Tag Archives: hybrid

Scientists accidentally create the ‘Sturddlefish’: half sturgeon, half paddlefish

Two examples of sturddlefish hybrids. Credit: Attila Mozsar.

While they were investigating the possibility of breeding sturgeons and paddlefish in captivity, scientists accidentally created a hybrid of the two. The resulting hybrid, which I guess you could call a “Sturddlefish”, shares characteristics from both species

The Russian sturgeon and the American paddlefish have quite a few things in common. They’re both known as living fossils due to their ancient lineage and extremely slow rate of evolution. Unfortunately, both are also critically endangered.

Sturgeons can live for up to 100 years and do not reproduce annually, which means they take many years to recover from any population declines. This makes them extremely vulnerable to overfishing — and there’s plenty of that. Either legally or illegally, many people venture into the Caspian sea and other known sturgeon habitats on the prowl for their prized caviar, which can fetch up to $10,000/kg.

Paddlefish have a gray, shark-like body with a deeply forked tail, and a long, flat blade-like snout that resembles a kitchen spatula. Because both sturgeons and paddlefish belong to the same group of fish called Acipenseriforms, many turn to paddlefish caviar as a substitute for the sturgeon variety. Needless to say, this adds extra pressure on an endangered species that has been decimated by extensive commercial fishing and habitat loss.

Given two fish’s precarious status, researchers in Hungary used some alternative breeding techniques in order to see how the offspring of the two species would fair in captivity.

The researchers were experimenting with gynogenesis — an asexual form of reproduction that can produce offspring from eggs and sperm without the latter actually contributing any DNA — when they accidentally used untreated paddlefish sperm to fertilize a sturgeon egg. The American paddlefish sperm was meant to act as a control for the gynogenesis trial, but it turned into a new experiment in its own right.

Against all odds, the eggs hatched into hybridized fish. The sturddlefish was born.

Russian sturgeon (A), two hybrids (B, C), and the American paddlefish (D). Credit: Attila Mozsar.

Some of these hybrids looked more like sturgeons than paddlefish due to having twice as much maternal DNA. Those who had the same amount of maternal and paternal DNA had an equal mix of sturgeon and paddlefish features.

The researchers led by Attila Mozsár from the Research Institute for Fisheries and Aquaculture in Hungary described their findings in the journal Genes, writing that:

“This was the first successful hybridization between these two species and between members of the family Acipenseridae and Polyodontidae.”

The fertilization resulted in hundreds of hybrid eggs, most of which survived 30 days after hatching.

But although this was a happy accident, the authors of the study vowed to never repeat it. Releasing such a hybrid into the wild might cause harm to ecosystems. There’s really no way of telling what might happen. In any event, these human-made hybrids are sterile, so they wouldn’t have been able to reproduce in the wild anyway. 

Scientists sight rare hybrid dolphin hybrid — just don’t call it a ‘wholphin’

For the first time, biologists have reported the sighting of a hybrid between a melon-headed whale and a rough-toothed dolphin, off the coast of Hawaii. Just don’t call it a ‘wholphin’, they say.

The hybrid, in the foreground, swimming next to a melon-headed whale near Kauai, Hawaii. Photograph: Kimberly A Wood/ Cascadia Research Collective.

Here’s the thing. The rough-toothed dolphin (Steno bredanensis) is a species of dolphin that enjoys deep warm and tropical waters around the world. The melon-headed whale (Peponocephala electra), despite its name, is also a dolphin. So while it is still a hybrid, it’s a dolphin-dolphin hybrid — not a dolphin-whale one.

“Calling it something like a wholphin doesn’t make any sense,” said one of authors of the study describing the hybrid, Robin Baird, a Hawaii research biologist with Washington state-based Cascadia Research Collective. “I think calling it a wholphin just confuses the situation more than it already is.”

