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TA的每日心情 | 开心 2021-8-11 17:59 |
|---|
签到天数: 17 天 [LV.4]偶尔看看III 网络挑战赛参赛者 网络挑战赛参赛者 - 自我介绍
- 本人女,毕业于内蒙古科技大学,担任文职专业,毕业专业英语。
 群组: 2018美赛大象算法课程 群组: 2018美赛护航培训课程 群组: 2019年 数学中国站长建 群组: 2019年数据分析师课程 群组: 2018年大象老师国赛优 |
基因组测序模拟
9 b2 { B7 v' J) s4 s基因组测序模拟
% ~ z4 A9 B0 M" W; K+ D3 A( _# p
. l, x: ]0 }5 J+ E一、摘要2 h7 v, U1 }( g$ X5 V, p+ Y" z
3 F$ b( P! q1 v. U9 R4 C( b# N通过熟悉已有的基因组测序模拟和评估程序,加深全基因组鸟枪法测序原理的理解,并且能够编写程序模拟全基因组鸟枪法测序,理解覆盖度、测序深度、拷贝数等概念,设置测序相关参数,生成单端/双端测序结果文件
0 [0 Y8 U" ~2 Y2 R# {
]# N+ q* M. A) |4 P二、材料和方法
$ x; P: O1 A$ V& E& ?$ t
, T% |/ n2 c. p# B. a: {/ B1、硬件平台+ ]' g a: f& N% I( s
- n/ E5 `. ~2 F8 j处理器:Intel(R) Core(TM)i7-4710MQ CPU @ 2.50GHz
. Q1 H6 w B% H, C! ~安装内存(RAM):16.0GB: v( P' v5 ]% S
! N! R8 d- D H+ P. p5 ~: }
2、系统平台
! Q' ?. ?# A# z, OWindows 8.1,Ubuntu
5 h" w* Z( q/ Y6 Z. S3 U# @ X7 j9 m4 [3 E- }
3、软件平台9 x: ?# U# F4 k, F! R8 z
( i) z! a& U/ f5 ^& k$ [4 x
art_454
2 M# q, {- g6 e8 FGenomeABC http://crdd.osdd.net/raghava/genomeabc/
: ?2 ]9 g; J% |( Y+ h7 t9 L2 KPython3.5
$ K' f; d t! i4 {Biopython
) z' q" D1 n& E4 `4、数据库资源& c& i* Q& U9 o- O7 \4 ]; z4 x: J5 a" N
- I$ g [8 S4 y `& F1 PNCBI数据库:https://www.ncbi.nlm.nih.gov/
5 d; S+ `1 @* P( J
$ ]: f) l+ m+ [7 h u8 x5、研究对象4 V- n' H4 I; \* G, W1 U# m
. G( P* K. l \$ b7 N
酵母基因组Saccharomyces cerevisiae S288c (assembly R64) 8 D* D5 l- ^% `+ e; L
ftp://ftp.ncbi.nlm.nih.gov/genomes/all/GCF/000/146/045/GCF_000146045.2_R64/GCF_000146045.2_R64_genomic.fna.gz c1 @$ C% }9 W, l; W2 O+ } B
2 f$ z& ^4 v( q T
6、方法
) H6 p) [. R9 m1 f1 ~- s
o! t* A7 h3 ~: Cart_454的使用 , L1 O2 X* m% U9 `- O
首先至art系列软件的官网,下载软件,在ubuntu系统安装,然后阅读相关参数设置的帮助文档,运行程序。. H2 P w3 S% D0 o1 { i7 ^
GenomeABC ( B5 w$ F/ W6 u; i, F
进入GenomeABC(http://crdd.osdd.net/raghava/genomeabc/),输入参数,获得模拟测序结果。8 u0 Y% f7 b2 a/ f- `
