விண்வெளியில் 50 ஆண்டுகால இந்திய சாதனைப் பயணம்

 

It's 50 years today since India launched its first rocket from Thumba

Thursday, Nov 21, 2013, 14:10 IST | Place: THIRUVANANTHAPURAM | Agency: PTI

The Union Government took the first step in its space programme in August 1961 by entrusting the Department of Atomic Energy with the task of conducting space research and peaceful uses of outer space.

Source: Wordpress

India today entered the golden jubilee of the launch of its first rocket from the sylvan settings of the coastal hamlet of Thumba near here, marking the decisive step of the country's space odyssey which has witnessed landmarks like Chandrayaan and Mars mission. The sleepy palm-fringed village became part of modern India's quest to scale dizzying heights of scientific research when an American-built rocket Nike-Apache was fired on November 21, 1963.

The launch site in due course came to be known as Thumba Equatorial Rocket Launch Station (TERLS) and later became Vikram Sarabhai Space Centre (VSSC), a major centre of ISRO named after pioneer of Indian space programme Vikram Sarabhai.

It was Sarabhai who gathered a team of young scientists and engineers for the mission and sent them to the US for hands-on training in sounding rockets.His early recruits included former President APJ Abdul Kalam. According to scientists, Thumba was identified for locating the launch station as the magnetic equator passes through South Kerala making it an ideal spot for the launch.

The Union Government took the first step in its space programme in August 1961 by entrusting the Department of Atomic Energy with the task of conducting space research and peaceful uses of outer space.

In 1962, a national committee on space research was formed under the chairmanship of Sarabhai for carrying on the mission and the next year on November 21 the first sounding rocket, a US-built Nike Apache was launched from Thumba. The launch facility was prepared by shifting several fishermen families from Thumba to an adjacent coastal stretch with the then Catholic Bishop playing a vital role in persuading the villagers. A church in the locality has been retained as such and later converted into a space museum.

http://www.dnaindia.com/scitech/report-it-s-50-years-today-since-india-launched-its-first-rocket-from-thumba-1922649

November 21, 2013

Finding the time and the money for space

P.V. Manoranjan Rao

On November 21, 1963, a small foreign rocket took off from Thumba, an obscure fishing hamlet near Trivandrum. This marked the birth of the Thumba Equatorial Rocket Launching Station (TERLS) and of the Indian space programme.

The two scientists who launched the space programme were Vikram A. Sarabhai and Homi J. Bhabha. Both were scions of rich and cultured families, cosmic ray physicists, and determined to do their bit for emerging India. Bhabha brought atomic energy to India and Sarabhai, space. In this they were supported by Prime Minister Jawaharlal Nehru and later, by Mrs. Indira Gandhi.

The Sarabhai decade

Thumba was chosen because it is close to the magnetic equator. At heights around 110 km above the magnetic equator, certain processes occur that fascinate scientists. These regions are most conveniently studied using sounding rockets which, after carrying a scientific payload to a specified altitude, fall back to the ground.

For Bhabha and Sarabhai, TERLS was the first step in acquiring rocket technology: first sounding rockets and then bigger and more complex rockets, known as launch vehicles, capable of orbiting satellites.

Sarabhai was a man in a hurry. He got U.N. sponsorship for TERLS; created the Space Science and Technology Centre (SSTC) close to TERLS; established the Experimental Satellite Communications Earth Station in Ahmedabad; saw the first indigenous sounding rocket take off from Thumba; created the Indian Space Research Organisation (ISRO); sowed the seeds of remote sensing and satellite communications; completed formalities for an agreement with the Soviet Union to launch India’s first satellite (Aryabhata); signed an agreement with NASA for joint conduct of the Satellite Instructional Television Experiment; obtained a licence to produce the French sounding rocket, Centaure, in India; got Sriharikota island on the east coast for establishing a rocket launching range; flagged off the development of India’s first satellite launch vehicle, SLV-3; drew the road map that ISRO followed for the next four decades and then died in his sleep on December 30, 1971. He was just 52.

Dhawan era

In an inspired move, Prime Minister Indira Gandhi chose Satish Dhawan, then Director of the Indian Institute of Science, Bangalore, to succeed Sarabhai. Dhawan took his time to plan an organisational structure for the space programme which we still see in operation today. With support from Indira Gandhi, he created the Space Commission and the Department of Space (DOS) in June 1972. Then in August 1972, he obtained a broad national consensus on the main objectives of the space programme through a national seminar held in Ahmedabad. He took charge of ISRO only in September 1972.

Now, Dhawan was Chairman of the Space Commission, Secretary of DOS and Chairman of ISRO — all three rolled into one. Borrowed from the Atomic Energy programme, this concept was crucial to the success of the space programme. This arrangement which ensures perfect harmony between nation’s space policies (the commission), the R&D programmes (ISRO) and the budgetary provisions (DOS) still holds today.

Dhawan chose the hierarchically junior A.P.J. Abdul Kalam to lead the SLV-3 project that made India a space faring nation. Prior to this, Kalam was just one of a dozen engineers managing the SLV-3 project. “I was puzzled when I got the offer in my hand,” Kalam wrote later. “On the one side there were many experienced senior people in the organisation and on other side, I had to tap talents of thousands of engineers both from ISRO and academic institutions.”

