Scientists at Academia Sinica have identified a new form of cell division that occurs without the replication of DNA, challenging the scientific consensus on one of the most basic biological processes.
Since the 19th century, scientists have known of only two main types of cell division in animals — meiosis in germ cells (sperm or egg cells) and mitosis in somatic cells, which comprise all other cells in the body.
However, in a new paper published in the British scientific journal Nature, an Academia Sinica team described a previously unknown form of cell division which, unlike mitosis, does not involve the duplication of DNA.
Photo courtesy of Academia Sinica
The team, led by Chen Chen-hui (陳振輝), an assistant research fellow at the academy’s Institute of Cellular and Organismic Biology, held a news conference on Monday to explain their findings.
To conduct the research, Chen’s team used a custom-made computer tagging system to color and track individual cells on zebrafish larvae as they developed.
To do so, the researchers had to catch and anesthetize the 0.5cm fish every 12 hours and photograph them under a high-powered microscope.
They discovered that during a specific stage in the fishes’ growth, some of the outer layers of their skin cells underwent up to two rounds of cell division (one cell becoming four cells) by splitting, rather than duplicating, their DNA.
The phenomenon, called asynthetic fission, is a temporary measure used to expand the coverage of epithelial cells, or outer skin cells, during a period of rapid growth, Chen said.
According to a video produced by Nature, the process happens so quickly that cells even appeared to make “mistakes,” such as not cleanly separating the DNA between the new cells.
However, within a few weeks the zebrafish get rid of the unusual cells and replace them with regular cells containing normal amounts of DNA, the video said.
While the team is still in the early stages of understanding the process, this mode of cell proliferation might occur in contexts beyond zebrafish skin expansion, Chen said.
The article, titled Skin cells undergo asynthetic fission to expand body surfaces in zebrafish, was published on Wednesday last week.
The journal’s video on the research, A new kind of cell division, was released on Sunday.
Actor Darren Wang (王大陸) was questioned by prosecutors for allegedly orchestrating an attack on a taxi driver after he was allegedly driven on a longer than necessary route in a car he disliked. The questioning at the New Taipei City District Prosecutors’ Office was ongoing as of press time last night. Police have recommended charges of attempted murder. The legally embattled actor — known for his role in the coming-of-age film Our Times (我的少女時代) — is under a separate investigation for allegedly using fake medical documents to evade mandatory military service. According to local media reports, police said Wang earlier last year ordered a
CAUTION: Based on intelligence from the nation’s security agencies, MOFA has cautioned Taiwanese travelers about heightened safety risks in China-friendly countries The Ministry of Foreign Affairs (MOFA) yesterday urged Taiwanese to be aware of their safety when traveling abroad, especially in countries that are friendly to China. China in June last year issued 22 guidelines that allow its courts to try in absentia and sentence to death so-called “diehard” Taiwanese independence activists, even though Chinese courts have no jurisdiction in Taiwan. Late last month, a senior Chinese official gave closed-door instructions to state security units to implement the guidelines in countries friendly to China, a government memo and a senior Taiwan security official said, based on information gathered by Taiwan’s intelligence agency. The
President William Lai (賴清德) should protect Taiwan Semiconductor Manufacturing Co (TSMC), and stop supporting domestic strife and discord, former president Ma Ying-jeou (馬英九) wrote on Facebook yesterday. US President Donald Trump and TSMC on Monday jointly announced that the company would invest an additional US$100 billion over the next few years to expand its semiconductor manufacturing operations in the US. The TSMC plans have promoted concern in Taiwan that it would effectively lead to the chipmaking giant becoming Americanized. The Lai administration lacks tangible policies to address concerns that Taiwan might follow in Ukraine’s footsteps, Ma wrote. Instead, it seems to think it could
Taiwan Semiconductor Manufacturing Co (TSMC), the world’s largest contract chipmaker, said yesterday that it is looking to hire 8,000 people this year, at a time when the tech giant is expanding production capacity to maintain its lead over competitors. To attract talent, TSMC would launch a large-scale recruitment campaign on campuses across Taiwan, where a newly recruited engineer with a master’s degree could expect to receive an average salary of NT$2.2 million (US$60,912), which is much higher than the 2023 national average of NT$709,000 for those in the same category, according to government statistics. TSMC, which accounted for more than 60 percent
RSS