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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How to predict a mRNA secondary structure with a large sequence?

When I use some web servers to predict a mRNA secondary structure, I find they always required in a small size sequence. If I use a long sequence and cut it into small parts, do these small parts ...
2
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3answers
656 views

What is the biological significance of finding palindromes in DNA sequence?

I found a function called palindromes in Matlab that finds palindromes from DNA sequence. Now what is the biological intention behind incorporating this function? What the biological significance of ...
3
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2answers
151 views

Is there a database of cell images?

We're working on an algorithm for processing images of cells, similar to but much more basic than Cell Profiler, and we are looking for a large database of cell images to test our software. Can anyone ...
2
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1answer
36 views

Why my base-quality in alignment is not perfect?

I have a fasta file with some DNA sequences. I would like to simulate next-generation sequencing reads from it. I'm doing it without any base error and mutation error. ...
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0answers
40 views

Shortest path and influenza spread

I have been researching on the applications of the shortest path problem to biology. I thought about modelling the spread of influenza virus and wondering if there was previous research on the topic. ...
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0answers
25 views

NCBI EUtils. Get Homolog infromation using Gene ID

How to retrieve homologs information in xml or json format from NCBI using gene ID? I tried one URL: ...
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1answer
13 views

num_tol_term in PeptideProphet result

What is the meaning of the num_tol_term attribute in a PeptideProphet (pep.xml) search_hit? ...
2
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1answer
85 views

What is biological intuition?

Whenever I read or learn about prediction tools or aligners or motif detectors, I also hear that they are lacking in something called biological intuition. But I haven't been able to find a solid ...
4
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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 ...
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0answers
42 views

What program was used to create this visualization of a neighbor-joining tree?

I know there are many programs out there to visualize neighbor-joining trees in phylogenetics. I have a tree in Newick format. Does anyone recognize the features of this image as coming from a ...
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0answers
81 views

How to identify a pseudogene to a specific protein coding genes?

Pseudogenes are those sequences in the genome that bear similarity to specific protein coding genes, but nevertheless are unable to produce functional proteins due to existence of frameshifts, prema- ...
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1answer
106 views

How to find a Cancer PPI network data [closed]

I need a Protein Protein Interactions network of Cancer (any type - just I want a PPI of any type cancer), I search and see DIP PPI and .... How to specify that is Cancer PPI and how to get a PPI of ...
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2answers
1k views

Why and how does uniprot list around 150,000 proteins in the human genome?

Using organism:"Homo sapiens (Human) [9606]" as a query in uniprot returns about 146,000 proteins. I was under the impression that there were only 20-25,000 protein ...
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3answers
2k views

120-year-old gene regulation problem independently solved by a computer. How?

My Background: I'm a mathematics graduate student with a physics background. I have a very little biology knowledge and a little knowledge of machine learning and statistics. Topic: I recently ...
3
votes
1answer
103 views

Why perform imputation?

Genetics datasets contain measurements for millions of single nucleotide polymorphisms (SNPs). Some (usually small) percentage of these values are of low confidence, and are labeled as missing values. ...
1
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1answer
71 views

How to interpret the simple sequence repeat (SSR) on the coding sequence, but not the related protein sequence?

I have predicted some SSR repeat on the gene of interest using SSRLocator program, which the result creates a question for me. Please consider the below sequence, which is part of gene sequence of ...
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0answers
67 views

How to characterise a protein family in a putative genome island?

We have sequenced the genome of 200 bacterial strains belonging to the same species, a swine bacterial pathogen. In a previous work, it was observed that a protein family of adhesins is present in ...
3
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1answer
57 views

blastn: What substitution matrix is used?

I'm currently working aligning sequences, and I need to compute similarity between pairs of DNA 'words' of a particular length. For amino acids I am able to use the substitution matrices in Biopython ...
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2answers
57 views

How can I find some pieces of the genome of a microorganism?

I have figured out how to download the fasta of the genomes of microorganisms, for example the botulism bacteria and the spirulina algae. However, I want to find a fasta file for some significant ...
0
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1answer
159 views

Normalised gene counts to edgeR/DESeq2?

Both very popular differential expression packages assume a raw gene matrix count. This makes sense because the statistical model models the library depth. But what if I normalize my counts with say, ...
1
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1answer
61 views

Is studying complete mitochondrial genome need biological lab work?

The research complete mitochondrial genome study done on species: Juema pig Sus scrofa (Suina: Suidae) from southern Gansu red rainbowfish speckled dace, Rhinichthys osculus white char Salvelinus ...
3
votes
1answer
162 views

What is the last heavy atom of an amino acid?

I'm a electrical engineer and I'm learning about bioinformatics. I was reading this paper that uses the last heavy atom to search for active sites of a protein but what would be a heavy atom? Is it ...
2
votes
2answers
93 views

It's right to say coding sequence is part of exon sequence?

Some basic ambiguities making me confused. I downloaded 5'UTR, CDS, 3'UTR, and exon sequences, separately from Biomart for a gene P4HA2 (Homo sapiens) and found some simple sequence repeat (SSR) on ...
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1answer
66 views

What is difference between several mRNA RefSeq for one gene?

