Assignment 1
Edith Chan
9/27/2021
Assignment: Your assignment is to use your notes from class - along with help from classmates, UTAs, and me - to turn this script into a fleshed-out description of what is going on.
This is a substantial project - we’ll work on it in steps over the rest of the unit.
We are currently focused on the overall process and will cover the details over the rest of this unit.
Your first assignment is to get this script to run from top to bottom by adding all of the missing R commands. Once you have done that, you can knit it into an HTML file and upload it to RPubs. (Note - you’ll need to add the YAML header!)
Your second assignment, which will be posted later, is to answer all the TODO and other prompts to add information. You can start on this, but you don’t have to do this on your first time through the code.
Delete all the prompts like TODO() as you compete them. Use RStudio’s search function to see if you’ve missed any - there are a LOT!
A complete bioinformatics workflow in R
By: Nathan L. Brouwer
“Worked example: Building a phylogeny in R”
Introduction
Phylogeny is an important part of biology because scientists can understand the evolutionary relationships among organisms through it. Furthermore, scientists can graphically demonstrate these relationships through a phylogenetic tree.
Vocab
Accession number = an unique number assigned by a particular database as an additional means tp find the article Fasta file = text-based format for representing either nucleotide sequences or amino acid sequences Pairwise alignment = identify regions of similarity between Fasta Files MSA (Multiple Sequence Alignment) = maximizes the similarity between files Distance matrice = summarizes Reproduceable workflow = R code that can be adaptable to compute (Package) :: (Function) = the double colon gets the function from the package /n = creates a new line; new line character Node = a branch-point in a phylogeny Clade = a group of organisms that are monophyletic = composed of a common ancestor and all its lineal descendants
Key functions
rentrez::entrez_fetch Biostrings::pid compbio4all::entrez_fetch_list ggmsa::ggmsa stringr::str_split
Software Preliminaires
Load packages into memory
# github packages
library(compbio4all)
# CRAN packages
library(rentrez)
library(seqinr)
library(ape)
# Bioconductor packages
library(msa)
library(Biostrings)Retrieving macromolecular sequences
Getting the information for the Human shroom 3 sequences and storing it into the variable hShroom3
# Human shroom 3 (H. sapiens)
hShroom3 <- rentrez::entrez_fetch(db = "protein",
id = "NP_065910",
rettype = "fasta")The cat() converts the information stored in hShroom3 to character values and prints it out
cat(hShroom3)## >NP_065910.3 protein Shroom3 [Homo sapiens]