编程模拟测序 4 J$ C; w2 v$ g T' ~0 x; {* _; h/ a
下载安装python,并且安装biopython扩展模块,编写程序,模拟单端/双端测序。
. m( o; n( U( A三、结果
) Q3 X8 r& X( a( e' x# B: C2 W
1、art_454的运行结果5 R0 i$ n) P) K" V$ T3 l$ |
) }- P | x# P* j7 d; \无参数art_454运行,阅读帮助文档
" ^ D8 ]& t6 H1 v. Z$ a4 t6 e/ {3 Y; X
图表 1无参数art_454运行
0 O( C& l" y9 a对酵母基因组进行基因组单端测序模拟,FOLD_COVERAGE设为20,即覆盖度为20.
4 a* V1 z* G+ w- h- W下图为模拟单端测序,程序运行过程及结果 % i$ I- Z$ [* n% D U4 c6 }
# i k4 H8 v/ P6 W# J( Z: s图表 2 art454单端测序
" Y$ ?2 v& w& u% ?" j b2 O- A
& f/ \- b) E* }8 W! Y/ s* |5 V图表 3 art454单端模拟结果 9 U' H7 j5 e+ s( H: Z. `; ?7 B3 f' J, M
双端测序模拟,FOLD_COVERAGE设为20,即覆盖度为20;MEAN_FRAG_LEN设为1500,即平均片段长度为1500;STD_DEV设为20,即长度的标准差为20
. P& v& }' O# N+ w8 o0 Q2 [( `下图为模拟双端测序,程序运行过程及结果
m: j, C7 C. [* [0 Q/ Q9 v5 `8 g# E9 i1 C
图表 4 art454双端测序 ( S1 L9 i- `- X& b k, f9 s5 T
$ y( S; [7 w; Q4 t& u图表 5 art454双端模拟结果 ) r& ]! U& A; L* W2 J: N
2、GenomeABC
6 ^( A) v0 ]" L# E6 y下图为设置参数页面
( p F4 i# k/ U# C! M! r1 C" b! {3 c3 x* }9 Q H
下图为结果下载页面 * a0 K) }+ i9 ~% K
. d6 t# q' }+ u! Q图表 6 结果下载页面
* b1 S2 H) u$ s) ^/ y3、编程模拟测序结果
( w! ?3 c* H9 V/ q/ e$ r' F拷贝数是这里的N值;覆盖度是m,测序深度是宏观的量,在这里与覆盖度意思相同,就是测序仪10X,20X。
& t# L' f$ r9 R8 v单端测序
3 x P, I7 {0 Y! J. R. h# G( U: \7 K8 G' ?* W c7 ?9 }/ M/ I0 a
图表 7 程序模拟单端测序
6 `6 u# l7 f% x0 G双端测序
* F- q. l5 l- W- Z* S
: P& ^" L. q1 R$ k图表 8 程序模拟双端测序
R3 e% T) w9 X5 g& u) H# D' d' L测序结果
2 F. V1 W$ l; l- U0 {
; o0 `+ D( u; u/ Q I# Z! `$ u; p图表 9 结果文件& q) k, }9 f* c9 C3 q( A5 D5 K
6 ~, N6 ?& x% H( K& j
因为期望片段长度是600bp,在片段长度区间200-1000bp内,所以大部分的片段都没有删除。
% {2 X" d* X% q( L测序结果统计表2 M; [1 i2 P$ ~( P
. E- U( l9 v a: A
测序方式 基因组大小(bp) 片段长度区间 (bp) N值 期望片段长度 克隆保留率 片段数量 Reads长度范围(bp) Reads总数量 Reads总长度 覆盖度(m值) 理论丢失率(e-m) 覆盖率(1-e-m)
! p- I; ^: x) B9 r1 Q) l' v0 e单端 12157kb 200-1000 10 600 0.95 107378 50-100 101968 7645.541kb 0.62889 0.53318 0.46682
" ~7 c- T% c( `, f- y9 @单端 12157kb 200-1000 20 600 0.95 213722 50-100 202996 15227.882kb 1.25259 0.28576 0.71424% q& x) L4 v0 \, V2 P
双端 12157kb 200-1000 10 600 0.95 106704 50-100 202770 15212.662kb 1.25134 0.28612 0.71388! G% B: O6 `5 t( U# N
双端 12157kb 200-1000 20 600 0.95 214212 50-100 407186 30534.265kb 2.51164 0.08114 0.91886% F/ A5 t1 w" k; v" i1 a4 f
四、讨论和结论5 w- z1 h4 H3 j( v! r: e& y
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程序运行方法
; _, x( o; a9 g! `. c1 q% o9 {
在类的构造方法init()中,调整参数。 7 s2 r& E: \+ p& l' a! W/ q! E; m& j
Averagefragmentlength为片段平均的长度;
0 }8 D9 F. i* k* q2 _3 gminfragmentlength和maxfragmentlength是保留片段的范围; : v9 v3 l3 g0 |5 t* j- j( x6 ]
cloneRetainprobability是克隆的保留率;
& c9 q! H+ B, f- p6 E6 aminreadslength和maxreadslength是测序reads的长度范围) @3 q! }& O. H& ^: x+ x
