Bioinformatics connects life sciences and quantitative sciences, typically involving the application of software and algorithms to solve computationally intensive questions, such as those in genomics, sequence analysis, and systems biology. Questions tagged Bioinformatics should have a direct ...

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1answer
81 views

Using RNA-seq to compare gene expression across patients instead of between Control and Experimental conditions

I am working with RNA-seq data from the Cancer Genome Atlas TCGA and I have been reading about how people have compared gene expression levels measured by RNA-seq. Many of the papers I have read talk ...
2
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1answer
50 views

How can I view modENCODE data faster?

I am trying to view several data tracks in the modENCODE GBrowse genomic browser. However, the site is so slow, it is practically unworkable. Is there a faster way to explore the data?
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1answer
55 views

Genome Assembly Using Reads

I'm taking an online bioinformatics class and I am stuck on a problem. The resources I have found don't help that much. Here is the problem: "Assemble the error-free reads from a circular genome on ...
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2answers
137 views

Draw simplified phylogenetic tree for kids

I need to draw simple, phylogenetic tree for kids lecture. I am looking for an online tool where I can enter organisms (e.g., human, wasp, fungus) and get figure of a phylogenetic tree. Tree should ...
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1answer
42 views

How to selectively download 3 fields from every record in UniProtKB?

I want to download a comprehensive table of protein names from uniprot.org. More precisely, I want to generate a tab-delimited table consisting of the id ...
3
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1answer
45 views

Regarding the NCBI FTP site

I am trying to extract information about SNP data from the FTP server of NCBI. Could someone please explain to me how the directory is organised? There are many many files and folders and I can't ...
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0answers
15 views

How are HSPs identified in UCLUST

I am new in Bioinformatics and recently studying UCLUST algorithm by Robert Edgar(2010). It is a fast sequence searching and clustering algorithm. The algorithm is heuristic based. I studied that ...
2
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2answers
44 views

Hiding identical sequences in NCBI web interface

Sometimes there are identical sequences in Genbank/Genpept, most often coming from the same species but different strains. Ie if I look up "bacteria chitin synthase", the 624-aa protein from Dickeya ...
4
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1answer
145 views

What makes a DNA sequence motif a DNA sequence motif?

I've read about DNA sequence motifs, but still don't understand what makes some sequence a DNA sequence motif. Is this a well-defined concept? For, example, What are DNA sequence motifs? says: ...
4
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2answers
247 views

Why is assembling paired end illumina without any input parameters an important problem?

In one of the comments in this question about multiple sequence alignment, it was stated @5heikki: btw if you want a good bioinformatics problem, come up with an assembler that assembles any ...
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2answers
58 views

Recommended sequence clustering algorithm for transcriptome data

I'm working on a project where I'm going to analyze a large amount of transcriptome data. After assembling our RNA-Seq reads into contigs using Trinity, it looks like I'm going to have about 10GB of ...
3
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1answer
97 views

What is the state-of-the-art algorithm for multiple sequence alignment?

Which algorithm or algorithms are considered the standard or state-of-the-art for multiple sequence alignment? How big is the need for better algorithms? How many sequences need to be alignment in a ...
3
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2answers
110 views

How to use Autodock just for (re)scoring

I have some protein-ligand complexed that I have been docking with some other software and just want to use Autodock to evaluate those complexes. So, basically I just want to use it as a scoring ...
2
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2answers
79 views

Sequence alignment scoring

The following table is from Deonier's text Computational Gene Analysis at p. 152. This is an exercise in global sequence alignment and scoring of alternative sequences. The text proposed a solution ...
2
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1answer
109 views

MOL2 to PDBQT conversion via OpenBabel and MGLTools removes hydrogen atoms

I am trying to convert a MOL2 file (includes partial charges and hydrogen atoms) into a PDBQT file for re-scoring in AutoDock Vina. However, both approaches that I tried don't keep the hydrogen atoms ...
2
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1answer
56 views

Comparing Shine Dalgarno scores, creating a distribution

I am in the process of creating a poster for the phage that I recently annotated. The phage is an A4 and the portion of the poster I am working on is analyzing the data that we have collected. I have ...
2
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1answer
50 views

Converting Ensembl Compara gene tree DNA alignment to corresponding amino acid alignment

I have Ensembl compara gene tree alignments (Compara.gene_trees.57.fasta.gz downloaded from ftp://ftp.ensembl.org/pub/release-57/emf/ensembl-compara/homologies/) in nucleotide format. According to ...
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1answer
50 views

To what extent is it possible to understand if a bacteria can produce a protein? (in silico only!)

