News Release, National Institutes of Health
Many human cells are adorned with hair-like projections called cilia. Scientists now realize that these specialized structures play many important roles throughout the body, including directing or sensing various signals such as fluid flow. Their improper function has been linked to a wide range of health conditions, such as kidney disease, scoliosis, and obesity.
Studying cilia in people can be pretty challenging. It’s less tricky in a commonly used model organism: Xenopus laevis, or the African clawed frog. This image highlights a healthy patch of motile cilia (yellow) on embryonic skin cells (red) of Xenopus laevis. The cilia found in humans and all other vertebrates are built from essentially the same elongated structures known as microtubules. That’s why researchers can learn a lot about human cilia by studying frogs.
Vanja Krneta-Stankic, a Ph.D. student in Rachel K. Miller’s lab at McGovern Medical School, University of Texas Health Science Center at Houston, snapped this image using a confocal microscope equipped with super-resolution capabilities. The cilia that you see here keep water moving over the skin of newly hatched frog tadpoles, preventing bacteria from accumulating before they are old enough to swim.
As fascinating as the process of frog development may be, Krneta-Stankic’s primary research interest is to understand the role of cilia in sensing fluid flow in the tubules of human kidneys. These tubules help collect urine and move it on to the bladder. The Miller lab wants to understand how abnormalities in the formation or function of cilia may lead to the formation of kidney cysts, a condition that can progress to kidney failure.
Kidney cysts are common among children born with genetic conditions characterized by cilia defects, which are collectively known as ciliopathies. The hope is that these studies in frogs will allow scientists to take a leap forward in understanding how to help such kids. In the meantime, this work is generating some real eye-catching photos like this one, a winner in the Federation of American Societies for Experimental Biology’s 2017 BioArt competition.