Gee thanks, Dad!

A study published three days ago in the journal Science investigates the hypothesis that physiological effects of life experiences may be inherited by a man's offspring, through epigenetic markers maintain in his sperm. As CpG methylation of DNA has shown to be seldom passed from germ-line cells to sperm and subsequent posterity, this team of scientists from Canadian and Swiss universities instead looked at methylation of the histones that DNA intertwines itself with in vivo. In human sperm, when germ-line cells undergo the final stages of spermatogenesis, 85% of histones are removed from the nuclear DNA so that the genetic material may condense itself to fit in the tiny sperm cell; in the remaining 15% of histones, however, methylation or demethylation of the histones may have effects on offspring and possibly even subsequent generations. Here, the researchers overexpress human KDM1A histone lysine 2 demethylase in male transgenic mice and find that offspring overwhelming present birth defects, mortality, and changes in the their transcriptome; even if an offspring was born from a sperm that happened not to carry the transgenic KDM1A, the mouse exhibited changes in histone methylation resultant from KDM1A overexpression in the parent testis. This may bear implications for humans as well---our fathers' and even our grandfathers' mutagenic experiences, if affecting epigenetic controls in reproductively relevant tissue, may have ramifications in our own bodies today.

Fig. 1 - "The Force is strong in my family." - Luke Skywalker commenting on the heritability of communing with the Force, after learning that Darth Vader / Anakin is his father. This lends to the hypothesis that strength in the Force is related to epigenetic events in the paternal lineage.