Daily Archives: June 24, 2022

The issue of human reproductive cloning has recently received a great deal attention in public discourse. Bioethicists, policy makers, and the media have been quick to identify the key ethical issues involved in human reproductive cloning and to argue, almost unanimously, for an international ban on such attempts. Meanwhile, scientists have proceeded with extensive research agendas in the cloning of animals. Despite this research, there has been little public discussion of the ethical issues raised by animal cloning projects. Polling data show that the public is decidedly against the cloning of animals. To understand the public's reaction and fill the void of reasoned debate about the issue, we need to review the possible objections to animal cloning and assess the merits of the anti-animal cloning stance. Some objections to animal cloning (e.g., the impact of cloning on the population of unwanted animals) can be easily addressed, while others (e.g., the health of cloned animals) require more serious attention by the public and policy makers.

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Ethical issues in animal cloning - PubMed

In the mid-1990s, aquatic pet owners in Germany noticed something strange: Somehow, their solitary female crayfish kept multiplying. Within days, they could have dozens of daughters, all without a single male in sight. Since its discovery in 1995 this crayfish, Procambarus virginalis, known as the marbled crayfish for the speckles on its carapace, has become one of the most studied organisms in decades.

The marbled crayfish reproduces through parthenogenesis, where females lay large clutches of fertile, genetically identical eggs. Essentially, the crayfish clone themselves by the hundreds every few months. Parthenogenesis is a rare process in vertebrates and usually occurs when two different species mate and reproduce. But the marbled crayfish is unique in two ways. First, it is the only decapod (an order of crustaceans including crabs, shrimp, and lobsters) known to reproduce by parthenogenesis. Second, before 1995, it did not exist. With a history younger than the advent of the internet, these crayfish have given researchers a unique opportunity to observe and track the evolution of parthenogenesis in animals.

Thought to have been introduced in a German pet market in 1995, the marbled crayfish probably spread when owners who didnt sign up for rapidly self-duplicating pets dumped the crayfish into rivers and lakes, where they thrived and immediately began to outcompete native crayfish. Since then, the marbled crayfish has invaded Asia, Europe, and Africa. In a 2009 paper, two prominent researchers studying the appearance of the crayfish in Madagascar called it the perfect invader. The marbled crayfish can store from 200 to 700 eggs at a time. With such incredible fecundity some six times that of native Madagascar crayfish it is all but certain to outcompete and devastate native populations.

Unlike often happens with invasive species, researchers identified the marbled crayfish quickly. They have intently tracked its movements ever since. In essentially every situation, marbled crayfish outcompete native species because they can grow and reproduce faster. Plus, by forgoing an entire sex, they save time and energy by eliminating the pesky tasks of courtship and mating. Though the marbled crayfish has yet to be found in the United States, some states are beginning to prepare for its arrival, outlawing the species as pets and establishing monitoring programs.

If the marbled crayfish does make it to our shores, it will be reunited with a close family member, Procambarus fallax, the slough crayfish, which is native to the southern United States. Most researchers agree that the marbled crayfish is a direct descendent of P. fallax. Indeed, some scientists suggest that the two species are so similar genetically that they should be considered a single species. In a 2015 experiment, researchers found that the marbled crayfish and P. fallax recognized each other as sexual partners. However, all the progeny of their doomed affairs turned out to be pure marbled crayfish clones. This reproductive barrier prompted the researchers to suggest that the marbled crayfish be treated as a separate, asexual species. It was in this same study that researchers confirmed all marbled crayfish descended from a single clone discovered in Heidelberg, Germany in 1995.

In 2018, researchers characterized the genome of the marbled crayfish, publishing their findings in Nature Ecology and Evolution. The results showed an astounding genome size of approximately 3.5 gigabase pairs, with more than 21,000 genes. This puts it on par with the size of the human genome. The most intriguing discovery, though, was that the crayfish had three copies of their chromosomes, rather than the usual two. The marbled crayfish genome has two nearly identical copies of a genotype, as well as a third copy of a different but related genotype. This finding supports the theory that two very distantly related P. fallax individuals met in an aquarium one day and mated, producing the marbled crayfish as their highly mutated progeny.

These three sets of genes probably protect the animal from Mullers ratchet, a phenomenon by which asexual species have an increased susceptibility to genetic disease and mutation. Without sexual recombination to shuffle around the parents genomes, harmful and irreversible mutations tend to accumulate in populations, leading to disease and eventual species die-off. (Mullers ratchet can also explain why inbreeding creates health issues in offspring.)

