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A digital reconstruction of the juvenile skull found in Hualongdong, China.Credit: Xiujie Wu
Jawbone hints at new human species
A 300,000-year-old jawbone discovered in a cave in eastern China could represent a new branch of the human family tree. The bone bears a curious mix of modern and archaic features: it’s thick along the jawline, a feature shared with early human species, and lacks the true chin of Homo sapiens. But the side of the mandible is more reminiscent of that of modern humans. The finding deepens the mystery of which ancient human species inhabited East Asia during the Pleistocene, and whether any of them could be ancestors of modern humans.
Reference: Journal of Human Evolution paper
Base-editing tool makes a clinical-trial debut
Base editing is being used in a US clinical trial to test more complex genome edits in humans than ever. Researchers tweaked the genes of immune cells from healthy people and gave the cells to a person with a hard-to-treat form of leukaemia. Base editing is a high-precision successor to CRISPR genome editing that generally cuts only one strand of DNA (CRISPR cuts both). The result is fewer unwanted edits. Even so, researchers will be watching these first clinical trials closely. “Any kind of gene editing should come with serious concern for possible safety impacts,” says paediatric oncologist Caroline Diorio.
Reference: New England Journal of Medicine paper & Nature Biotechnology paper
How brain cells die in Alzheimer’s
Neurons undergo ‘cellular suicide’ in response to amyloid plaques, the tangles of abnormal proteins that accumulate in the brains of people with Alzheimer’s disease. It’s the first clue to a mechanism that has eluded scientists for decades. In the presence of plaques, brain cells increase expression of a gene that triggers programmed cell death. When the gene was blocked, the neurons survived.
Conservationist released from Iran prison
Morad Tahbaz, the co-founder of a wildlife-conservation charity, is among the small group of US citizens who have been released by Iran in a prisoner-swap deal with the United States. Businessman Siamak Namazi, who was also released, made a statement highlighting those left behind, including Tahbaz’s seven colleagues (the charity’s other co-founder, sociologist Kavous Seyed Emami, died in jail). “People like Niloufar Bayani, Sepideh Kashani, Houman Jokar, Taher Ghadirian, Amirhossein Khaleghi, and Sam Rajabi — the renowned environmentalists whose eminent goodness shines so vividly that it can illuminate Evin Prison’s bleakest cells,” wrote Namazi.
The Independent | 4 min read & CBC | 5 min read
Read more: Global science must stand up for Iran’s imprisoned scholars (Nature | 4 min read, from 2022, paywall)
Reference: Siamak Namazi statement
Features & opinion
Cryo-ET catches proteins at play
Cryo-electron tomography (cryo-ET) could help to visualize the real-world interplay of proteins in their cellular environment. “We see everything, so that comes with the opportunity to observe unexpected things,” says structural biologist Wolfgang Baumeister. “But it comes also with the huge challenge of identifying and annotating all the densities we see in the tomogram.” Researchers are still working out how best to get to the proteins that interest them in the densely packed environment of the cell — and how to turn the grainy monochrome static of raw cryo-ET data into useful images.
Pointers for getting a promotion
For researchers in industry, it’s not unusual to move from bench-based work to science-related, non-research positions. “I think one of the biggest challenges is knowing what you need to do,” or what drives you, says Kathleen Engelbrecht, research manager at the personal-care company Kimberly-Clark. Here are some tips for planning a move into a new role:
• Tell your manager about your career goals
• Network with colleagues outside your immediate team
• Look for opportunities to join projects outside your department
Image of the week
The prehistoric carvers who carpeted the Doro! Nawas mountains with rock art were good — and now we know just how good, thanks to present-day Indigenous trackers. Hundreds of the carvings, in what is now Namibia, represent human and animal footprints. “The experts were able to define the species, sex, age group and exact leg of the specific animal or human depicted in more than 90% of the engravings they analysed,” say the authors of a study published this month. The detailed descriptions “go well beyond the general ability of archaeologists to fully appreciate such engravings”, says anthropologist Gary Haynes. (Science | 5 min read)
