It is widely accepted that maternal folic acid (FA) deficiency during pregnancy is a risk factor for abnormal development. The tongue, with multiple genes working together in a coordinated cascade in time and place, has emerged as a target organ for testing the effect of FA during development. A FA-deficient (FAD) diet was administered to eight-week-old C57/BL/6J mouse females for 2-16 weeks. Pregnant dams were sacrificed at gestational day 17 (E17). The tongues and heads of 15 control and 210 experimental fetuses were studied. In the tongues, the maximum width, base width, height and area were compared with width, height and area of the head. All measurements decreased from 10% to 38% with increasing number of weeks on maternal FAD diet. Decreased head and tongue areas showed a harmonic reduction (Spearman nonparametric correlation, Rho = 0.802) with respect to weeks on a maternal FAD diet. Tongue congenital abnormalities showed a 10.9% prevalence, divided in aglossia (3.3%) and microglossia (7.6%), always accompanied by agnathia (5.6%) or micrognathia (5.2%). This is the first time that tongue alterations have been related experimentally to maternal FAD diet in mice. We propose that the tongue should be included in the list of FA-sensitive birth defect organs due to its relevance in several key food and nutrition processes.
Keywords: C57 mouse; aglossia; congenital abnormalities; head development; maternal folic acid-deficient diet; microglossia; tongue development.