When you think of blood, chances are you think of the color red. But blood actually comes in a variety of colors, including red, blue, green, and purple. This rainbow of colors can be traced to the protein molecules that carry oxygen in the blood. Different proteins produce different colors.Continue reading “Roses are red and so is . . . blood?”
Ten years ago, Chris McCulloh planned to enter medical school and fulfill his dream of becoming a surgeon. Instead, just months before he was to start med school, he ended up a patient. A freak accident—slipping on a hardwood floor, flying backwards, and landing neck-first on the edge of a glass coffee table—left him with both legs paralyzed at age 28. Undaunted, he deferred entering medical school for a year, undergoing surgery and spending months in rehab.
McCulloh has since finished medical school and recently completed a 2-year pediatric surgery research fellowship at Nationwide Children’s Hospital in Columbus, Ohio. He is now two-thirds of the way through his surgical residency at the Morristown (New Jersey) Medical Center, thanks to the assistance of a specialized wheelchair that allows him to stand nearly to his 6-foot-3 height and helps him perform five to six surgeries a day.
He’s received plenty of attention for being a surgeon with a disability. Along with several print media stories, he was interviewed in 2013 for CBS’ “The Doctors,” and in 2017, ABC’s “20/20” included McCulloh in an episode on physicians with disabilities. But it’s not the wheelchair that distinguishes McCulloh, says Gail Besner, a pediatric surgeon and researcher who hired McCulloh as a postdoctoral fellow. Rather, it’s his enthusiasm, natural research skills, and exceptional surgical prowess that make him special. Besner sees no reason why he won’t reach his goal of landing a highly competitive pediatric surgical residency. “I think he’s capable of doing anything he puts his mind to,” she says.
Apart from the tell-tale stripes that give me my nickname, zebrafish, I look a lot like your standard minnow swimming in the shallows of any pond, lake, or river. But I like to think I’m more important than that. In fact, researchers around the world have turned to me and my extended family to understand some of the most basic mysteries of life. From studying us, they’re learning about how embryos develop, how cancer works, and whether someday humans might be able to rebuild a heart, repair a spinal cord injury, or regrow a severed limb.
Why us? Because zebrafish are pretty special and researchers think we’re easy to work with. First, unlike your standard lab mouse or rat, we lay lots of eggs, producing baby fish that grow up fast. We develop outside our mothers and go from egg to embryo to free-swimming larva in just 3 days (check out this video of how we grow, cell by cell, during the first 24 hours). Within 3 months, we’re fully mature.
Not only do zebrafish moms have many babies at the same time, and not only do these babies grow up quickly, but our eggs and embryos are see-through, so scientists can literally watch us grow one cell at a time. We stay mostly transparent for a few weeks after hatching. That makes it super easy for scientists to monitor us for both normal and abnormal development. In fact, scientists have learned how to turn off the genes that give our skin its color. These zebrafish, named casper, after the “friendly ghost” of cartoon fame, stay semi-transparent, or translucent, through adulthood.
And last, but certainly not least, did I mention that we can regenerate? If parts of my body are damaged, even to a significant degree, they can regrow. This holds true for my heart, fins, spinal cord, and even brain tissue. Our regenerative capacity is seemingly unlimited; my caudal fin, for example, can grow back dozens of times. Continue reading “Zebrafish Scrapbook”
If you’ve ever visited an aquarium or snorkeled along a coral reef, you’ve witnessed the dazzling colors and patterns on tropical fish. The iridescent stripes and dots come from pigment cells, which also tint skin, hair and eyes in all kinds of animals, including humans. Typically, bright colors help attract mates, while dull ones provide camouflage. In humans, pigment helps protect skin from DNA-damaging UV light.
Researchers study cellular hues not only to decipher how they color our world, but also to understand skin cancers that originate from pigment cells. Some of these researchers work their way back, developmentally speaking, to focus on the type of cell, known as a neural crest cell, that is the precursor of pigment cells.
Present at the earliest stages of development, neural crest cells migrate throughout an embryo and transform into many different types of cells and tissues, including nerve cells, cartilage, bone and skin. The images here, from research on neural crest cells in fish and salamanders, showcase the beauty and versatility of pigment cells in nature’s palette.