PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

How a tiny gene ensures the survival of male birds

Researchers from Heidelberg and Edinburgh identify a mechanism that balances the genetic disparity between sex chromosomes

2025-07-16
(Press-News.org) Birds have developed a unique evolutionary solution to ensure the survival of males – a powerful microRNA. This tiny gene allows male embryos to survive despite a genetic imbalance between the sexes by balancing the activity of the sex chromosomes. An international research team led by biologists from Heidelberg University and the University of Edinburgh (Scotland) has discovered this previously unknown mechanism, which differs significantly from the system that mammals have developed in the course of evolution to address the same biological challenge.

Sex chromosomes, which determine whether an individual is male or female, originated from an ordinary pair of chromosomes. In mammals, females carry two X chromosomes, while males have one X and one Y chromosome. In contrast, male birds have two Z chromosomes, and female birds have one Z and one W chromosome. Over time, the Y chromosome in mammals and the W in birds lost most of their genes due to their highly specialized sex-specific roles, meaning one sex retains two copies of most genes while the other has only one. Mammals compensate for this genetic imbalance by boosting the activity of the X chromosome in both sexes and “silencing” one of the two X chromosomes in females.

Using chickens as an example, the international research team has now demonstrated how birds resolve this issue. The loss of genetic material on the female-specific W chromosome is offset by increased activity of key genes on the Z chromosome. While this is vital for the survival of female birds, it leads to genetic overactivity in males with two Z chromosomes, resulting in growth defects if left unbalanced. The researchers, led by Prof. Dr Henrik Kaessmann (Heidelberg University) and Dr Mike McGrew (University of Edinburgh), suspected that a previously discovered microRNA – a short regulatory ribonucleic acid – plays a crucial role in this process.

“This microRNA is predominantly active in male birds, which led us to assume that it helps balance the activity of the Z chromosome,” explains Prof. Kaessmann, who conducts research at the Center for Molecular Biology of Heidelberg University (ZMBH). To test their hypothesis, the researchers used gene editing to remove the microRNA and studied the effects during early chicken development. While male embryos could not survive without the microRNA, females developed normally. According to the researchers, the same tiny gene is found in all bird species examined thus far, but not in other animals. “It is the only known microRNA that is essential for the survival of one sex, but not the other,” says Dr Amir Fallahshahroudi, former postdoc in Prof. Kaessmann’s team at the ZMBH and current group leader at Uppsala University in Sweden.

According to Dr McGrew, the mechanism of the male-specific microRNA works like a dimmer switch, dialing down the overactive genes on the two male Z chromosomes. “Our findings show that birds have developed a distinct evolutionary solution to offset the genetic imbalance between sex chromosomes and ensure the survival of male animals,” he emphasizes. They also highlight that evolution can arrive at different solutions for the same biological problem – and that tiny genes can have a dramatic impact on survival. “We now have to ask whether other animal species also use microRNAs to regulate their sex chromosomes, or whether they rely on different systems entirely,” adds Prof. Kaessmann.

Alongside the researchers from Heidelberg, Edinburgh and Uppsala, scientists from Abu Dhabi and China were also involved in the study. This research was funded by various organizations and foundations, including the European Research Council, the NOMIS Foundation, the Swedish Research Council and the Biotechnology and Biological Sciences Research Council (UK). The results have been published in the journal “Nature”.

END


ELSE PRESS RELEASES FROM THIS DATE:

New insights into ovarian cancer: why whole-genome doubling may hold the key to future HGSOC treatment strategies

2025-07-16
Research led by Memorial Sloan Kettering Cancer Center (MSK) is shedding new light on how ovarian cancer evolves — insights that could help researchers develop more effective treatment strategies. While ovarian cancer diagnoses and deaths have decreased over recent decades, the disease remains a leading cause of cancer-related death in women. This is largely because the cancer often spreads at a microscopic level within the abdomen early on, resulting in diagnosis at an advanced stage when treatment is less effective. A ...

Battery sharing could cut energy costs for communities

2025-07-16
What if neighbourhoods could lower their electricity bills without investing in expensive battery systems? An international study led by researchers at CWI (the national research institute for mathematics and computer science in the Netherlands) suggests exactly that: by leasing capacity from large, commercially operated batteries, communities can access the benefits of energy storage without the high upfront costs or additional technical challenges. In collaboration with GIGA Storage, a leading operator of grid-connected batteries in the Netherlands, the University of Glasgow (UK) and ...

Expanded research tool to crack the code on Parkinson’s, the fastest-growing neurodegenerative disease

2025-07-16
WASHINGTON, D.C., (July 16, 2025) – Researchers now have a powerful new way to understand the types of brain cells that are affected in neurodegenerative diseases and to uncover connections between conditions such as Parkinson’s, Alzheimer’s, and other forms of dementia. The Aligning Science Across Parkinson’s (ASAP) initiative and Allen Institute are joining forces to unlock insights into Parkinson’s and other neurodegenerative diseases through an expansion of the Allen Brain Cell (ABC) Atlas visualization tool – uniting data from millions of human brain cells and enabling researchers to explore the brain ...

Can AI detect hidden heart disease?

2025-07-16
NEW YORK, NY (July 16, 2025)--With the help of artificial intelligence (AI), an inexpensive test found in many doctors’ offices may soon be used to screen for hidden heart disease.   Structural heart disease, including valve disease, congenital heart disease, and other issues that impair heart function, affects millions of people worldwide. Yet in the absence of a routine, affordable screening test, many structural heart problems go undetected until significant function has been lost.   “We have colonoscopies, we have mammograms, but we have ...

