Abstract # 94:

Scheduled for Thursday, June 18, 2015 06:00 PM-08:00 PM: (Cascade AJBCD) Poster Presentation


IS AMYLASE EXPRESSION BY THE HUMAN MAMMARY A GENUS HOMO SPECIFIC TRAIT?

M. L. Power1, M. M. Alonge1 and E. A. Quinn2
1Nutrition Laboratory, Conservation Ecology Center, National Zoological Park, Smithsonian Conservation Biology Institute, Washington, DC 20013, USA, 2Department of Anthropology, Washington University
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     Human milk contains salivary amylase, a starch-digesting enzyme. In humans, the salivary amylase gene has undergone multiple gene duplication events, such that amylase concentration in saliva and milk is highly variable. European and US public health officials recommend combining feeding starchy supplementary foods (e.g. cereals) with a nursing bout, or even mixing breast milk with the cereal to aid digestion. Milk amylase may have been an important adaptation allowing human infants to be provided with starchy supplemental foods at an early age. Gorilla and orangutan infants are nursed by their mothers for 3-5 years; this overlaps time periods when the infant is eating foods that may contain starch. Is the high concentration of amylase in human milk an enhancement of an existing condition, or is milk amylase a unique adaptation of genus Homo? Human milks and milks from three gorillas (Gorilla gorilla) and three orangutans (Pongo abelii and P. pygmaeus) were assayed for amylase activity. Human milks showed high and variable amylase activity (46-91 units/min). Milk from orangutans and one of the gorillas showed no amylase activity; milk from the other two gorillas showed very low activity (1-2 units/min). Since other enzymes potentially in milk can digest starch, the next step is to measure amylase peptide in gorilla milks that exhibit activity. These data suggest that mammary expression of amylase may be human specific.