Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA.
Am J Phys Anthropol. 2013 May;151(1):144-50. doi: 10.1002/ajpa.22229. Epub 2013 Feb 28.
Mother's milk provides building blocks necessary for infant development and growth postnatally. Minerals in milk are particularly important for infant skeletal development and may reflect maternal characteristics that are associated with the capacity to synthesize milk and sex-specific developmental priorities of the infant. Using a large sample of mother-infant dyads assigned to the outdoor breeding colony at the California National Primate Research Center (N=104), we investigated the relationship of milk calcium (Ca) and phosphorus (P) concentrations and the ratio of Ca/P to maternal and infant characteristics and to other milk variables. Ca and P are largely associated with casein micelles, and as expected, both Ca and P were positively correlated with protein concentrations in milk. Neither Ca nor P concentrations were associated with maternal parity. Mothers rearing daughters tended to produce higher mean Ca concentration in milk, and consequently a higher Ca/P ratio, than did mothers rearing sons, even though protein concentration was not elevated. These results suggest that the Ca/P ratio in rhesus milk may have been under separate selective pressure from protein content to facilitate the accelerated rate of skeletal calcification that has been observed in female Macaca mulatta infants.
母乳为婴儿出生后发育和生长提供必需的构建块。牛奶中的矿物质对婴儿骨骼发育尤为重要，可能反映了与合成乳汁能力相关的母体特征，以及与婴儿性别特定发育优先事项相关的特征。本研究使用了在加利福尼亚国家灵长类动物研究中心（CNPRC）户外繁殖群体中分配给母婴对的大量样本（N=104），调查了牛奶中钙（Ca）和磷（P）浓度以及 Ca/P 比值与母体和婴儿特征以及其他牛奶变量的关系。Ca 和 P 主要与酪蛋白胶束相关，与预期一致，Ca 和 P 均与牛奶中的蛋白质浓度呈正相关。Ca 和 P 浓度均与母亲的产次无关。与养育儿子的母亲相比，养育女儿的母亲的牛奶中 Ca 浓度均值更高，因此 Ca/P 比值也更高，尽管蛋白质浓度并未升高。这些结果表明，恒河猴奶中的 Ca/P 比值可能受到与蛋白质含量分开的选择性压力，以促进在雌性猕猴婴儿中观察到的加速骨骼钙化速度。