The rather unfortunate name ‘wholphin’ has stuck around since the 1980s, when a hybrid between a false killer whale and an Atlantic bottle-nose dolphin was reported by Hawaii’s Sea Life Park. That hybrid, called Kekaimalu, still lives at the marine mammal park, and is fertile — she has given birth to a calf at least once. But Kekaimalu, like this newly-observed hybrid, is not a whale-dolphin hybrid because, despite the name, false killer whales (Pseudorca crassidens) are also dolphins, not whales. This is why most biologists are averse to using the term ‘wholphin’ although it has caught on, particularly in the media.

Its name aside, the sighting suggesting that the ocean is even more diverse than we thought, and gives researchers a push to look for other hybrids, Sea Life Park curator Jeff Pawloski said.

“I always thought they were out there in the wild existing—it only makes sense,” he said. “And to know she has cousins out there in the ocean is an amazing thing to know.”

At this point, it’s unclear how many such dolphin hybrids exist in the wild and barring chance sightings, it’s difficult to carry out a larger study of their occurrence. However, we do know that hybrids are more likely to appear when there’s a decline in the population in one of the parental species, so that’s a good place to start looking.

As for how this particular individual came to be, it seems likely that a melon-headed whale got separated from its group and ended up traveling with rough-toothed dolphins.

It’s important to note that this is not a new species — although hybridization can lead to the emergence of a new species, there’s no indication that this is the case here. Lone hybrids are most often reabsorbed into the genetic bank of one of the two species, or cannot reproduce themselves.

“That isn’t the case, although there are examples where hybridization has resulted in a new species,” Baird said. “There’s no evidence to suggest it’s leading toward anything like species formation.”

Grey Wolf Female.

Most grey wolves today are actually wolf-dog hybrids, due to cross-breeding

Crying wolf isn’t what it used to be — today, we’re more likely to cry ‘hybrid’. Hundreds of years of the two species living in close proximity have left quite a lot of ‘dog’ in wild wolves’ genome, research shows.

Grey Wolf Female.

Image credits Seney Natural History Association / Flickr.

An international research effort has uncovered that around 60% of Eurasian grey wolf (Canis lupus lupus) genomes carry inklings of domestic dog DNA. The phenomenon was less frequent in North American wolf populations. Such findings reinforce the idea that wolves and dogs have been cross-breeding for centuries in Europe and Asia.

Woof wolf

The team analyzed DNA data from grey wolves — the ancestors of man’s best friend — to see how much of it is still ‘original’, and how much of it was diluted with genes from domestic dogs. The research was prompted in part by our lack of proper understanding of the underlying genetic dynamics of wolf populations.

“The fact that wild wolves can cross-breed with dogs is well-documented, but little was previously known about how widespread this phenomenon has been and how it has affected the genetic composition of wild wolf populations,” says lead researcher Dr. Malgorzata Pilot.

Such knowledge is also important because grey wolves are a keystone species in their ecosystems — meaning they take an active and central role in maintaining its natural balance and functions. Wolves are a protected species but hybrids are not — their legal status is unregulated and remains uncertain thus far. So getting a better idea of where wolf-dog hybrids fit in the picture was necessary for us to better tailor regulations to the reality on the ground.

To that end, the team looked for a specific genetic variation in the DNA sequences of dogs and wolves, called SNPs — Single Nucleotide Polymorphisms. DNA sequences are formed of a chain of four nucleotide bases, and if one individual has a different nucleotide than the rest of its group in any four places in the sequence, it’s classified as an SNP. Based on these, the team was able to pinpoint where dog genes inserted themselves into the genome of wolves.

Despite the evidence of widespread hybridization between Eurasian grey wolves and dogs, the team notes, wolves have remained genetically distinct from dogs. This suggests that cross-breeding with dogs isn’t enough to blend the lines between the two species, provided it occurs at relatively low levels.

“We found that while hybridisation has not compromised the genetic distinctiveness of wolf populations, a large number of wild wolves in Eurasia carry a small proportion of gene variants derived from dogs, leading to the ambiguity of how we define genetically ‘pure wolves’,” Pilot adds.

