Maternal Exercise Activates Genes Associated with Mitochondrial Biogenesis in Fetal Myocardium of Mouse

Maternal exercise during pregnancy has been shown to improve long-term metabolic health on offspring in later life. Mitochondria are the critical site of metabolism, and are inherited by maternal origin. However, the effects of maternal exercise during pregnancy on fetal mitochondrial biogenesis are not well understood. PURPOSE: To test whether maternal exercise can activate genes associate with mitochondrial biogenesis in the fetal heart. METHODS: Female C57BL/6 mice were divided into sedentary and exercise groups. The mice in the exercise group were exposed to voluntary cage-wheel from gestational day 1 through 17, at which time they were sacrificed. Litter size and individual fetal weights (3 days before birth) were taken when pregnant dams were sacrificed. All fetuses were sexed and two to three hearts from same sex within the group were pooled to study gene expression: all data were presented by group since there was no sex difference within group. RESULTS: Exercise dams ran an average of 7.22 ± 0.41km/day until mid-pregnancy and gradually decreased to low levels (1.39 ± 0.43 km/day) through the remainder of gestation. Weight gain during pregnancy was not significantly different between exercise (14.45 ± 0.99g) and sedentary (15.99 ± 1.13g) pregnant dams. There were no significant differences in litter size, sex distribution, and average fetal body weight per litter between sedentary and exercise dams. Genes associated with mitochondrial biogenesis, including Ppargc1a (peroxisome proliferator-activated receptor gamma, coactivator 1 alpha), Nrf1 (nuclear respiratory factor-1), and Nrf2 (nuclear respiratory factor-2) were significantly upregulated in fetuses from exercise dams. CONCLUSION: Although total kilometers run per day (km/day) were significantly decreased in later stage of pregnancy, maternal exercise initiated at day 1 of gestation significantly increased genes associated with mitochondria biogenesis, indicating that maternal exercise enhances mitochondrial biogenesis and mitochondrial function

The interaction of nutrition and fertility among Au Forager-Horticulturalists of Papua New Guinea

The major goals of this study were to examine the effects of repeated reproductive episodes on the nutritional status of mothers, and on the growth and development of their offspring in a small natural fertility population. The study was conducted over a 16 month period among the Au forager-horticulturalists of Papua New Guinea. Anthropometric, bioelectrical impedance, and hematological measures of nutritional status were taken on 500 Au mothers of known ages and parities. Birth weights and data on weight and recumbent length were collected for 800 Au children aged 0 to 5 years. Finally, data on breast-feeding and supplementation patterns, and duration of postpartum amenorrhea were collected for 300 mother-offspring pairs. A series of probit analyses indicates that the Au have one of the longest durations of breast-feeding (43 months), and postpartum amenorrhea (25 months) ever reported. Moreover, when a sample of over 400 mothers is stratified by percent body fat, an inverse relationship between fatness and the duration of postpartum amenorrhea is apparent. Neither differences in breast-feeding patterns, nor supplementation can completely account for this effect. Thus, this study demonstrates a significant effect of maternal nutritional status on postpartum amenorrhea independent of breast-feeding patterns. Another major finding of this research is that the adiposity of Au mothers declines throughout the period of lactation. This short-term decline in adiposity also continues over successive reproductive episodes. Thus, Au mothers exhibit a progressive depletion of their stored energy reserves over the course of their reproductive life spans. This finding corroborates the prediction of evolutionary theory that organisms engage in trade-offs between their reproductive and somatic energy budgets, and that every round of reproduction entails a reduction in the residual reproductive energy of the parent. Finally, although the birth weights of Au neonates and their growth velocity during the first 5 years of life are extremely low, no birth order-related variation in either prenatal or postnatal growth was detected. This suggests that fertility-related maternal depletion may be a coping mechanism that assists chronically-undernourished mothers in producing viable offspring.Ph.D.Health and Environmental SciencesNutritionPhysical anthropologySocial SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/128781/2/9135710.pd

The 'Spiteful' origins of human cooperation

We analyse generosity, second-party (‘spiteful’) punishment (2PP), and third-party (‘altruistic’) punishment (3PP) in a cross-cultural experimental economics project. We show that smaller societies are less generous in the Dictator Game but no less prone to 2PP in the Ultimatum Game. We might assume people everywhere would be more willing to punish someone who hurt them directly (2PP) than someone who hurt an anonymous third person (3PP). While this is true of small societies, people in large societies are actually more likely to engage in 3PP than 2PP. Strong reciprocity, including generous offers and 3PP, exists mostly in large, complex societies that face numerous challenging collective action problems. We argue that ‘spiteful’ 2PP, motivated by the basic emotion of anger, is more universal than 3PP and sufficient to explain the origins of human cooperation

Homo Æqualis: A Cross-Society Experimental Analysis of Three Bargaining Games ∗

Abstract. Data from three bargaining games—the Dictator Game, the Ultimatum Game, and the Third-Party Punishment Game—played in 15 societies are presented. The societies range from US undergraduates to Amazonian, Arctic, and African hunter-gatherers. Behaviour within the games varies markedly across societies. The paper investigates whether this behavioural diversity can be explained solely by variations in inequality aversion. Combining a single parameter utility function with the notion of subgame perfection generates a number of testable predictions. While most of these are supported, there are some telling divergences between theory and data: uncertainty and preferences relating to acts of vengeance may have influenced play in the Ultimatum and Third-Party Punishment Games; and a few subjects used the games as an opportunity to engage in costly signalling. 1