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This combination of multiple genomes and obligate asexual reproduction is common in plants, but rare in animals. The marbled crayfish provides a fascinating new model system to study asexual evolution in animals, and by studying a creature with such a young evolutionary history, scientists hope they might identify critical events for this type of unique speciation event.

Marbled crayfish offer another important research opportunity. The creatures reproduce clonally from a single cell and adapt to various environments quickly. These traits are shared by another type of lifeform of immediate interest to humans: cancer. Researchers promptly noticed the parallel and the outstanding opportunity to use the creature as a model specimen for clonal genomes. So scientists closely study the marbled crayfish genome, watching for any mutations. This research will help us disentangle what types of mutations are most impactful to clonal genome evolution, an insight with implications for cancer research.

Invasive species management is defined by an uncomfortable truth: We will never eradicate all invasive species, or even prevent all of them from spreading. Fast-growing, dominant invasive species like kudzu grass, the cane toad, and the zebra mussel show how futile our attempts to do so can be. This reality presents a severe dilemma for conservationists. Should we continue to fight a war we cannot win, or should we try to adapt our environments to these newcomers and mitigate their impacts?

In Madagascar, where native crayfish have threatened fishermens livelihood and wreaked havoc on ecological networks, scientists are approaching the problem with a different strategy. Researchers noticed that the marbled crayfish feeds on the snails that host the parasitic flatworm responsible for schistosomiasis, a disease affecting millions in Madagascar. This observation prompted Julia Jones from Bangor University, and Ranja Andriantsoa, a Malagasy biologist and marbled crayfish expert, to start The Perfect Invader project, which aims to explore how marbled crayfish affect human health.

Scientists involved in the project study how the marbled crayfish can be used as a biological tool to reduce the transmission of schistosomiasis. Additionally, they study whether the creature could be useful as a food source for humans. As it turns out, the marbled crayfish is tasty and contains high-quality animal protein. Because this crayfish is so easy to propagate, it could easily be farmed and used to alleviate malnutrition.

Of course, we should not ignore the negative ecological impacts of the creatures spread. But in a world interconnected by shipping, air transport, and freight lines, invasive species will always manage to hitch a ride beneath our unsuspecting gaze. Why not explore the possible benefits of siding with the enemy? Creative, resourceful scientists have already found several silver linings: an increased understanding of the evolution of cancer tumors, biocontrol for a deadly disease, and a significant, cheap food source. Also, as visitors to some of Berlins top restaurants have discovered, the marbled crayfish, found on menus as the Berlin lobster, pairs nicely with some butter and garlic.

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The marbled crayfish has been cloning itself for 30 years. Can it teach us about cancer? - Big Think

What Alida Bailleul saw through the microscope made no sense. She was examining thin sections of fossilised skull from a young hadrosaur, a duck-billed, plant-eating beast that roamed what is now Montana 75m years ago, when she spotted features that made her draw a breath.

Bailleul was inspecting the fossils, from a collection at the Museum of the Rockies in Bozeman, Montana, to understand how dinosaur skulls developed. But what caught her eye should not, the textbooks said, be there. Embedded in calcified cartilage at the back of the skull were what appeared to be fossilised cells. Some contained tiny structures that resembled nuclei. In one was what looked like a clump of chromosomes, the threads that bear an organisms DNA.

Bailleul showed the specimens to Mary Schweitzer, a professor and specialist in molecular palaeontology at North Carolina State University, who was visiting the museum. Schweitzer had done her PhD in Montana under the supervision of Jack Horner, the resident fossil hunter who inspired the Jurassic Park character Alan Grant. Schweitzer herself had become famous and faced waves of criticism for claiming to have found soft tissue in dinosaur fossils, from blood vessels to fragments of proteins.

Schweitzer was intrigued by Bailleuls discovery and the two joined forces to study the fossils further. In early 2020, as the world was dealing with the arrival of Covid, they published a bombshell paper on their findings. Their report laid out not only evidence for dinosaur cells and nuclei in the hadrosaur fossils, but results from chemical tests that pointed to DNA, or something like it, coiled up inside.

The idea of recovering biological material from dinosaur fossils is controversial and profound. Schweitzer doesnt claim to have found dinosaur DNA the evidence is too weak to be sure but she says scientists should not dismiss the possibility that it could persist in prehistoric remains.

I dont think we should ever rule out getting dinosaur DNA from dinosaur fossils, she says. Were not there yet, and maybe we wont find it, but I guarantee we wont if we dont continue to look.

