Monthly report – February 2025

Welcome to Issue 2 of Project BioLogical!

This month is February, and it is all but certain that one event comes to mind when it rolls around: Valentine’s Day. Love is in the air – and that’s not just for humans!

This month, we bring you two stories about animals that are timely indeed for the season. First, you’ll be introduced to a lab rat born from a highly unusual love story. Two male parents are its genetic ancestors, making it the first organism to be born with two biologically male parents. Secondly, for the lovebirds out there, we’ll address how not just sociology but bird ecology needs to focus on both sexes rather than just males, and the consequences of overlooking the “duller sex” as far as their scientific study and preservation are concerned.

Apart from that, a shockwave in recent news – the United States has pulled out of the World Health Organisation. Politics aside, what does this really mean for the US? And does it have more consequences for the rest of the world? Find out in our monthly report!

Rats!

Chinese scientists using CRISPR have managed to create the unthinkable. Live pups were born and survived to adulthood using DNA from two male cells rather than the expected male-female pairing. How did they do this?

In fact, experiments on how to create viable embryos from two male cells have been underway for several decades now. One major problem that has always stood in the way of making this a reality, though, is that a viable embryo often receives two groups of “imprinted genes”, one from each parent. These genes are expressed differently depending on whether they are received from the father or the mother of an organism. When trying to make an embryo from just male DNA, one runs the risk of having a double dose of the same paternal imprinted genes, resulting in failed development, severe deformities and abnormalities in the offspring that cause them to be unviable.

A team led by Zhi-Kun Li has found a way to circumvent this.

After culturing sperm DNA to obtain stem cells, the scientists used CRISPR to eliminate 20 of the most important imprinted genes from the mice's genomes. Following that, they injected the edited cells together with normal ones into egg cells (which had their nuclei removed) and created embryos fertilised with DNA that had originated from two fathers. Following that, they moved them into unique “embryo” shells that contained cells required to differentiate into placental parts before placing them inside surrogate mothers.

Of the 164 pups produced using this method, a small number survived until birth and adulthood. Despite that, a great number of them also showed deformities such as being larger than normal or having enlarged organs, suggesting that the procedure still requires refinement.

This study built on previous methods by Japanese researcher Katsuhiko Hayashi’s methods, which involved creating induced pluripotent stem cells (iPSCs) from male skin cells and removing the existing Y chromosomes, adding in an X chromosome instead “borrowed” from other cells to create two X chromosomes in the cells. These were then turned into immature eggs that could be fertilised by sperm, creating pups with two fathers. Hayashi’s procedure was simpler and produced healthier offspring that could produce children, unlike Li’s infertile rat pups, but still had a success rate of only 20% as much as normal female eggs.

It seems there is still a long way to go before reliable eggs can be made with male DNA. And once we surmount that obstacle, it remains to be seen whether society would allow this technology to be applied to humans or other animals on a large scale.

Birds of a feather.

It is known that in bird ecology, male birds are more eye-catching and easier to record than female birds. Often, it is simply assumed that females act and live the same way as males, allowing their ecology to be inferred from the male population.

A new study published in Ibis argues otherwise. According to this research, female birds not only behave differently from males but more importantly have different ecological niches and pressures compared with males, meaning that overlooking them in favour of the other sex would result in a massive gap in understanding of bird ecology.

Female birds tend to have shorter life expectancies – but if this is not accounted for in the species survival rate, it would leave scientists puzzled when a population crisis arises because there are not enough females. Females have different migration patterns – what happens when climate change disrupts this and leaves them isolated from the other sex when they arrive at the breeding ground?

A key example is mentioned in the article. Amongst golden-winged warblers, the females typically live on lower branches than males. This means that they also tend to inhabit shorter trees: trees that are prime for being cut down for logging. By failing to account for the differences between the two sexes, we wouldn’t realise that the amount of territory female warblers have lost to deforestation is twice that which has been lost by males. Conservation efforts, too, are thus impaired by failing to account for both sexes.  Apart from this, social systems such as same-sex or multi-individual mating are known to occur amongst birds, so simply assorting birds into male and female fails to account for the dynamics of the population.