I'm looking for mRNA RefSeq sequences for a given gene in the UCSC genome browser by searching gene name "HLA-F" in human (scroll to Refseq genes section). There are several RefSeq mRNA for the gene, ...
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2answers
285 views

Plot coverage per base for BAM file

I have a BAM file and a BED file for my own chromosome. I would like to get coverage per base and ideally construct a histogram of coverage across each gene. The motivation is to visualise the ...
0
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1answer
37 views

Bioinformatics - DNA binding, sequence-specific protein data

I am a computer scientist and we are working on protein function prediction algorithms. Right now, we would like to examine protein-DNA binding properties computationaly. For this, we would make use ...
0
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1answer
34 views

Marker validation using transcriptome and genomic sequences derived from a single cell

I conducted a SSR marker analysis using bioinformatic tool on some RNA-seq data of human tissues. Now, my supervisor believed that we have to validate these SSR on a transcriptomic and genomic ...
2
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1answer
114 views

Differential gene expression analysis between species

I have RNA Seq data from mouse and human skin ( 2 replicates each) and want to compare the expression of the orthologous genes to find any which are differentially expressed. I have quantile ...
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0answers
45 views

How does the brain store information? [duplicate]

In all electronic devices with the possibility of saving there are tiny magnets that can store your data by the state they are in. In general, there has to be something changed to store information ...
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0answers
34 views

Normalise protein database domain-wise

Suppose we've collected a big (hundreds of thousands) library of different protein sequences with certain features. Then we want to use this data base to train a classifier. And for several ...
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0answers
123 views

How to model missing residues on a protein from multiple PDB files?

I have multiple X-ray structures (PDB files) of the same protein. All of them have missing stretches of residues. I want to use all of them to build a single model, with as little missing residues as ...
0
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1answer
37 views

E value cutoff for RNASeq search

I am trying to narrow down the possible search criteria from an RNASeq experiment. I already have the cds sequences so I took these and used Blast+ program to blast the data against itself to find ...
2
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0answers
68 views

Do mutations come in pairs? [closed]

As DNA is organized in a double-helix, a change in one strand must be accompanied by a corresponding change in the other strand. Let's say an original sequence CATCAT mutates into CATGAT. The other ...
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0answers
92 views

How to get Population Genotype Frequency from 1000 genomes Perl API

Posted a similar question on Biostars but got no response. Not sure if I'm allowed to link to it? Basically I want to pull genotype frequency data for a population group (such as CEU) instead of ...
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2answers
75 views

Molecular graphics

anybody know of some great free molecular graphics systems that can allow for PDB code input? I prefer that it doesn't use Java. I also prefer that it is online, although if there is a great system ...
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1answer
45 views

Is there a good site or software to see if a primer pair spans an exon junction?

I am going to perform some RT-qPCR tests to validate an experiment.  I'm currently in the process of ordering primers, and I would like to get them from the Harvard Primer Bank since these have been ...
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0answers
16 views

What is the best aCGH normalization procedure for hyper-ploid tumor samples?

I'm currently working on aCGH data of Triple Negative Breast Cancer patients xenografts and primary tumor samples. A substantial amount of my samples is highly aberrated which leads to offsets of the ...
1
vote
1answer
108 views

A tool to get annotation features by position in the reference genome

Previously, when I needed to find a genomic feature (promoter, CDS, repeat etc) that underwent mutation (SNP) I used my own scripts to load an annotation file, parse it, map the SNP's position and ...
2
votes
1answer
660 views

What is the strand specificity of a reference genome?

It's a simple question but I've come across many people who have this question, is the reference genome Positive of Negative strand? Indeed, I've had heated arguments over the same issue. So here's ...
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3answers
432 views

Merge several .ab1 sequence files into a single FASTA file?

I have several .ab1 files generated from Chromas. I want to merge all of them into a single FASTA sequence file. How can I do this in an automated way? Note that I don't have Chromas installed (the ...
1
vote
1answer
289 views

IC50 calculation [closed]

I am a computer science student and I'm in an internship at a genomics and biotechnologies research institute. My current task is to calculate the IC50 and the EC50 given a set of data as a table. ...
1
vote
1answer
92 views

How to compare two RNA transcripts?

In this paper, the cuffcompare RNA package is reported: Because of the stochastic nature of sequencing, assembly of the same transcript in two different samples may result in transfrags of ...
9
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6answers
505 views

Introductory literature for synthetic / systems biology?

I'm a computer engineer (MsC Computer Engineering) who's looking to switch into the field of synthetic / systems biology. I've got a comprehensive layman's understanding of evolution, genetics, ...
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0answers
173 views

Interpretation of qPCR results for low expression genes

I am attempting to validate existence of a transcript using 40 cycle qPCR. I designed primers for a unique feature of this transcript, and also designed primers for a sequence in the transcript that ...
7
votes
2answers
218 views

What are some (bioinformatic) methods to characterize potentially novel gene transcripts?

I am working with a few novel transcripts of genes- before I confirm their existence experimentally, I would like to perform some bioinformatic analysis. I have already considered coding potential, ...
0
votes
1answer
47 views

What does “each pathway define an independent genotype” mean?

In a section of this paper. However, if the question of independency is posed in the form: “Does each pathway shown define an independent genotype?,” then each of these three pathways is ...
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3answers
2k views

Databases for gene regulatory network graphs?

What databases are available for gene regulatory network graphs starting from a given gene? For example, starting from p53 gene, where can I find a gene regulatory network image that can be exported ...
0
votes
2answers
1k views

What are the programming languages important to learn for a geneticist or bioinformatician? [closed]

I am interested in learning more about both genomics and bioinformatics, with emphasis on genomics. I was told after taking an introductory course of genomics that the programming language "R" and "...
2
votes
1answer
128 views

Extract protein sequences from a GBK(GenBank) file without scripting [closed]

How to extract protein sequences from a GBK(GenBank) file without scripting? I know that writting a script using BioPerl or Biopython can do this, but it is not elegant and daunting to beginners and ...
2
votes
1answer
49 views

Hodgin-Huxley model for a single neuron - continuation

As continuation to This question I have posted. Another set of questions is given for the same model : This time it is also given that for $t<0$ the membrane potential is $u_0$, and at $t=0$ it ...