More at https://pubmed.ncbi.nlm.nih.gov/20494974/

Address of the bookmark: http://www.sequenceontology.org/cgi-bin/soba.cgi

What is Genome Assembly?

Genome assembly involves piecing together short DNA sequence reads generated by sequencing platforms (e.g., Illumina, PacBio, Oxford Nanopore) into longer, contiguous sequences called contigs. This can be performed as:

• De Novo Assembly: Without a reference genome.
• Reference-Guided Assembly: Using a reference genome to guide the assembly process.

Step 1: Preparing Your Data

Before starting the assembly, ensure that your raw sequencing data is high quality.

1. Input Data

   • Short Reads: Illumina sequencing generates short, accurate reads ideal for scaffolding.
   • Long Reads: PacBio and Nanopore sequencing provide long reads for resolving repetitive regions.

2. Quality Control (QC)
   Use tools like FastQC or MultiQC to assess the quality of your reads:

   fastqc reads.fastq multiqc .

   Look for issues like low-quality bases, adapter contamination, or overrepresented sequences.

3. Read Trimming and Filtering
   Trim low-quality bases and adapters using Trimmomatic or Cutadapt:

   trimmomatic PE reads_R1.fastq reads_R2.fastq trimmed_R1.fastq trimmed_R2.fastq \ ILLUMINACLIP:adapters.fa:2:30:10 LEADING:3 TRAILING:3 SLIDINGWINDOW:4:20 MINLEN:36

Step 2: Choosing an Assembly Strategy

Select an assembly strategy based on your data type:

• Short-Read Assemblers:

  • SPAdes: Popular for microbial genomes.
  • Velvet: Fast for smaller genomes.

• Long-Read Assemblers:

  • Canu: Ideal for long-read datasets.
  • Flye: Versatile for small and large genomes.

• Hybrid Assemblers:

  • MaSuRCA: Combines short and long reads.
  • Unicycler: Optimized for bacterial genomes.

Step 3: Running the Assembly

3.1. SPAdes (Short-Read Assembly)

SPAdes is an excellent choice for small genomes, such as bacteria.

The output includes assembled contigs (contigs.fasta) and scaffolds (scaffolds.fasta).

3.2. Canu (Long-Read Assembly)

Canu is designed for high-error long reads from PacBio or Nanopore.

The output will be in canu_output/genome.contigs.fasta.

3.3. Hybrid Assembly with Unicycler

Unicycler combines short and long reads for improved assemblies.

Step 4: Assessing Assembly Quality

After assembly, evaluate its quality using the following tools:

1. QUAST
   QUAST generates assembly statistics, such as N50, genome size, and GC content:

   quast contigs.fasta -o quast_output

2. BUSCO
   BUSCO checks genome completeness by identifying conserved genes:

   busco -i contigs.fasta -o busco_output -l fungi_odb10 -m genome

3. Assembly Graph Visualization
   Visualize assembly graphs with Bandage:

   Bandage load assembly_graph.gfa

Step 5: Post-Assembly Steps

1. Polishing
   Improve assembly accuracy using tools like Pilon (for short reads) or Racon (for long reads).

   racon long_reads.fasta mapped_reads.sam contigs.fasta > polished_contigs.fasta

2. Scaffolding
   Link contigs into scaffolds using tools like SSPACE or Opera-LG if required.

3. Annotation
   Annotate the assembled genome using Prokka for prokaryotes or Maker for eukaryotes.

   prokka --outdir annotation_output --prefix genome contigs.fasta

Step 6: Sharing and Archiving

1. Submit to Public Repositories
   Share your assembly in databases like NCBI GenBank, ENA, or DDBJ.

2. Metadata Preparation
   Include detailed metadata for your submission, such as organism name, sequencing platform, and coverage.

Best Practices

• Always perform quality checks at each stage to ensure data integrity.
• Use multiple tools to cross-validate results when working with complex genomes.
• Document parameters and software versions for reproducibility.

Conclusion

Genome assembly is a powerful process that transforms raw sequencing data into a coherent representation of an organism’s genome. By following this step-by-step guide, you can successfully assemble genomes and uncover valuable biological insights. Whether you’re assembling a microbial genome or tackling the complexities of a eukaryotic genome, these tools and strategies will set you on the path to success.

