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کشف بزرگترين ويروس جهان و احتمال آمدن آن از سياره مريخ

 محققان فرانسوی موفق به کشف بزرگترین ویروس جهان به طول یک میکرومتر شده‌اند که دو برابر اندازه مگاویروس است.مگاویروس به طول 440 نانومتر پیش از این، عنوان بزرگترین ویروس جهان را از آن خود کرده بود، اما محققان گونه جدید ویروس موسوم به «پاندورا ویروس» را در سواحل شیلی و استرالیا کشف کرده اند.

 پاندورا ویروس (Pandoravirus) اندازه‌ای دو برابر مگاویروس داشته و دارای کد ژنتیکی عجیبی است که در هیچ نمونه دیگری تاکنون مشاهده نشده است.دکتر «ژان میشل کلاور» از محققان دانشگاه اکس مارسی با بررسی نشانه هایی از پاندورا ویروس در آب های مناطق ساحلی شیلی و استرالیا، موفق به کشف این ویروس شده است.بدلیل اندازه بزرگ و شکل غیر معمول این ویروس، در تحقیقات قبلی از آن بعنوان باکتری کوچک تر از حد معمول یاد شده بود.

نمونه‌های جمع‌آوری شده از سواحل شیلی و ملبورن استرالیا در محلول آنتی بیوتیک برای کشتن هرگونه باکتری و سپس نمونه فاقد باکتری در معرض آمیب‌ها قرار داده شدند و زمانی که همه نمونه ها از بین رفتند، محققان دریافتند که آنها چیزی بجز باکتری هستند.

مقادیر زیاد پاندورا ویروس فاقد شباهت موفولوژیکی یا ژنومی با گونه های شناخته شده ویروس هستند و این ویروس زیر آبی تاکنون باعث انتشار هیچگونه بیماری در جهان نشده است.

به گفته دانشمندان، این ویروس نوع سلولی اجدادی جدیدی محسوب می شود که دیگر وجود نداشته و فرضیه هایی در خصوص احتمال تعلق آن به دیگر سیارات از جمله مریخ مطرح شده است.

نتایج این کشف در مجله Science منتشر شده است.

منبع : en.gadgetnews.ir

 

Never-before-seen GIANT virus found that's so unusual it may have come from Mars

The Pandoravirus is one micrometre big – ten times the size of other viruses
It is found underwater but is not considered a threat to humans
The virus has been spotted off the coast of Chile and in an Australian pond
Only six per cent of its genes resemble those seen before on Earth

Scientists have found a new virus thought to be the biggest ever seen on Earth. The virus, dubbed Pandoravirus, is one micrometre big – up to ten times the size of other viruses – and only six per cent of its genes resemble anything seen on Earth before. This has led French researchers to believe the virus may have come from an ancient time or even another planet, such as Mars.

Scientists have found a new virus, Pandoravirus (pictured), which is the biggest ever seen on Earth. It is found underwater and is not thought to pose a serious risk to humans
The giant virus is only found underwater and is not thought to pose a serious risk to humans.
However, the researchers, who published their findings in the journal Science, believe that the virus opens up a range of questions about the history of life on Earth.
Dr Jean-Michel Claverie of Aix-Marseille University in France, who found the virus, told NPR: ‘We believe that these new Pandoraviruses have emerged from a new ancestral cellular type that no longer exists.’
Many traditional viruses range in size from around 10 nanometres (nm) to around 500nm.
The Pandoravirus is around one micrometre big and there are 1,000nm in a micrometre.
This means the Pandoravirus is big enough to be seen under the most basic microscopes.
Dr Claverie explained that because the virus is very big and lacks the regular shape normally associated with viruses, he initially thought it was a small bacterium.
His team went on a hunt for giant viruses after a survey identified signs of them in seawater.
The scientists who found the Pandoravirus believe that it could have originated on Mars. Only six per cent of its genes resemble genes seen before in other organisms on Earth
They took sediment samples from the coast off Chile and from a pond in Australia.
They took the samples to their laboratory and put them in a solution packed with antibiotics in an attempt to kill any bacteria present.
he Megavirus, pictured, was previously thought to have been the biggest virus on Earth at 440nm – half the size of the new Pandoravirus
The Megavirus, pictured, was previously thought to have been the biggest virus on Earth at 440nm – half the size of the new Pandoravirus
These bacteria-free samples were then exposed to amoebas knowing that if they died, there must be something else in the samples killing them.
This proved to be successful and large amounts of Pandoravirus were spawned.
When the team studied them they found that their genetic code was twice the size of the Megavirus, which was previously the biggest virus ever found at around 440nm.
However, they were in for more of a shock as only six per cent of its genes resembled genes seen before in other organisms on Earth.
Dr Claverie told NPR: ‘We believe that those new Pandoraviruses have emerged from a new ancestral cellular type that no longer exists.’
He went on to explain that it is possible that they have come from another planet, such as Mars.
The researchers do not yet know why this cellular form became a virus but they speculate that it could have evolved as a survival strategy.
Alternatively, its unusual genome could have developed as a result of it picking up genetic material from its hosts.
the researchers say that they now expect to find more giant viruses.

 

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