Scientists from Cardiff University’s School of Biosciences reported that a father’s gene may have an impact on the quality of care that is furnished by the mother to her newborn offspring. One of the most crucial roles of a mother is being able to provide and attend to the needs of her offspring, especially during the time of conception up to the time of nursing the offspring. Good quality maternal care is essential to ensure a healthy development of the newborn and the recent study on mice suggests that a father’s gene may have an effect on the mother’s nurturing behavior towards her offspring before and after they are born.
Imprinting of genes
In humans, the zygote is a diploid cell that results from the union of two haploid sex cells. This means that the zygote will possess two copies of the genome, i.e. one coming from the mother and the other one from the father. The autosomal genes of the zygote would therefore occur in pairs or as two copies. Their expressions occur simultaneously except for a few genes whose expressions will depend on the parent-of-origin. Depending on the parent source, one of the gene copies will be imprinted, which means it will be ”silent”. For example, a father’s gene that is imprinted will be “silent” and will not be expressed but the other copy of the gene (from the mother) will be expressed, or “vice versa“. This phenomenon is called genomic imprinting. An imprinted gene is one in which the DNA is methylated. A methylated gene means that its expression is suppressed.1
Phlda2 gene – overview
Pleckstrin homology-like domain family A member 2 (Phlda2) gene is an example of a gene whose expression accords to the phenomenon of genomic imprinting. The gene is located in the cluster of imprinted genes on chromosome 11p15.5.2 It encodes for the Phlda2 protein. It was also found that only one copy of the Phlda2 gene is “switched on” and that the other copy of the gene that is “silent” comes from the father.3 In rodents, one of its physiological roles is identified to be associated with the regulation of the activity of the placental cells called spongiotrophoblasts, which are cells responsible for the production of placental hormones. It was reported that the Phlda2 gene controls their size, and therefore their hormone production activity. 3
Phlda2 gene – impact on mother’s behavior
Scientists from Cardiff University’s School of Biosciences found that female mice carrying pup embryos with two active Phlda2 genes, and thus with relatively higher Phlda2 levels and probably reduced placental hormone activity, exhibited decreased nursing and grooming of pups but with an increased focus in nest building. On the contrary, mothers carrying pup embryos with lower Phlda2 levels were more focused at nurturing their pups than on nest building. They also identified corresponding changes in the brain regions essential for maternal care behavior (particularly, hippocampus and hypothalamus) of the mothers during pregnancy. Their findings implicate that the Phlda2 gene activity may have an effect on the maternal care behavior of mice.3
Based on the recent findings, scientists speculate that Phlda2 gene activity may also have an impact in human pregnancies. Many regard motherhood as an epitome of a woman’s existence. Apparently, there are instances when the quality of maternal care provided to the child is inadequate due to various factors. If these findings are relevant to humans, then, this is a potential aspect to probe in order to understand the biology of maternal care behavior – one that involves Phlda2 gene.
— written by Maria Victoria Gonzaga
1 Genomic imprinting. (n.d.). Biology-Online Dictionary. Retrieved from https://www.biology-online.org/dictionary/Genomic_imprinting
2 PHLDA2 pleckstrin homology like domain family A member 2 [Homo sapiens (human)]. (8 July 2018). National Center for Biotechnology Information, U.S. National Library of Medicine. Retrieved from https://www.ncbi.nlm.nih.gov/gene?Db=gene&Cmd=ShowDetailView&TermToSearch=7262
3 Creeth, H.D.J., McNamara, G.I., Tunster, S.J., Boque-Sastre, R., Allen, B., Sumption, L., et al. (2018). Maternal care boosted by paternal imprinting in mammals. PLoS Biol, DOI: 10.1371/journal.pbio.2006599