CRISPRTool / cas12.py
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from keras import Model
from keras.layers import Input
from keras.layers import Multiply
from keras.layers import Dense, Dropout, Activation, Flatten
from keras.layers import Convolution1D, AveragePooling1D
import pandas as pd
import numpy as np
import keras
import requests
from functools import reduce
from operator import add
from Bio.SeqRecord import SeqRecord
from Bio.SeqFeature import SeqFeature, FeatureLocation
from Bio.Seq import Seq
from Bio import SeqIO
ntmap = {'A': (1, 0, 0, 0),
'C': (0, 1, 0, 0),
'G': (0, 0, 1, 0),
'T': (0, 0, 0, 1)
}
def get_seqcode(seq):
return np.array(reduce(add, map(lambda c: ntmap[c], seq.upper()))).reshape((1, len(seq), -1))
def Seq_DeepCpf1_model(input_shape):
Seq_deepCpf1_Input_SEQ = Input(shape=input_shape)
Seq_deepCpf1_C1 = Convolution1D(80, 5, activation='relu')(Seq_deepCpf1_Input_SEQ)
Seq_deepCpf1_P1 = AveragePooling1D(2)(Seq_deepCpf1_C1)
Seq_deepCpf1_F = Flatten()(Seq_deepCpf1_P1)
Seq_deepCpf1_DO1 = Dropout(0.3)(Seq_deepCpf1_F)
Seq_deepCpf1_D1 = Dense(80, activation='relu')(Seq_deepCpf1_DO1)
Seq_deepCpf1_DO2 = Dropout(0.3)(Seq_deepCpf1_D1)
Seq_deepCpf1_D2 = Dense(40, activation='relu')(Seq_deepCpf1_DO2)
Seq_deepCpf1_DO3 = Dropout(0.3)(Seq_deepCpf1_D2)
Seq_deepCpf1_D3 = Dense(40, activation='relu')(Seq_deepCpf1_DO3)
Seq_deepCpf1_DO4 = Dropout(0.3)(Seq_deepCpf1_D3)
Seq_deepCpf1_Output = Dense(1, activation='linear')(Seq_deepCpf1_DO4)
Seq_deepCpf1 = Model(inputs=[Seq_deepCpf1_Input_SEQ], outputs=[Seq_deepCpf1_Output])
return Seq_deepCpf1
# seq-ca model (DeepCpf1)
def DeepCpf1_model(input_shape):
DeepCpf1_Input_SEQ = Input(shape=input_shape)
DeepCpf1_C1 = Convolution1D(80, 5, activation='relu')(DeepCpf1_Input_SEQ)
DeepCpf1_P1 = AveragePooling1D(2)(DeepCpf1_C1)
DeepCpf1_F = Flatten()(DeepCpf1_P1)
DeepCpf1_DO1 = Dropout(0.3)(DeepCpf1_F)
DeepCpf1_D1 = Dense(80, activation='relu')(DeepCpf1_DO1)
DeepCpf1_DO2 = Dropout(0.3)(DeepCpf1_D1)
DeepCpf1_D2 = Dense(40, activation='relu')(DeepCpf1_DO2)
DeepCpf1_DO3 = Dropout(0.3)(DeepCpf1_D2)
DeepCpf1_D3_SEQ = Dense(40, activation='relu')(DeepCpf1_DO3)
DeepCpf1_Input_CA = Input(shape=(1,))
DeepCpf1_D3_CA = Dense(40, activation='relu')(DeepCpf1_Input_CA)
DeepCpf1_M = Multiply()([DeepCpf1_D3_SEQ, DeepCpf1_D3_CA])
DeepCpf1_DO4 = Dropout(0.3)(DeepCpf1_M)
DeepCpf1_Output = Dense(1, activation='linear')(DeepCpf1_DO4)
DeepCpf1 = Model(inputs=[DeepCpf1_Input_SEQ, DeepCpf1_Input_CA], outputs=[DeepCpf1_Output])
return DeepCpf1
def fetch_ensembl_transcripts(gene_symbol):
url = f"https://rest.ensembl.org/lookup/symbol/homo_sapiens/{gene_symbol}?expand=1;content-type=application/json"
response = requests.get(url)
if response.status_code == 200:
gene_data = response.json()
if 'Transcript' in gene_data:
return gene_data['Transcript']
else:
print("No transcripts found for gene:", gene_symbol)
return None
else:
print(f"Error fetching gene data from Ensembl: {response.text}")
return None
def fetch_ensembl_sequence(transcript_id):
url = f"https://rest.ensembl.org/sequence/id/{transcript_id}?content-type=application/json"
response = requests.get(url)
if response.status_code == 200:
sequence_data = response.json()
if 'seq' in sequence_data:
return sequence_data['seq']
else:
print("No sequence found for transcript:", transcript_id)
return None
else:
print(f"Error fetching sequence data from Ensembl: {response.text}")
return None
def find_crispr_targets(sequence, chr, start, strand, pam="TTTN", target_length=34):
targets = []
len_sequence = len(sequence)
for i in range(len_sequence - target_length + 1):
target_seq = sequence[i:i + target_length]
if target_seq[4:7] == 'TTT':
tar_start = start + i
tar_end = start + i + target_length
gRNA = target_seq[8:28]
targets.append([target_seq, gRNA, chr, str(tar_start), str(tar_end), str(strand)])
return targets
def format_prediction_output(targets, seq_deepCpf1):
formatted_data = []
for target in targets:
# Predict
encoded_seq = get_seqcode(target[0]) # 'target' seems to be the full sequence including PAM
prediction = seq_deepCpf1.predict(encoded_seq)
# Format output
gRNA = target[1] # gRNA is presumably the guide RNA sequence
chr = target[2] # Chromosome
start = target[3] # Start position
end = target[4] # End position
strand = target[5] # Strand
target_seq = target[0] # Full target sequence including PAM
formatted_data.append([chr, start, end, strand, target_seq, gRNA, prediction[0][0]])
return formatted_data
def process_gene(gene_symbol, model_path):
transcripts = fetch_ensembl_transcripts(gene_symbol)
all_data = []
gene_sequence = '' # Initialize an empty string for the gene sequence
# Load the model
seq_deepCpf1 = Seq_DeepCpf1_model(input_shape=(34, 4))
seq_deepCpf1.load_weights(model_path)
if transcripts:
for transcript in transcripts:
transcript_id = transcript['id']
chr = transcript.get('seq_region_name', 'unknown')
start = transcript.get('start', 0)
strand = transcript.get('strand', 'unknown')
# Fetch the sequence here and concatenate if multiple transcripts
gene_sequence += fetch_ensembl_sequence(transcript_id) or ''
if gene_sequence:
targets = find_crispr_targets(gene_sequence, chr, start, strand)
if targets:
formatted_data = format_prediction_output(targets, seq_deepCpf1)
all_data.extend(formatted_data)
else:
print("Failed to retrieve transcripts.")
return all_data, gene_sequence
def create_genbank_features(formatted_data):
features = []
for data in formatted_data:
location = FeatureLocation(start=int(data[1]), end=int(data[2]), strand=(1 if data[3] == '+' else -1))
feature = SeqFeature(location=location, type="misc_feature", qualifiers={
'label': data[5], # gRNA as label
'note': f"Prediction: {data[6]}" # Prediction score in note
})
features.append(feature)
return features
def generate_genbank_file_from_data(formatted_data, gene_sequence, gene_symbol, output_path):
features = create_genbank_features(formatted_data)
record = SeqRecord(Seq(gene_sequence), id=gene_symbol, name=gene_symbol,
description='CRISPR Cas12 predicted targets', features=features)
record.annotations["molecule_type"] = "DNA"
SeqIO.write(record, output_path, "genbank")
def generate_bed_file_from_data(formatted_data, output_path):
with open(output_path, 'w') as bed_file:
for data in formatted_data:
chrom = data[0]
start = data[1]
end = data[2]
strand = data[3]
gRNA = data[5]
score = data[6]
bed_file.write(f"{chrom}\t{start}\t{end}\t{gRNA}\t{score}\t{strand}\n")