns:
ori, ter (int): origin and terminus positions.
"""
dna = gb.seq
w = 100
cum_gcskew = np.cumsum(GC_skew(dna, window=w))
ori = np.argmin(cum_gcskew) * w
ter = np.argmax(cum_gcskew) * w
print("Found ori and ter positions: %d, %d" % (ori, ter))
return ori, ter
def fa2bed(fa, window, step):
# genome bed file
genomeBed = open("genome.bed","w")
#genomeBed.write("chr\tstart\tend\n")
record_dict = SeqIO.to_dict(SeqIO.parse(fa, "fasta"))
# GC% distribution file
gcBed = open("gc.bed","w")
#gcBed.write("chr\tstart\tend\tgc\n")
#GC-skew bed file
gcSkewBed = open("gcSkew.bed","w")
#gcSkewBed.write("chr\tstart\tend\tgcSkew\n")
window_len = int(window)
step_len = int(step)
for k,v in record_dict.items():
chrom = v.id
chrom_seq = v.seq
length = len(chrom_seq)
genomeBed.write(chrom+"\t0\t%d\n"%length)
for i in range(0, length, step_len):
start0 = i
end0 = i+step_len if i+step_len<=length else length
start = i-window_len/2 if i-window_len/2>=0 else 0
end = i+window_len/2 if i+window_len/2<=length else length
s = chrom_seq[start : end]
gc = GC(s)
skew = GC_skew(s, window_len)[0]
gcBed.write(chrom+"\t%d\t%d\t%.3f\n"%(start0,end0,gc))
gcSkewBed.write(chrom+"\t%d\t%d\t%.3f\n"%(start0,end0,skew))
genomeBed.close()
gcBed.close()
gcSkewBed.close()
file_list = sorted(file_list)
# get data
data = []
names = []
for file_path in file_list:
for record in SeqIO.parse(file_path, "fasta"):
names.append(record.id)
data.append(record.seq)
print(names)
number_strains = len(data)
GC_skews = []
for i in data:
GC_skews.append(GC_skew(i, window=200))
#comparing specific strains
if True:
fig = plt.figure(figsize=(10, 10))
pos_jvci1 = names.index("JCVI1")
pos_jvci2 = names.index("JCVI2")
pos_jvci3 = names.index("JCVI3")
pos_gm12wt = names.index("GM12WT")
pos_gm12d86 = names.index("GM12delta68")
pos_mg37 = names.index("MG37")
pos_Mf5583 = names.index("Mf5583")
compared = [
#!/usr/bin/python
# testing python script
import Bio as bio
import matplotlib.pyplot as plot
from Bio.Seq import Seq
from Bio.Alphabet import generic_rna,generic_dna
from Bio.SeqUtils import GC123,GC,GC_skew
seq = "ataccaggctgaggcccattaatgatgcaatttgctgggcttctctattttctccgtgcttccatcctcttctccgtcggcggggagaagtgaaatgccgtggagatgggcggcggcggcggcgacggcggcgacgagaaagctcaccgggatctctcagtcgcgagtttcagtagcctttaccggccgtcttctctaccgctcgttcggaagcgactccagtgaaagccgcaagaggtcactgccacggggggtcgtatcgatcggggccatcagccttgctggaggtctcgtgctcagcgccgtcaacgacctcgccatcttcaatggatgcacaacgaaggcaattgagcatgctgctgacaaccctgctgttgtggaagcaattggagtgcctatagtcagaggaccgtggtatgatgcttctcttgaggtgggccatcgacggcggtctgtgtcatgcacattccctgtatctgggccacatgggtcaggatttctccagattaaggcaacccgagatggagaggatggtctgctttcgtttctgcggcatcacgactggaagatcctattgctggaggctcatcttgaagcaccatcagatgatgaggaccagagaaagctggttaaggtgaatcttgcaagcagtggccgtggggaagatggggatccagagagtggttaatcttttgtactgaattccatggtgagtggaagatcgtgtcatctgaatggactccaaatattaaatgacatggagatctagggaagcaaaaaaaaaaaaaaaa"
print GC123(seq)
print GC(seq)
plot(GC_skew(seq,window=100),c="r")
xlabel("Window")
ylabel("(G-C)/(G+C)")
title("GC-skew")
def circos_cumul_gc_skew(record, windows=1000, shift=0, initial=0):
'''
:param record:
:return: circos string with difference as compared to the average GC
ex: average = 32
GC(seq[3000:4000]) = 44
diff = 44 - 32 = 12%
'''
from Bio.SeqFeature import FeatureLocation
circos_string = ''
#print "GENOME SIZE:", len(record.seq)
gap_locations = []
for feature in record.features:
if feature.type == "assembly_gap":
gap_locations.append(feature.location)
if len(gap_locations) == 0:
gap_locations.append(FeatureLocation(0, len(record.seq)))
else:
#gap_locations.append(FeatureLocation(gap_locations[-1].end + 1, len(record.seq)))
gap_locations.append(FeatureLocation(len(record.seq), len(record.seq)))