In November 1963, when the first sounding rocket was launched from TERLS, virtually everything came from abroad. Fifty years later, in November 2013, when ISRO launched its Mars Orbiter, virtually everything was indigenous! Today, over 20 Indian satellites provide operational services to the nation in telecommunications, TV broadcasting, meteorology, disaster warning, and remote sensing. All Indian remote sensing satellites are now launched by ISRO’s own Polar Satellite Launch Vehicle (PSLV).

But, perhaps the most important achievement of our space programme is the establishment of a string of R&D laboratories and facilities that enable our scientists and engineers to work at the forefront of space technology.

During the pioneering days under Sarabhai and Dhawan, people in ISRO felt that they were working collectively for a vital national enterprise in which each individual’s contribution was of paramount importance. By nurturing that spirit of individual commitment, India’s space efforts scaled greater heights.

(Dr. P.V. Manoranjan Rao retired as group director, Vikram Sarabhai Space Centre.)

E-mail: rao.manoranjan@gmail.com

The most important achievement of India’s 50-year space programme is

the establishment of R&D facilities

Copyright© 2013, The Hindu

விண்வெளியில் 50 ஆண்டுகால இந்திய சாதனைப் பயணம்

By dn, சென்னை

First Published : 21 November 2013 01:40 AM IST

 

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  முதன்முதலில் ஏவப்பட்ட அமெரிக்காவின் நைக் அப்பாச்சே ராக்கெட். (ஃபைல் படம்)

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  திம்பாவில் உள்ள ராக்கெட் ஏவுதளத்துக்கு சைக்கிளில் வைத்து எடுத்துச்செல்லப்படும் ராக்கெட்டின் பாகம்.

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  ராக்கெட் திட்டம் குறித்து விக்ரம் சாராபாயுடன் விவாதிக்கும் இளம் வயது அப்துல் கலாம் (இடது ஓரம்).

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  செயின்ட் மேரி மேக்தலீன் சர்ச்.

 

விண்வெளியில் இஸ்ரோ காலடி எடுத்துவைத்து 50 ஆண்டுகள் வியாழக்கிழமையுடன் நிறைவடைகிறது. இந்தியா புரிந்துள்ள இந்தச் சாதனைப் பயணத்தின் தொடக்கப்புள்ளி, எளிமையான ஒரு சிறிய கிறிஸ்தவ தேவாலயத்தில் உருவானது என்றால் அது மிகையாகாது.

ஐம்பதாண்டுகளுக்கு முன்பு... செயின்ட் மேரி மேக்தலீன் சர்ச்!

அதுதான் இந்திய விஞ்ஞானிகளின் முக்கிய அலுவலகமாக மாற்றப்பட்ட தேவாலயம். அதையொட்டி, இருந்த கடலோரப் பகுதியில்தான் இந்தியாவின் முதல் ராக்கெட் ஏவுதளம் அமைக்கப்பட்டது. அந்த தேவாலயத்தின் பாதிரியார் வீடு ராக்கெட் பணிமனையாகவும், அருகிலிருந்த மாட்டுத்தொழுவம் ஆய்வகமாகவும் மாற்றப்பட்டது.

விக்ரம் சாராபாயும், அவரது சக விஞ்ஞானிகளும் அயராது உழைத்ததில் திருவனந்தபுரம் அருகே திம்பா எனும் கிராமத்தில் சில மாதங்களிலேயே ராக்கெட் ஏவுதள மையம் உருவானது.

நாசா வழங்கிய நைக் அபாச்சே (சண்ந்ங்-அல்ஹஸ்ரீட்ங்) என்ற சிறிய ரக ராக்கெட்டை 1963 ஆம் ஆண்டில் நவம்பர் 21 ஆம் தேதியன்று விண்ணில் செலுத்தியதன் மூலம் இந்திய விண்வெளி பயணம் தொடங்கியது.

அந்த தேவாலயத்தை அலுவலகமாக மாற்றியபோது பீடம் உள்ள பகுதியை மட்டும் விட்டுவிட்டு மீதமுள்ள பகுதியைப் பயன்படுத்திக்கொள்ளுங்கள் என்று அந்த சர்ச்சின் பாதிரியார் கூறியதாக மூத்த விஞ்ஞானி யு.ஆர்.ராவ் கூறினார்.

அந்த முதல் திட்டத்திலும், அதன்பிறகு சில ஆண்டுகளும் சைக்கிள்களில் வைத்துதான் ராக்கெட்டின் பாகங்கள் ஏவுதளத்துக்குக் கொண்டுசெல்லப்பட்டன. விண்வெளி ஆராய்ச்சிக்காக அப்போது எந்த அடிப்படை வசதியும் இல்லை. எனவே, எந்த வாகனம் கிடைத்ததோ அதைப் பயன்படுத்திக்கொண்டோம் என்று அவர் கூறினார்.

