Spiderman Suit from Nanotechnology

Carbon nanotube-based technology could be used to develop nano-molecular hooks and loops that would function like microscopic Velcro.

A physicist at Polytechnic of Turin, Italy, has formulated a hierarchy of adhesive forces that will be strong enough to suspend a person's full body weight against a wall or on a ceiling, while also being easy to detach.

Here are the details of the news Item.

Cleopatra and Venom enzymes

My favorite Biochemistry Professor,in his popular blog has written a post on enzymes of Snake venom.Have a look at it to see where cleopatra comes into the picture.

Don't miss it.

"We love swapping genes "- Bacteria

Science has an article on results of experiments on lateral gene transfer in Bacteria Get Promiscuous.

List of medical/scientific video sites

Science Roll gives the complete list of video sites here

AEP is a sex specific compound

AEP -2-aminoethyl phosphonate is a metabolite found only in male crabs. It is supposed to be the first metabolite to have discovered to be sex specific. Find out more from this article in Science Daily

Improving male sexual performance by eating the male head-Macabre cannibalism of female mantises

The female praying mantises improves the male's sexual performance by eating his head.

Both the term "Praying" and "Mantis" (Greek: "prophet") refer to the distinctive way these creatures tend to hold up their front legs (as if "in prayer",

Mantises are large carnivorous insects.They normally eat small insects,but they will attack anything that moves.When they mate,the male cautiously creep up on the female,mounts her and copulates.If the female gets a chance,she will eat him,begining by biting his head off,either as the male is approachingor immediately after he mounts or after they seperate.It might seem more sensible for her to wait until copulation is over before she starts to eat him.But the loss of head does not seem to throw the rest of the males's body off its sexual stride. Indeed,since the insect head is the seat of some inhibitory nerve centres,it is possible that the female improves male's sexual performance by eating his head.

From the book The Selfish Gene by Richard Dawkins.

A NewDelhi teacher -Beyond Islands of excellence

Science Magazine ,June Issue had an article on Nandula Raghuram's [a molecular biologist at Guru Gobind Singh Indraprastha University (GGSIPU) ] hands-on approach gives students a solid foundation for a biotech career.

Hope more such teachers reform science teaching in schools and colleges across India.

Blue Roses

It is possible to modify the color of the flowers by mordern molecular breeding technologies.It is the anthocyanin pigments and its pattern that gives colors to the flowers.

The blue hues in flower is because of the presence of the pigment Delphinidin (Purple anthocyanin).It is a anthocyanidin.The precursor of the purple anthocyanin is dihydroflavonols (anthocyanin dihydrokaempferol -DHK.) Flavonoid 3',5'-hydroxylase (F3'5'H) is a cytochrome P450 enzyme (Cyt P450) that catalyzes the 3',5'-hydroxylation of dihydroflavonols.Roses lack this enzyme.

Earlier attempts to replace the gene for Delphinidin in roses had failed .Delphinidin gene cloned from petunia and expressed in roses created a dark burgundy rose ,not blue. So instead of modifying the color,scientists were looking for a genes/proteins involved in pathways before any color formation in roses. They found an enzyme dihydroflavinol reductase (DFR) which modifies the pigmentation from white to another color. In other words,until this enzyme acts, all the pigment molecules are colorless.

The solution to create a blue rose is obtaining a DFR mutant white rose. How to knock out the gene for the enzyme? The answer is in RNAi technology.

Using RNAi,they suppressed the DFR gene and cloned a new verson of Delphinidin in roses.

More on the technology here.

Bruce Alberts

Image source : http://www.nature.com/

A leading textbook and a bible for any Biosciences is "MOLECULAR BIOLOGY OF THE CELL" by Bruce Alberts, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, Peter Walter .You can have a full access to the entire textbook here at NCBI

Bruce Alberts is an Amercian Biochemist known for his extensive study of the protein
complexes that allow chromosomes to be replicated.

The Work of Bruce Alberts on DNA Polymerase and Leading and Lagging Strand
Synthesis is well explained in this JBC classics.

Profile of Bruce Alberts as an Education President when he was the President of the National Academy of Sciences states

Alberts found the companion laboratory sections to be even more frustrating than the assigned textbooks. Laboratory assignments consisted of following a set of instructions, he says, then comparing answers with a friend, fudging data to get the right answer, and turning in a pointless notebook. "Cooking classes," he calls them.

All of us who are professors did well with lecture-style teaching and tests," he says, "and so we think that everybody else should be able to learn well in exactly the same way."

I admire him as a teacher than a researcher.Salutations to this great Educationist.

