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 ...

learn more… | top users | synonyms (1)

5
votes
2answers
65 views

What ways are there to determine how big genera are?

I want to look at genera as a whole, across the animal kingdom to determine the range of sizes of genera. I have examined species richness and genetic diversity (pairwise distance from sequence data ...
5
votes
3answers
150 views

Finding a template/oligo combination for my first PCR experiment

I'm an information technology engineer. I love biology so I research biological topics and have an interest in PCR. That's why I have decided to create a PCR machine. Everything is done now and I ...
5
votes
1answer
97 views

Why do we encode information in DNA in binary and not in base 4?

I recently read an article about Harvard scientists encoding 700Tb of data in DNA strands. But they encoded the information in base 2, so T and G was a 1 and C and A was a 0. But why binary? Why didn'...
5
votes
2answers
1k views

What are we missing about the real workings of the evolutionary process? [closed]

As a scientist (and a computer scientist at that) my view is that if we cannot simulate a process we have not understood it properly. I have been following the interesting field of Artificial Life for ...
5
votes
1answer
256 views

Where to find E.coli gene expression data?

I am searching E.coli whole genome expression data with different conditions, any suggestion is appreciated. Condition could be for example different growth temperature, different medias, etc. I have ...
5
votes
2answers
200 views

Where can I find mutation datasets for cancer?

My lab has been using TCGA data (somatic mutations and clinical data) to develop panels of genes and of mutations we expect to see in certain cancer populations. We'd like to validate our panels by ...
5
votes
5answers
244 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 ...
5
votes
2answers
690 views

Could be an union/synergy between Math, Computer Science and Marine Biology?

I'm studing for my bachelor's degree in Natural Science and I have to chose the path for my future life. I have to chose the right kind of graduate studies. Since I love computer science, maths and ...
5
votes
1answer
56 views

Data on Gene Position in Human Genome

I am trying to get some data on gene position in the human genome and I need some help What I tried I downloaded ...
5
votes
1answer
104 views

Why are fifth order Markov Models, the ones most often used for gene prediction?

As far as we know that smallest polypeptide chain length is 60 amino acids - so if we found an Open Reading Frame (ORF) of about 60 codons without the interruption of stop codon we can consider it to ...
5
votes
1answer
1k views

How to check if a fastq file has single or paired end reads

I am trying to check if a fastq file has single or paired end reads. How can I achieve this with an error-proof method? I checked wikipedia and MAQ but I want to know if is there a reliable document ...
5
votes
2answers
384 views

How to get smallest subtree containing a set of nodes from BioPhylo?

I'm testing out various phylogenetic libraries in Python. I want to read in a Newick tree, then, given a list of taxa, generate the smallest tree that contains them all. This task is quite simple and ...
5
votes
1answer
379 views

Which way to run BLAST?

I have a set of scaffolds from a genome assembly, and I want to align a collection of proteins from various species to it. I can do this using BLAST in two ways: Create a BLAST database of the ...
5
votes
1answer
172 views

Determining if a Protein Model Contains a Backbone Clash

I have an ensemble of homology models of a protein, and I now wish to remove those models which have backbone clashes. I could obviously check by eye but this is subjective and probably will not be ...
5
votes
1answer
85 views

How many genes does D. melanogaster have?

Obviously there is no 100% exact number, but I came across this on flybase, the gold standard for annotation. I am confused now. "Genes located to the genome", is that what I am looking for? If so, ...
5
votes
2answers
69 views

Where can I find histograms and tables of prevalence of mutations in cancer?

At some point in the past I found a cancer portal site which had aggregated data for the relationships between various mutations and their prevalence in cancer types and tumor data. The data was ...
5
votes
1answer
92 views

Base Substitution Probabilities Derivation

In Felsenstein's 1981 Paper Evolutionary Trees from DNA Sequences: A Maximum Likelihood Approach, he describes (in equations (6) and (7)) a derivation of the equation of the probability of a ...
5
votes
3answers
591 views

Tool for nucleotide alignment with all nucleotide codes (e.g. R, Y, W, S, etc.)?

I have a vector sequence and would like to find the following nucleotide sequence in it. AASYWSRA This query sequence uses several degenerate symbols, defined as:...
5
votes
1answer
800 views

Primer Dimer / Hairpin Algorithms

What are the algorithms / methods in use for the calculation of primer dimers and hairpins? As an example, IDT's OligoAnalyzer tool will generate these analysis given particular sequences. The homo-...
5
votes
1answer
126 views

How do I prepare a PDB for submission to the Protein Data Bank?

I have a couple structures that are nearly ready to be deposited in the PDB. Out of curiosity, I ran them through the ADIT's precheck tool and they failed with one error after another, as I lacked ...
5
votes
2answers
123 views

Help with STRING database data

I'm working with data downloaded from STRING database (string-db.org) for protein-protein interactions. My idea is to compare the topology of connections of the same protein on different organisms. ...
4
votes
3answers
115 views

How to create a collection of anonymous sequences for teaching and testing? [closed]

I am looking for a large collection (>1000) of sequence files (eg. FASTA) from any real organism or a tool to create such a collection. The sequence files would be used for teaching and for testing ...
4
votes
3answers
280 views

Why do we need deep sequencing?

Why do we need deep sequencing? Why cannot the sequencing technologies read all the nucleotides correctly at the first read? Sorry since this question is too trivial, I don't have a biological ...
4
votes
2answers
807 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 ...
4
votes
3answers
687 views

Does anyone know a good software for producing tanglegrams?