#print 'gap locations', gap_locations
if len(gap_locations) > 1:
for i in range(0, len(gap_locations)):
if i == 0:
seq = record.seq[0:gap_locations[i].start]
chr_start = 0
else:
seq = record.seq[gap_locations[i -
1].end:gap_locations[i].start]
chr_start = gap_locations[i - 1].end
#print i, "seq", gap_locations[i-1].end, gap_locations[i].start, gap_locations[i].start - gap_locations[i-1].end
try:
values = GC_skew(seq, windows)
except:
print(len(seq), seq)
contig_name = record.name + "_%s" % (i + 1)
for i in range(0, len(values)):
start = i * windows
stop = start + windows
#gc = ((GC(record.seq[start:stop])/average_gc) - 1)*100
section_start = chr_start + start
section_end = chr_start + stop
circos_string += "%s %s %s %s\n" % (
contig_name, section_start + shift, section_end + shift,
values[i])
else:
try:
values = GC_skew(record.seq, windows)
except:
values = GC_skew(record.seq, 2000)
# skip last value
acc = initial
for i in range(0, len(values) - 1):
gc = values[i]
acc += gc
start = i * windows
stop = start + windows
circos_string += "%s %s %s %s\n" % (
record.id.split(".")[0], start + shift, stop + shift, acc)
return circos_string, acc
def test_GC_skew(self):
seq = "A" * 50
self.assertEqual(GC_skew(seq)[0], 0)
def circos_gc_skew(record, windows=1000, shift=0):
'''
:param record:
:return: circos string with difference as compared to the average GC
ex: average = 32
GC(seq[3000:4000]) = 44
diff = 44 - 32 = 12%
NEW 12.06.2017: calculate GC based on whole sequence
'''
from Bio.SeqFeature import FeatureLocation
circos_string = ''
#print "GENOME SIZE:", len(record.seq)
gap_locations = []
for feature in record.features:
if feature.type == "assembly_gap":
gap_locations.append(feature.location)
if len(gap_locations) == 0:
gap_locations.append(FeatureLocation(0, len(record.seq)))
else:
#gap_locations.append(FeatureLocation(gap_locations[-1].end + 1, len(record.seq)))
gap_locations.append(FeatureLocation(len(record.seq), len(record.seq)))
#print 'gap locations', gap_locations
if len(gap_locations) > 1:
from chlamdb.plots import circos_convert_contigs_coords
contig_coords = []
start = 0
for i, coord in enumerate(gap_locations):
contig_name = record.name + "_%s" % (i + 1)
contig_coords.append([contig_name, start, int(coord.start)])
start = coord.end + 1
values = GC_skew(record.seq, windows)
data_list = []
for n_value, value in enumerate(values):
start = (windows * n_value) + 1
end = (start + windows)
#for i in range(0, len(gap_locations)):
data_list.append([record.name, start, end, value])
'''
if i == 0:
seq = record.seq[0:gap_locations[i].start]
chr_start = 0
else:
seq = record.seq[gap_locations[i-1].end+1:gap_locations[i].start]
chr_start = gap_locations[i-1].end+1
if 'n' in seq or 'N' in seq:
print 'n in seq!!!!!!!!!!!!!!'
#print i, "seq", gap_locations[i-1].end, gap_locations[i].start, gap_locations[i].start - gap_locations[i-1].end
try:
values = GC_skew(seq, windows)
except:
print len(seq), seq
# skip very small contigs!!!!!!!!
if len(values)<5:
continue
for i in range(0, len(values)):
start = i *windows
stop = start + windows
#gc = ((GC(record.seq[start:stop])/average_gc) - 1)*100
section_start = chr_start + start
section_end = chr_start + stop
circos_string += "%s %s %s %s\n" % (contig_name, section_start+shift, section_end+shift, values[i])
'''
#print "contig_coords", contig_coords
#print "data_list", data_list[0:4]
renamed_data = circos_convert_contigs_coords.rename_karyotype(
contig_coords, data_list)
for row in renamed_data:
contig_name = row[0]
start = row[1]
end = row[2]
try:
value = row[3]
except:
#print 'problem with', row
continue
circos_string += "%s %s %s %s\n" % (contig_name, start, end, value)
else:
#print 'no gaps!'
