It’s no secret that smoking is bad, now new evidence shows that smoking during pregnancy could be very dangerous for a fetus. In a recent report, Baylor College of Medicine researchers found that moms who light up are also altering their babies’ epigenomes and transcriptomes.
In some previous work, the scientists had only looked at the methylation of a single gene. But now, they lived up to their Texas roots and went big—as in, genome-wide—for this study. They measured changes in placental epigenomes and transcriptomes using transcription and methylation arrays in 18 nonsmokers and 18 smokers who were pregnant. Here’s what they found:
- Over 1000 placental CpGs were differentially methylated in smokers vs. nonsmokers. Only 38 of these were really significant.
- When they took gene expression into account, they found that 438 genes were differentially methylated and deregulated in the smoking group.
- Many of those genes are involved in oxidative phosphorylation, mitochondrial dysfunction, and cell signaling.
- After analyzing the data even more, they found that differential methylation at six CpG sites were correlated with maternal smoking and low birth weight.
The team says that their results “suggest that a common perinatal exposure (such as maternal smoking) deregulates placental methylation, which correlates with meaningful alterations in gene expression.”
Get a clear view of the smoky details at Epigenetics, November 2011.