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11/08/2016, 09:00

Scientists have found the origin of HIV

More than 35 million people worldwide are living with HIV, yet little is known about the disease’s evolutionary history and origin.

Until recently, the oldest known lentiviruses – the family from which HIV belongs – were thought to date back to 12 million years ago.

But new research into lemurs suggests that lentivruses may have emerged as early as 60 million years ago.

New research into lemurs suggests that lentivruses may have emerged as early as 60 million years ago. The research, from the Czech Academy of Sciences, used genetic data from the Malayan flying lemur

Lentiviruses come from around nine evolutionary branches, and affect a range of animals, including primates, cats and horses.

Dr Elleder explained: ‘Classical viruses, including lentiviruses, evolve very fast, because they have very high mutation.

‘For example, in the case of HIV, scientists can tell apart samples that originated in the 1980s and 1950s.’

However, the lentivirus found in this study was endogenous, meaning it inserts itself into the DNA and passes between generations. 

This means it has a much smaller rate of change, which allowed the researchers to reconstruct how they might have looked tens of millions of years ago.

The research, from the Czech Academy of Sciences, used genetic data from the Malayan flying lemur.

The researchers looked at three samples of ancient genetic data, which revealed that lentiviruses may have originated as early as 60 million years ago.

Lentiviruses are slow viruses with long incubation periods that cause a wide range of diseases in different animal species.

Dr Daniel Elleder, who led the study, told MailOnline: ‘We first found evidence of this lentivirus by a computational screen of all available animal genomes.

‘To our surprise, the resulting age (40-60 millions of years) was much higher than all the three previously known lentiviruses.’

Lentiviruses come from around nine evolutionary branches, and affect a range of animals, including primates, cats and horses.

Lentiviruses come from around nine evolutionary branches, and affect a range of animals, including primates, cats and horses. Pictured, an artwork of a HIV cell in the blood

Dr Elleder explained: ‘Classical viruses, including lentiviruses, evolve very fast, because they have very high mutation.

‘For example, in the case of HIV, scientists can tell apart samples that originated in the 1980s and 1950s.’

However, the lentivirus found in this study was endogenous, meaning it inserts itself into the DNA and passes between generations. 

This means it has a much smaller rate of change, which allowed the researchers to reconstruct how they might have looked tens of millions of years ago.

The findings were published in the journal Molecular Biology and Evolution.

In future studies, the team hopes to follow the timeline even deeper into the past by surveying a broad spectrum of animals, hoping to identify more pieces of the puzzle of lentivirus evolution.

In March this year, a study claimed HIV was also passed to humans from gorillas.

Two of the four known groups of viruses that cause the disease were traced back to the great apes that share about 98 per cent of their DNA with humans.

The connection was uncovered after researchers analysed faecal samples collected in remote forests.

They found HIV-1 groups known as 'O' and 'P' originated in western lowland gorillas. HIV-1 has jumped species to infect humans on at least four separate occasions, the research found.

It had been known simian immunodeficiency virus (SIV) - the monkey equivalent of HIV - had jumped from chimpanzees into humans, but now it seems gorillas in Cameroon also played a vital role. 

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