I have to answer a question about a sub-task of my thesis: Can the bacteria X produce the protein Y? I searched of course Google and BLAST. There is no data supporting that this specific bacteria ...
4
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4answers
289 views

E-value BLAST cut-off

What is the best cut-off for e-value in BLAST? Some say 0.01 ,others 0.0001? Even BLAST tutorials don't give a very clear idea about which cutoff suits which purpose? Could some experts give me a ...
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1answer
43 views

About the quality of microsatellites

I built a script to detect microsatellites in a FASTA file. However, there are thousands of possibilities. So, my question is: what are the markers of a "good" or "useful" microsatellite? - How ...
3
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0answers
67 views

Accuracy of genome size estimation by flow cytometry

I'm working on a genome project and using an in silico k-mer analysis to estimate the size of our genome based on the available Illumina reads. The k-mer based estimate is consistent across a wide ...
1
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2answers
106 views

Heterochromatin binding sites position information

I am working on a project and I'm trying to find data on the position of genes and heterochromatin binding sites such as HP1 in Drosophila melanogaster. Is this information available for the DGRP ...
2
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2answers
83 views

chimeric sequences [closed]

I understand that chimeric sequence identification is done in results of sequencing projects to remove them and improve the quality of the output. I am unsure as to how they show up during sequencing. ...
1
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1answer
64 views

Convert gene name to uniprot ID

i have a list of gene name in a file CHRNB2 EGR2 GCK KRT14 LMNA FGF3 TK2 ABCC8 How can I map them to uniprot ID ? P.S I tried Uniprot "ID mapping" ...
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2answers
55 views

is there a way to do batch download for all gene pathways?

I would like to download all the gene pathways and genes of each pathway. Preferably, gene length of each gene as well. It would be a lot more convenient if there is an R package.
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1answer
32 views

Alleles notation in SNPPedia criteria

I can understand the allele notation when is in the form rs8176719(T;T) or rs8176719(G) but recently i found this ones rs8176719(T;-) or rs8176719(-;T). So im confused, rs8176719(T;-) is the same as ...
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1answer
74 views

Recombination-based vs. Sequence-based genetic mapping

Now that sequencing is becoming increasingly cheap, what is the value of recombination-based genetic mapping against the sequence-based genetic mapping? I think that in the past recombination-based ...
2
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0answers
46 views

Can a heterozygous allele show non-heterozygous expression in a family?

I'm doing a family study looking for novel cancer-associated variants in germ-line samples; the goal is to find candidate biomarkers which might be used for early detection. At an earlier step our ...
0
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1answer
57 views

Can someone suggest me good opencourseware links for learning computational biology basics?

My internet is slow and I have only 1GB data usage allowed for this month. And I want to make maximum out of it for learning some basics of computational biology. Which are the best online course ...
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5answers
139 views

What are some examples of evolving networks in biology?

I'm a master student working on networks analysis in general. A network is something that has nodes and there are links between the nodes. Nodes and links could have attributes. An evolving network is ...
2
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0answers
85 views

Software to calculate Fst from sequence data

I'm looking for a software to calculate Fst from 3 loci DNA data of individuals from a metapopulation. I don't have any prior on the population structure (have no idea of the number of subpopulations ...
4
votes
1answer
70 views

Blosum matrix with probabilities instead of the positive and negative scores

I am trying to find a version of the BLOSUM matrix that has the frequencies instead of the scaled log-odds. i.e. instead of the common version that tells us that the score LEU/ASP is -4, I would like ...
8
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2answers
988 views

How can rooted and unrooted (phylogenetic) trees be distinguished from one another