## MMRTTEDFHKPSATLNSNTATKGRYIYLEAFLEGGAPWGFTLKGGLEHGEPLIISKVEEGGKADTLSSKL
## QAGDEVVHINEVTLSSSRKEAVSLVKGSYKTLRLVVRRDVCTDPGHADTGASNFVSPEHLTSGPQHRKAA
## WSGGVKLRLKHRRSEPAGRPHSWHTTKSGEKQPDASMMQISQGMIGPPWHQSYHSSSSTSDLSNYDHAYL
## RRSPDQCSSQGSMESLEPSGAYPPCHLSPAKSTGSIDQLSHFHNKRDSAYSSFSTSSSILEYPHPGISGR
## ERSGSMDNTSARGGLLEGMRQADIRYVKTVYDTRRGVSAEYEVNSSALLLQGREARASANGQGYDKWSNI
## PRGKGVPPPSWSQQCPSSLETATDNLPPKVGAPLPPARSDSYAAFRHRERPSSWSSLDQKRLCRPQANSL
## GSLKSPFIEEQLHTVLEKSPENSPPVKPKHNYTQKAQPGQPLLPTSIYPVPSLEPHFAQVPQPSVSSNGM
## LYPALAKESGYIAPQGACNKMATIDENGNQNGSGRPGFAFCQPLEHDLLSPVEKKPEATAKYVPSKVHFC
## SVPENEEDASLKRHLTPPQGNSPHSNERKSTHSNKPSSHPHSLKCPQAQAWQAGEDKRSSRLSEPWEGDF
## QEDHNANLWRRLEREGLGQSLSGNFGKTKSAFSSLQNIPESLRRHSSLELGRGTQEGYPGGRPTCAVNTK
## AEDPGRKAAPDLGSHLDRQVSYPRPEGRTGASASFNSTDPSPEEPPAPSHPHTSSLGRRGPGPGSASALQ
## GFQYGKPHCSVLEKVSKFEQREQGSQRPSVGGSGFGHNYRPHRTVSTSSTSGNDFEETKAHIRFSESAEP
## LGNGEQHFKNGELKLEEASRQPCGQQLSGGASDSGRGPQRPDARLLRSQSTFQLSSEPEREPEWRDRPGS
## PESPLLDAPFSRAYRNSIKDAQSRVLGATSFRRRDLELGAPVASRSWRPRPSSAHVGLRSPEASASASPH
## TPRERHSVTPAEGDLARPVPPAARRGARRRLTPEQKKRSYSEPEKMNEVGIVEEAEPAPLGPQRNGMRFP
## ESSVADRRRLFERDGKACSTLSLSGPELKQFQQSALADYIQRKTGKRPTSAAGCSLQEPGPLRERAQSAY
## LQPGPAALEGSGLASASSLSSLREPSLQPRREATLLPATVAETQQAPRDRSSSFAGGRRLGERRRGDLLS
## GANGGTRGTQRGDETPREPSSWGARAGKSMSAEDLLERSDVLAGPVHVRSRSSPATADKRQDVLLGQDSG
## FGLVKDPCYLAGPGSRSLSCSERGQEEMLPLFHHLTPRWGGSGCKAIGDSSVPSECPGTLDHQRQASRTP
## CPRPPLAGTQGLVTDTRAAPLTPIGTPLPSAIPSGYCSQDGQTGRQPLPPYTPAMMHRSNGHTLTQPPGP
## RGCEGDGPEHGVEEGTRKRVSLPQWPPPSRAKWAHAAREDSLPEESSAPDFANLKHYQKQQSLPSLCSTS
## DPDTPLGAPSTPGRISLRISESVLRDSPPPHEDYEDEVFVRDPHPKATSSPTFEPLPPPPPPPPSQETPV
## YSMDDFPPPPPHTVCEAQLDSEDPEGPRPSFNKLSKVTIARERHMPGAAHVVGSQTLASRLQTSIKGSEA
## ESTPPSFMSVHAQLAGSLGGQPAPIQTQSLSHDPVSGTQGLEKKVSPDPQKSSEDIRTEALAKEIVHQDK
## SLADILDPDSRLKTTMDLMEGLFPRDVNLLKENSVKRKAIQRTVSSSGCEGKRNEDKEAVSMLVNCPAYY
## SVSAPKAELLNKIKEMPAEVNEEEEQADVNEKKAELIGSLTHKLETLQEAKGSLLTDIKLNNALGEEVEA
## LISELCKPNEFDKYRMFIGDLDKVVNLLLSLSGRLARVENVLSGLGEDASNEERSSLYEKRKILAGQHED
## ARELKENLDRRERVVLGILANYLSEEQLQDYQHFVKMKSTLLIEQRKLDDKIKLGQEQVKCLLESLPSDF
## IPKAGALALPPNLTSEPIPAGGCTFSGIFPTLTSPL#cat function respects the new line character#humans have 3 different shroom genes
Retrieving the information for the Mouse shroom 3a, Human shroom 2, and Sea-urchin shroom sequences and storing them in their respective variables (mShroom3a, hShroom2, and sShroom)
# Mouse shroom 3a (M. musculus)
mShroom3a <- rentrez::entrez_fetch(db = "protein",
id = "AAF13269",
rettype = "fasta")
# Human shroom 2 (H. sapiens)
hShroom2 <- rentrez::entrez_fetch(db = "protein",
id = "CAA58534",
rettype = "fasta")
# Sea-urchin shroom
sShroom <- rentrez::entrez_fetch(db = "protein",
id = "XP_783573",
rettype = "fasta")#nchar (number of characters): does include /n # // this is raw sequence that is why /n is counted as character