" ]5 ?0 T) I% S$ k6 {: W
模拟测序的诸多方法都封装成了Sequencing类,只需要创建类,并调用singlereadsequencing()和pairreadsequencing()方法,传入文件名的参数即可。) S: W# i+ H( F$ m) v0 {3 J
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附录; T& E b* {: Y8 c7 |: F
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from Bio import SeqIO
) x$ l7 b- K% c% bfrom math import exp9 h) y0 A. u, l# i6 I. U
import random
6 {/ j8 x9 N9 x: |+ p( {; A, n9 u" H; h0 m
class Sequencing:
+ T5 C! m6 m9 a # N代表拷贝份数/ G& t4 ~) k5 B' r
def __init__(self)
; K% ~& a1 p% G% F" I; k self.fragmentList = []
; s, N9 X" o9 \& f. H. B8 @ self.readsID = 1
( H+ N0 B+ f1 n+ l% r/ ]" U self.readsList = []* S" w: z) h* u; s8 ^% M
self.averagefragmentlength = 650
0 m1 |! l u/ w& ~" B& q6 Z% ^ self.minfragmentlength = 500
1 m+ I) Z4 M/ `* k self.maxfragmentlength = 800
( i9 x) W5 j: ?9 L. e0 h self.cloneRetainprobability = 18 W5 [6 ?/ [$ k7 x- k
self.minreadslength = 50
6 @, v; {% e5 ~0 T- p" U# ~ self.maxreadslength = 150
6 R7 P9 l8 z$ A6 B6 z* J6 b R! V self.N = 10* K a) Q+ f2 r S. p
self.genomeLength = 07 n) l. F5 h8 J0 f
self.allreadslength = 0
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# 生成断裂点# e/ f4 `" X7 W: u; w8 @
def generatebreakpoint(self, seqlen, averageLength):
- C; d) ^6 x4 R. I1 j$ k, P # 假设平均每500bp 产生一个断裂点(averageLength = 500),通过随机函数生成seqlen/500个随机断裂点(1到seqlen之间的随机整数)
8 A4 X& k2 U- a4 M breakpoint = [random.randint(0, seqlen) for _ in range(int(seqlen / averageLength))]6 @8 i. l: p p
breakpoint.append(seqlen)9 A0 O2 _2 n1 x2 z6 K
breakpoint.append(0)
* ]" ]* D4 ^; g5 B% o # 把随机断裂点从小到大排序
: J5 u" @* S9 g1 ^& i* s) d# r breakpoint.sort()
1 t& v' Q. B, [7 |; V. f+ K# z- B return breakpoint: i& S. Y/ Z7 j: K8 h6 L
+ [( u9 a! `3 e! V( Q' }0 W- v
# 沿断裂点打断基因组,并删除不符合长度要求的序列片段,定义片段范围:200-1000bp4 @5 l7 O9 I( L
def breakgenome(self, seq, breakpoint, minfragmentlength, maxfragmentlength):
2 q# O4 k; O. E for i in range(len(breakpoint) - 1):; C9 ^5 o. L/ G3 D5 h1 B! z
fragment = seq[breakpoint:breakpoint[i + 1]], H! ]8 O" Q! a- [9 x6 I1 Q
if maxfragmentlength > len(fragment) > minfragmentlength:. v& y% W6 H' }1 e9 Z1 t: `" r) s
self.fragmentList.append(fragment)
4 y" [- Q( u6 e return self.fragmentList' h# m6 d% K; _+ ]; ]# a9 X9 y; M7 E
/ v2 |6 h$ T" J # 模拟克隆时的随机丢失情况,random.random()生成0-1的保留概率
* z, t5 i& [9 p def clonefragment(self, fragmentList, cloneRetainprobability):8 `7 Q- M; ~, Y- }
clonedfragmentList = []
2 C# k: g; v4 w4 ^# p Lossprobability = [random.random() for _ in range(len(fragmentList))]
: F) d' j6 k4 r4 h0 H- b for i in range(len(fragmentList)):
8 `- h' Y! X) y* Y0 ~8 T% D7 u% w7 v if Lossprobability <= cloneRetainprobability:
+ D4 U7 q" \$ [# }4 P/ O7 A clonedfragmentList.append(fragmentList): Z5 Q2 Y. a% u8 V6 g
return clonedfragmentList
5 I# r. W- Q8 F6 u: w8 z3 F6 `% Z u% {
# 模拟单端测序,并修改reads的ID号
" n# ` ^. t' F: q2 o' ? def singleread(self, clonedfragmentList):; J1 U. m) T4 g5 X
for fragment in clonedfragmentList:
1 F/ @% u0 F# O3 T0 x fragment.id = ""
, L2 b+ I2 h* L9 Z fragment.name = ""1 f* F& O5 X6 i
fragment.description = fragment.description[12:].split(",")[0]3 A' A1 D. V1 { q7 ^# ]/ e6 {
fragment.description = str(self.readsID) + "." + fragment.description* E t- m" b: C3 k
self.readsID += 1
* r, E9 Q6 \! Y L1 o readslength = random.randint(self.minreadslength, self.maxreadslength)7 N4 |* }, ?5 U i
self.allreadslength += readslength
. L$ o. g) l; x. ?5 R# k self.readsList.append(fragment[:readslength])
% k, l( _& K1 W! C1 p/ P m$ a7 _% u/ X) L. i8 m% B$ |4 E6 v
def singlereadsequencing(self, genomedata, sequencingResult):
7 R" X, v4 ^; v3 u$ r6 d9 m, W! r1 z for seq_record in SeqIO.parse(genomedata, "fasta"):
- r- r" q( A. _* a( y seqlen = len(seq_record)
# W0 `3 S1 l+ [3 K# T Z; O self.genomeLength += seqlen
q- H# \0 i: T for i in range(self.N):
; p3 ]! p# ]/ a! m+ n# s2 C # 生成断裂点0 z7 u! E9 k" A+ \0 a. p6 D
breakpoint = self.generatebreakpoint(seqlen, self.averagefragmentlength)
" M4 L, q4 q4 R* K, V; I* } # 沿断裂点打断基因组5 h) ^2 v( b/ r+ H* Q4 A, e
self.breakgenome(seq_record, breakpoint, self.minfragmentlength, self.maxfragmentlength) ?) Y h% M7 H' w2 e( v
# 模拟克隆时的随机丢失情况
+ \$ q' M: `/ d$ Y( X! |9 Q" V clonedfragmentList = self.clonefragment(self.fragmentList, self.cloneRetainprobability)
3 b' `( p4 ]& o( u) w% q # 模拟单端测序% x$ c3 l w: h! p: I/ I# y; c
self.singleread(clonedfragmentList)
- S9 C! c T2 _8 Y9 |( B/ p/ A SeqIO.write(self.readsList, sequencingResult, "fasta")# X; P& s, q: o: R
. ^0 {4 l, v% M* X def pairread(self, clonedfragmentList):9 G' \6 n( W8 B" D2 B; Q+ k
for fragment in clonedfragmentList:
% h% Y( o: f( g9 ~3 q fragment.id = ""* H" A8 o6 m4 o9 y* c
fragment.name = ""
4 B4 M# g$ [$ H' H9 ?2 a description = fragment.description[12:].split(",")[0]& Y$ f/ H% K* S7 l @4 H- q+ k
fragment.description = str(self.readsID) + "." + description7 J/ b4 R3 S8 I) d1 d) q( f
readslength = random.randint(self.minreadslength, self.maxreadslength)
8 f& B, E" V3 f" L* E self.allreadslength += readslength; z4 s% G: x$ J
self.readsList.append(fragment[:readslength])
1 ?% y4 {8 q( H/ {! P+ q& \: r! Q3 d( I8 s
readslength = random.randint(self.minreadslength, self.maxreadslength)
: [: N: s! m) z. B" k, ^: r self.allreadslength += readslength& w% i# h% N8 Z& c: _8 m
