Questions tagged [sequence-analysis]

Analysis of DNA, RNA or protein (amino acid) sequences. Here sequences are compared so analyze similarities and conserved regions. Sequence analysis is usually done by specialized software.

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Simple template for calculating Shannon diversity index from FASTQ files with R [migrated]

I have a bunch of files in FASTQ format and need to calculate the Shannon diversity index from all of them. Is there a simple way to do that with R, some kind of step-by-step recipe? Grateful for ...
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What results would come from DNA analysis of several different types of DNA mixed together?

By "types," I mean several different species of animals. If, post extraction, the pure, isolated DNA of several different animals were mixed together and run through DNA analysis, I know the ...
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How are DNA virus cladograms actually calculated in practice? Is the procedure different for RNA viruses? Are these processes somewhat subjective?

The May 24, 2022 Bloomberg opinion piece Monkeypox Isn’t Looking Like a Covid-Sized Threat; It’s still early, but contact-tracing efforts and analysis of the virus’s genome offer hope that this ...
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Hierarchial and shotgun sequencing vs Massively Parallel Sequencing

Why is the cloning step unnecessary prior to sequencing with massively parallel sequencing (MPS; Illumina or similar technologies), when it is necessary for hierarchical and shotgun sequencing? I know ...
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Alignment given two sequence

I have two sequences and I need to perform sequence alignment to determine all possible sequence alignments. I have created the matrix and managed to find 16 alignments. I wanted to understand if I ...
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Zayed et al. (2022) "Cryptic and abundant marine viruses at the evolutionary origins of Earth’s RNA virome"; expressed sequences or transcribed?

Phys.org's Ocean water samples yield treasure trove of RNA virus data summarizes Zayed et al. (April 7, 2022) in Science Cryptic and abundant marine viruses at the evolutionary origins of Earth’s RNA ...
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What is the difference between 4th generation sequencing and NGS?

The generation of sequencing technologies has come on leaps and bounds and there are stark differences between the types of technology used. There is a great Q&A here What is the difference ...
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Is there a newer/better book than Genome-Scale Algorithm Design available? It's from 2015

I'm considering buying the book "Genome-Scale Algorithm Design: Biological Sequence Analysis in the Era of High-Throughput Sequencing" by Veli Mäkinnen and others. However, as this book was ...
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Meaning of ‘motif’ in molecular biology

I would like to understand the meaning of the term motif as used in molecular biology. In an article in Nature Biotechnology, Patrik D’haeseleer states: Sequence motifs are short, recurring patterns ...
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What is the typical arrangement of amplified genes in archaea genome?

I have to check if some genes are amplified with bioinformatics tools, but, in order to do it, I need to know what this means from a biological point of view. It seems not so difficult to understand, ...
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Calculating sequence divergence score for a protein from identity or similarity score?

I have % identity and % similarity scores for ~50K protein alignments, that I fetched from Ensembl Compara database. The issue ...
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How to calculate the occurrence of a stretch of nucleotides in a genome?

I have seen that the formula to calculate the number of times a given sequence of nucleotides occur in a target genome is derived from that to calculate the expected frequency of restriction sites: <...
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Looking for study/genome data for HIV in different organs

I am looking for a research study or data base that has HIV genome data available in fasta or similar format. Specifically I need genome data of HIV taken from different organs in the same subject. I ...
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Why do I get cytosine to guanine/adenine transitions in bisulphite treated sequences?

I got my sequencing results (bisulphite treated and non treated sequences of same species Allium cepa) and now I have to do analysis in Cymate online tool. I prepared all sequences as it is written in ...
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Sequence of DNA

While giving an amateur reading to DNA. I was stuck within the first few lines: Refined resolution of the structure of DNA, based on X-ray crystallography of short synthetic pieces of DNA, has shown ...
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Why are some protein sequences known but their 3D structure isn't?

Why are there some proteins that have a known amino acid sequence, but their 3D structure is not known? Wouldn't finding the former in a lab lead to the discovery of the latter? Please correct me if I ...
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Convert fasta to ascii?

Is there an algorithm or tool to convert a fasta sequence file (such as the file linked below) into an ascii file for the purpose of gene synthesis? https://www.rcsb.org/fasta/entry/6EQJ To the best ...
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Available Protein sequence alignment dataset and HMM model

I am new to biology and I find my algorithm may be used in the Protein sequence alignment, since it is a henced HMM model. I find that people use HMM to generate noisy copies of the consensus sequence ...
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Extract mutations from fasta sequences

I have a large amount of protein sequences in the .fasta format and I would like to extract only the amino acid mutations from these sequences, so that, in the end, I want to have a list that looks ...
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How to find the enhancer region of a specific gene?

I am new to these concepts in biology and need some help understanding. My main concern is how to find the enhancer of my gene of interest, specifically the sequence of the enhancer. I am working on a ...
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What tool can I use to align multiple protein sequences to one reference sequence?

I have a protein of interest which is ~300 amino acids in length. I also have around 40 short sequences (all 9 amino acids in length); these are all very different from each other. I would like to ...
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Comparative evolutionary study: is amino acid or nucleotide comparison more useful?

I am a high school student and am currently learning about evolutionary relationship study in biology. My teacher said that a comparative study of amino acid sequences is more useful than a ...
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Is there a system biology approach to compare pathways or famillies of proteins from an evolutionary point of view for the same organism?

I would be interested to know if there is a method/analysis or a set of methods to compare two groups of pathways or families of proteins. I would specifically be interested by a system biology ...
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Lysozyme amino acid sequence: N-terminal extension

I looked up the amino acid sequence of lysozyme here: http://www.biology-pages.info/L/Lysozyme.html Then I crossed referenced that with the lysozyme sequence on UniProt: https://www.uniprot.org/...
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How to interpret different results from Clustal Omega and Multalin?