The team notes that outward characteristics (phenotype) aren’t a reliable indicator of a wolf’s genetic ‘purity’. Some individuals that had been deemed pure wolves based on physical characteristics actually turned out to be of mixed ancestry once the team took a fine-toothed comb to their DNA. On the other hand, two specimens from Italy that sported unusual, strikingly black coats — which, as you may already suspect, is strange for grey wolves — turned out to have virtually pure genomes; the only evidence of cross-breeding the team could recover were dog-derived gene variants linked to dark fur coloration.

The findings go to show how ambiguous the definition of a genetically ‘pure’ wolf can become, how blurry the lines between hybrid and non-hybrid can get. This also means that using the trusty old MK.I eyeball to tell apart a hybrid from a true wolf can be very difficult if not impossible. Viewed in this light, current management strategies that call for the removal of suspected hybrids from wolf packs aren’t just inefficient — they’re laughably inefficient.

“Instead, our study has highlighted a need to reduce the factors which can cause hybridisation, such as abundance of free-ranging dogs, small wolf population sizes, and unregulated hunting.”

The paper “A new macroecological pattern: The latitudinal gradient in species range shape” has been published in the journal Global Ecology and Biogeography.

 

sheep

Scientists breed first sheep-human hybrid — but there’s no reason to freak out

It sounds like something out of a bad science fiction novel, but scientists really have produced sheep-human hybrid embryos. Only a tiny fraction of the resulting embryos contains human cells, however. In time, as scientists breed hybrids with a higher and higher fraction of human cells, such chimeras could have their organs harvested for human transplants.

sheep

Credit: Pixabay.

The startling research was carried out by a team led by researchers at Stanford University. This is the second time scientists have successfully created a human-animal hybrid since last year’s breakthrough, when a pig-human hybrid was bred.

This isn’t some pointless mad science. Ultimately, human-animal chimeras could be bred to supply people who are in dire need of a transplant with fully biocompatible organs. In the United States alone, 22 people on the list for organ transplants die each day because there aren’t enough donors. And even if a patient is lucky enough to access a donor’s organs, life isn’t easy at all following the transplant.

Today, even the most well-matched organs can’t last long because our immune system continuously attacks them, seeing them as foreign bodies that need to be destroyed. That’s what immunosuppressant drugs are for, which transplant patients have to take all their lives. In the worst case, complications can force them to undergo a new transplant surgery or risk death.

That’s the end goal but, so far, we’re quite far from attaining it. The sheep-human embryos that Pablo Ross of the University of California, Davis, and colleagues, produced have only about one human cell for every 10,000 sheep cells. Scientists say that for a transplant to work, at least one percent of the embryo’s cells would need to be human. The hybrid embryos were destroyed after 28 days.

To make a chimera, scientists first isolate stem cells from the organisms they want to cross — the kind that can differentiate into any type of cell, i.e. skin, liver, etc. Then, stem cells from one species are inserted into the embryo of another. By hacking the embryo’s DNA, it is theoretically possible to instruct the organism not to grow a particular organ, which offers the interloping cells the opportunity to fill in the gap. This is how scientists hope to ultimately grow functional human organs, such as a heart or liver, inside a pig or other animal.

human pig chimera

Pig-human hybrid embryo from earlier research, in early 2017. Credit: Juan Carlos Izpisua Belmonte. 

Sheep embryos have desirable properties that made them appealing to the American researchers. They can be easily produced by in vitro fertilization (IVF) and require fewer embryos to be transplanted into an adult than pigs. According to Ross, scientists typically transfer 50 embryos to one recipient pig while for a sheep only four embryos per recipient are typically needed. Like pigs, sheep produce organs of about the right size for the human body, such as the heart and lungs.

These most recent developments presented last Saturday at the 2018 American Association for the Advancement of Science annual meeting in Austin, Texas, signify a new step forward in this direction. In the future, the researchers will gradually increase the human cell count in the hybrids, fine tuning the procedure until one day whole organs can be grown and ultimately harvested. But meanwhile, with each new iteration, the ethical debate will only intensify.

“The contribution of human cells so far is very small. It’s nothing like a pig with a human face or human brain,” said Hiro Nakauchi, a Stanford University researcher.