2 G. V5 {; o3 M; N/ F
fragmentcomplement = fragment.reverse_complement()# |! M5 Z6 g5 k9 \
fragmentcomplement.id = "", b( [" ^1 v* H" V- q( u- R4 X
fragmentcomplement.name = ""* }7 c: z5 E9 z2 S/ e
fragmentcomplement.description = str(self.readsID) + "." + description
8 C! c8 R' [) ] self.readsList.append(fragmentcomplement[:readslength])
2 Q: {% X2 i3 `( ^0 B/ p% R! x& j( A5 Q- {
self.readsID += 1. N/ f* Y7 C6 g
# X0 O% k7 G: E$ @, } def pairreadsequencing(self,genomedata, sequencingResult_1, sequencingResult_2):
. g1 [7 H- d! _9 ] m; I4 G& i9 l0 F7 T for seq_record in SeqIO.parse(genomedata, "fasta"):
$ S- S5 @& r- P( v8 [ seqlen = len(seq_record)
7 p" D0 d" d9 \5 n- c7 b) B self.genomeLength += seqlen6 ^$ J# J- d6 }0 f7 q6 b4 M
for i in range(self.N):
; G9 t3 H5 o8 K' O9 s1 P6 N' p: [' L, ? # 生成断裂点# r8 L" i3 j' k- O
breakpoint = self.generatebreakpoint(seqlen, self.averagefragmentlength)3 o; x; b) B" l; \; l
# 沿断裂点打断基因组
; p! f* f8 N" \ I @ self.breakgenome(seq_record, breakpoint, self.minfragmentlength, self.maxfragmentlength)8 r2 J. H( ? C7 q; [8 \% i4 s
# 模拟克隆时的随机丢失情况 a6 a: K9 d- w. u
clonedfragmentList = self.clonefragment(self.fragmentList, self.cloneRetainprobability)
4 T& f# f5 J! H; M7 b0 ]. c # 模拟双端测序
2 H' ?% K! v' j3 E0 }1 C5 A; ]! ] self.pairread(clonedfragmentList)
5 o$ O# V" n% t readsList_1 = [self.readsList for i in range(len(self.readsList)) if i % 2 == 0]
) n! q/ h2 H. c9 _( c/ ?, o1 y6 s& I" t readsList_2 = [self.readsList for i in range(len(self.readsList)) if i % 2 == 1]/ @! ]. b% p5 g) o! f7 k6 _! @
SeqIO.write(readsList_1, sequencingResult_1, "fasta")
0 J3 [7 y) H b. K1 x0 v2 r1 M SeqIO.write(readsList_2, sequencingResult_2, "fasta")$ F l3 L7 p8 t L. u _: t+ Y
/ a& d5 n' W6 m3 W$ I! q2 y
def resultsummary(self):
; _; ~& p7 `3 }7 {3 X5 F: ] print("基因组长度:" + str(self.genomeLength / 1000) + "kb")
# L& O" K+ X& {; k% j print("片段长度区间:" + str(self.minfragmentlength) + "-" + str(self.maxfragmentlength))+ b$ k; i2 n/ w
print("N值:" + str(self.N))4 n( O& `8 p1 |
print("期望片段长度:" + str(self.averagefragmentlength))
4 H* V! P+ W6 X k: t a print("克隆保留率:" + str(self.cloneRetainprobability))) V% F' t# D: I& Y! [6 j, B
print("片段数量:" + str(len(self.fragmentList)))% x# y% y7 U. S$ b5 h
print("reads长度:" + str(self.minreadslength) + "-" + str(self.maxreadslength))
/ K N/ A. l7 Y2 z print("reads总数量:" + str(len(self.readsList)))8 [7 n" ~& J; a2 b4 ]
print("reads总长度:" + str(self.allreadslength / 1000) + "kb")" A6 H; j3 _0 r. J2 Z
m = self.allreadslength / self.genomeLength& m& J/ V7 J' D( j$ p n, ?