##Returns the raw sequences for each protein nchar returns the number of characters, or in this case, the number of amino acids in each respective Shroom
nchar(hShroom3)## [1] 2070nchar(mShroom3a)## [1] 2083nchar(sShroom)## [1] 1758nchar(hShroom2) # number of amino acids in the human shroom## [1] 1673Prepping macromolecular sequences
##fasta_cleaner cleans up the raw sequences by removing any unnecessary characters such as “” which may be counter as a character in thesequences
fasta_cleaner## function (fasta_object, parse = TRUE)
## {
## fasta_object <- sub("^(>)(.*?)(\\n)(.*)(\\n\\n)", "\\4",
## fasta_object)
## fasta_object <- gsub("\n", "", fasta_object)
## if (parse == TRUE) {
## fasta_object <- stringr::str_split(fasta_object, pattern = "",
## simplify = FALSE)
## }
## return(fasta_object[[1]])
## }
## <bytecode: 0x7ffe89411e60>
## <environment: namespace:compbio4all>TODO: explain how to add the function to your R session even if you can’t download compbio4all
fasta_cleaner <- function(fasta_object, parse = TRUE){
fasta_object <- sub("^(>)(.*?)(\\n)(.*)(\\n\\n)","\\4",fasta_object)
fasta_object <- gsub("\n", "", fasta_object)
if(parse == TRUE){
fasta_object <- stringr::str_split(fasta_object,
pattern = "",
simplify = FALSE)
}
return(fasta_object[[1]])
}Cleans up the raw sequences for each protein by usign fasta_cleaner and stores it into the respective variable/protein
hShroom3 <- fasta_cleaner(hShroom3, parse = F)
mShroom3a <- fasta_cleaner(mShroom3a, parse = F)
hShroom2 <- fasta_cleaner(hShroom2, parse = F)
sShroom <- fasta_cleaner(sShroom, parse = F)hShroom3## [1] "MMRTTEDFHKPSATLNSNTATKGRYIYLEAFLEGGAPWGFTLKGGLEHGEPLIISKVEEGGKADTLSSKLQAGDEVVHINEVTLSSSRKEAVSLVKGSYKTLRLVVRRDVCTDPGHADTGASNFVSPEHLTSGPQHRKAAWSGGVKLRLKHRRSEPAGRPHSWHTTKSGEKQPDASMMQISQGMIGPPWHQSYHSSSSTSDLSNYDHAYLRRSPDQCSSQGSMESLEPSGAYPPCHLSPAKSTGSIDQLSHFHNKRDSAYSSFSTSSSILEYPHPGISGRERSGSMDNTSARGGLLEGMRQADIRYVKTVYDTRRGVSAEYEVNSSALLLQGREARASANGQGYDKWSNIPRGKGVPPPSWSQQCPSSLETATDNLPPKVGAPLPPARSDSYAAFRHRERPSSWSSLDQKRLCRPQANSLGSLKSPFIEEQLHTVLEKSPENSPPVKPKHNYTQKAQPGQPLLPTSIYPVPSLEPHFAQVPQPSVSSNGMLYPALAKESGYIAPQGACNKMATIDENGNQNGSGRPGFAFCQPLEHDLLSPVEKKPEATAKYVPSKVHFCSVPENEEDASLKRHLTPPQGNSPHSNERKSTHSNKPSSHPHSLKCPQAQAWQAGEDKRSSRLSEPWEGDFQEDHNANLWRRLEREGLGQSLSGNFGKTKSAFSSLQNIPESLRRHSSLELGRGTQEGYPGGRPTCAVNTKAEDPGRKAAPDLGSHLDRQVSYPRPEGRTGASASFNSTDPSPEEPPAPSHPHTSSLGRRGPGPGSASALQGFQYGKPHCSVLEKVSKFEQREQGSQRPSVGGSGFGHNYRPHRTVSTSSTSGNDFEETKAHIRFSESAEPLGNGEQHFKNGELKLEEASRQPCGQQLSGGASDSGRGPQRPDARLLRSQSTFQLSSEPEREPEWRDRPGSPESPLLDAPFSRAYRNSIKDAQSRVLGATSFRRRDLELGAPVASRSWRPRPSSAHVGLRSPEASASASPHTPRERHSVTPAEGDLARPVPPAARRGARRRLTPEQKKRSYSEPEKMNEVGIVEEAEPAPLGPQRNGMRFPESSVADRRRLFERDGKACSTLSLSGPELKQFQQSALADYIQRKTGKRPTSAAGCSLQEPGPLRERAQSAYLQPGPAALEGSGLASASSLSSLREPSLQPRREATLLPATVAETQQAPRDRSSSFAGGRRLGERRRGDLLSGANGGTRGTQRGDETPREPSSWGARAGKSMSAEDLLERSDVLAGPVHVRSRSSPATADKRQDVLLGQDSGFGLVKDPCYLAGPGSRSLSCSERGQEEMLPLFHHLTPRWGGSGCKAIGDSSVPSECPGTLDHQRQASRTPCPRPPLAGTQGLVTDTRAAPLTPIGTPLPSAIPSGYCSQDGQTGRQPLPPYTPAMMHRSNGHTLTQPPGPRGCEGDGPEHGVEEGTRKRVSLPQWPPPSRAKWAHAAREDSLPEESSAPDFANLKHYQKQQSLPSLCSTSDPDTPLGAPSTPGRISLRISESVLRDSPPPHEDYEDEVFVRDPHPKATSSPTFEPLPPPPPPPPSQETPVYSMDDFPPPPPHTVCEAQLDSEDPEGPRPSFNKLSKVTIARERHMPGAAHVVGSQTLASRLQTSIKGSEAESTPPSFMSVHAQLAGSLGGQPAPIQTQSLSHDPVSGTQGLEKKVSPDPQKSSEDIRTEALAKEIVHQDKSLADILDPDSRLKTTMDLMEGLFPRDVNLLKENSVKRKAIQRTVSSSGCEGKRNEDKEAVSMLVNCPAYYSVSAPKAELLNKIKEMPAEVNEEEEQADVNEKKAELIGSLTHKLETLQEAKGSLLTDIKLNNALGEEVEALISELCKPNEFDKYRMFIGDLDKVVNLLLSLSGRLARVENVLSGLGEDASNEERSSLYEKRKILAGQHEDARELKENLDRRERVVLGILANYLSEEQLQDYQHFVKMKSTLLIEQRKLDDKIKLGQEQVKCLLESLPSDFIPKAGALALPPNLTSEPIPAGGCTFSGIFPTLTSPL"Comparing sequences
A pairwise sequence alignment is performed between Human Shroom 3 and Mouse Shroom 3a to determine their similarities in sequences
# add necessary function
align.h3.vs.m3a <- Biostrings::pairwiseAlignment(
hShroom3,
mShroom3a)TODO: In 1-2 sentence explain what this object shows ## The hShroom3 and mShroom3a sequences are aligned and compared. A score is given based on how similar their sequences are.
align.h3.vs.m3a## Global PairwiseAlignmentsSingleSubject (1 of 1)
## pattern: MMRTTEDFHKPSATLN-SNTATKGRYIYLEAFLE...KAGALALPPNLTSEPIPAGGCTFSGIFPTLTSPL
## subject: MK-TPENLEEPSATPNPSRTPTE-RFVYLEALLE...KAGAISLPPALTGHATPGGTSVFGGVFPTLTSPL
## score: 2189.934The percent sequence identity for the pairwise sequence alignment between hShroom3 and mShroom3a is represented below. The value reveals howidentical the two sequences are in percentage.
# add necessary function
Biostrings::pid(align.h3.vs.m3a)## [1] 70.56511TODO: briefly explain what is going on here versus the previous code chunk ## A pairwise sequence alignment is performed between Human Shroom 3 and Human Shroom 2 to determine their similarities in sequences. Two human proteins are compared here instead of comparing a human protein and a mouse protein.
align.h3.vs.h2 <- Biostrings::pairwiseAlignment(
hShroom3,
hShroom2)A score is given to the hShroom3 and mShroom2 sequences base on how similar they are after their alignment and comparison of sequences. The score is significantly lower in comparison to a pairwise sequence alignment of a human protein and a mouse protein.
score(align.h3.vs.h2)## [1] -5673.853TODO: briefly explian the difference between the output of score() and pid() (can be very brief - we’ll get into the details later) ## The output values of score() and pid() are different because score() is length dependent, whereas pid() takes into consideration the identical and aligned positions between the sequqences and any indels.