Scraps of prehistoric tissue, proteins or DNA could transform the field of molecular palaeontology and unlock many of the mysteries of dinosaurs lives. But the prospect of having the intact genetic code from a tyrannosaur or velociraptor raises questions scientists have become used to fielding since the original Jurassic Park movie in 1993. Armed with sufficient dino DNA, could we bring back the lumbering beasts?

Rapid advances in biotechnology have paved the way for elegant approaches to de-extinction, where a species once considered lost for ever gets a second shot at life on Earth. For now, the focus is on creatures that humans once shared the planet with and which we helped to drive out of existence.

Arguably the most high-profile de-extinction programme aims to recreate, in some sense, the woolly mammoth and return herds of the beasts to the Siberian tundra thousands of years after they died out. The company behind the venture, Colossal, was founded by the Harvard geneticist George Church, and Ben Lamm, a tech entrepreneur, who claim that thousands of woolly mammoths could help to restore the degraded habitat: for example, by knocking down trees, fertilising the soil with their dung, and encouraging grasslands to regrow. If all goes to plan and it may well not the first calves could be born within six years.

What lies ahead is a formidable challenge. Despite well-preserved mammoths being dug out of the tundra, no living cells were found to clone them using the approach that produced Dolly the sheep, the first cloned mammal. So Colossal has devised a workaround. First, the team compared the genomes of the woolly mammoth and a close living relative, the Asian elephant. This revealed genetic variants that equipped the woolly mammoth for the cold: the dense coat of hair, the shortened ears, the thick layers of fat for insulation and so on.

The next step is to use gene editing tools to rewrite the genome of an Asian elephant cell. If the 50 or so expected edits have the desired effect, the team will insert one of the mammothified elephant cells into an Asian elephant egg that has had the nucleus removed. A zap of electricity will be applied to spark fertilisation and the egg should start to divide and grow into an embryo. Finally, the embryo will be transferred to a surrogate mother or, given the aim to produce thousands of the creatures, an artificial womb that can carry the foetus to term.

Colossals project highlights one of the greatest misunderstandings about de-extinction programmes. For all the talk of bringing species back, these will not be copies of extinct animals. Colossals woolly mammoth, as Church readily admits, will be an elephant modified to survive the cold.

Whether that matters depends on the motive. If the aim is to restore the health of an ecosystem, then the animals behaviour trumps its identity. But if the driver is nostalgia, or an attempt to assuage human guilt for destroying a species, de-extinction may be little more than a scientific strategy for fooling ourselves.

The California-based non-profit Revive and Restore has projects under way to help revive more than 40 species through the shrewd application of biotechnology. The organisation has cloned a black-footed ferret, named Elizabeth Ann, which is on course to become the first cloned mammal to help save an endangered species. The hope is that Elizabeth Ann, who was created from cells frozen in the 1980s, will bring much-needed genetic diversity to wild colonies of ferrets that are threatened by inbreeding.

Revive and Restore intends to bring back two extinct bird species, the heath hen and the passenger pigeon, as soon as the 2030s. After holding on for decades in Marthas Vineyard, an island near Cape Cod in Massachusetts, the heath hen eventually died out in 1932. Under the de-extinction plan, scientists will create a replacement bird by editing the DNA of the closely related prairie chicken to carry heath hen genes. The passenger pigeon project takes a similar approach, using the band-tailed pigeon as the genetic template.

Ben Novak, the lead scientist at Revive and Restore, likens de-extinction to rewilding efforts that reintroduce lost species to improve local habitats. Introducing biotechnology is simply expanding this existing practice to be able to consider species that were off the table before, he says. To worry that animals created through de-extinction projects are not exact replicas of lost species is missing the point, he adds. We are not recreating these species to satisfy human philosophy we are doing this for conservation purposes. For conservation, what matters is an ecosystem, and ecosystems do not sit around pontificating on classification schemes, he says.

Should humans try to prevent all future extinctions? Every species dies out at some point. But while extinction is normal in ecosystem evolution, human activity is driving species to the brink faster than most species can adapt. Novak says preventing all extinctions is a good goal but the reality, he adds, is that the worlds governments have not prioritised conservation over exploitation. No matter how many people really work hard, we have the majority of humanity still working against that goal, he says. What we can do is prevent as many as possible right now, and re-diversify the world in a way that gives us the ecological stability to prevent further extinctions.

The dodo is a prime candidate for de-extinction. Once native to Mauritius (and only Mauritius), the large, flightless bird died out in the 17th century after humans settled on the island. On top of the widespread destruction of its habitat, the dodo was further threatened by pigs, cats and monkeys that sailors brought with them.