print("覆盖度(m值):" + str(round(m, 5)))2 e: ?' e, C) b9 I
print("理论丢失率(e^-m):" + str(round(exp(-m), 5)))
: w( Y" a$ O* |& B5 f print("覆盖率(1-e^-m):" + str(round(1 - exp(-m), 5)))2 p; }" g: d: n( S
# -------------------------------------------主程序-------------------------------------------$ e& k. R$ p0 a- j4 |( W! ?, o
# 模拟单端测序: ] w- M0 o! Q& f4 c
sequencingObj = Sequencing()9 g" @& d) {, t! i/ r
sequencingObj.singlereadsequencing("data/NC_025452.fasta", "result/virusSingleRead.fa")
- m' u1 C' i1 \9 ^/ \1 LsequencingObj.resultsummary()
- o/ p$ {, [8 Z# q# J S
' G4 a+ X* M3 [8 k+ [ d- [0 P: K9 h# 模拟双端测序
/ {2 F" y. c# S* Z) SsequencingObj = Sequencing()
3 l5 F# w! U% L1 u* ^3 g$ S# [sequencingObj.pairreadsequencing("data/GCF_000146045.2_R64_genomic.fna", "result/yeastPairRead_1.fa", "result/yeastPairRead_2.fa")" a4 U% q. a. y7 e" I
sequencingObj.resultsummary()3 V# R# h1 Z: ?: ^
from Bio import SeqIO
6 f$ h" K2 N- I1 r) Hfrom math import exp
0 }% _" \) I* ^import random/ N6 z& G6 _( S4 Y
0 b" E8 ]' |7 }. mclass Sequencing:$ S# m1 B1 e- V1 i# g, a
# N代表拷贝份数
) i' @0 c; ?9 v- y def __init__(self):( b* G: e* d& x3 p( ]
self.fragmentList = []- n0 i7 U9 ~/ J3 e' n
self.readsID = 1) D( S- ?) F* L
self.readsList = []1 @) t3 Z; T3 \: l% h' x5 u
self.averagefragmentlength = 650, V. `( C0 ]0 W1 }
self.minfragmentlength = 5008 g/ a% h/ y2 `( I( y
self.maxfragmentlength = 8003 ~8 `' P3 M1 K3 f6 ?. w, q; Y' {: _9 j
self.cloneRetainprobability = 1
/ D w" W. R8 b+ P8 z self.minreadslength = 50# o& d4 I0 D" I& S0 c
self.maxreadslength = 150
8 l6 Q3 r+ \& [ self.N = 10
6 G* U; e& M& _% ^ self.genomeLength = 0- y9 ?& U' @4 J. V
self.allreadslength = 0
# i2 }9 d' p+ `
. I9 t/ {% u+ D) B# l e ` # 生成断裂点8 I, X6 P8 J1 ]! ^% W6 k) W: M
def generatebreakpoint(self, seqlen, averageLength):; Y1 Z8 r1 e. [3 n) d7 U* A
# 假设平均每500bp 产生一个断裂点(averageLength = 500),通过随机函数生成seqlen/500个随机断裂点(1到seqlen之间的随机整数)- q7 u3 }: Q8 \, S/ P7 @, R
breakpoint = [random.randint(0, seqlen) for _ in range(int(seqlen / averageLength))]4 @" ^# }8 v4 Z q4 \
breakpoint.append(seqlen)% F! n& g0 a5 T4 s7 J
breakpoint.append(0)* \+ ~/ Z9 b, k: y
# 把随机断裂点从小到大排序" k- r" L- m! D# L$ |7 ^ q
breakpoint.sort() `$ U& B0 [5 g& k( U' e7 J
return breakpoint; l/ S2 Y6 _: \
1 X# ]% u" N9 `/ |' a
# 沿断裂点打断基因组,并删除不符合长度要求的序列片段,定义片段范围:200-1000bp
1 g% J8 R/ p$ Z; \/ q def breakgenome(self, seq, breakpoint, minfragmentlength, maxfragmentlength):
( H) D: j# q/ R. \; Q9 N* Y for i in range(len(breakpoint) - 1):8 _7 U. q' ^3 v' b# \) h1 s! p
fragment = seq[breakpoint:breakpoint[i + 1]]! Z- ?) S) X7 ~1 h' B& W+ h) s* P
if maxfragmentlength > len(fragment) > minfragmentlength:
2 Z+ m x3 l' ^7 [- [ self.fragmentList.append(fragment)0 J# ~: s! G: ^0 j+ \# r
return self.fragmentList
7 z8 M+ n5 D# U/ l! D6 b% V- r. H0 W$ y# }; V
# 模拟克隆时的随机丢失情况,random.random()生成0-1的保留概率
' |- H+ \ ^( G+ C# V def clonefragment(self, fragmentList, cloneRetainprobability):$ B; m1 Z5 x8 W$ ?6 Z% U% T/ g. N
clonedfragmentList = []
$ w# T: M& v) V Lossprobability = [random.random() for _ in range(len(fragmentList))]