Biostrings::pid(align.h3.vs.h2)## [1] 33.83277The shroom family of genes
This shows the different types of shrooms there are and where the particular shroom genes we are looking at belong
shroom_table <- c("CAA78718" , "X. laevis Apx" , "xShroom1",
"NP_597713" , "H. sapiens APXL2" , "hShroom1",
"CAA58534" , "H. sapiens APXL", "hShroom2",
"ABD19518" , "M. musculus Apxl" , "mShroom2",
"AAF13269" , "M. musculus ShroomL" , "mShroom3a",
"AAF13270" , "M. musculus ShroomS" , "mShroom3b",
"NP_065910", "H. sapiens Shroom" , "hShroom3",
"ABD59319" , "X. laevis Shroom-like", "xShroom3",
"NP_065768", "H. sapiens KIAA1202" , "hShroom4a",
"AAK95579" , "H. sapiens SHAP-A" , "hShroom4b",
#"DQ435686" , "M. musculus KIAA1202" , "mShroom4",
"ABA81834" , "D. melanogaster Shroom", "dmShroom",
"EAA12598" , "A. gambiae Shroom", "agShroom",
"XP_392427" , "A. mellifera Shroom" , "amShroom",
"XP_783573" , "S. purpuratus Shroom" , "spShroom") #sea urchinGathers all the data in the shroom table and organize it in a more presentable way
# convert to matrix
shroom_table_matrix <- matrix(shroom_table,
byrow = T,
nrow = 14, #Or nrow = 14?
ncol = 3)
# convert to data frame
shroom_table <- data.frame(shroom_table_matrix,
stringsAsFactors = F)
# Naming columns
names(shroom_table) <- c("accession", "name.orig","name.new")
# Create simplified species names
shroom_table$spp <- "Homo"
shroom_table$spp[grep("laevis",shroom_table$name.orig)] <- "Xenopus"
shroom_table$spp[grep("musculus",shroom_table$name.orig)] <- "Mus"
shroom_table$spp[grep("melanogaster",shroom_table$name.orig)] <- "Drosophila"
shroom_table$spp[grep("gambiae",shroom_table$name.orig)] <- "mosquito"
shroom_table$spp[grep("mellifera",shroom_table$name.orig)] <- "bee"
shroom_table$spp[grep("purpuratus",shroom_table$name.orig)] <- "sea urchin"Prints out the data in a cleaned up and more presentable data table
shroom_table## accession name.orig name.new spp
## 1 CAA78718 X. laevis Apx xShroom1 Xenopus
## 2 NP_597713 H. sapiens APXL2 hShroom1 Homo
## 3 CAA58534 H. sapiens APXL hShroom2 Homo
## 4 ABD19518 M. musculus Apxl mShroom2 Mus
## 5 AAF13269 M. musculus ShroomL mShroom3a Mus
## 6 AAF13270 M. musculus ShroomS mShroom3b Mus
## 7 NP_065910 H. sapiens Shroom hShroom3 Homo
## 8 ABD59319 X. laevis Shroom-like xShroom3 Xenopus
## 9 NP_065768 H. sapiens KIAA1202 hShroom4a Homo
## 10 AAK95579 H. sapiens SHAP-A hShroom4b Homo
## 11 ABA81834 D. melanogaster Shroom dmShroom Drosophila
## 12 EAA12598 A. gambiae Shroom agShroom mosquito
## 13 XP_392427 A. mellifera Shroom amShroom bee
## 14 XP_783573 S. purpuratus Shroom spShroom sea urchinAccessing multiple sequences
The $ allows us to access the accession column and print out the data
shroom_table$accession## [1] "CAA78718" "NP_597713" "CAA58534" "ABD19518" "AAF13269" "AAF13270"
## [7] "NP_065910" "ABD59319" "NP_065768" "AAK95579" "ABA81834" "EAA12598"
## [13] "XP_392427" "XP_783573"Retrieving the information for the multiple sequences and storing it into the variable shrooms
shrooms <-entrez_fetch(db = "protein",
id = shroom_table$accession,
rettype = "fasta")The cat() converts the information stored in shrooms to character values and prints it out
cat(shrooms)Retrieving the acession information for each shroom and storing them in the shrooms_list variable. This is done to make the data more presentable and easy to interpret.
shrooms_list <- entrez_fetch_list(db = "protein",
id = shroom_table$accession,
rettype = "fasta")Gives you a better idea of the type, length and number of characters (amino acids) in each shroom
is(shrooms_list)## [1] "list" "vector" "list_OR_List" "vector_OR_Vector"
## [5] "vector_OR_factor"length(shrooms_list)## [1] 14nchar(shrooms_list)## CAA78718 NP_597713 CAA58534 ABD19518 AAF13269 AAF13270 NP_065910 ABD59319
## 1486 915 1673 1543 2083 1895 2070 1864
## NP_065768 AAK95579 ABA81834 EAA12598 XP_392427 XP_783573
## 1560 778 1647 750 2230 1758TODO: briefly explain what I am doing this. We will get into the details of for() loops in R later in the semester.
