University of Antwerp

Hidden within fish DNA are powerful genetic twists that may explain one of nature’s biggest mysteries: how new species form so quickly. In Lake Malawi, hundreds of cichlid fish species evolved at lightning speed, and scientists now think “flipped” sections of DNA—called chromosomal inversions—are the secret. These inversions lock together useful gene combinations, creating “supergenes” that help fish rapidly adapt to different environments, from deep waters to sandy shores.Researchers have uncovered a powerful genetic mechanism that may help explain how some species evolve with surprising speed. Certain sections of DNA, known as "flipped" segments, appear to help fish rapidly adapt to new environments and even split into entirely new species. These genetic features act like evolutionary accelerators, preserving useful traits and speeding up change. One of biology's biggest questions is how Earth became home to such a vast range of plants and animals. Cichlid fish in Lake Malawi, located in East Africa, provide a striking example. In this single lake, more than 800 species have emerged from a shared ancestor in far less time than it took humans and chimpanzees to diverge. Even more remarkable, all of this diversification occurred within the same body of water. Some cichlids evolved into predators, while others specialized in feeding on algae, sifting sand, or consuming plankton. Each species carved out its own ecological role despite living side by side. Scientists from the Universities of Cambridge and Antwerp set out to understand how this rapid burst of evolution was possible. Their findings were published in the journal Science. The Discovery of Flipped DNA Segments To investigate, researchers analyzed the DNA of more than 1,300 cichlid fish. They were searching for genetic features that could explain the unusually fast pace of evolution. "We discovered that, in some species, large chunks of DNA on five chromosomes are flipped -- a type of mutation called a chromosomal inversion," said senior author Hennes Svardal from the University of Antwerp. Under normal conditions, reproduction involves recombination, a process where DNA from both parents is mixed together. However, within these flipped regions, this mixing is blocked. As a result, groups of genes remain linked and are passed down intact from one generation to the next. This preserves combinations of traits that are already beneficial, allowing evolution to proceed more efficiently. "It's sort of like a toolbox where all the most useful tools are stuck together, preserving winning genetic combinations that help fish adapt to different environments," said first author Moritz Blumer from Cambridge's Department of Genetics. "Supergenes" and Rapid Adaptation These linked gene clusters are often referred to as 'supergenes. In cichlid fish, they appear to play a major role in shaping species differences. Even though different species can still interbreed, these inversions limit how much their DNA mixes, helping maintain distinct traits. This is especially important in areas where species overlap, such as open sandy regions of the lake where there are no clear physical boundaries separating habitats. Many of the genes within these supergenes influence traits essential for survival and reproduction, including vision, hearing, and behaviour. For instance, fish that live deep underwater (down to 200 meters) must cope with low light, high pressure, and different food sources compared to those near the surface. Their supergenes help preserve the specific adaptations needed for those conditions. "When different cichlid species interbred, entire inversions can be passed between them -- bringing along key survival traits, like adaptations to specific environments, speeding up the process of evolution," said Blumer. A Broader Role in Evolution Chromosomal inversions do more than preserve helpful traits. They can also function as sex chromosomes, influencing whether an individual develops as male or female. Because sex determination plays a role in how species form, this adds another layer to understanding evolution. "While our study focused on cichlids, chromosomal inversions aren't unique to them," said co-senior author Professor Richard Durbin, from Cambridge's Department of Genetics. "They're also found in many other animals -- including humans -- and are increasingly seen as a key factor in evolution and biodiversity." Researchers believe these findings could help answer a long-standing question about how life diversifies so rapidly under the right conditions. "We have been studying the process of speciation for a long time," said Svardal. "Now, by understanding how these supergenes evolve and spread, we're getting closer to answering one of science's big questions: how life on Earth becomes so rich and varied."