. B( q" b. s) W, F8 a( l+ H/ K1 b9 N5 ^ for i in range(len(fragmentList)):! E5 T. _' w3 Y1 l Y/ o6 d0 F
if Lossprobability <= cloneRetainprobability:3 u0 @1 f' H- A
clonedfragmentList.append(fragmentList)# N. q; q& z0 z! T
return clonedfragmentList4 m: w% c8 R% _& K. w) L4 |3 R
+ F4 z+ B- k) ?8 S' b
# 模拟单端测序,并修改reads的ID号
# t) W: u! P* G/ z7 o4 v def singleread(self, clonedfragmentList):
8 A9 L/ u" B* Y; x# s5 t for fragment in clonedfragmentList:
& Q3 x: B5 V1 \7 d1 S7 o5 @$ }9 } fragment.id = ""
" e0 {" d6 _5 k) V fragment.name = """ J$ K8 s* T6 d2 e3 d- i
fragment.description = fragment.description[12:].split(",")[0]
1 {4 W# B1 }7 T% `0 S8 Z fragment.description = str(self.readsID) + "." + fragment.description# M% |. h( J. m! a. O6 P
self.readsID += 1
2 q8 L) ?5 G- ~0 k% ?3 r* w readslength = random.randint(self.minreadslength, self.maxreadslength)5 p" D( w E: }, A/ p" ^7 s' d: \& l
self.allreadslength += readslength
4 q; ]5 k* }& e) p/ Z8 {9 ]. X: v self.readsList.append(fragment[:readslength])) l2 I) V1 n% k* ^) z7 V2 l. ?5 Z
( M/ R% M, w) r n" @0 G def singlereadsequencing(self, genomedata, sequencingResult):
& B3 B5 X' O5 ~6 x, A2 W. @8 A% w for seq_record in SeqIO.parse(genomedata, "fasta"):) y L# G# b/ D% \: \. ]
seqlen = len(seq_record)% s$ k1 v M& D6 o
self.genomeLength += seqlen, [+ B! p5 @6 N
for i in range(self.N):4 s- ^5 E+ S5 {
# 生成断裂点+ z4 a. L6 Y* O
breakpoint = self.generatebreakpoint(seqlen, self.averagefragmentlength)* ], R9 J+ q2 b+ g
# 沿断裂点打断基因组
5 T1 m/ o8 n% E+ I5 y; d self.breakgenome(seq_record, breakpoint, self.minfragmentlength, self.maxfragmentlength), Y4 o+ G. a* k6 O5 t
# 模拟克隆时的随机丢失情况
7 Q2 g: e5 L; K4 V1 e clonedfragmentList = self.clonefragment(self.fragmentList, self.cloneRetainprobability)2 i# c, ^9 a1 F/ Q9 B+ h$ M
# 模拟单端测序/ U8 }* T! U2 K, H- h
self.singleread(clonedfragmentList), g# z* d" V6 |& [, [9 A. q/ ?
SeqIO.write(self.readsList, sequencingResult, "fasta")& q, x! J- X9 P8 s1 S8 ~
! R6 p8 j7 E# X
def pairread(self, clonedfragmentList):
. h. x- S% V/ w7 N1 w4 M1 O. [* @1 ~ for fragment in clonedfragmentList:$ @( I7 O9 m. H, Z1 W) m
fragment.id = ""
% [/ U+ V, }2 O7 ^% p fragment.name = "") x' W4 `' C0 a4 {% O
description = fragment.description[12:].split(",")[0]8 z& p; e# `, S
fragment.description = str(self.readsID) + "." + description
# K8 G" I+ ?# H" R A readslength = random.randint(self.minreadslength, self.maxreadslength)
. p% H- r1 X- _6 Z% E self.allreadslength += readslength
0 A, A: X* Z# }8 S self.readsList.append(fragment[:readslength])
; `7 o8 X9 T7 M/ D. n8 t! x5 a4 E$ P7 M# q; l o# @
readslength = random.randint(self.minreadslength, self.maxreadslength)
* f, t9 ]1 ]% {3 ~ self.allreadslength += readslength' d# M) ^: k, H( j$ u2 c
" s) h) a: M5 \* p1 ~: g, K. _
fragmentcomplement = fragment.reverse_complement()
8 `& U' u A1 v+ z* U! m fragmentcomplement.id = ""5 e3 }( U7 n5 A0 h; j
fragmentcomplement.name = ""6 E" W4 ]; ]( | X+ |
fragmentcomplement.description = str(self.readsID) + "." + description
) q' U1 H6 c" f6 Y self.readsList.append(fragmentcomplement[:readslength])
; k5 A5 f8 w0 F/ o1 {- m$ Q. C1 N8 A4 E, a& i0 @6 V+ p$ n
