Obese Male Mice Father Offspring With Higher Levels of Body Fat (its not only mums epigenetics that matter!?)

http://www.sciencedaily.com/releases/2013/06/130616155202.htm

To conduct the study, the researchers fed male mice a high-fat diet for 13 weeks before mating. (The female mates were fed a matched low-fat diet.) Male and female offspring were fed a standard low-fat diet and studied at 20 days, six weeks and at six and 12 months. [ to me this suggests that the effects are solely transmited by the male, and probably reflect epigenetic change in either choice of gene transfer (heresy I hear you cry!), or aspects of gene expression. The fact that it is from the male father is what makes things of interest. So its not just mum's health before and during pregnancy and breast feeding that is key, but also likely the father's state of health... (even if it turns out to be less so?)

Compared with offspring from control mice (who were fed the low-fat diet), the male offspring of paternal mice with diet-induced obesity had higher body weight at six weeks of age. They also were more obese at the six- and 12-month study markers. In addition, the male offspring of obese fathers had different patterns of body fat composition -- a marker for health and propensity for disease -- than the control mice.

The researchers were surprised, however, to find that the offspring of the obese paternal mice also were more physically active. At six weeks, the male offspring voluntarily ran more, and their female siblings demonstrated the same behavior at six and 12 months, the scientists report. Nowak's team is studying possible causes for this behavior, which might offset the increased body fat and reduce the offspring's risk of metabolic disease such as diabetes and heart disease.

It's not only mum's that have to worry about epigenetics:

http://www.sciencedaily.com/releases/2013/06/130612132656.htm
A father's life stress exposure leaves a mark on a sperms epigenetics, which can affect offsprings brain development!

While environmental challenges, like diet, drug abuse, and chronic stress, felt by mothers during pregnancy have been shown to affect offspring neurodevelopment and increase the risk for certain diseases, dad's influence on his children are less well understood. 

...stress on preadolescent and adult male mice induced an epigenetic mark in their sperm that reprogrammed their offspring's hypothalamic-pituitary-adrenal (HPA) axis, a region of the brain that governs responses to stress. Surprisingly, both male and female offspring had abnormally low reactivity to stress...Researchers found that offspring from paternal stress groups displayed significantly blunted levels of the stress hormone corticosterone -- in humans, it's cortisol -- in response to stress...This stress pathway dysregulation -- when reactivity is either heightened or reduced -- is a sign that an organism doesn't have the ability to respond appropriately to a changing environment. And as a result, their stress response becomes irregular, which can lead to stress-related disorders.

believed mechanism by which this happens = increased expression of glucocorticoid-responsive genes in the PVN, a change that supports a possible mechanism whereby increased negative feedback sensitivity may be explained.
Also = microRNAs (miRs) in the sperm that uniquely contribute to post-fertilization gene expression to examine the epigenetic mechanisms of transmission to the next generation. - In both groups of stressed dads, there was a significant increase in expression of nine miRs. These miRs may be targeting the stored maternal messenger RNAs in the egg at fertilization, so that dad's sperm can regulate some aspect of early development to inform his offspring about the environment, according to the authors.

They also point out that a reduced physiological stress response may reflect some adaptive evolutionary benefit passed on to offspring to ensure survival in what is expected to be a more stressful environment.