A team led by Beth Shapiro, a professor of ecology and evolutionary biology at the University of California, Santa Cruz, has sequenced the dodo genome from a museum specimen in Copenhagen. In theory, a dodo-like bird could be created by editing the Nicobar pigeon genome to contain dodo DNA, but, as with all de-extinction projects, creating the animal is not enough: there has to be a habitat for it to thrive in, or the exercise becomes pointless.

I think its crucial that, as we prioritise species and ecosystems for protection, we do so while considering what our planet will be like 50 or 100 years from now, rather than imagining that we can somehow turn back the clock and re-establish ecosystems of the past, Shapiro says.

The biggest problem many species face today is that the rate of change in their habitats is too fast for evolution to keep up. This is where our new technologies can be useful. We can sequence genomes and make more informed breeding decisions. We can resurrect lost diversity by cloning like Elizabeth Ann, the black-footed ferret and we may even be able to move adaptive traits between populations and species. Our new technologies may make it possible for us to increase the rate at which species can adapt, perhaps saving some from the same fate as the dodo and the mammoth, she adds.

Most de-extinction projects are viable because researchers have either living cells or the entire genome from the lost species, and a close living relative that can be both genetic template and surrogate mother for the resurrected animal. In the case of dinosaurs, these may be insurmountable hurdles.

The work by Schweitzer, Bailleul and others challenges the textbook explanation of fossilisation as the wholesale replacement of tissue with rock: life turned literally to stone. They see a more complex process at work, with the fossilisation process occasionally preserving the molecules of life, for perhaps tens of millions of years.

But even if soft tissue can survive in fossils, that may not be true for dinosaur DNA. Genetic material starts to break down soon after death, so anything preserved could be highly fragmented. The oldest DNA yet recovered is from the tooth of a million-year-old mammoth preserved in the eastern Siberian permafrost. Older DNA may well be found, but will scientists be able to read the code and understand how it shaped the prehistoric creatures?

Other hurdles abound, Schweitzer says. Armed with the entire genome of Tyrannosaurus rex, researchers would have no idea how the genes were ordered on how many chromosomes. Solve that puzzle, somehow, and you still have to find a close living relative that can be gene-edited to carry the dinosaur genes. While birds are distant relatives of dinosaurs, an ostrich might struggle to carry a T rex to term. You end up just going down the list, says Schweitzer. If we can solve this, then theres this, and if we can solve this, then theres this. I dont think technology can overcome it, at least not in the foreseeable future.

But what if life can find a way? An approach championed by Schweitzers former supervisor, Jack Horner, is to take a living relative of the dinosaur the chicken and rewrite its genome to make birds with dinosaur-like features. By tinkering with bird genomes, researchers have recreated dinosaur-like teeth, tails and even hands, similar to those on the velociraptor. Keep going, says Horner, and you end up with a chickenosaurus.

Technology cannot solve everything, though. A sustainable population, with healthy genetic variation, might call for 500 or so animals. Where are we going to put them? And which modern species are you going to drive to extinction so that dinosaurs have a place again on this planet? says Schweitzer. We might be able to put one in a zoo for people to spend zillions of dollars to come and look at, but is that fair to the animal?

Instead of trying to recreate the beasts, Schweitzer simply wants to understand them better. Organic molecules locked up in fossils could shed light on the endless mysteries that surround the dinosaurs. Did they produce enzymes to get more nutrition from plants? How did they cope with carbon dioxide levels more than twice as high as today? And how did they maintain their often enormous body sizes?

I dont think its unreasonable to suggest that as technology and our understanding of degradation catches up, we may get informative DNA, she says. Think of the questions we can answer if we do thats what I find exciting.

I dont hold my breath that well ever see a dinosaur walking around. Im not going to rule it out a scientist should never say never but I think its human hubris to bring back a dinosaur just so we can say we did it. We need to have more reason than that.

More:

Life will find a way: could scientists make Jurassic Park a reality? - The Guardian

At Amazons Re:Mars conference, Alexas senior vice-president Rohit Prasad exhibited a startling new voice assistant capability: the supposed ability to mimic voices. So far, there's no timeline whatsoever as to when or if this feature will be released to the public.

Stranger still, Amazon framed this copycatting ability as a way to commemorate lost loved ones. It played a demonstration video in which Alexa read to a child in the voice of his recently deceased grandmother. Prasad stressed that the company was seeking ways to make AI as personal as possible. While AI cant eliminate that pain of loss, he said, "it can definitely make the memories last. An Amazon spokesperson told Engadget that the new skill can create a synthetic voiceprint after being trained on as little as a minute of audio of the individual it's supposed to be replicating.