வளிமண்டல மேற்பரப்பை ஆய்வு செய்யும் சவுண்டிங் ராக்கெட்ஸ் (நர்ன்ய்க்ண்ய்ஞ் தர்ஸ்ரீந்ங்ற்ள்) எனும் சிறிய ரக ராக்கெட்டுகளை ஏவுவதற்கு உலகிலேயே மிகவும் ஏற்ற இடம் என்ற பெயரையும் அந்த மையம் பெற்றது. இந்த ராக்கெட்டுகள் 100 முதல் 500 கி.மீ. உயரத்துக்கு வளிமண்டல ஆய்வுக் கருவிகளை எடுத்துச்செல்லும் திறன் பெற்றவை.

பூமியின் காந்த மையக்கோடுக்கு (ஙஹஞ்ய்ங்ற்ண்ஸ்ரீ உவ்ன்ஹற்ர்ழ்) அருகில் திம்பா அமைந்திருந்ததால் அமெரிக்கா, ரஷ்யா உள்ளிட்ட பல நாடுகளும் தங்களது சிறிய ரக ராக்கெட்டுகளை இங்கிருந்து விண்ணில் செலுத்தின.

வளிமண்டலத்தை ஆராய்வதற்காக இந்தியாவிலேயே தயாரிக்கப்பட்ட ஆர்எச்-75 என்ற சிறிய ரக ராக்கெட் முதன்முதலாக 1967, நவம்பர் 20-ம் தேதி திம்பாவில் இருந்து ஏவப்பட்டது.

இந்திய விண்வெளி ஆராய்ச்சிக் கழகம் 1969, ஆகஸ்ட் 15-இல்தான் ஏற்படுத்தப்பட்டது. அதற்கு முன்னதாக, இந்த அமைப்பு இந்திய தேசிய விண்வெளி ஆராய்ச்சிக் குழுவாக இருந்தது. அதன் பிறகு ஸ்ரீஹரிகோட்டாவில் மிகப்பெரிய ராக்கெட்டுகளை அனுப்புவதற்கான புதிய ஏவுதளம் உள்ளிட்ட பல்வேறு வசதிகளும் உருவாக்கப்பட்டன.

முதல் செயற்கைக்கோள்: இந்தியாவின் முதல் செயற்கைக்கோளான ஆர்யபட்டா மிகக் குறைந்த நேரத்தில், அதாவது இரண்டரை ஆண்டுகளிலேயே கட்டமைக்கப்பட்டதாக யு.ஆர். ராவ் கூறினார்.

1972-ல் செயற்கைக்கோளை உருவாக்குவது என்று முடிவு எடுத்ததும் ஏராளமான இளைஞர்களைப் புதிதாக பணிக்குச் சேர்த்தோம். ஆனால், ஆய்வகத்தின் நிலையைப் பார்த்ததும் பலர் தயக்கத்துடன் பணியில் சேரவில்லை எனச் சொல்லி சிரிக்கிறார் ராவ்.

செயற்கைக்கோளை உருவாக்குவதில் இருந்த ஆர்வத்தின் காரணமாக நாங்கள் எந்த சிரமத்தையும் பொருட்படுத்தவில்லை. ஆர்யாபட்டாவை ரஷியாவிலிருந்து விண்ணுக்கு அனுப்புவதற்கு முன்னால் அதிலிருந்து சிக்னல்களைப் பெறுவதற்கு ஸ்ரீஹரிகோட்டாவைத் தவிர மற்றுமொரு இடத்தில் சிக்னல் மையம் அமைக்கலாம் என்ற எண்ணம் தோன்றியது.

பெங்களூரில் எங்கள் அலுவலகம் இருந்த தொழிற்பேட்டையில் இடவசதி இல்லை. எனவே, அங்கிருந்த பெண்கள் கழிவறையையே எங்களுக்கான ஆய்வகமாக மாற்றிக்கொண்டோம் என்றார் அவர்.

இந்தியாவின் முதல் செயற்கைக்கோளான ஆர்யபட்டா , 1975 ஆம் ஆண்டு ஏப்ரல் 19-இல் விண்ணில் ஏவப்பட்டது.

இந்திய விண்வெளி வரலாற்றில் மிகப்பெரிய முன்னேற்றமாக கூறப்படுவது எஸ்.எல்.வி., ஏ.எஸ்.எல்.வி. ரக ராக்கெட்டுகள்தான். அதில் கிடைத்த அனுபவத்தில்தான் மிகவும் வெற்றிகரமான பி.எஸ்.எல்.வி. ராக்கெட் உருவானதாக இஸ்ரோவின் மூத்த விஞ்ஞானிகள் தெரிவித்தனர்.

இந்தியாவிலேயே தயாரிக்கப்பட்ட எஸ்.எல்.வி.-3 ராக்கெட் மூலம் ஆர்.எஸ்.-1 செயற்கைக்கோள், 1980ஆம் ஆண்டு ஜூலை 18-இல் வெற்றிகரமாக விண்ணில் அனுப்பப்பட்டது. இந்த எஸ்.எல்.வி-3 திட்ட இயக்குநராக இருந்தவர் புகழ்பெற்ற விஞ்ஞானியும், குடியரசு முன்னாள் தலைவருமான ஏ.பி.ஜே.அப்துல்கலாம். அந்த வெற்றியில் தொடங்கி, தொலைதொடர்புக்கு இன்சாட் வரிசை செயற்கைக்கோள்கள், தொலையுணர்வுக்கு ஐ.ஆர்.எஸ். செயற்கைக்கோள்கள், கல்விக்கு எஜுசாட் செயற்கைக்கோள், நிலவுக்கு சந்திரயான் விண்கலம் என விண்வெளி அரங்கில் இஸ்ரோ அமைப்பு பிரம்மாண்டமாக உருவெடுத்துள்ளது.

