When a mammal has a baby, the mother and father support the success of their offspring — but their interests are somewhat at odds with each other. During pregnancy, a female is primed to become a mother through epigenetics and hormonal changes, and these changes can produce motherly behaviors which increase the “biological fitness” of the mother or the father of the child. In a new study published in PLOS Biology titled “Maternal care boosted by paternal imprinting in mammals” researchers looked at how the activation or deactivation of a gene called Phlda2 (pleckstrin homology-like domain family A member 2) during pregnancy influenced the behavior of mammal mothers after giving birth. (1) Researchers found the Phlda2 gene negatively regulates hormone production in the placenta of pregnant mammals called the spongiotrophoblast.

Differences in maternal care of mothers with Phlda2 turned “on” or “off”

Silencing, or deactivation of Phlda2 increased the quality of maternal care in mammals. Mothers giving birth to offspring with Phlda2 deactivated increased the nurturing of offspring, and self-directed behavior towards offspring in general, but decreased nest building. On the other hand, mothers who had the Phlda2 genes turned on, or activated, exhibited behaviors of increased nest building and less nursing behaviors towards their offspring.

Are the activity of genes during pregnancy altering behavior post pregnancy?

According to the mentioned study, the activity of genes during pregnancy does result in behavior changes post pregnancy. If both Phlda2 genes are “on” the mother exhibits behavior that benefits herself more than her children. She will spend more time preparing her environment for another future pregnancy and give less attention toward caring for herself and her children. Researchers categorized this behavior as “maternal” because it benefits the mother’s biological fitness the most. On the other hand, when both Phlda2 genes are turned “off” the mother puts more energy into caring for herself and the nurturing of her children. Researchers categorized this behavior as “paternal” because it benefits the biological fitness of the father the most, by increasing the survival and vitality of the children.

Conclusion

Epigenetics role in pregnancy and post-pregnancy becomes evident with this first of its kind study. The link  is clear between gene activity, pregnancy and post-pregnancy behavior. This study raises plenty of logistical and ethical questions. In the future, will genes be turned on or off to produce desirable maternal behavior? Can we increase the survival rates of species at risk or endangered? Does gene activity in human pregnancy produce similar outcomes with maternal behavior? These are all questions that need to be asked. Given a choice, do you think we should attempt to influence maternal behavior post-pregnancy through silencing or activating specific genes? Comment below with your thoughts.

Reference

1. Creeth, H. D. J., McNamara, G. I., Tunster, S. J., Boque-Sastre, R., Allen, B., Sumption, L., ... & John, R. M. (2018). Maternal care boosted by paternal imprinting in mammals. PLoS biology, 16(7), e2006599.