Simple rules govern soil microbiome responses to environmental change

2025-07-16
Just like any living organism, the soil has its own metabolism. Plants, worms, insects, and most importantly, microorganisms in the soil, break down organic matter, consume and generate nutrients, and process other materials to give the soil a life of its own. Soil microbiomes, which drive much of the metabolism in these ecosystems, are immensely complex – comprised of thousands of species with untold interactions and dynamics. Given the complexity of the soil, however, it can be nearly impossible to understand how the communities of microbes living there respond to changes in the environment, such as temperature, moisture, acidity, and nutrient availability. Solving this problem is ...

Researchers track the willingness of gun owners to temporarily store guns outside their homes

2025-07-16
Rutgers researchers have found that firearm owners are more likely to consider temporary out-of-home storage when worried about the safety of others. Their study reveals that firearm owners prioritize the safety of household members over their own self-protection when deciding whether to temporarily store their firearms outside the home. At the same time, many remain concerned about leaving the home defenseless. Researchers surveyed 3,018 U.S. adults living in households with firearms through an online survey. The respondents were asked who lived in a home with a firearm and their willingness to temporarily store their firearms with either ...

Living near St. Louis-area Coldwater Creek during childhood linked with higher risk of cancer from radiation

2025-07-16
Boston, MA—Living near Coldwater Creek—a Missouri River tributary north of St. Louis that was polluted by nuclear waste from the development of the first atomic bomb—in childhood in the 1940s, ’50s, and ’60s was associated with an elevated risk of cancer, according to a new study led by Harvard T.H. Chan School of Public Health. The researchers say the findings corroborate health concerns long held by community members. The study will be published July 16 in JAMA Network Open. It coincides with Congress having passed an expanded version of the Radiation Exposure Compensation Act (RECA) as part of the Trump tax ...

Prevalence of extremely severe obesity and metabolic dysfunction among US children and adolescents

2025-07-16
About The Study: In this nationally representative cross-sectional study of U.S. children and adolescents, prevalence of extremely severe obesity significantly increased over time, particularly among older adolescents and non-Hispanic Black participants. Extremely severe obesity was associated with severe metabolic and cardiovascular complications, including metabolic dysfunction–associated steatotic liver disease, prediabetes or diabetes, severe insulin resistance, and metabolic syndrome. These findings emphasize the urgent need for public health interventions and policies to address pediatric obesity broadly.  Corresponding Author: To contact the corresponding ...

Estimated burden of influenza and direct and indirect benefits of influenza vaccination

2025-07-16
About The Study: In this analytical model study, influenza vaccination provided substantial benefit in reducing infections to both the vaccinated and unvaccinated portions of the population. Even when both vaccine effectiveness and vaccine uptake were low, vaccination showed marked reductions in disease burden for transmission levels characteristic of seasonal influenza. However, when the level of transmission was very high, even a highly effective vaccine did not protect unvaccinated individuals. These findings underscore the importance of vaccination in disease prevention and ...

Projected health system and economic impacts of 2025 Medicaid policy proposals

2025-07-16
About The Study: This analysis indicates that proposed Medicaid reforms would have far-reaching consequences beyond federal budget savings, including negative health outcomes, economic losses, and health care system disruptions, with rural and underserved communities disproportionately affected. Corresponding Author: To contact the corresponding author, Sanjay Y. Basu, MD, PhD, email sanjay.basu@ucsf.edu. To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/ (doi:10.1001/jamahealthforum.2025.3187) Editor’s Note: Please see the article for additional information, including ...

LAST 30 PRESS RELEASES:

The American Ornithological Society announces its 2025 research grantees

Fetal exposure to vape liquids linked to changes in skull shape

Did a meteor impact trigger a landslide in the Grand Canyon?

Study suggests some maternal HIV infections may be missed during pregnancy

Bacterial genomes hold clues for creating personalized probiotics

Rice University scientists discover way to engineer stronger soft devices through smarter silicone bonding

Innovation Crossroads welcomes six entrepreneurs for Cohort 2025

Researchers explore ways to better safeguard romaine supply

Spider’s visual trickery can fool AI

During pregnancy, are newer antiseizure medications safer than older drugs?

Do race and ethnicity play a role in a person’s risk of peripheral neuropathy?

Older adults who increased their regular walking pace by just 14 steps per minute were more likely to experience clinically significant improvements in a test of aerobic capacity and walking endurance

For adults with hearing loss, linear amplification (amplification across all sound levels, available with some hearing aids) might restore their ability to recognize emotion in voices

Self-reporting climate anxiety in the United States is linked to being young, female, believing climate change will impact you personally, and more frequent media and community discussions around clim

A “silent epidemic” of stimulant use is shadowing the most recent opioid epidemic

Food insecurity causes anxiety and depression

New approach to kidney transplant matching could lead to better long-term outcomes

The patterns of elites who conceal their assets offshore

Elephant robot demonstrates bioinspired 3D printing technology

Walking slightly faster could help older adults stay fit

Private health industry lobby group uses marketing and publicity strategies similar to Big Tobacco and other unhealthy commodity industry groups

Government rollbacks of climate monitoring is a public health emergency

Robots that grow by consuming other robots

MD Anderson Research Highlights for July 16, 2025

Interbreeding with Neanderthals may be responsible for modern-day brain condition, SFU study finds

Tiny crystals provide insight to massive 2006 Augustine Volcano eruption

Six-month follow-up results announced from a first-of-its-kind robotic-assisted cerebral aneurysm embolization study

Why some elephants take more risks around people than others

Hope in sight for autosomal dominant optic atrophy (ADOA)

Snacking on avocado before bed may be linked to health impacts the next morning in adults with prediabetes

[Press-News.org] How a tiny gene ensures the survival of male birds
Researchers from Heidelberg and Edinburgh identify a mechanism that balances the genetic disparity between sex chromosomes