மாட்டுத்தொழுவத்தில் தொடங்கிய விண்வெளிப் பயணம் இப்போது மங்கள்யான் வரை வந்துள்ளது.

© Copyright 2012, Dinamani.com.

Question corner: Nail growth

September 25, 2013

Updated: September 26, 2013 12:52 IST

If nails are dead tissue, how are they able to grow?

EDWIN BRO KOMAGAL A.

Chennai

Nail is not made up of dead tissue. It is a part of a living tissue, like bone internally. Nail has a nail bed, and root from which it grows. It contains a thick keratin protein, which is equivalent to animal nails, or horns.

It grows from its root, like a hair grows from root. Cutting the hair is painless, but we do not call it dead tissue. It is the outgrowth of the living nail bed, which is meant to protect the soft tip of the finger from the injury, which we touch.

Patients with removed nail, subject themselves to severe injury, since a sense of deep sensation is passed by the nail to the underlying nervous tissue, called Pacinian corpuscles and free nerve endings underneath.

There is enormous blood circulation beneath the nail, capillaries which are visible in fair individuals, through the nail like a ground glass. There is a small semicircular white area under the base of the nail, called lunula, which is the growing part. Nail lives with the man. Many diseases are identified through nail, as it reflects health, and does not behave like dead tissue.

For example, diseases like anemia of various types, chronic arsenic poising, psoriasis, neuro-cutaneous markings, jaundice, etc. If it is a dead tissue it will not reflect the health. Only the terminal portion of the nail which protrudes away from the tip of the finger, has no sensation and no blood supply which is equivalent to a horn of animals.

DR. V. NAGARAAJAN

Professor Emeritus in Neuro Sciences

Tamil Nadu Govt Dr MGR Medical University

Madurai, Tamil Nadu

This story has been corrected for a typo error

Copyright© 2013, The Hindu

C.N.R. Rao laments lack of industry contribution to science

Bangalore, November 24, 2013

‘Mukesh Ambani, Ratan Tata should loosen their purse strings’

Eminent scientist C.N.R. Rao at an interaction with the media in Bangalore on Saturday.— Photo: V. Sreenivasa Murthy

Science in India gets no contribution from the industry, C.N.R. Rao, head of the scientific advisory council to the Prime Minister, has said. “Industry magnates such as Mukesh Ambani and Ratan Tata should loosen their purse strings,” he said here on Saturday.

They after all “reap the fruits of science,” Prof. Rao said during a question-and-answer session organised by Bangalore Press Club.

Over 50 per cent of research funding in the United States, Japan and South Korea, comes from industry, he said. Prof. Rao reiterated that the government investment in science should be increased from 0.9 per cent to 2 per cent of the gross domestic product.

“Only countries that have advanced in science actually have made significant progress,” Prof. Rao said, adding that India was “lagging behind in innovation.”

He said the quality of science in India wasn’t good, and it was reflected in the fact that “of the top 1 per cent of global research, India’s contribution is less than 1 per cent… the USA’s contribution is 63 per cent.” However, Prof. Rao pointed out that India fared rather well in terms of salaries for scientists.

“India is number 3 in the world for salaries to scientists.”

While he said around 150 PhD students work under him, in the last 15 years, “none of them are from Bangalore”. “Most of my students [at the Jawaharlal Nehru Centre for Advanced Scientific Research] are from West Bengal, Andhra Pradesh and Kerala.”

Young people appear to choose banking, business and Information Technology over science, he said, adding that while he was “not against IT”, he believed that “other sectors should not be denied bright talent.” While everyone still knows Bangalore as ‘IT city’… they should begin seeing it ‘science city’.

Copyright© 2013, The Hindu

Chemists show life on Earth was not a fluke

October 24, 2013

Updated: October 24, 2013 19:01 IST

Andrew Bissette, University of Oxford

In them, began life.

How life came about from inanimate sets of chemicals is still a mystery. While we may never be certain which chemicals existed on prebiotic Earth, we can study the biomolecules we have today to give us clues about what happened three billion years ago.

Now scientists have used a set of these biomolecules to show one way in which life might have started. They found that these molecular machines, which exist in living cells today, don’t do much on their own. But as soon as they add fatty chemicals, which form a primitive version of a cell membrane, it got the chemicals close enough to react in a highly specific manner.

This form of self-organisation is remarkable, and figuring out how it happens may hold the key to understanding life on earth formed and perhaps how it might form on other planets.

The 1987 Nobel Prize in Chemistry was given to chemists for showing how complex molecules can perform very precise functions. One of the behaviours of these molecules is called self-organisation, where different chemicals come together because of the many forces acting on them and become a molecular machine capable of even more complex tasks. Each living cell is full of these molecular machines.

