Izaiah Ornelas
Borrowing Gene Switches from Across the Tree of Life
Working with understudied animals offers scientists major opportunities for discovery — but also presents cumbersome technical challenges. Gilliam Fellow Izaiah Ornelas is working to help reduce some of those barriers.
At the University of California, Berkeley, Ornelas is earning his PhD in Hanna Gray Fellow James Nuñez’s labexternal link, opens in a new tab. They partnered with the Shih lab to test over 300 chromatin regulators sourced from a wide variety of species across plants, animals, fungi, and other complex life forms. Chromatin regulators are proteins that control DNA accessibility, and scientists use them to turn specific genes on and off.
The team showed that most regulators display species-specific activity, but a few exceptional ones functioned across organisms — including plant-derived activation proteins that can outperform commonly used gene activation tools in human cells. In doing so, they not only identifiedexternal link, opens in a new tab regulators that are functional across species but also expanded the available toolkit for synthetic gene regulation across plants and human cells.
“We found two chromatin regulators, RCOR1 and MTA2, that function as kinds of universal repressors — they can turn off genes across biological kingdoms, from mammals to plants to fungi,” Ornelas explains. “We hope that they will be a helpful starting point for scientists studying species that lack well-developed genetic tools.”
Destiny Tiburcio
The Hidden Chemicals that May Be Fueling Breast Cancer
If only 5–10% of breast cancer cases are hereditary, what role might environmental and lifestyle factors play in the rest? This question underlies Gilliam Fellow Destiny Tiburcio’s recent review of phthalatesexternal link, opens in a new tab as a potential environmental contributor to breast cancer.
Phthalates are widespread chemicals found in plastics, cosmetics, food packaging, and some medical devices. In the review, Tiburcio and her colleagues summarize evidence suggesting that phthalates may promote tumor growth, increase their aggressiveness, reduce treatment effectiveness, and support metastasis.
“Phthalates are endocrine disruptors, which means that they interfere with proper hormonal function,” explains Tiburcio, a PhD student in Michal Toborek’s labexternal link, opens in a new tab at the University of Miami Miller School of Medicine. Evidence suggests some phthalates can also mimic estrogen-like activity and affect estrogen signaling. The review also describes evidence that phthalates may contribute to epithelial-mesenchymal transition, a process that can make cells more mobile and invasive.
“Phthalates are so pervasive — there’s evidence that we’re even exposed in utero. My hope is to educate people on how their environment and behavior can impact health in ways they may not even realize.”
Media Contact: Halea Kerr-Layton, Media Relations Manager [email protected]
Media Contact: Halea Kerr-Layton, Media Relations Manager [email protected]