Milking It

Although milk production (lactation) is one of the defining features of mammals, such as mice and humans, we know relatively little about how milk is made. To find out what’s going on, researchers have developed a technique called intravital imaging to look inside living animal tissues. These strange green shapes, squirming under the microscope, are cells in a milk duct in the mammary gland of a live female mouse. The red blobs are fat droplets – one of the major components of milk. Following injection with oxytocin (a hormone that encourages lactation), fat droplets are released from cells in the ducts, with smaller droplets fusing together to create larger ones. Then they’re squeezed out of the duct by muscular contractions. This technique opens a window on the mysterious process of milk production, and could help to explain what happens when human mums struggle to produce enough milk to feed their babies.

Written by Kat Arney

Kat Arney

Writer

Dr Kat Arney is an award-winning science writer, broadcaster and public speaker, and is the founder and Creative Director of First Create The Media.

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• Image/video from work by Andrius Masedunskas and colleagues
• Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
• Image/video originally published under an Attribution–Share Alike 3.0-Unported (CC BY-SA 3.0) Creative Commons Licence
• Published in Molecular Biology of the Cell, April 2017