Pasquale Stano at the University of Roma Tre and his colleagues were interested in using this knowledge to probe the origins of life. To make things simple, they chose an assembly that produces proteins. This assembly consists of 83 different molecules including DNA, which was programmed to produce a special green fluorescent protein (GFP) that could be observed under a confocal microscope.

The assembly can only produce proteins when its molecules are close enough together to react with each other. When the assembly is diluted with water, they can no longer react. This is one reason that the insides of living cells are very crowded, concentrated places: to allow the chemistry of life to work.

In order to recreate this molecular crowding, Stano added a chemical called POPC to the dilute solution. Fatty molecules such as POPC do not mix with water, and when placed into water they automatically form liposomes. These have a very similar structure to the membranes of living cells and are widely used to study the evolution of cells.

Stano reports in the journal Angewandte Chemie that many of these liposomes trapped some molecules of the assembly. But remarkably, five in every 1,000 such liposomes had all 83 of the molecules needed to produce a protein. These liposomes produced large amount of GFP and glowed green under a microscope.

Computer calculations reveal that even by chance, five liposomes in 1,000 could not have trapped all 83 molecules of the assembly. Their calculated probability for even one such liposome to form is essentially zero. The fact that any such liposomes formed and that GFP was produced means something quite unique is happening.

Stano and his colleagues do not yet understand why this happened. It may yet be a random process that a better statistical model will explain. It may be that these particular molecules are suited to this kind of self-organisation because they are already highly evolved. An important next step is to see if similar, but less complex, molecules are also capable of this feat.

Regardless of the limitations, Stano’s experiment has shown for the first time that self-assembly into simple cells may be an inevitable physical process. Finding out how exactly this self-assembly happens will mean taking a big step towards understanding how life was formed.

Andrew Bissette does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

This article was originally published at The Conversation. Read the original article.

RNA Controls Splicing During Gene Expression, Further Evidence of 'RNA World' Origin in Modern Life

 

Nov. 6, 2013 — RNA is the key functional component of spliceosomes, molecular machines that control how genes are expressed, report scientists from the University of Chicago online, Nov. 6 in Nature. The discovery establishes that RNA, not protein, is responsible for catalyzing this fundamental biological process and enriches the hypothesis that life on earth began in a world based solely on RNA.

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Ribonucleic acid (RNA) is a molecule similar to DNA. Unlike DNA, RNA is single-stranded. An RNA strand has a backbone made of alternating sugar (ribose) and phosphate groups. Attached to each sugar is one of four bases--adenine (A), uracil (U), cytosine (C), or guanine (G). Different types of RNA exist in the cell: messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA). More recently, some small RNAs have been found to be involved in regulating gene expression. (Credit: Darryl Leja, NHGRI)

"Two of the three major processes in eukaryotic gene expression -- splicing and translation -- are now shown to be catalyzed by RNA," said Jonathan Staley, PhD, associate professor of molecular genetics and cell biology at the University of Chicago and co-corresponding author on the study. "The eukaryotic gene expression pathway is more of an RNA-based pathway than protein-based."

For genes to be expressed, DNA must be translated into proteins, the structural and functional molecules that catalyze chemical reactions necessary for life. To do so, genetic information stored in DNA is first copied into strands of messenger RNA (mRNA), which are subsequently used to create proteins.

In eukaryotes, almost all genes undergo alternative splicing, in which a precursor form of mRNA is cut and re-stitched together in numerous different combinations. This significantly increases the number of proteins a single gene codes for, and is thought to explain much of the complexity in higher-order organisms. Splicing is a critical biological mechanism -- at least 15 percent of all human diseases are due to splicing errors, for example.

Spliceosomes, made from proteins and short, noncoding RNA fragments, carry out splicing via catalysis, which in biological processes is usually attributed to protein-based enzymes. However, previous research has hinted that RNA in the spliceosome might be responsible. Despite decades of study, this question has thus far remained unanswered.

To address this, Staley and Joseph Piccirilli, PhD, professor of biochemistry and molecular biology and chemistry at the University of Chicago, partnered with graduate students Sebastian Fica and Nicole Tuttle, co-lead authors on the study.

The researchers first disabled the ability of the spliceosome to self-correct errors in splicing. They then modified single atoms at sites on mRNA precursors known to be cut during splicing, as well as several on U6, an RNA subunit of the spliceosome hypothesized to be important for catalysis. Some of these modifications rendered splicing ineffective. They went through and systematically rescued this loss-of function, investigating sites individually and in combination. This allowed them to hone in on locations critical to splicing function and to identify connections between U6 and mRNA precursors.

The team found that the U6 RNA subunit directly controls catalytic function -- effectively acting as the blade of the spliceosome. This is the first experimental proof that RNA is the key functional component of this critical biological mechanism.

They also found remarkable similarities in structure and function between spliceosome RNAs and group II introns, an evolutionarily-ancient class of self-splicing, catalytic RNA found in all major branches of life. They believe this indicates that these two RNA-based splicing catalysts share a common evolutionary origin, providing further evidence that key modern RNA-protein complexes, including the spliceosome and the ribosome, evolved from an RNA world.