Careers for Lifescience Graduates

More Avenues for Lifescience Graduates at THE HINDU

Leading and Lagging

All biology students must be aware that DNA replication ( The process of making an identical copy of a section of duplex (double-stranded) DNA, using existing DNA as a template for the synthesis of new DNA strands) takes place through Leading and Lagging strand synthesis.

Leading strand refers to a process by which one of the new strand is synthesised by adding nucleotides one by one using a parent strand as template,whereas in lagging strand sysnthesis,nuclotides are added as chunks.Replication can occur easily in leading strand as the enzyme moves along in 3' to 5' direction continously,whereas the lagging strand synthesis is discontinous and takes place in the direction opposite to that the leading strand.

Anyone understanding these feautures think why lagging strand synthesis appears so nonsensical,while there is easy continous way to synthesise strands.

Lagging strand synthesis takes place with a purpose.The need for error correction during DNA replication.A good explanation is given inKleinsmith, LJ. and Kish, VM. Principles of Cell and Molecular Biology, 2nd ed.

Given the complexity of this model, one may wonder why cells don't simply produce an enzyme that synthesizes DNA in the 3' to 5' direction. One possible answer is related to the need for error correction during DNA replication. About one out of every 10,000 nucleotides incorporated during DNA replication is incorrectly base-paired with the template DNA strand. Such mistakes are usually corrected by a proofreading mechanism, which utilizes the same DNA polymerase molecule that catalyzes DNA synthesis. Proofreading is made possible by the fact that the DNA polymerase exhibits a 3'-exonuclease activity, which catalyzes the removal improperly base-paired nucleotides from the 3' end of the polynucleotide chain. This proofreading capability improves the fidelity of DNA replication to the point where an average of only one error occurs for every billion base pairs replicated. If cells did contain an enzyme capable of synthesizing DNA in the 3' to 5' direction, proofreading would not work because a DNA chain growing in the 3' to 5' direction would contain a nucleotide triphosphate at its 5' end. If this 5' nucleotide were an incorrect base that needed to be removed during proofreading, its removal would eliminate the triphosphate group that provides the free energy that allows DNA polymerase to add nucleotides to a growing DNA chain. Hence no further elongation of the DNA chain could take place.

It was Bruce Alberts who gave explanation of how DNA polymerase can replicate both the leading and lagging DNA strands simultaneously. (My next post will be on Bruce Alberts)

Everything has a purpose.

Oh,my wife ?.Sorry I don't recognise your face

Forgetting your loved ones or unable to recognise them can be due to a delusional misidentification syndrome.People with this syndrome have a delusional belief that a person/persons close to them as imposters.Mistaken for insanity,this syndrome is called Capgras syndrome.

The Capgras' patient identifies his or her spouse as being an imposter - identical in every possible way, but an identical replica. The patient will accept living with these imposters but will secretly "know" that they are not the people they claim to be.

The official portal of Capgras syndrome is here

The bizarre misperception of body doubles is named after French psychiatrist Jean Marie Joseph Capgras, who in 1923 with colleague Jean Reboul-Lachaux described the case of a Madame M,claimed to have had eighty husbands.

"Invasion of the Body Snatchers " and "I married a monster from outer space " are the two science fiction films based on Capgras syndrome.

The case has been well portrayed by Dr.V.S Ramachandran in his popular book"Phantoms in the Brain"He reported that connections from the face processing areas in the temporal lobes to the limbic system(involved in emotions) have been damaged in these patients. The online format of the 1997 paper by Dr.Ramacandran on neural mechanism behind capgras is available here.

A novel on The Echo maker based on this fascinating syndrome by Richard Powers makes a good summer reading

Expressing your passion for science

Express yourself by having a tattoo of your science passion onto your skin. It is real fun to note people tattooing themselves with DNA,with mathematical equations etc.

Carl zimmer has more photos of people branded with science.

Kumbakarnan sleep -revisited genetically

Before I get into the genetic stuff,let me tell you who is Kumbakarnan and what is great in him.
Kumabakarna is a demon (a Rakshasha) and a brother of Ravana.U who slept for six months nonstop Usually, Kumbhakarna means a person who is fond of sleeping. The person who spends most of the time in sleeping is consider as Kumbhakarna.

The story of kumbakarna sleeping is here

Sometime back in Feruary 2007,Aranthangi Tamil Sangam organised a lecture on Kumbakarnan,where a tamil scholar remembered him as the epitome of virtues, integrity, gratitude, valour and bravery.

Now to the genetic angle ,scientists have recently revealed that low expression of MX2 gene exists in White blood cells of Narcoleptics.(people with a sleep disorder who sleep uncontrollably all through the day)[via Scientific blogging]

MX2 is an intracellular protein that plays a role in immunity.

Is it that MX2 is completely lost or some other genes implied in kumbakarna's sleep for six months?