Zebrafish have long been studied by humans in the quest to unlock answers about skin and hair biology and disease.
Now scientists from Penn State College of Medicine, US, have developed a new technique that enables them to visualise every cell containing melanin pigment in 3D in whole zebrafish, potentially advancing our understanding even further.
Using a modified version of a CT imaging technique, previously developed by Dr Keith Cheng, professor of pathology, pharmacology and biochemistry and molecular biology, a student has been able to specifically investigate melanin in whole zebrafish.
The technique is a modification of Cheng’s X-ray histotomography – a cellular form of CT imaging; it allows for the study of the 3D architecture of cells in biological samples at extremely high resolution and clarity.
Part of Cheng’s team, medical scientist training programme student, Spencer Katz, used silver to stain the fishes’ melanin, allowing him to determine the 3D location and density of melanin from scans of whole zebrafish to the level of every melanocyte cell.
The work not only helps to answer questions pertaining to human skin and hair pigmentation, but also to diseases such as albinism and melanin-containing cancers or melanomas.
Previously, studying melanin – the brown to black pigment that gives colour to human skin – has been a challenge because it blocks the light used in traditional microscopy.
Melanin also gives zebrafish their stripes and, as a result, the study of the freshwater animal in relation to humans has been ongoing for years.