I'm trying to look at relationships between parasite and host phylogenetic trees. I have done a bit of searching for a software in which to do this with, and I have tried using Dendroscope and TreeMap,...
4
votes
4answers
2k views

Multiple sequence alignment - how to align everything to 1 gene sequence? [closed]

I'm having trouble aligning 3 sequences together - the total gene (~2500bp) and the forward and reverse sequences that are ~1000bp in length. Now I'm using Clustal X2, but the problem is that the ...
4
votes
2answers
2k views

explanation of meaning of high-throughput

Almost all of the papers about bioinformatics, I faced with the high-throughput word, but I could not find any explanation about it (I think it is so easy to understand and thats why anyone explains ...
4
votes
2answers
72 views

where to find the relative frequency distribution of synonymous codons

Most amino acids can be encoded by more than one codon. For example, Serine can be encoded by any one of ...
4
votes
2answers
375 views

positive and negative feedback

I want to know more about positive feedback in gene regulation and to know the similarity and differences between positive and negative feedbacks.
4
votes
2answers
267 views

How can I fetch nucleotide sequences based on ENA accession numbers and positions?

I have a list of ENA accession numbers and a start and end position in each sequence. In the end I want to align all those sequences, but first I have to fetch them and the list is too long to do that ...
4
votes
1answer
240 views

What do the letters 'p' and 'c' mean in mutation descriptions?

Example: NM_000525.3(KCNJ11):c. 67A>G ( p. Lys23Glu) AND Permanent neonatal diabetes mellitus Does "p" stand for "polymorphism"? What does the letter "c" stand for?
4
votes
1answer
169 views

How do I make a multiple sequence alignment (MSA)?

I have a DNA sequence that makes protein 1, but now I have asked to: compare the amino acid sequence of protein 1 with nine homologous proteins and make a multialignment of the sequences. Determine ...
4
votes
2answers
134 views

Do the bacterial species X, Y, Z code for proteins A, B, C?

My PI has assigned me a task to gather evidence to determine whether or not a list of particular species of Campylobacter and Helicobacter code for a list of several proteins. To put it simply I’ve ...
4
votes
1answer
191 views

What do “e” “-” “C” and “E” mean in this output?

I have given an input of this protein sequence: MEPVDPRLEPWKHPGSQPKTACTTCYCKKCCFHCQVCFTTKALGISYGRKKRRQRRRPPQGSQTHQVSLSKQPTSQPRGDPTGPKE from this website along ...
4
votes
4answers
464 views

Is there a PSI-BLAST for nucleotide sequences?

I understand that one can translate a nucleotide sequence and run PSI-BLAST on the protein (proteins if you take the 6 reading frames), but I'm looking for distant homology for bacterial small RNAs (...
4
votes
1answer
206 views

What is benjamini

I was doing some gene expression analysis using this tool http://david.abcc.ncifcrf.gov/summary.jsp. However, I have a confusion about what benjamini is. I fed it some gene list and it gave me some ...
4
votes
1answer
62 views

Is copy number variation dynamic?

Is there any evidence showing that copy number variation changes over time? I'm wanting to model interactions in expression level as a dynamic bayesian network, but an assumption my approach will need ...
4
votes
2answers
69 views

Main methods used to predict functional annotations in GO

Can someone provide me some information about the main method used to predict the inferred electronic annotations in Gene Ontology?
4
votes
1answer
218 views

How the genome assembly be done after k-mer counting?

As far I know, before assembly of a genome, all k-mers from read should be counted. But after that, how the genome assembly be done? Is there any other thing needed along with k-mer counts? How ...
4
votes
1answer
58 views

What does “~mitochondrial DNA ~bp linear DNA” means?

I'm surfing NCBI website -Nucleotide- to find some examples of real DNA sequences to use in my small homework project. My question is related to the title of a DNA sequence below: Sus scrofa ...
4
votes
2answers
198 views

Basic Local Alignment Search Tool (BLAST)

Why would BLASTP (Basic Local Alignment Search Tool) be a poor tool to search for motifs in protein sequences?
4
votes
1answer
204 views

Nomenclature of genes and proteins

With respect to this paper: Identification of Host Proteins Required for HIV Infection Through a Functional Genomic Screen In the abstract, I found names such as Rab6 and Vps35 and TNPO3. So Rab6 ...
4
votes
2answers
65 views

Grouping OMIM disease codes

I have ~100 sets of genes, and each set includes between 2 and 70 genes. I'd like to perform an enrichment analysis on each of these sets to test if they're enriched for OMIM disease labels. However, ...
4
votes
2answers
117 views

Is it possible to create a restriction map using python? [closed]

I have some fragments of DNA from single and double digests using three different restriction enzymes. I'm trying to construct a restriction map of a linear fragment of DNA. The map needs indicate the ...
4
votes
1answer
177 views

Why is ab initio protein secondary structure prediction less reliable than alternatives?

To predict secondary structure of proteins three types of Algorithms are used Ab initio, homology based and neural networks. Among these neural networks prove to be more accurate and give good results ...
4
votes
1answer
75 views

Question about SAM CIGAR string

My question is about the CIGAR specification. The documentation states: M 0 alignment match (can be a sequence match or mismatch) ...
4
votes
1answer
67 views

determining meaning of basic biological keywords about C. elegans

First of all I have to say that I have no biology background since I'm a undergraduate computer science student. Nowadays, for my research I need to use some of the databases related with ...
4
votes
1answer
128 views

Visualising a subset of the tree of life

I understand that many curated trees of life already exist (eg http://tolweb.org/tree/) but is there any website that allows one to input a list of organisms, and then produce the current best guess ...
4
votes
3answers
267 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 ...
4
votes
1answer
265 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 ...