I have been working on aptamers, which are nucleotide sequences. They bind to various targets, in my case a particular cell surface receptor. The people associated with the project performed SELEX and ...
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What do lower case nucleotides mean in this gene sequence?

The following table (image linked below) shows promoter sequences recognized by different sigma factors. The sequence given for, e.g. sigma B is "GTTTaa"; why are the "a"s lowercase? (from "A sigma ...
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Methods for microbial identification in soil

I'm trying to perform a survey of the life in a soil sample. I want to know what species of bacteria, fungi, and other organisms are in it. I've heard that ITS sequencing and 16S rRNA sequencing are ...
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How to convert enrichment/depletion to frequency for comparing deep sequencing to sequence profile?

I have two datasets, from different sources, that I need to compare. The first set is deep sequencing results of a directed evolution experiment, where I have the naive library and selected library ...
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why and how multi allele gets reported during variant calling in vcf?

This might be a very basic question for many here. With the basic understanding of inheritance, eventhough there is a possibility of multiple genotypes due to multi alleles, the resulting genotype can ...
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List of proteins by number of amino acids / chain length

Is there any protein database online where I could obtain a list of proteins ordered by the length of their chains / number of amino acids, starting from the shortest, as well as to see their amino ...
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How to know which residues belong to the variable or constant regions of a Fab (fragment antibody)?

I have a fragment of antibody (Fab) structure, and I know its amino acid sequences of its heavy chain and light chain. As each chain of Fab can be divided into variable and constant regions, how can I ...
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If we sequenced the genome of every species, would all phylogenies agree?

The Tree of Life is still up for debate. Most of this debate seems to be due to a lack of genomic information, but that deficiency is decreasing rapidly with advances in technology and sequencing ...
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Why does deamination in the lagging strand lead to an increase in the relative number of guanine and thymine to cytosine and adenine?

My question arose from this article on Wikipedia on the GC-skew in bacterial genomes: https://en.wikipedia.org/wiki/GC_skew As far as I understood, the lagging strand (the template strand), during ...
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Breakpoint resolution for copy number variation analysis

I am reading [1]. One limitation of the Read Depth approach is that "the breakpoint resolution is often poor". Which is the meaning of low-resolution breakpoint in this case? Breakpoint is ...
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Confirming exon shuffling in a gene

I'm trying to confirm that the sequence of a novel gene is derived by exon shuffling between several different genes. I have the promoter sequence, gene sequence, and mRNA (with defined exon/intro ...
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How to calculate RPM?

I´m just starting my postdoctoral fellow and my new project involve sRNA Deep Seq. I´m having problems with the data normalization. I´ve been reading papers about it and the variety of normalization ...
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Is there a database for immunoglobulin domain structure?

is there a database where I can find the sequences of the hypervariable domain of immunoglobulins and the sequences of the related antigens? Thank you
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What are the exact reason causing missing calls in a VCF file from exome sequencing?

My data is a VCF file from exome sequencing variant call. I'm not very familiar with the sequencing process and variant calling process. I noticed that there are some missing genotypes, which is ...
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Where are examples of Interspersed repeats? [closed]

Interspersed repeats are often defined as repetitive sequences dispersed throughout the genome. However such definition (IMO) does not exclude Tandem Repeat Sequences. So I started to search for ...
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Difference between Classic Satellite DNA and Microsatellites/Minisatellites

I am very new to this community and have a basic question about repetitive DNA sequences. How is different (classic) satellite DNA from microsatellites/minisatellites? All textbooks give concrete ...
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An efficient and free method of assembling a large number of Sanger sequencing reads?

I have a rather large number of Sanger Sequencing reads.  Is there a automated method in either Ugene or a similiar freeware that allows you to quickly assemble forward and reverse reads. Ideally ...
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Which DNA sequence will have higher melting temperature: CCCCCC... or GCGCGC...?

I tried this service to calculate temperatures. The nearest neighbour method consistently gives larger results for sequences like GCGCGC over sequences like ...
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Why do we use klenow fragment in pyrosequencing?

Why do we use klenow fragment in pyrosequencing instead of polymerase
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How can sequence analysis establish whether a genomic sequence is a functional gene or a pseudogene?

BLASTX of a query gene shows 5 hits in my subject, how can I find out which of these are expressed and which are pseudogenes (using DNA sequence or by sequence analysis)??
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Which analytical techniques could you use to research relationships between 2 proteins? [closed]

Two of the proteins I am researching are known to interact. However, I would like to know if they interact with other proteins as well, and possibly form a pathway. Which analytical technique(s) I ...
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Is it possible to establish a newer animal model completely based on Bioinformatics studies?

I wanted to know, if it is possible to prove a new organism as an animal model for any human disease by only Bioinformatics methods like NGS and Structural bioinformatics. For Example, let's say ...
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Which is the reference 16S rRNA?

Recently, I've stumbled upon a fact, which hasn't bothered me for many years. The fact is that all universal 16S primers are written as "[FR][0-9]+" (in regex notation), that is they have a position ...
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Are there any examples of weighted edit distance genome alignments?

It has been said that weighted edit distance is a preferred way to compare/align genomes in practice, e.g., when identifying genetically similar patients. I wonder if there are some concrete examples ...
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What factors should I consider when selecting a reference genome for mapping?

I am under the impression that the most recent reference genome is typically the best case. What other things should I consider when selecting a reference genome? For example, is there any particular ...
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What is the significance of cysteine in a protein sequence?

What is the importance of cysteine-cysteine in amino acid sequence? What can I infer if I get a high percentage of C from a protein sequence?
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