Breast cells develop two nuclei as the lactation process to nurture the newborn begins, researchers said, uncovering one of the secrets to rich milk production.
This change begins to occur in late pregnancy with the generation of vast numbers of cells with two nuclei, researchers have said.
Using unique three-dimensional (3-D) imaging technology, they found huge numbers of cells became binucleated (developed a second nucleus) - a process that is critical to milk production.
The process - which lasts only for the duration of lactation - is important for the newborn to thrive when breast milk was the sole nutrient.
"We know that these cells are milk-producing factories. What is interesting to find is they change according to a very tightly regulated regime - they develop two nuclei, not three or four and then return to one nucleus after lactation," said Jane Visvader from Walter and Eliza Hall Institute in Australia.
"Presumably this is important to avoid mishaps," Visvader said.
The study showed how mammals, including humans, wallabies and seals, were primed to adapt to pregnancy in ways that best supported the survival of their babies, researchers said.
"Based on their presence in five different species, these findings suggest that this process has evolved in mammals as a mechanism to maximise milk production, which is essential for nourishing the newborn and the survival of mammalian species," said Geoff Lindeman from Walter and Eliza Hall Institute.
The findings were published in the journal Nature Communications.
