Tag Archives: Offspring

The Mouse with Two Dads Welcomes Its First Offspring

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Adult male mouse with two fathers and possessing their own offspring

Yang Chang Wei

For the first time, male mice with two fathers have successfully produced offspring. This significant advancement paves the way for the possibility of two men having a genetically related child, although there are still numerous obstacles to overcome before this could be realized in people.

Yang Chang Wei in Shanghai, China, achieved this by merging two sperm cells with eggs stripped of their nucleus. The research team also reprogrammed seven areas of sperm DNA through a process called epigenome editing to facilitate embryo development.

Out of 259 embryos transferred to female mice, only two male offspring survived and grew, highlighting the low success rates. After mating with a female, both offspring were found to be descendants of the father, exhibiting normal size, weight, and appearance.

Generating a mouse with two fathers has proven far more challenging than producing one with two mothers. The initial report of a viable mouse with two mothers, named Kaguya, surfaced in 2004.

While Kaguya was genetically modified, Wei and his team successfully created similar paternalless mice in 2022 utilizing only epigenome editing without altering DNA sequences. This method was also instrumental in developing motherless mice.

The birth of mammals with two fathers or mothers is notably significant due to the concept of imprinting, which occurs as most animals possess two sets of chromosomes.

During the formation of eggs and sperm, chemical markers are applied to these chromosomes, activating certain genes while deactivating others. These alterations are termed “epigenetic” because they do not modify the actual DNA sequence, yet they can influence gene expression during cell division.

Crucially, the epigenetic programming of mothers differs from that of fathers; genes marked “active” in sperm may be marked “inactive” in eggs, and vice versa.

This discrepancy means that if an egg contains two sets of paternal chromosomes or maternal chromosomes, it will struggle to develop correctly. A gene that should be turned on in one chromosome could become overactive if only one copy of both is present or if both copies are included.

In Kaguya’s scenario, researchers managed this issue by removing some genes, normalizing overall gene activity. However, creating a mouse with two fathers necessitates additional alterations.

Earlier this year, a different team from China managed to produce mice with two fathers after implementing 20 genetic modifications to standardize gene activity, but these mice exhibited neither full health nor fertility.

Although modifying gene activity through genetic alterations aids in researching imprinting in laboratory animals, it remains unpalatable for human application, especially considering the unknown implications of genetic modifications.

For their epigenetic approach, Wei and his team employed modified versions of the CRISPR protein, typically utilized for gene editing. These modified proteins, like standard CRISPR versions, are designed to locate specific sites in the genome. When these sites are identified, the modified proteins can add or remove epigenetic labels without altering the DNA itself.

This research marks a significant breakthrough. Helen O’Neill, University College London, stated, “We confirm that genome imprinting is the primary barrier to mammalian reproduction overnight and demonstrate that it can be surpassed.”

Since this technique does not involve direct genetic modification, it may, in theory, allow same-sex couples to have genetically related children. However, a considerably higher success rate is necessary before such a method can be deemed acceptable for human use. “While this study on producing offspring from same-sex parents is encouraging, it is unlikely to translate to humans due to the vast number of eggs required, the large pool of surrogate women necessary, and the low success rate,” explained Christoph Galichet from the Sainsbury Welcome Centre in the UK.

The low success rate can be attributed to various factors. Firstly, merging the two sperm cells resulted in some embryos containing two Y chromosomes, leading to underdevelopment. Additionally, for effective epigenome editing, all seven targeted sites in the embryo must be successfully modified, and there might have been off-target effects in some instances.

It’s plausible that animal success rates and health could be enhanced by modifying more than seven sites; however, these modifications likely wouldn’t be applicable to human use, considering the differing sites that require changes in humans compared to mice.

If a human baby were to be conceived using this method, the mitochondria within the cell—containing a small amount of DNA—would originate from the egg donor, essentially making it three contributing genetic sources.

In 2023, a Japanese team reported the birth of a mouse puppy with two fathers through a distinct method involving the conversion of mouse stem cells into eggs. However, it remains uncertain whether the puppies thrived into adulthood, and no successful attempts have yet been made to transform human stem cells into eggs.

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Source: www.newscientist.com

Chimpanzee mother’s engage in playful interactions with their offspring during challenging circumstances

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Chimpanzee mother and child in Kibale National Park, Uganda

Dr. Chris Sabbi, Tufts University

When they have less to eat, most chimpanzees stop playing altogether to conserve energy, but mothers continue to spend a lot of time playing with their children. Because play is essential to the physical and psychological development of young chimpanzees, mothers may channel their energy into this behavior to nurture their young, even during difficult times.

Great apes such as gorillas, bonobos, and chimpanzees all tend to engage in play, such as tickling, pecking, and chasing each other. “Play helps develop both motor and social skills,” he says. Zarin Machanda At Tufts University, Massachusetts. “That's really what the baby needs to develop properly.”

For more than a decade, Machanda and colleagues have been observing a community of about 60 Eastern chimpanzees.Pan Troglodytes Schweinfurti) lives in Kibale National Park, Uganda. The team played a total of 3,891 games between 2010 and 2019.

“We had a great summer in 2016 or 2017 when there was nothing but food everywhere on site,” says Manchanda. “And one of the things we noticed was a lot of adult chimpanzees playing with each other.”

When food was abundant, teams recorded at least one play on 97% of observation days, but when food was scarce, this decreased to only 38%.

However, mother chimpanzees continued to play with their children at even higher rates during times of low food availability.

“We were really surprised,” team members say. Chris Sabbi Food is generally more important to female chimpanzees because the energetic cost of reproduction is much higher, according to a Harvard University study.

