Summary: Researchers uncovered how both maternal and fetal genes, alongside nutritional factors, influence the development of a baby’s cerebral cortex. Their research, leveraging the UK Biobank’s extensive data, found a direct association between higher birth weight, influenced by specific genetic variants, and increased cortical surface area.
The study highlights the significant roles of fetal insulin-related genes and maternal genes aiding toxin elimination in brain growth. Intriguingly, exposure to nutritional stresses like wartime famine showed a generational impact, emphasizing the critical interplay between genetics and environmental factors in prenatal and early life brain development.
Key Facts:
- Genetic and Nutritional Influences: Genetic variants in both the mother and baby that contribute to birth weight are closely linked to the growth of the cerebral cortex, with maternal and fetal genes playing distinct roles.
- Impact of Food Availability: The study demonstrates that the availability of food can modulate the influence of these genetic variants on brain development, with maternal detoxification genes being more crucial during times of famine.
- Generational Effects: Exposure to extreme conditions such as the Dutch winter famine of 1944-45 highlighted the enduring impact of maternal genes on offspring’s cortical development, suggesting a transgenerational transmission of adaptive traits.
Source: University of Montreal
A new population-based study led by CHU Sainte-Justine researcher and Université de Montréal medical professor Tomas Paus reveals the roles of maternal and fetal genes in the growth of a baby’s cerebral cortex.
Published last week in Nature Communications, the study shows that genetic variants associated with higher birth weight are also associated with greater growth of the cerebral cortex.
However, food abundance or scarcity seems to influence the extent of the role played by the genes of the mother and the unborn baby.
With postdoctoral fellow Daniel Vosberg, Paus analyzed birth weight, birthweight genes and brain magnetic resonance imaging (MRI) data from several thousand adults in the UK Biobank, a biomedical database in the United Kingdom.
These analyses confirmed that higher birth weight is associated with larger cortex size (measured by surface area). In addition, the genetic variants present in the mother and baby that are associated with birthweight are also associated with cortical surface. In the baby, genes associated with insulin action are decisive, while in the mother, genetic variants favoring toxin elimination at the cellular level play a major role.
The two groups of genetic variants are not always equally important in determining cortex size.
“By comparing data by birth year and using statistical modeling and cellular interaction analysis, we’ve demonstrated the role of exposure to food restriction during gestation or infancy,” said Paus.
Exposed to wartime famine
In those who were exposed to wartime famine during the “Dutch winter” of 1944–45, maternal detoxification genes had the greatest impact on cortical growth.
This trait seems to be transmitted from one generation to the next, since the association is also found in the children of people who were thus exposed. In others, cortical growth is mainly associated with genes associated with fetal insulin action.
The analyses suggest that the genes that counteract the negative effects of food restriction, particularly in terms of cellular stress and immune activation, are critical.
“In times of famine, when cells are multiplying, the risk of errors is much greater,” said Paus. “That could explain why, in this context, the genes responsible for DNA repair are decisive for the baby’s brain growth.”
With a better understanding of the relationship between low birth weight and brain growth, and the importance of malnourishment as a mediating factor, the researchers will next evaluate the best way to promote cortical growth after birth in small babies.
In collaboration with CHU Sainte-Justine pediatrician and UdeM clinical associate professor Thuy Mai Luu, “we’ll soon be launching a pilot project to determine the best way to support optimal brain development in low-birth-weight babies,” said Paus.
About this genetics and neurodevelopment research news
Author: Tomas Paus
Source: University of Montreal
Contact: Tomas Paus – University of Montreal
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Intrauterine growth and the tangential expansion of the human cerebral cortex in times of food scarcity and abundance” by Tomas Paus et al. Nature Communications
Abstract
Intrauterine growth and the tangential expansion of the human cerebral cortex in times of food scarcity and abundance
Tangential growth of the human cerebral cortex is driven by cell proliferation during the first and second trimester of pregnancy. Fetal growth peaks in mid-gestation.
Here, we explore how genes associated with fetal growth relate to cortical growth. We find that both maternal and fetal genetic variants associated with higher birthweight predict larger cortical surface area.
The relative dominance of the maternal vs. fetal variants in these associations show striking variations across birth years (1943 to 1966). The birth-year patterns vary as a function of the epigenetic status near genes differentially methylated in individuals exposed (or not) to famine during the Dutch Winter of 1944/1945.
Thus, it appears that the two sets of molecular processes contribute to early cortical development to a different degree in times of food scarcity or its abundance.