try:
values = GC_skew(record.seq, windows)
except:
values = GC_skew(record.seq, 2000)
# skip last value
for i in range(0, len(values) - 1):
start = i * windows
stop = start + windows
circos_string += "%s %s %s %s\n" % (record.id.split(".")[0],
start + shift, stop + shift,
values[i])
return circos_string
def gc_skew(sequence, **kwargs):
values = GC_skew(sequence)
# Average GC skew
if len(values) == 0:
return 0
return reduce(lambda x, y: x + y, values) / float(len(values))
def xGC_skew_mod(name,
seq,
outpath,
window=None,
zoom=100,
r=300,
px=100,
py=100):
__doc__ = """Copy of from Bio.SeqUtils import xGC_skew. to make it print"""
#
if not window:
window = round(len(seq) / 720)
from Bio.SeqUtils import GC, GC_skew
from math import pi, sin, cos
try:
import Tkinter as tkinter # Python 2
except ImportError:
import tkinter # Python 3
yscroll = tkinter.Scrollbar(orient=tkinter.VERTICAL)
xscroll = tkinter.Scrollbar(orient=tkinter.HORIZONTAL)
canvas = tkinter.Canvas(yscrollcommand=yscroll.set,
xscrollcommand=xscroll.set,
background='white')
win = canvas.winfo_toplevel()
win.geometry('900x900')
yscroll.config(command=canvas.yview)
xscroll.config(command=canvas.xview)
yscroll.pack(side=tkinter.RIGHT, fill=tkinter.Y)
xscroll.pack(side=tkinter.BOTTOM, fill=tkinter.X)
canvas.pack(fill=tkinter.BOTH, side=tkinter.LEFT, expand=1)
canvas.update()
X0, Y0 = r + px, r + py
x1, x2, y1, y2 = X0 - r, X0 + r, Y0 - r, Y0 + r
ty = Y0
canvas.create_text(X0, ty, text=name)
ty += 20
canvas.create_text(X0, ty, text='GC %3.2f%%' % (GC(seq)))
ty += 20
canvas.create_text(X0, ty, text='GC Skew', fill='blue')
ty += 20
canvas.create_text(X0, ty, text='Accumulated GC Skew', fill='magenta')
ty += 20
canvas.create_oval(x1, y1, x2, y2)
acc = 0
start = 0
for gc in GC_skew(seq, window):
r1 = r
acc += gc
# GC skew
alpha = pi - (2 * pi * start) / len(seq)
r2 = r1 - gc * zoom
x1 = X0 + r1 * sin(alpha)
y1 = Y0 + r1 * cos(alpha)
x2 = X0 + r2 * sin(alpha)
y2 = Y0 + r2 * cos(alpha)
canvas.create_line(x1, y1, x2, y2, fill='blue')
# accumulated GC skew
r1 = r - 50
r2 = r1 - acc
x1 = X0 + r1 * sin(alpha)
y1 = Y0 + r1 * cos(alpha)
x2 = X0 + r2 * sin(alpha)
y2 = Y0 + r2 * cos(alpha)
canvas.create_line(x1, y1, x2, y2, fill='magenta')
canvas.update()
start += window
canvas.configure(scrollregion=canvas.bbox(tkinter.ALL))
canvas.postscript(file=outpath)
canvas.destroy()
#!/usr/bin/env python3
import argparse
parser = argparse.ArgumentParser()
parser.add_argument('fasta')
args = parser.parse_args()
from Bio import SeqIO
from Bio.SeqUtils import GC_skew
for record in SeqIO.parse(args.fasta, 'fasta'):
for skew in GC_skew(record.seq, window=100):
print(skew)
def complete_tasks(full_seq, des, unique_key):
file_details = st.radio("Details", ("Description", "Sequence"),
key=unique_key)
#Show description and sequence in DNA Analysis section
if file_details == "Description":
st.write(des)
elif file_details == "Sequence":
st.write(full_seq)
#Nucleotide occurances plot and color selector for the bars
st.subheader("Plot Nucleotide Frequency")
full_seq_freq = OrderedDict(Counter(full_seq))
bar1_colour = st.beta_color_picker("Pick Colour for Bar 1", key=unique_key)
bar2_colour = st.beta_color_picker("Pick Colour for Bar 2", key=unique_key)
bar3_colour = st.beta_color_picker("Pick Colour for Bar 3", key=unique_key)
bar4_colour = st.beta_color_picker("Pick Colour for Bar 4", key=unique_key)
if st.button("Plot Frequency", key=unique_key):
barlist = plt.bar(full_seq_freq.keys(), full_seq_freq.values())
barlist[0].set_color(bar1_colour)
barlist[1].set_color(bar2_colour)
barlist[2].set_color(bar3_colour)
barlist[3].set_color(bar4_colour)
st.pyplot()