During periods of food stress, chimpanzees tend to spend more time alone to avoid competing for resources, so mothers are often the only social partners for their babies. As a result, the mother spends even more time playing with her children to compensate for the lack of interaction with her peers and other adults.

“The fact that mothers continue to play with their babies, even at personal sacrifices, shows how important this is to the child's development,” Machanda said. “It's like the hidden cost of being a mother.”

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Source: www.newscientist.com

Paleontologists claim Dinocephalosaurus was a fully aquatic reptile that delivered offspring in the ocean

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Detailed explanations are provided by paleontologists from Germany, China, the United Kingdom, and the United States. Dinocephalosaurus orientalis a remarkable marine reptile from the Middle Triassic of China, based on seven beautifully preserved specimens.

repair of Dinocephalosaurus orientalis It is depicted in a school of large predatory actinopterygian fishes. Saurictis. Image credit: Marlene Donnelly.

Dinocephalosaurus orientalis They lived in what is now China during the Triassic period about 240 million years ago.

This aquatic reptile could reach up to 6 m (20 ft) in length and had an extremely long neck with 32 separate vertebrae.

the animal looked very similar Tanystropheus hydrides another strange marine reptile that lived during the Middle Triassic period of both Europe and China.

“Both reptiles were similar in size and had some common skull features, including a fish-catching type of dentition,” said Dr Nick Fraser, head of natural sciences at the National Museum of Scotland, and colleagues. Stated.

“but, Dinocephalosaurus orientalis It is unique in having more vertebrae in both its neck and torso, giving it a more snake-like appearance. ”

Dinocephalosaurus orientalis. Image credit: National Museums of Scotland.

Dinocephalosaurus orientalis They are strictly marine reptiles and almost certainly gave birth at sea.

The exact function of its extraordinarily long neck is unknown, but it almost certainly helped catch fish, and in one specimen it is preserved in the stomach contents.

Despite superficial similarities, this reptile was not closely related to the famous long-necked plesiosaur, which evolved only about 40 million years later and inspired the Loch Ness Monster myth.

“This discovery allows us, for the first time, to see the entire body of this amazing long-necked animal,” Dr Fraser said.

“This is another example of the weird and wonderful world of the Triassic that continues to baffle paleontologists.”

“With its striking appearance reminiscent of the long, serpentine dragon of Chinese mythology, we are confident it will capture imaginations around the world.”

Dinocephalosaurus orientalis First described in 2003, the discovery of additional, more complete specimens has allowed the authors to fully describe this strange long-necked creature for the first time.

“Among the amazing discoveries we made in the Triassic of Guizhou, Dinocephalosaurus orientalis It probably stands out as the most remarkable,” said Professor Li Chun, a paleontologist at the Institute of Vertebrate Paleontology and Paleoanthropology.

of findings Published in today's magazine Earth and Environmental Sciences: Papers of the Royal Society of Edinburgh.

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Stephen NF Speakman other. Dinocephalosaurus orientalis Li, 2003: A remarkable marine archosaur from the Middle Triassic of southwestern China. Earth and Environmental Sciences: Papers of the Royal Society of Edinburgh, published online on February 23, 2024. doi: 10.1017/S175569102400001X

Source: www.sci.news

Deadly Plants: Lethal to Pollinators but Nourishing to Their Offspring

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The Arisaema plant is a death trap for pollinating mushroom gnats.

ArchivePL/Alamy

Pulpit flowers, famous for trapping and killing pollinators, may also act as nurseries for insect eggs, revealing a more subtle and mutually beneficial relationship that challenges existing assumptions. Become.

These jug-shaped plants are Alisa EmmaThey mimic the look and smell of musty mushrooms to attract fungus gnats, which are major pollinators. But when insects dip into the flower's spathe in search of this pungent food, they are unable to crawl out because the interior of the flower's elongated hood is too waxy. The gnat struggles violently inside its mottled red-green cup, scattering pollen all around it to thoroughly pollinate the plant, but eventually dies of exhaustion.

At least this is what botanists think I've been thinking about it for a long time.

But when Kenji Suetsugu A team from Japan's Kobe University hatched 62 flowers of the Asian pulpit jack-in-the-pulpit species Alisa Emmathunbergi, they realized something was wrong. The gnat was helplessly captured and laid eggs in the crown of the flower. When the flowers begin to wither, these larvae feed on the shriveled and rotting flesh and emerge as adults a few weeks later.

The fact that traps can serve the dual function of pollination sites and nurseries for the next generation of pollinators is “really surprising,” Suetsugu says.

Furthermore, some adults are able to escape from flower traps before it is too late. So the ducks aren't “technically lethal,” Suetsugu said. This suggests that plants strike a balance between ensuring pollination and not completely depleting the number of pollinating gnats.

These findings suggest that the relationship between jack-in-the-pulpit and its pollinators is much more complex than previously thought and cannot be neatly categorized as purely mutualistic or antagonistic.”, says Suetsugu.

This relationship may represent a step in the evolution of plants, from purely deceptive pollinators to mutually beneficial relationships with pollinators. Importantly, the findings may also suggest that there is more to the relationships between other plants and pollinators around the world than meets the eye.

Indeed, these findings challenge some preconceived ecological concepts. Jeff Ollerton at the University of Northampton, UK. In this particular case, the situation is mixed, as only some insects seem to be benefiting.He has more types of Alisa Emma (This genus includes more than 190 species) To learn more, you need to study this species in detail.

“The deeper we look into plant-pollinator interactions, the more we learn about the ability of plants to manipulate pollinator behavior and how pollinators can evolve strategies to acquire resources. There are more surprises to come,” Ollerton said.

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Source: www.newscientist.com