"In modern life, protein enzymes catalyze most biological reactions," Piccirilli said. "The finding that a system like the spliceosome, which contains more protein than RNA, uses RNA for catalysis and has a molecular ancestor composed entirely of RNA suggests that the spliceosome's reaction center may be a molecular fossil from the 'RNA World.'"

 

RNA Controls Splicing: Implications for Origin of Life on Earth

RNA is a crucial part of life and now, scientists have discovered a little bit more about its importance. It turns out that RNA is the key functional component of spliceosomes, molecular machines that control how genes are expressed. The findings point to the hypothesis that life on Earth began in a world based solely on RNA. (Photo : AFTA)

RNA is a crucial part of life and now, scientists have discovered a little bit more about its importance. It turns out that RNA is the key functional component of spliceosomes, molecular machines that control how genes are expressed. The finding establishes that RNA and not protein is responsible for catalyzing this fundamental biological process. Not only that, it points to the hypothesis that life on Earth began in a world based solely on RNA.

For genes to be expressed, DNA must be translated into proteins, the structural and functional molecules that catalyze chemical reactions necessary for life. In order to do so, genetic information stored in DNA is first copied into strands of messenger RNA (mRNA) which are then used to create proteins.

In eukaryotes, almost all genes undergo alternative slicing. This process involves a prescursor form of mRNA being cut and re-stitched together in numerous different combinations. This increases the number of proteins a single gene codes for and could explain much of the complexity in higher-order organisms.

Spliceosomes, made from proteins and short, noncoding RNA fragments, actually carry out splicing via catalysts. However, previous research has hinted that RNA in the spliceosome might be responsible. In order to find out whether or not this is true, though, researchers decided to investigate a bit further.

The scientists first disabled the ability of spliceosomes to self-correct errors in splicing. They then modified single atoms at sites on mRNA precursors known to be cut during splicing, as well as several on U6, an RNA subunit of the spliceosome hypothesized to be important for catalysis. Some of these modifications rendered splicing to be ineffective. After systematically rescuing this loss-of function, the researchers were able to hone in on locations critical to splicing function.

In the end, the scientists found that the U6 RNA subunit directly controls catalytic function. It effectively acts as the blade of the spliceosome. This particular finding is the first experimental proof that RNA is the key functional component of this critical biological mechanism.

"In modern life, protein enzymes catalyze most biological reactions," said Joseph Piccirilli, one of the researchers, in a news release. "The finding that a system like the spliceosome, which contains more protein than RNA, uses RNA for catalysis and has a molecular ancestor composed entirely of RNA suggests that the spliceosome's reaction center may be a molecular fossil from the 'RNA World.'"

The findings are published in the journal Nature.

Quest for self-replicating RNA edges closer to life’s possible origin

RNA can't copy itself, but can copy over 200 bases of other RNAs.

by John Timmer - Oct 25 2013, 10:00pm IST

The discovery of nucleic acid molecules that can catalyze chemical reactions has revolutionized thinking about the origin of life. These catalytic RNAs, called ribozymes, showed that a single molecule could embody two of the major aspects of life: genetic information and chemical activity. They also raised the intriguing possibility that it might be possible to find an RNA molecule that could copy itself. After all, once you have a single self-duplicating molecule, you would quickly end up with a large collection of self-duplicating molecules competing for resources. Evolution would be off and running.

So far, though, efforts to make a self-replicating ribozyme have come up short. Most RNA molecules with this sort of activity have been around 200 bases long and have tended to stall before copying more than a few dozen bases. But now, scientists have produced the first molecule that can copy RNAs longer than itself. The scientists found it by selecting for RNAs that work in conditions that are normally the death of biochemical activity: sub-zero mixtures of ice and water.

Makin’ copies

The path to a potential self-replicating RNA has, so far at least, been a bit convoluted. Starting with a collection of RNA molecules with random sequences, researchers come up with a ribozyme that could link two RNAs together (termed a ligase). Rounds of mutation meant to improve that activity succeeded in doing so, but they also popped out a different class of molecules entirely; they could make copies of a specific group of short sequences. Further experiments with mutation and selection made these catalytic RNAs work more generally and extended the molecules they could copy to longer sequences. But the RNAs themselves were over 200 bases long, and they tended to fall short of copying molecules that were much smaller than that.

The Cambridge researchers behind the new paper noticed something unusual. Although this catalytic RNA was originally evolved to work at room temperature, it worked even better on ice. Ice tends to slow down reactions, but partly freezing a solution will cause the remaining salts and RNA to concentrate in the gaps between the frozen ice. A network of water-filled crevices tends to form, and the water within them stays liquid to well below 0°C, giving the ribozymes something to work with. (Environments like this currently exist in polar regions.)

If the ribozyme worked well on ice as-is, the authors reasoned that it would work even better with a chance to adapt to the cold environment. So they subjected the ribozyme to a few rounds of mutation, followed by selection for its ability to copy RNA molecules in an icy environment. The RNA they produced this way not only worked better in the cold environment, but it was more active in all conditions tested, including in temperatures up to 27°C.