Breeding animals for the sole purpose of harvesting their organs may seem cruel and vile. Then again, some might argue that breeding livestock for food is not all that different, and most people don’t seem to have any qualms there. Certainly, this is no easy discussion.

“All of these approaches are controversial, and none of them are perfect, but they offer hope to people who are dying on a daily basis,” Ross says.

“We need to explore all possible alternatives to provide organs to ailing people.”

 

Alaskan butterfly may be a rare hybrid

It takes some hardcore survival skills to make it to the frozen wastelands of Alaska – and this butterfly has what it takes. Oeneis tanana, or the Tanana Arctic has the ability to produce antifreeze-like substances in its blood to stave off punishing Alaskan temperatures.

A scattering of tiny white freckles give the Tanana arctic butterfly a “frosted” appearance. Photo by the University of Florida/Andrew Warren

It’s the first species discovered in the state in the past 28 years, and may very well be the only endemic butterfly species to Alaska. It was hiding in plain sight, as researchers have probably seen it before several times, but they didn’t recognize it as a new species because it’s so similar to the Chryxus Arctic species.

The butterfly may have emerged as a hybrid between two other species — a very rare process for animals.

“Hybrid species demonstrate that animals evolved in a way that people haven’t really thought about much before, although the phenomenon is fairly well studied in plants,” said Warren, senior collections manager at the McGuire Center for Lepidoptera and Biodiversity at the Florida Museum of Natural History on the UF campus. “Scientists who study plants and fish have suggested that unglaciated parts of ancient Alaska known as Beringia, including the strip of land that once connected Asia and what’s now Alaska, served as a refuge where plants and animals waited out the last ice age and then moved eastward or southward from there. This is potentially a supporting piece of evidence for that.”

Furthermore, its evolution may even shed light on Alaska’s geologic past, especially regarding the events that happened during the last glaciation.

“Scientists who study plants and fish have suggested that unglaciated parts of ancient Alaska known as Beringia, including the strip of land that once connected Asia and what’s now Alaska, served as a refuge where plants and animals waited out the last ice age and then moved eastward or southward from there,” Warren explained. “This is potentially a supporting piece of evidence for that.”

However, in order to prove this theory, they first need to conduct genetic studies on the butterfly.

“Once we sequence the genome, we’ll be able to say whether any special traits helped the butterfly survive in harsh environments,” he said. “This study is just the first of what will undoubtedly be many on this cool butterfly.”

For now, Warren wants to return to Alaska, hoping to find out new clues about the butterfly, and perhaps even more species.

“New butterflies are not discovered very often in the U.S. because our fauna is relatively well-known,” Warren said. “There are around 825 species recorded from the U.S. and Canada. But with the complex geography in the western U.S., there are still going to be some surprises.”

Full study here.

The sea lamprey, a very simple organism which dwells in the Atlantic waters, which scientists will use as inspiration for a bio-mechanical device capable of traveling through your body. Not that much of looker, but he's on our side. (c) U.S. Fish and Wildlife Service.

Bio-mechanical hybrid robot might detect diseases from inside your body

Scientists at Newcastle University are currently developing a tiny bio-inspired robot, just one centimeter in length, which in less than five years might be used to diagnose and pinpoint diseases from inside the human body.

The sea lamprey, a very simple organism which dwells in the Atlantic waters, which scientists will use as inspiration for a bio-mechanical device capable of traveling through your body. Not that much of looker, but he's on our side. (c)  U.S. Fish and Wildlife Service.

The sea lamprey, a very simple organism which dwells in the Atlantic waters, which scientists will use as inspiration for a bio-mechanical device capable of traveling through your body. Not that much of looker, but he's on our side. (c) U.S. Fish and Wildlife Service.

The researchers, backed-up by the American National Science Foundation and the UK’s Engineering and Physical Sciences Research Council,  are hoping to succeed where other scientists at nano labs across the world have been painstakingly trying to achieve as well – a working, safe tiny device which can swim through the blood stream and collect critical information, irretrievable otherwise.

