The smallest dog on the planet has been cloned a record-breaking 49 times – making her a two-time world record holder.

Scientists have created 49 genetically-identical dogs based on genes from the tiny Chihuahua, known as 'Miracle Milly'.

The six-year-old pup was replicated by scientists hoping to unearth the genetic code behind her tiny stature.

'Miracle Milly' purportedly weighed less than an ounce at birth, and could curl up inside the head of a teaspoon, leading vets to speculate she would not survive.

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The world's smallest dog has now been cloned 49 times by scientists hoping to discover the genetic code behind her tiny stature. The genetically identical versions of 'Miracle Milly' have given her a second World record

The six-year-old dog has been replicated 49 times by scientists who are hoping to discover genes that explain why she is so small

However, the tiny dog has gone on to thrive, thanks to loving mum Vanesa Semler, 38, of Kissimmee, Florida, who fed the puppy every two hours using an eyedropper.

Since 2012, Miracle Milly was awarded the Guinness World Record for Smallest Living Dog, standing at less than 10cm (3.8in) tall and weighing just over a pound – the same as a large apple.

Her minuscule measurements led to worldwide adoration.

Researchers at the Sooam Biotech Research Foundation in Seoul, Korea approached Ms Semler to clone the dog to try and determine the genetic code behind her size.

To carry this out, scientists extracted cells from Milly and used the nucleus, which holds her genetic information, which was then transplanted to a donor egg cell.

From there, the developing embryo was placed into a surrogate mother who would give birth to the pups – in a process similar to the 1996 Dolly the sheep experiment.

HOW WAS DOLLY THE SHEEP CREATED? Dolly was the only surviving lamb from 277 cloning attempts and was created from a mammary cell taken from a six-year-old Finn Dorset sheep. She was created in 1996 at a laboratory in Edinburgh using a technique called somatic cell nuclear transfer (SCNT). The pioneering technique involved transferring the nucleus of an adult cell into an unfertilised egg cell whose own nucleus had been removed. Dolly the sheep made history 20 years ago after being cloned at the Roslin Institute in Edinburgh. Pictured is Dolly in 2002 An electric shock stimulated the hybrid cell to begin dividing and generate an embryo, which was then implanted into the womb of a surrogate mother. Dolly was the first successfully produced clone from a cell taken from an adult mammal. Dolly's creation showed that genes in the nucleus of a mature cell are still able to revert back to an embryonic totipotent state - meaning the cell can divide to produce all of the difference cells in an animal. Advertisement

Since 2012, Miracle Milly has held the Guinness World Record for Smallest Living Dog, standing at less than 10cm (3.8in) tall and weighing just over a pound - the same as a large apple

It is claimed at birth she weighed less than an ounce and could fit into a teaspoon. Last month, the family received the accolade for 'Most Cloned Dog' by The Academy Of World Records

Her minuscule measurements led to worldwide adoration and for Ms Semler to be approached by Sooam Biotech Research Foundation in Seoul, Korea who wanted to clone the dog. The process is similar to the 1996 Dolly the sheep experiment

To carry the process out, scientists extracted cells from Milly and used the nucleus, which holds her genetic information, was then transplanted to a donor egg cell. From there, the developing embryo was placed into a surrogate mother who would give birth to the pups

In August last year, the first litter of Milly's clones were born.

All 12 of the doggie doppelgangers now live with the Semler family, who have named the Milly clones: Molly, Mally, Melly, Molly, Mumu, Mila, Mary, Mimi, Moni, Mini, Mela and Mulan.

According to their owners, the pups have exactly the same personalities and looks, however, some are slightly bigger than Miracle Milly.

Last month, the family received the accolade for 'Most Cloned Dog' by The Academy Of World Records.

Mr Semler, who works as a Chihuahua breeder, said: 'Miracle Milly is the actual World Record Holder for the Smallest Living dog from 2012-2018 and now she's the most cloned dog with more than 49 clones.

'The original idea was to make ten clones in total, nine for research and one for us, but they decided to clone her more times.

MIRACLE MILLY FACT FILE BORN -December 2011 BREED - Chihuahua BIRTH WEIGHT - less than one ounce CURRENT AGE - Six years old CURRENT WEIGHT - 1.2 pounds CURRENT HEIGHT - 3.8 inches Advertisement

'She was chosen for being the smallest dog in the world. They want to find out why she was so small and then study her genes to find out what makes her so tiny.

'It's amazing to be around all of her clones, they are so smart, very playful like Milly and have really similar personalities. We love them, they are all our babies. But it's a lot of hard work having 12 clones of Milly.

'The clones all look like her, but they aren't her, they are slightly different in size.

'They are sweet and loving, but Milly is unique, while they have the same eyes and markings on their coats, in my opinion you could never reproduce her.'

When Milly was born in Dorado, Puerto Rico, in 2011, she was so tiny it was thought she wouldn't survive.

Fortunately, doting mum Ms Semler would feed her milk every two hours with an eyedropper to ensure she survived.

While they knew the family was small, it was only while watching a news report that they realised Milly was a contender for the World Record.