FRIDAY, Feb. 27, 2026 -- Perioperative enfortumab vedotin plus pembrolizumab and surgery lead to significantly better outcomes among patients with muscle-invasive bladder cancer who are ineligible for cisplatin -based chemotherapy compared with surgery alone, according to a study published online Feb. 18 in the New England Journal of Medicine . Christof Vulsteke, M.D., Ph.D., from Antwerp University in Belgium, and colleagues assessed whether perioperative therapy may improve outcomes among patients with muscle-invasive bladder cancer who are ineligible for cisplatin-based chemotherapy. The analysis included 344 participants randomly assigned to perioperative (neoadjuvant and adjuvant) enfortumab vedotin-pembrolizumab (170 patients) or surgery alone (control; 174 patients). The researchers found that at two years, estimated event-free survival was 74.7 percent in the enfortumab vedotin-pembrolizumab group versus 39.4 percent in the control group (hazard ratio for an event or death, 0.40). Estimated overall survival was 79.7 and 63.1 percent, respectively (hazard ratio for death, 0.50). A pathological complete response was achieved in 57.1 percent in the enfortumab vedotin-pembrolizumab group and 8.6 percent in the control group. All participants in the enfortumab vedotin-pembrolizumab group experienced adverse events (grade ≥3, 71.3 percent; grade ≥3 drug-related, 45.5 percent), as did 64.8 percent of patients in the control group (grade ≥3, 45.9 percent). "On the basis of this trial, the Food and Drug Administration approved neoadjuvant followed by adjuvant enfortumab vedotin plus pembrolizumab after cystectomy as a new treatment option for adults with muscle-invasive bladder cancer who are ineligible for cisplatin," the authors write. Several authors disclosed ties to pharmaceutical companies, including Merck Sharp and Dohme, which manufactures pembrolizumab and funded the study. Abstract/Full Text (subscription or payment may be required) Editorial (subscription or payment may be required)

COPENHAGEN, Denmark I June 26, 2025 I Bavarian Nordic A/S (OMX: BAVA) announced today the initiation of the first of two clinical trials designed to support approval and use of the MVA-BN ® mpox/smallpox vaccine in vulnerable populations: infants under 2 years of age and pregnant and breastfeeding women The first participants have been vaccinated in a study ( NCT06844487 ), evaluating the safety and immunogenicity of MVA-BN in 344 infants aged 4-24 months. Recruitment has also started in a second study ( NCT06844500 ), which is planned to enrol 359 women (pregnant or breastfeeding), also to be evaluated for safety and immunogenicity of MVA-BN. Both studies are conducted in the Democratic Republic of Congo (DRC), the epicentre of the ongoing mpox outbreak, where infants and pregnant women remain highly vulnerable to mpox. Paul Chaplin, President & CEO of Bavarian Nordic , said: “ Through partnerships we have made significant advances already by expanding access to our mpox vaccine for children and adolescents. These new studies will fill the gap by providing important data about the use of MVA-BN in infants and pregnant women, and we applaud the study partners as well as the funding partners, EDCTP3 and CEPI for supporting this important work which could help support a label expansion for MVA-BN to include the most vulnerable populations. ” Both studies are part of the PregInPoxVac research project, led by the University of Antwerp and the University of Kinshasa. The project is further supported by partners in Kenya (ACE Research) and Italy (Penta Foundation), funded by the European Union Global Health EDCTP3, the Coalition for Epidemic Preparedness Innovations (CEPI), and Bavarian Nordic. In addition, Bavarian Nordic is sponsoring a trial of MVA-BN in children aged 2-11 years, which has received funding support from CEPI. Topline results from this trial ( NCT06549530 ) are anticipated in the third quarter of 2025. Once full results become available, these could potentially support regulatory approval of MVA-BN for younger children. About the mpox vaccine MVA-BN or Modified Vaccinia Ankara-Bavarian Nordic is the only non-replicating mpox vaccine approved in the U.S., Switzerland, Singapore and Mexico (marketed as JYNNEOS ® ), Canada (marketed as IMVAMUNE ® ), and the EU/EAA and United Kingdom (marketed as IMVANEX ® ). Originally developed as a smallpox vaccine in collaboration with the U.S. government to ensure the supply of a smallpox vaccine for the entire population, including immunocompromised individuals who are not recommended vaccination with traditional replicating smallpox vaccines, MVA-BN has been indicated for use in the general population in individuals considered at risk for smallpox or mpox infection. About Bavarian Nordic Bavarian Nordic is a global vaccine company with a mission to improve health and save lives through innovative vaccines. We are a preferred supplier of mpox and smallpox vaccines to governments to enhance public health preparedness and have a leading portfolio of travel vaccines. For more information, visit www.bavarian-nordic.com . SOURCE: Bavarian Nordic