Called the “Cyberplasm”, the Newcastle scientists’ take involvesa  biomimicking robot that functions like a living creature loaded with sensors derived from animal cells, inspired by the  sea lamprey, a creature found mainly in the Atlantic Ocean. The animal has an extremely nervous system, making it perfect for bio-mechanical mimicking.

“Nothing matches a living creature’s natural ability to see and smell its environment and therefore to collect data on what’s going on around it,” Dr Frankel noted.

Cyberplasm will have an electronic nervous system, ‘eye’ and ‘nose’ sensors derived from mammalian cells, and artificial muscles that use glucose as an energy source. Its sensors are being developed to respond to external stimuli, like chemical signals or light, much in the same way organisms do in nature by converting them into electronic impulses that are sent to an electronic ‘brain’ equipped with sophisticated microchips. This information will be then used by the brain to send electronic messages to artificial muscles, telling them to contract or relax, resulting in an undulating motion which propels the Cyberplasm and allows it to navigate through the human body. Data on the chemical make-up of the robot’s surroundings can be collected and stored for later recovery, information later used for diagnosis.

Besides disease diagnosis, the researchers believe the Cyberplasm might have some immediate applications in the prosthetics sector, where the tiny bio-robot might be used to stimulate  living muscle tissue to contract and relax.  The researchers are currently developing the components of Cyberplasm individually, and while the initial prototype will be one centimeter long, they’re confident they can scale it down to nano-size in time – a working device should be ready within five years.

“We’re currently developing and testing Cyberplasm’s individual components,” Frankel concluded. “We hope to get to the assembly stage within a couple of years. We believe Cyberplasm could start being used in real world situations within five years”.

University of Newcastle  / Eureka Alert

Future cars could be partially powered by their bodywork

Parts of the car’s bodywork could double up as it’s batter in a not so far away future; at least that’s what the people involved in the 3.4 million project believe. They are working on a prototype that can store and discharge electrical energy; the material is also light and very hard.

Ultimately, this will not only double the battery, but it will make cars lighter, more compact and more energy efficient, allowing drivers to travel longer distances without having to recharge. Furthermore, the material could also be used in different fields, such as mobile phones or computers, so they wouldn’t need a separate battery.

“We are really excited about the potential of this new technology. We think the car of the future could be drawing power from its roof, its bonnet or even the door, thanks to our new composite material. Even the Sat Nav could be powered by its own casing. The future applications for this material don’t stop there – you might have a mobile phone that is as thin as a credit card because it no longer needs a bulky battery, or a laptop that can draw energy from its casing so it can run for a longer time without recharging. We’re at the first stage of this project and there is a long way to go, but we think our composite material shows real promise.”, said The project co-ordinator, Dr Emile Greenhalgh, from the Department of Aeronautics at Imperial College London

You can find a demonstration and additional details here.

Thriving Hybrid Salamanders

 

hybrid

So a new study conducted by UC Davis research revealed interesting things from interbred salamanders, results that go against what was the dominant idea about interbread species.

The salamander experts studied the survival rates and genetic makeup of three types of salamanders: native California tiger salamanders (Ambystoma californiense), which are protected under the U.S. Endangered Species Act; barred tiger salamanders that were introduced in California from Texas in the 1950s (Ambystoma tigrinum mavortium); and the hybrid offspring born when the two species mated. They found that hybrids did better when released into their habitat than the natural species. The belief was that hybrids are not as fit as their parents and they are weaker.

But hybrids favour natural selection and this may be an answer for the salamander endagered population. Some think that they are just threats to the native salamanders (awesome salamander here). But this is a thing to look to in the future since it is harder and harder for numerous species with the dissapearance of their habitat.

It is bad that people consider hybrids to be less valuable than the so called pure species. We find it very easy to forget where we came from and how the human species evolved from microscopic ancestors and later from larger creatures thanks to endless interbreeds. People should understand that hybrids exist and they are part of natural selection and they should be regarded as beings, equal to and just as valuable as “pure breeds”.