self.readsID += 1
. ?7 T+ j( c/ Z; X3 `" _* A$ k0 f- }: a; c: p( s3 d# d
def pairreadsequencing(self,genomedata, sequencingResult_1, sequencingResult_2):
7 A3 z( [3 G7 W for seq_record in SeqIO.parse(genomedata, "fasta"):
# ~! q$ \9 t# V9 s. z seqlen = len(seq_record)# |9 x' R1 q' N4 h
self.genomeLength += seqlen
5 ^3 u& C; k5 D B: |( I3 R2 X( i for i in range(self.N):
! w. C/ Y( V! V3 M4 L # 生成断裂点! V$ m9 G) x( N9 G
breakpoint = self.generatebreakpoint(seqlen, self.averagefragmentlength)5 p! u# s3 E7 ^
# 沿断裂点打断基因组$ N! m" Q5 k+ S e. ?' t
self.breakgenome(seq_record, breakpoint, self.minfragmentlength, self.maxfragmentlength)
^- q( n2 u8 Z # 模拟克隆时的随机丢失情况
+ Z/ r% e+ x! U! I clonedfragmentList = self.clonefragment(self.fragmentList, self.cloneRetainprobability)
3 B- A- T3 M# Y" O8 O3 k, u& _ # 模拟双端测序
0 |# K- \$ O: t( m9 f self.pairread(clonedfragmentList)
% l* @( D, B ?- Y readsList_1 = [self.readsList for i in range(len(self.readsList)) if i % 2 == 0]6 B/ ?, F# ]! t
readsList_2 = [self.readsList for i in range(len(self.readsList)) if i % 2 == 1]
% J1 m2 k- Q1 d SeqIO.write(readsList_1, sequencingResult_1, "fasta")4 V: Q) w( K% E* L+ X: F B
SeqIO.write(readsList_2, sequencingResult_2, "fasta")
) \, ~- R6 |* @* p
4 ] n: t: \! Q# u6 i5 {: g- J' h: n def resultsummary(self):: y' s% p6 {8 N- L! I( f
print("基因组长度:" + str(self.genomeLength / 1000) + "kb")
% L4 t5 N% v3 h& R" _$ B print("片段长度区间:" + str(self.minfragmentlength) + "-" + str(self.maxfragmentlength))% ^; E- M3 o T
print("N值:" + str(self.N))9 i& r1 o0 I& o3 e+ C7 U% @% o
print("期望片段长度:" + str(self.averagefragmentlength))
8 W7 W* M5 K9 G3 C* {4 d& ~ print("克隆保留率:" + str(self.cloneRetainprobability))
1 {: ] }" z* v1 ]8 B print("片段数量:" + str(len(self.fragmentList)))
* l! W( v! h5 O7 h+ D" | print("reads长度:" + str(self.minreadslength) + "-" + str(self.maxreadslength))
1 X( ^: V- Z2 s: y5 a! Q/ c print("reads总数量:" + str(len(self.readsList)))- Y' j9 o& W; ?3 c+ w7 m2 p
print("reads总长度:" + str(self.allreadslength / 1000) + "kb")' o( p- ^" b4 ]! k
m = self.allreadslength / self.genomeLength
6 ~3 Z8 ~0 n- D% a- M print("覆盖度(m值):" + str(round(m, 5)))+ O1 s7 Q6 i6 g% P1 H" q) U( K
print("理论丢失率(e^-m):" + str(round(exp(-m), 5)))
6 z! K1 L! P& H: [2 N+ k print("覆盖率(1-e^-m):" + str(round(1 - exp(-m), 5)))
( I' D0 u8 t' c. \! ^% c9 V+ g9 W4 w# -------------------------------------------主程序-------------------------------------------
& A/ T7 @, S5 Z# 模拟单端测序
0 M3 h0 x- _! U. MsequencingObj = Sequencing()" s2 X H* I& w# Z( }) t2 w
sequencingObj.singlereadsequencing("data/NC_025452.fasta", "result/virusSingleRead.fa"): h. o6 s) G$ }; F" J0 _
sequencingObj.resultsummary()
Y9 A; H6 C3 J, _6 g3 s! Y& L2 r6 S) p- f. m3 c/ Z' Y
# 模拟双端测序
: Q4 ~* t, A) c0 b/ d) qsequencingObj = Sequencing()- x; W: u2 {- O6 X
sequencingObj.pairreadsequencing("data/GCF_000146045.2_R64_genomic.fna", "result/yeastPairRead_1.fa", "result/yeastPairRead_2.fa")
# O! h6 a7 d1 G1 OsequencingObj.resultsummary()$ d5 U7 h8 F) b K- M8 a I* ?9 V
6 w/ F' \$ C# N5 a. y n
6 [, W' T6 o- K# `% l9 L
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