When Milly was born in Dorado, Puerto Rico, in 2011, she was so tiny it was believed she wouldn't survive

Mr Semler, a certified Chihuahua Breeder (pictured), said: 'Miracle Milly is the actual World Record Holder for the Smallest Living dog from 2012-2018 and now she's the most cloned dog with more than 49 clones'

In August last year, Milly's clones were born and now 12 of the doggie doppelgangers live with the Semler family. Named: Molly, Mally, Melly, Molly, Mumu, Mila, Mary, Mimi, Moni, Mini, Mela and Mulan, they have identical personalities and looks apart from a few being slightly bigger

Ms Semler said: 'She was really small and was so tiny she could fit onto a teaspoon.

'We saw this puppy on TV who was competing for the Guinness World Record who was four times bigger than Milly. I did an interview about her that went all around the world and then Guinness contacted me.'

Since then, she's become an internet sensation, with several trips internationally and more than 300,000 followers online.

Ms Semler said: 'She travels around the world for shows and everything else, she's been to China, Thailand, everywhere.

'It's nice a lot of people want to know how she is doing, what she is eating and how she is feeding.'

One standout feature is her personality, according to Ms Semler, who believes Miracle Milly does not know she is a dog.

Ms Semler added: 'We believe she has no idea she is a dog, because she never barks and only cries when she wants something. She is like our baby child.

'She only eats fresh chicken and salmon, she tells me if she doesn't like anything by not eating it. You have to change her food to whatever she wants, everyday it's something different.

'We call her a diva because while being filmed, when she was hungry she would turn her back on the camera and start crying.

WHAT IS CLONING AND COULD WE ONE DAY CLONE HUMANS? What is cloning? Cloning describes several different processes that can be used to produce genetically identical copies of a plant or animal. In its most basic form, cloning works by taking an organism's DNA and copying it to another place. There are three different types of artificial cloning: Gene cloning, reproductive cloning and therapeutic cloning. Gene cloning creates copies of genes or parts of DNA. Reproductive cloning creates copies of whole animals. Therapeutic cloning produces embryonic stem cells for tests aimed at creating tissues to replace injured or diseased tissues. To create somatic cell nuclear transfer (SCNT) clones, scientists take DNA (red circle) from tissue and insert it into egg cells (yellow) with their DNA (green) removed. The scientists then switch on or off certain genes to help the cells replicate (right) Dolly the Sheep was cloned in 1996 using a reproductive cloning process known as somatic cell nuclear transfer (SCNT). This takes a somatic cell, such as a skin cell, and moves its DNA to an egg cell with its nucleus removed. Another more recent method of cloning uses Induced pluripotent stem cells (iPSC). iPSCs are skin or blood cells that have been reprogrammed back into an embryonic-like state. This allows scientists to design them into any type of cell needed. Could we ever clone a human? Currently there is no scientific evidence that human embryos can be cloned. In 1998, South Korean scientists claimed to have successfully cloned a human embryo, but said the experiment was interrupted when the clone was just a group of four cells. In 2002, Clonaid, part of a religious group that believes humans were created by extraterrestrials, held a news conference to announce the birth of what it claimed to be the first cloned human, a girl named Eve. This was widely dismissed as a publicity stunt. In 2004, a group led by Woo-Suk Hwang of Seoul National University in South Korea published a paper in the journal Science in which it claimed to have created a cloned human embryo in a test tube. Gene cloning creates copies of genes or parts of DNA. Reproductive cloning creates copies of whole animals (stock image) In 2006 that paper was retracted. According to the National Human Genome Research Institute, from a technical perspective cloning humans is extremley difficult. 'One reason is that two proteins essential to cell division, known as spindle proteins, are located very close to the chromosomes in primate eggs,' it writes. 'Consequently, removal of the egg's nucleus to make room for the donor nucleus also removes the spindle proteins, interfering with cell division.' The group explains that in other mammals, such as cats, rabbits and mice, the two spindle proteins are spread throughout the egg. Advertisement

Soaam Biotech Research Foundation is a biotech lab offering people the chance to clone their pets for £75,600 ($100,000) - even able to extract cells from dead pets

'After we fed her she started playing and doing tricks for the camera again. She's so funny, she tells you exactly what she wants.'

Despite her diminutive appearance, Milly miraculously has no health problems and has managed to stay out of harm's way.

Ms Semler added: 'At first her getting hurt was my biggest concern, but the longer she has lived the less I worry.

'She's a really smart dog, she never runs around and instead waits for you to pick her up. I'm more worried about other people..'

Soaam Biotech Research Foundation is a biotech lab offering people the chance to clone their pets for £75,600 ($100,000) - even able to extract cells from dead pets.

David Kim, from the Soaam, said: 'We will be working together with the Director as well as four specialists from the world renown Beijing Genomics Institute (BGI) as well as other collaborating scientists to characterize the genetic and epi-genetic factors of the of the cloned Milly and the original Milly.

'The research data will be analysed to prepare to publish a scientific article.'