That increased activity produced the ability to copy longer RNA molecules for the first time. In fact, the paper's authors were able to get their ribozyme to copy one that was 206 bases long, while the RNA that did the copying was only 202 bases long.

It's great progress, but the result still comes far short of a molecule that can copy itself. For one thing, the ribozyme tended to stop short of the end of the molecule it was copying, mostly because the two fell out of contact. The authors could tether the two RNA molecules (the ribozyme and the template it was copying) together, which improved matters but didn't solve the problem entirely. The second problem was the fact that the molecule being copied folded over and formed base pairs with itself, which prevented the ribozyme from copying through the folded structure.

This creates a serious problem since the activity of the ribozyme depends on it being able to fold into a three-dimensional structure—which creates a bit of a chicken-and-egg problem for making a self-replicating ribozyme.

The authors suggest that the way around this issue might be to make the molecule even longer. If they could find a ribozyme that disrupts these folds, it might be possible to link it to the one that does the copying. Combined, the two may be able to work their way through copies of even large molecules. Ultimately, this could be the route to building the first self-copying genetic molecule.

Nature Chemistry, 2013. DOI: 10.1038/NCHEM.1781  (About DOIs).

 

Science News

... from universities, journals, and other research organizations

 

Scientists Solve Major Piece in the Origin of Biological Complexity

Nov. 6, 2013 — Scientists have puzzled for centuries over how and why multicellular organisms evolved the almost universal trait of using single cells, such as eggs and sperm, to reproduce. Now researchers led by University of Minnesota College of Biological Sciences postdoctoral fellow William Ratcliff and associate professor Michael Travisano have set a big piece of that puzzle into place by applying experimental evolution to transform a single-celled algae into a multicellular one that reproduces by dispersing single cells.

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"Understanding the origins of biological complexity is one of the biggest challenges in science," Travisano said. "In this experiment we've reordered one of the first steps in the origin of multicellularity, showing that two key evolutionary steps can occur far faster than previously anticipated." (Credit: © abhijith3747 / Fotolia)

"Until now, biologists have assumed that this single-cell bottleneck evolved well after multicellularity, as a mechanism to reduce conflicts of interest among the cells making up the organism," says Ratcliff. "Instead, we found that it arose at the same time as multicellularity. This has big implications for how multicellular complexity might arise in nature, because it shows that this key trait, which opens the door to evolving greater multicellular complexity, can evolve rapidly."

In an article published today in the journal Nature Communications, the researchers described how they produced the multi-celled strain by repeatedly selecting and culturing algae that settled quickly to the bottom of a liquid-filled test tube. After 73 rounds, they discovered that the algae in one of the tubes had gone multicellular.

Observing the new form, Ratcliff and Travisano discovered that it reproduced by actively breaking up, shedding motile single cells that go on to grow into new multicellular clusters. They developed a mathematical model that explained the reproductive benefit of this single-celled strategy over hypothetical alternatives in which the cluster would produce larger propagules. The model predicted that reproduction from single cells would be more successful in the long run. Even though single cells are less likely to survive than larger propagules, this disadvantage is more than made up for by their sheer number.

In collaboration with Matthew Herron and Frank Rosenzweig at the University of Montana, the researchers are now working to find the genetic basis for multicellularity and experimentally evolve even greater multicellular complexity.

"Understanding the origins of biological complexity is one of the biggest challenges in science," Travisano said. "In this experiment we've reordered one of the first steps in the origin of multicellularity, showing that two key evolutionary steps can occur far faster than previously anticipated. Looking forward, we hope to directly investigate the origins of developmental complexity, or how juveniles become adults, using the multicellular organisms that we evolved in the lab."

Several years ago, Travisano and Ratcliff made international news when they evolved multicellularity in yeast. This work takes those findings further by initiating multicellularity in an organism that has never had a multicellular ancestor and provides a new hypothesis for the evolutionary origins of the single-cell bottleneck in multicellular life cycles.

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Story Source:

The above story is based on materials provided by University of Minnesota.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. William C. Ratcliff, Matthew D. Herron, Kathryn Howell, Jennifer T. Pentz, Frank Rosenzweig, Michael Travisano. Experimental evolution of an alternating uni- and multicellular life cycle in Chlamydomonas reinhardtii. Nature Communications, 2013; 4 DOI: 10.1038/ncomms3742

 

Texas Researcher Explains Evolution of Life

By Staff Reporter

Oct 30, 2013 09:23 AM EDT

(Photo : wikimedia creative commons)

Texas Tech University researcher says that meteorites that hit early earth kick-started life and complex forms took birth in the deep craters formed by the impact.

Origin of life on earth is a mystery that still baffles science. Many theories have been proposed to explain the origins of biological forms. However, none of them independently explain the start of life.  

Now, Sankar Chatterjee, Horn Professor of Geosciences and curator of paleontology at the Museum of Texas Tech University, says that he has connected the dots and found how life may have originated.

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The idea of life coming from elsewhere isn't new. For decades, it has been hypothesized that life might have originated at some other place in the Universe and accidently landed on Earth.

Ancient craters on Venus and Mars describe the struggle that the planets had to go through during their infant years.

