Bdelloid rotifers are small animals well known for their ability to survive in harsh conditions. They can endure extreme dehydration by entering a state of dormancy and then revive when water becomes available again. Scientists have always been interested in the degree to which these animals resist radiation, since radiation can severely damage DNA by causing both of its strands to break. Interestingly, Adineta vaga's ability to survive radiation may be connected to the way in which it tolerates drying out, as dehydration can also damage DNA. The rotifer probably evolved strong DNA protection and repair mechanisms primarily as a response to its severe environment. Its resistance to radiation is merely a byproduct of adapting to the cycles of drying and rehydration.

In order to find out more about this ability, the researchers subjected A. vaga to proton radiation and then examined what effect it had on its chromosomes. The radiation caused serious damage, resulting in hundreds of breaks in the DNA. For the vast majority of organisms, such extensive chromosome damage would be disastrous; it's similar to going through an instruction manual in a shredder and ending up with a large number of separate fragments. The scientists believed that the rotifers would repair their chromosomes before producing offspring. However, what they discovered was unexpected: some of the broken pieces of chromosome did survive and were passed on to the next generations, where the repair process continued.

The discovery took on even greater interest when the scientists examined the offspring of the irradiated rotifers. Rather than observing the same DNA damage in all the generations, they found different sized sections missing and evidence that some of the genetic regions which had been lost were being slowly restored. The researchers proposed that the rotifers use a repair mechanism known as Break-Induced Homologous Extension Repair, or BIHER. In simple terms, a broken piece of DNA can locate a matching sequence on the other chromosome and use it as a guide to rebuild itself. If the damage is beyond what can be repaired in one generation, the repair process can continue in the next.

What makes the rotifer's method of repairing DNA so unusual is that, normally, we consider DNA repair to take place immediately after damage has occurred, with the cell rapidly repairing the damaged DNA. In A. vaga, however, the repair process can be a lot longer. Certain pieces of chromosome survive the initial damage, are inherited, and then serve as the basis for further repairs in later generations. It's as if one generation begins mending a broken book, the next one continues the work, and another eventually completes the job until all the missing parts have been restored.

One reason why this might work is that bdelloid rotifers have holocentric chromosomes. Rather than having a single point, as most chromosomes do, which controls movement during cell division, the ability to move is distributed along the entire length of their chromosomes. As a result, fragments of chromosomes are sometimes able to retain the parts that are necessary for them to move and divide, and this may account for how broken pieces of chromosome can last long enough to be passed on and then repaired.

This finding could have implications that go beyond those concerning rotifers. Scientists are interested in understanding how genomes cope with severe chromosome damage, for example in the case of chromothripsis, where chromosomes break and are then reassembled in new configurations. Investigating A. vaga could help us to learn how cells manage large genetic issues. Moreover, its high resistance to radiation might also prove useful in research into extreme environments, such as the radiation hazards encountered on long space missions. However, these are ideas for future investigation; at present the rotifer's DNA repair mechanism cannot be used to protect people from radiation.

What is perhaps the most interesting aspect of this discovery is that the rotifer's remarkable ability could have developed for a very simple reason. Since an animal living in moss constantly undergoes periods of drying out and then getting wet again, the same mechanisms that protect its DNA when it is dehydrated might also enable it to survive radiation which would damage most other animals. Therefore, the rotifer probably did not evolve solely in order to resist radiation; instead, it became extremely good at coping with the difficult conditions it encounters, and radiation resistance was just a byproduct.

The case of Adineta vaga demonstrates that survival does not always mean avoiding damage; on some occasions it involves being able to recover from damage which appears to be impossible to repair. This small animal can survive having its chromosomes broken into many pieces, retain some of those pieces, pass them on to its offspring, and continue to repair them over successive generations. Although we generally regard DNA as something fragile that must always remain intact, the rotifer indicates an alternative possibility: perhaps a genome does not have to be perfect in order to survive, since sometimes the pieces last long enough for life to reassemble them, bit by bit, generation after generation.

Ream more at https://www.science.org/doi/10.1126/sciadv.aee0891

CSIR-IICT is conducting Walk in Interview for the following position on a purely temporary basis for the sponsored project "GENESIS (BSC-0121) at 10.00 AM on 19th August 2014 at IICT, Hyderabad

Position : Research Associate
No of Post : One
Desired Profile : PhD in computation biology or M.Tech in Computational Biology with three years experience in relevant subject and atleast one research paper in SCI journal

Experience : Knowledge in vector and vector borne disease, disease modeling, GIS mapping and modeling.
Age : 35 years
Stipend : Rs 22000/- + HRA

Eligible candidate may download the application form from our website http://www.iictindia.org and appear for interview along with the duly filled in application form supported by bio-data and one set of attested photo copies of certificates of educational qualification, age, experience, caste, latest photograph and the cadndidates are required to bring all the original certificates for verification

Walk in Interview : 19.08.14

https://gold.jgi.doe.gov/

Address of the bookmark: https://gold.jgi.doe.gov/

Applications are invited for the post of Junior Research Fellow (JRF) in a DBT funded IYBA project entitled “Generatingaprotein-ncRNA interactome for Dorsal mediated gene regulation and dorso-ventral patterning genes in Drosophila” in the Lab. Of Molecular Biology at the Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi. The project requires extensive use of molecular, genetic and genomic approaches.

POST: Junior Research Fellow (JRF)

NO. OF VACANCIE(S) - (01)

FELLOWSHIP: Rs. 16,000/- plus HRA

PROJECT DURATION: 2014-2016 (Two years)

LAST DATE FOR APPLICATION: Aug 18, 2014.

Eligibility criteria:

M.Sc./M.Tech./ in Biological Sciences/Biotechnology/Bio-Informatics. Candidates with research experience in the field of Drosophila/Yeast genetics will be preferred.

Application Procedure:

A covering letter along with your CV, copy of prior publications (if any) and proof of experience should be e-mailed to lmb_sau@aol.com. Hardcopy of the application should be brought on the day of interview along with other testimonials and marks statements for verification purpose.

IMPORTANT NOTE:

-No TA/DA will be paid for attending the interview.

-SAU may select candidates against the post depending upon qualification and experience of candidates and reserves the right to relax any of the qualifications in case the candidate is found otherwise well qualified by the Selection Committee

-The abovementioned post is temporary and will be initially offered for a period of one year and can be extended, on satisfactory performance.

More at http://www.sau.ac.in/recruitment/vacancy.html

Address of the bookmark: https://github.com/iansealy/coursera-assembly

Eligibility : MSc, M Phil / Phd, BE/B.Tech
Location : Himachal Pradesh-other
Job Category : Govt Jobs, Research, Walkin
Last Date : 20 Aug 2014

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Post : Project Fellow
Research Associate/ Project Fellow Jobs opportunity in CSIR-Institute of Himalayan Bioresource Technology
M.Sc. in Bioinformatics/Computer Science with 55% marks and (ii) M.Sc. Bioinformatics/ Computational biology/ P.G. Diploma in Bioinformatics/B.Tech. or higher Degree in Bioinformatics with 55% marks

Date of Interview: 29.08.2014.

More at http://www.ihbt.res.in/recruit/AdvtNo6_2014.pdf

Availability and implementation: Source code and binaries are freely available at https://github.com/rrwick/Bandage. Bandage is implemented in C++ and supported on Linux, OS X and Windows. A full feature list and screenshots are available at http://rrwick.github.io/Bandage.

Address of the bookmark: http://rrwick.github.io/Bandage/