Despite all this talk about birds, though, the heart of the issue is not just them. It’s selection bias. By capturing birds during mating instead of migration seasons, we erroneously over-represent males, for instance. Selection bias is a flaw that taints many an experimental methodology, making false assumptions about what samples are representative of a whole. When it comes to ecology, making such errors can endanger entire ecosystems.

Who is WHO?

The new United States administration made headlines on the very first day of its swearing-in by declaring that it would pull out of the World Health Organisation (WHO) This marks the first time in history that any nation, let alone a major power like the US, has moved to exit the group. But why is WHO important, and what consequences does this withdrawal have for the US and the rest of the world?

WHO is responsible for managing global health crises and programmes, ranging from dealing with warzone diseases or pandemics like COVID-19 to helping underdeveloped countries access vital medical resources and facilities. With these programmes also comes international cooperation. Countries can share information about health problems they face, as well as new treatments and ideas to help lower-income nations. The WHO’s funding comes from a portion of each member country’s GDP, resulting in the US (with the highest GDP of any nation) contributing the most to the resources available to it – the very reason the administration has cited for its withdrawal.

Yet with this withdrawal comes onerous consequences not just for the US, but for the rest of the world.

Many underdeveloped countries lack the means to access vital lifesaving resources, and these resources are usually contributed by WHO members. With a US withdrawal, much of this aid will disappear. As of now, one of the regions that is hardest hit by the new change is Africa, where medical leadership is sorely lacking. Two-thirds of the health programmes WHO pursues in Africa have less than half the required funding as of this year, and US funds are vital for various aims such as eradicating polio and combating HIV/AIDS.

Even more urgently, new epidemics such as the Marburg virus or the mpox virus have been managed under a US/WHO partnership, although occasional outbreaks continue to threaten the continent. With such viruses still posing a danger to African nations, the withdrawal of the US would mean severe short- and long-term consequences if they are allowed to spread rampantly. Not to mention, the impact of future outbreaks will be much more difficult to assess and the danger to the continent and the whole world may not be fully assessed until it is too late. Such dire future consequences are just a taste of what could happen to the world if the WHO is unable to function.

However, not everything is lost. With the US withdrawal, other nations will step in to fill the power vacuum. Though many expect that China, the next great superpower after the US, will soon begin to take the place of the US in the WHO, it is also possible that the future of the organisation will look more multilateral, with greater equity and voice for the smaller nations involved. Regardless of what happens, though, the future is still uncertain and the world must cautiously carry on from these upheavals.

That’s a wrap for Project Biological’s February report, and we’ll see you again soon!

References:

1. Devlin, Hannah. 2023. “Scientists Create Mice With Two Fathers After Making Eggs From Male Cells.” The Guardian, March 8, 2023. https://www.theguardian.com/science/2023/mar/08/scientists-create-mice-with-two-fathers-after-making-eggs-from-male-cells.

2. Finch, Alexandra, and Lawrence O. Gostin. n.d. “WHO in Africa: Three Ways the Continent Stands to Lose From Trump’s Decision to Pull Out.” The Conversation. https://theconversation.com/who-in-africa-three-ways-the-continent-stands-to-lose-from-trumps-decision-to-pull-out-248237.

3. Hamzelou, Jessica. 2025. “Mice With Two Dads Have Been Created Using CRISPR.” MIT Technology Review, January 28, 2025. https://www.technologyreview.com/2025/01/28/1110613/mice-with-two-dads-crispr/.

4. Jazeera, Al. 2025. “What a US Exit From the WHO Means for Global Healthcare.” Al Jazeera, January 29, 2025. https://www.aljazeera.com/news/2025/1/28/what-a-us-exit-from-the-who-means-for-global-healthcare.

5. Shepherd, Robyn. 2025. “In research, ignoring female birds harms scientific understanding.” Phys.Org, January 30, 2025. https://phys.org/news/2025-01-female-birds-scientific.html.