Pay Matrix Level-12
No. of Post-01
(UR)
Post – Sr. Scientist
Area Bioinformatics
Age limit : 37 years
PhD in Computational Biology/Bioinformatics with 2 years experience in desired area
Or
ME/M.Tech in Bioinformatics or Genome Informatics or Genetic Engineering with 3 years experience in desired area
Experience of understanding fundamental science behind Artificial Intelligence, machine learning, novel Artificial Intelligence algorithms and architectures, software engineering principles for Artificial Intelligence, natural language processing with proficiency in programming as evident by publications in SCI journals with high impact factor. To be part a group of scientists working in the area of genomics, running the central
bioinformatics facility, developing independent projects and providing bioinformatics support to the user scientists of the Institute.

More at

http://14.139.62.50/CSIR-IITR%20Scientist%20Recruitment%20Adv%202020.pdf

This is an opportunity to work on projects that would fundamentally alter the way certain chronic conditions are treated and monitored.

About acrannolife:

We are a team of Post Docs, PhDs, Engineers, Clinicians, and MBAs working towards a future where biology intersects with software(Computational Biology).

We are incubated in Atal Incubation Centre - CCMB and have been backed by some of the leading thought leaders ranging from business to clinical practices.

Interested candidates can fill this form. https://lnkd.in/gtq47hy

and send their CV to hr@acrannolife.com

Applications are invited for one position of Junior Research Fellow (JRF) in a Department of Biotechnology (DBT) sponsored research project entitled “Design, synthesis and evaluation of potent aminopeptidase inhibitors for malarial therapy” under the supervision of Dr. Shakti Sahi.

The monthly fellowship of JRF will be Rs 12,000/- plus HRA as per the University rules.

Essential Qualification: Master degree in any discipline of Life Science with NET qualified.

Desirable Qualification: Preference will be given to candidates having research experience in in silico drug designing/Bioinformatics.

Interested candidates may send their resume to undersigned on or before 14th July 2013 by post-mail/e-mail shaktis@gbu.ac.in or shaktisahi@gmail.com. No TA and DA will be paid for appearing for the interview. Dr. Shakti Sahi (Principle Investigator)

Advertisement:
www.gbu.ac.in/Recruitment/JRF_Advt_DBTProject_Shakt

The fellowship is part of a larger Nordic collaborative project, MarGen_II, financed by the EU Interreg Öresund-Kattegat-Skagerrak Programme, the Danish Rod and Net License Funds and the National Institute of Aquatic Resources (DTU Aqua). The project will primarily be carried out in the population genetics group, Section for Marine Living Resources, situated in Silkeborg, Denmark. DTU Aqua is an institute at the Technical University of Denmark. In addition, the position offers many opportunities for collaborating with Nordic and other European colleagues in the field.

Application:
Apply online at
https://www.dtu.dk/english/About/JOB-and-CAREER/vacant-positions/job?id=d198fd80-4856-4a56-943d-485106026504.
The deadline is 4 January 2021. For further information, please contact
Senior Researcher Jakob Hemmer-Hansen, jhh@aqua.dtu.dk.

You can read more about DTU Aqua at www.aqua.dtu.dk
and the population genetics group at
https://www.aqua.dtu.dk/english/research/population_genetics.

All interested candidates irrespective of age, gender, race, disability,
religion or ethnic background are encouraged to apply.

Jakob Hemmer Hansen

Our long-term research objective is to understand microtubule organization in living cells, with an emphasis on mitosis. We develop in-vitro assays, quantitative image analysis and cytosim, a computer simulation to study cellular architecture from a mechanistic angle, modeling the interactions of microtubules and related proteins such as molecular motors. In the past, we combined simulations and experiments to study microtubule self-organization, and the mechanical stability of two interacting asters. More recently, we looked at the focusing of mitotic fibers, the formation of antiparallel arrays of microtubules in fission yeast and the spindle positionning in C. elegans.
We are supported by BioMS, an initiative in Systems Biology, and involved in Cell networks.

Link: http://www.cytosim.org

Interested applicants must submit their complete, updated Curriculum Vitae, mentioning details of two references as well as various other details at – http://14.139.62.220/survey/index.php/2021/01/21/icgeb-dbt-project-vacancy/

The last date of submission of applications is January 31st, 2021.

Research Associate : PhD. Degree in Computational Biology/Bioinformatics.

Consolidated Salary: 58280/- pm (including HRA).

More at https://www.icgeb.org/project-positions-translational-bioinformatics-group/ and https://www.icgeb.org/category/vacancies/

Research Area:
Mapping loci in ENU mutants in mice in complex pedigrees
Investigation of DNA sharing in distantly related individuals
CNV analysis in pedigrees and connections to linkage studies
Statistical Genetics

Link @ http://www.wehi.edu.au/faculty_members/dr_melanie_bahlo