st.subheader("Properties")
#GC Content, GC Melting temp, GC_skew, Complement and reverse complement
gc_count = GC(full_seq)
st.write("GC Content: {}".format(gc_count))
mt = MeltingTemp.Tm_GC(full_seq, strict=False)
st.write("Melting Temperature based on GC Content: {}".format(mt))
gc_skew_bases = st.number_input("Enter number of bases", key=unique_key)
try:
gc_skew = GC_skew(full_seq, int(gc_skew_bases))
st.write("GC Skew for {} bases: {}".format(gc_skew_bases, gc_skew))
except ValueError:
st.write("Enter a Valid Number for bases")
if st.checkbox("Complement", key=unique_key):
st.write(full_seq.complement())
elif st.checkbox("Reverse Complement", key=unique_key):
st.write(full_seq.reverse_complement())
#Protein Synthesis
st.subheader("Protein Synthesis")
p1 = full_seq.translate()
if st.checkbox("Transcription: DNA to mRNA", key=unique_key):
st.write(full_seq.transcribe())
elif st.checkbox("Translation: DNA to 1 letter Amino Acid Sequence",
key=unique_key):
st.write(p1)
elif st.checkbox("Translation: DNA to 3 letter Amino Acid Sequence",
key=unique_key):
full_aa_name = str(p1).replace("*", "")
st.write(seq3(full_aa_name))
elif st.checkbox("Plot Amino Acid Frequency", key=unique_key):
aa_freq = OrderedDict(Counter(str(p1)))
bar_colour = st.beta_color_picker("Pick Colour for all Bars",
key=unique_key)
plt.bar(aa_freq.keys(), aa_freq.values(), color=bar_colour)
st.pyplot()
st.write("Asterisk (*) - Denotes Stop Codons.")
def draw_gc(sumgene, dwg, gc_color):
#gc kmer number
unit_num = 300
unit_len = int(sumgene.len / unit_num)
#first coordinates
start_unit = 0
end_unit = unit_len - 1
mid_unit = (end_unit - start_unit) / 2
#radius
gcc_r = 430
gcs_r = 230
gcc_range = (330, 530)
gcs_range = (130, 330)
gcc_mean = GC(sumgene.seq)
gc_contents = []
gc_skews = []
#compute gc
while (unit_num > 0):
gc_content = GC(sumgene.seq[start_unit:end_unit])
gcc_variance = gc_content - gcc_mean
gc_contents.append(gcc_variance)
gc_skew = GC_skew(sumgene.seq[start_unit:end_unit], window=unit_len)[0]
gc_skews.append(gc_skew)
start_unit += unit_len
if end_unit + unit_len <= sumgene.len:
end_unit += unit_len
else:
end_unit = sumgene.len
unit_num -= 1
gcc_max = max(gc_contents)
gcc_min = min(gc_contents)
gcs_max = max(gc_skews)
gcs_min = min(gc_skews)
gcc_scal = (gcc_range[1] - gcc_range[0]) / (gcc_max - gcc_min)
gcs_scal = (gcs_range[1] - gcs_range[0]) / (gcs_max - gcs_min)
gc_count = 0
unit_num = 300
start_unit = 0
end_unit = unit_len - 1
mid_unit = (end_unit - start_unit) / 2
while (unit_num > 0):
# draw gc_content
c_pos = position_mapping(sumgene, [start_unit, end_unit], gcc_r)
gcc_nr = (gc_contents[gc_count] - gcc_min) * gcc_scal + gcc_range[0]
cm_pos = position_mapping(sumgene, [mid_unit, 0], gcc_nr)
points = [(1500 + c_pos[0], 1500 - c_pos[1]),
(1500 + c_pos[2], 1500 - c_pos[3]),
(1500 + cm_pos[0], 1500 - cm_pos[1])]
if gcc_nr >= gcc_r:
dwg.add(dwg.polygon(points, fill=gc_color[0], stroke_width=0))
else:
dwg.add(dwg.polygon(points, fill=gc_color[1], stroke_width=0))
# draw gc_skew
s_pos = position_mapping(sumgene, [start_unit, end_unit], gcs_r)
gcs_nr = (gc_skews[gc_count] - gcs_min) * gcs_scal + gcs_range[0]
sm_pos = position_mapping(sumgene, [mid_unit, 0], gcs_nr)
points = [(1500 + s_pos[0], 1500 - s_pos[1]),
(1500 + s_pos[2], 1500 - s_pos[3]),
(1500 + sm_pos[0], 1500 - sm_pos[1])]
if gcs_nr >= gcs_r:
dwg.add(dwg.polygon(points, fill=gc_color[2], stroke_width=0))
else:
dwg.add(dwg.polygon(points, fill=gc_color[3], stroke_width=0))
start_unit += unit_len
if end_unit + unit_len <= sumgene.len:
end_unit += unit_len
else:
end_unit = sumgene.len
mid_unit += unit_len
unit_num -= 1
gc_count += 1
return dwg