Security experts have long held concerns that deep fake audio tools, which use text-to-speech technology to create synthetic voices, would pave the way for a flood of new scams. Voice cloning software has enabled a number of crimes, such as a 2020 incident in the United Arab Emirates where fraudsters fooled a bank manager into transferring $35 million after they impersonated a company director. But deep fake audio crimes are still relatively unusual, and the tools available to scammers are, for now, relatively primitive.

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Amazon's new pitch: let Alexa speak as your relatives from beyond the grave - Engadget

BioXp system and RapidAMP cell-free DNA kit rapidly accelerate antibody discovery pipelines by addressing critical bottlenecks associated with lead candidate gene synthesis, cloning, and scale-up

SAN DIEGO, June 01, 2022 (GLOBE NEWSWIRE) -- Codex DNA, Inc. ( DNAY), a pioneer in automated benchtop synthetic biology systems, today announced its speaker lineup for Antibody Engineering & Therapeutics Europe, which is being held on June 7-9, 2022 in Amsterdam and online. The company will be showcasing its automated BioXp system and RapidAMP technology for antibody and protein engineering workflows at booth #24.

In order to identify high-quality antibody leads for difficult target classes, scientists must be able to screen an increasing number of complex targets faster and more precisely than ever before, said Todd R. Nelson, PhD, CEO of Codex DNA. Codex DNAs fully automated benchtop BioXp system optimizes production workflows and allows customers to avoid the long wait times from synthetic biology service providers or labor-intensive manual protocols. With this approach, users can now go from digital antibody sequences to transfecting expression constructs for functional characterization in less than a day, all from the comfort of their own laboratory.

The combination of Codex DNAs automated BioXp system and RapidAMP technology enables researchers to synthesize lead candidate variable domains, clone them into expression vectors, and amplify the resulting plasmids to transfection scale with the push of a button. The BioXp RapidAMP cell-free DNA amplification kit contains all of the Gibson Assembly reagents necessary to amplify error-corrected genes cloned into a made-to-stock or customer vector to make up to 10 micrograms of DNA. The complete platform offers substantial workflow efficiency gains to help bridge the cloning throughput gap that divides lead candidate sequence identification and downstream functional characterization.

FEATURED PRESENTATION: Optimizing Antibody Discovery and Engineering Workflows with the BioXp System: Overcoming Process Bottlenecks Utilizing Automated End-to-End Synthetic Biology Solutions from Codex DNAPresenter: Jason Lehmann PhD, Senior Product Marketing Manager at Codex DNADate/Time: Wednesday, June 8th at 1:30 pm CEST Registration: Click here

About Codex DNACodex DNA is empowering scientists with the ability to create novel, synthetic biology-enabled solutions for many of humanitys greatest challenges. As inventors of the industry-standard Gibson Assembly method and the first commercial automated benchtop DNA and mRNA synthesis system, Codex DNA is enabling rapid, accurate, and reproducible writing of DNA and mRNA for numerous downstream markets. The award-winning BioXp system consolidates, automates, and optimizes the entire synthesis, cloning, and amplification workflow. As a result, it delivers virtually error-free synthesis of DNA and RNA at scale within days and hours instead of weeks or months. Scientists around the world are using the technology in their own laboratories to accelerate the design-build-test paradigm for novel, high-value products for precision medicine, biologics drug discovery, vaccine and therapeutic development, genome editing, and cell and gene therapy. Codex DNA is a public company based in San Diego. For more information, visit codexdna.com.

Codex DNA, the Codex DNA logo, Gibson Assembly, BioXp, and RapidAMP are trademarks of Codex DNA Inc.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Such forward-looking statements are based on Codex DNAs beliefs and assumptions and on information currently available to it on the date of this press release. Forward-looking statements may involve known and unknown risks, uncertainties and other factors that may cause Codex DNAs actual results, performance, or achievements to be materially different from those expressed or implied by the forward-looking statements. These and other risks are described more fully in Codex DNAs filings with the Securities and Exchange Commission (SEC) and other documents that Codex DNA subsequently files with the SEC from time to time. Except to the extent required by law, Codex DNA undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.

Media Contact Richard D. LepkeDirector, Investor Relations[emailprotected]

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Codex DNA Showcases Automated Synthetic Biology Solutions for Accelerating Discovery Workflows at the Antibody Engineering and Therapeutics Europe...