Chatterjee's research suggests meteorites got the essential ingredients to life-building from the distant corners of the Universe.

"When the Earth formed some 4.5 billion years ago, it was a sterile planet inhospitable to living organisms," Chatterjee said in a news release. "It was a seething cauldron of erupting volcanoes, raining meteors and hot, noxious gasses. One billion years later, it was a placid, watery planet teeming with microbial life - the ancestors to all living things."

According to Chatterjee, life began in four steps. It went from cosmic,  geological, chemical and arrived at its biological state.

The Cosmic Stage-

Between 4.1 to 3.8 billion years ago, earth was pounded daily by large meterorites. These rocks punched holes in the crust and created geothermal vents. Also, essential life ingredients from other parts of the Universe arrived on earth via these meteorites.

Recently, astronomers have found asteroids could even act as water-delivery systems.

Chaterjee studied fossil-rocks in Greenland, Australia and South Africa and believes that these might have been the places where life first appeared.

The Geological Stage-

Icy comets that came to earth melted due to earth's perfect proximity to the sun. The geothermal vents then heated these water-filled craters and created a thick primordial soup.

"The geological stage provides special dark, hot, and isolated environments of the crater basins with the hydrothermal vent systems that served as incubators for life," he said. "Segregation and concentration of organic molecules by convective currents took place here, something like the kinds we find on the ocean floor, but still very different. It was a bizarre and isolated world that would seem like a vision of hell with the foul smells of hydrogen sulfide, methane, nitric oxide and steam that provided life-sustaining energy."

The Chemical and Biological Stage-

In this stage, the chemicals in the water reacted and formed simple organic molecules.

One can create organic molecules in the lab, but not life. Chaterjee said that the ancient soup had a key biological ingredient- fatty lipid material, which came to earth on space body. Complex biological forms that had the ability to replicate underwent many trials and errors.

"The emergence of the first cells on the early Earth was the culmination of a long history of prior chemical, geological and cosmic processes," he said. 

© Copyright 2013 Nature World News. All Rights Reserved.

ndian-origin scientist reveals 'how life began on Earth more than 3.8 billion years ago'

Sunday, Nov 3, 2013, 12:03 IST | Place: Washington, DC | Agency: ANI

He believes that meteorites deposited organic materials in them and then icy comets that crashed into Earth melted, and filled them with water.

Indian-origin paleontologist, Dr. Sankar Chatterjee, believes that he has found the answer to the question about how life on Earth began more than 3.8 billion years ago.

Chatterjee, a professor of geoscience at Texas Tech University and curator of paleontology at the Museum Of Texas Tech University argues that in addition to bringing water and the chemical constituents of life, asteroids and meteors made impact craters that became “crucibles” in which chemical reactions that ultimately gave rise to living cells took place, the Huffington Post reported.

He believes that meteorites deposited organic materials in them and then icy comets that crashed into Earth melted, and filled them with water.

He said that additional meteorite strikes made volcanically driven geothermal vents in the Earth’s crust that heated and stirred the water.

The “primordial soup” then mixed the chemicals together and led to the formation of molecules of ever increasing complexity — and eventually life.

To arrive at this result, Chatterjee studied sites that contained world’s oldest fossils in Greenland, Australia, and South Africa.

Washington, November 4, 2013

Updated: November 4, 2013 02:27 IST

India-origin scientist explains how life began on earth

PTI

Dr. Sankar Chatterjee. Picture courtesy: Texas Tech University

Palaeontologist Sankar Chatterjee claims he has found the answer to how life began on earth

An Indian-origin scientist claims to have solved the mystery of how life on earth exactly began about 4 billion years ago after studying three sites containing the world’s oldest fossils.

According to Sankar Chatterjee, a Texas Tech University palaeontologist, meteorite bombardment left large craters on earth that contained water and chemical building blocks for life, which ultimately led to the first organisms.

How life began on earth has baffled humans for millennia.

Dr. Chatterjee, who was born in Kolkata, believes he has found the answer by connecting theories on chemical evolution with evidence related to our planet’s early geology. “This is bigger than finding any dinosaur. This is what we have all searched for — the Holy Grail of science,” he said.

Thanks to regular and heavy comet and meteorite bombardment of earth’s surface during its formative years 4 billion years ago, the large craters left behind not only contained water and the basic chemical building blocks for life, but also became the perfect crucible to concentrate and cook these chemicals to create the first simple organisms. Dr. Chatterjee’s research suggests meteorites can be givers of life as well as takers. He said it was likely that meteor and comet strikes brought the ingredients and created the right conditions for life on our planet.

By studying three sites containing the world’s oldest fossils, he believes he knows how the first single-celled organisms formed in hydrothermal crater basins. “When the earth formed some 4.5 billion years ago, it was a sterile planet inhospitable to living organisms,” Dr. Chatterjee said, going on to add: “It was a seething cauldron of erupting volcanoes, raining meteors and hot, noxious gasses. One billion years later, it was a placid, watery planet teeming with microbial life — the ancestors to all living things.”

Dr. Chatterjee presented his findings at the Annual Meeting of the Geological Society of America in Denver.