for(i in 1:length(shrooms_list)){
shrooms_list[[i]] <- fasta_cleaner(shrooms_list[[i]], parse = F)
}TODO: summarize what is going on in this code chunk, then annotate each line of code with what its doing
# XXXXXXXXCX
shrooms_vector <- rep(NA, length(shrooms_list))
# XXXXXXXXCX
for(i in 1:length(shrooms_vector)){
shrooms_vector[i] <- shrooms_list[[i]]
}
# XXXXXXXXCX
names(shrooms_vector) <- names(shrooms_list)TODO: explain what this is doing then add the necessary function.
# add necessary function
shrooms_vector_ss <- Biostrings::AAStringSet(shrooms_vector)MSA
TODO: briefly summarize what this section of the document will do.
Readings will be assigned to explain what MSAs are.
Building an XXXXXXXX (MSA)
TODO: briefly explain what this chunk does, then add the necessary function.
# add necessary function
shrooms_align <-msa(shrooms_vector_ss,
method = "ClustalW")## use default substitution matrixViewing an MSA
TODO: briefly summarize what this section will do.
Viewing an MSA in R
TODO: Briefly summarize what output is shown below
shrooms_align## CLUSTAL 2.1
##
## Call:
## msa(shrooms_vector_ss, method = "ClustalW")
##
## MsaAAMultipleAlignment with 14 rows and 2252 columns
## aln names
## [1] -------------------------...------------------------- NP_065768
## [2] -------------------------...------------------------- AAK95579
## [3] -------------------------...SVFGGVFPTLTSPL----------- AAF13269
## [4] -------------------------...SVFGGVFPTLTSPL----------- AAF13270
## [5] -------------------------...CTFSGIFPTLTSPL----------- NP_065910
## [6] -------------------------...NKS--LPPPLTSSL----------- ABD59319
## [7] -------------------------...------------------------- CAA58534
## [8] -------------------------...------------------------- ABD19518
## [9] -------------------------...LT----------------------- NP_597713
## [10] -------------------------...------------------------- CAA78718
## [11] -------------------------...------------------------- EAA12598
## [12] -------------------------...------------------------- ABA81834
## [13] MTELQPSPPGYRVQDEAPGPPSCPP...------------------------- XP_392427
## [14] -------------------------...AATSSSSNGIGGPEQLNSNATSSYC XP_783573
## Con -------------------------...------------------------- ConsensusTODO: briefly explain what is being done in this chunk. This is tricky (and annoying) so do your best
# WHAT IS THE LINE BELOW DOING? (its tricky - do your best)
class(shrooms_align) <- "AAMultipleAlignment"
# WHAT IS THE LINE BELOW DOING? This is simpler
shrooms_align_seqinr <- msaConvert(shrooms_align, type = "seqinr::alignment")TODO: what is the output this produces
print_msa(alignment = shrooms_align_seqinr,
chunksize = 60)Displaying an MSA XXXXXXXX
TODO: explain this output and how its differnet from the prevoius
## NEED TO INSTALL GGMSA
## add necessary function
ggmsa::ggmsa(shrooms_align, # shrooms_align, NOT shrooms_align_seqinr
start = 2000,
end = 2100) ## Registered S3 methods overwritten by 'ggalt':
## method from
## grid.draw.absoluteGrob ggplot2
## grobHeight.absoluteGrob ggplot2
## grobWidth.absoluteGrob ggplot2
## grobX.absoluteGrob ggplot2
## grobY.absoluteGrob ggplot2
Saving an MSA as PDF
TODO: explain what this command is doing. Add the package the function is coming from using :: notation This may not work for everyone. If its not working you can comment it out.
msaPrettyPrint(shrooms_align, # alignment
file = "shroom_msa.pdf", # file name
y=c(2000, 2100), # range
askForOverwrite=FALSE)TODO: explain what this command is doing
getwd()## [1] "/Users/edithchan/Desktop"