I understand that both are similar in structure But how can they be easily identified as one or the other? Is it simply based on the presence or lack of a named root (the root is identified as a ...
2
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1answer
38 views

Quantitative Comparisons of Phylogenetic trees

I am working on a broad phylogenomic analysis of proteins involved in one particular cellular process. I have constructed a phylogenetic tree for each protein. I am now working on comparing those ...
5
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3answers
178 views

Protein structures given in PDB and SNP's

There are millions of proteins given in PDB, the sequence for which we can download in FASTA format. There are also hundreds of SNP's given in NCBI dbSNP. My question is whether the proteins in PDB ...
3
votes
1answer
164 views

The parameter for setting the number of mismatches in standalone blast

In a standalone blast search, is there a parameter that could be specified to fix the number of mismatches allowed in an alignment. I went through the parameters and I could only find parameters to ...
3
votes
1answer
65 views

Should the sum of RPKMs be constant over experiments

I have cufflinks data from 18 different RNA-seq experiments. I've noticed that if the sum all the RPKM values for a particular experiment, are vastly different between experiments. How could this be? ...
2
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0answers
30 views

dbSNP database table desciptions

I am trying to build a local implementation of dbSNP. I would like to know the descriptions of tables listed on ftp://ftp.ncbi.nlm.nih.gov/snp/database/organism_data/human_9606 and on ...
1
vote
1answer
47 views

What is the close and related genome used for in Gene models?

all I am a little bit confused about using the related genome or reference genome. When we have a reference genome, we can do alignment. Also we can do the assembly. Can you give some more reason ...
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0answers
24 views

What percentage of chimeric takes up in a cDNA library?

I get a cDNA library of species of Mollusca,and complete some of the clones with polyA tails.But when I translate them with three frames,I find there is a large percentage of sequences that cannot ...
4
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1answer
76 views

Local storage of NCBI database in MongoDB [closed]

My short term goal in a project is to build a local database of the NCBI dbSNP database. The data and schema are available on the FTP site(). I was going to implement the database using MySQL, but I ...
2
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2answers
69 views

Databases for metabolic pathways of human disease

Which databases contain the metabolic pathway of human diseases? I have searched Metacyc and KEGG but didn't find the appropriate metabolic pathway.
3
votes
1answer
40 views

I2D vs STRING for protein-protein interactions

Can someone clearly explain me the differences between STRING and I2D(Interlogous interaction database) ? What does each database do best ? Which database is better for what kinds of studies etc ?
2
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1answer
47 views

What do the Clustal Alignment Symbols Mean?

Occasionally I will run protein alignments on peptide families and I can never remember what the symbols mean to show degrees of identity. What do they mean?
1
vote
1answer
20 views

Why are different lengths of nucleotides taken for structure prediction from an miRNA match area after BLAST analysis?

Generally in miRNA prediction most researchers do as Blast search with a set of miRNAs downloaded from miRBase with the parameters they require. Later on usually custom methods are utilized to get an ...
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0answers
37 views

Meta-Data Retrieval from Bio-Rad Images

I asked a related question on SO, but I also had some biology related questions to this issue. One of the big things I'd like to do is sort between DNA/UV images and Western/Chemi images. After ...
1
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1answer
62 views

downloading a reference genome for alignment

I am currently working through the code example on the MATLAB website. It requires me to download the reference genome of Arabidopsis thaliana (thale cress) so I can use BowTie2 to align the Chip-Seq ...
3
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1answer
63 views

mFOLD prediction result interpretation

I am trying to predict the secondary structure of certain predicted pre-miRNAs through mFOLD which is the generally accepted technique for structure prediction in most studies. I am finding it hard to ...
2
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1answer
67 views

Steps to confirm if predicted miRNA is good or bad

I aligned all miRNAs available to the supercontigs of a particular genome with certain parameters (e value of 0.01 and a word match of atleast 7 as suggested in this paper). I have also isolated the ...
7
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1answer
198 views

List of np-hard problems in biology/bioinformatics

I'm not sure if this is the right place for this but... I am looking for a list of computationally "hard" problems such that if a problem from this list could be solved effectively, it would be ...