A new publication from Environmental Health Sciences (EHS) doctoral student Oladele “Amos” Oluwayiose has been selected as an extramural paper of the month for September by the National Institute of Environmental Health Sciences (NIEHS).
The article, titled “Paternal preconception phthalate exposure alters sperm methylome and embryonic programming,” appeared online in June 2021 and will be featured in the October 2021 issue of the journal “Environment International.” Oluwayiose’s co-authors include senior author Richard Pilsner, formerly of UMass Amherst, who is now at Wayne State University; and UMass Amherst faculty members Alexander Suvorov and Jesse Mager,;students Chelsea Marcho and Emily Houle; Pilsner lab and EHS alumnus Haotian Wu; and Stephen A. Krawetz of Wayne State University.
With support from the UMass Amherst Graduate School’s Spaulding-Smith Fellowship, Oluwayiose has conducted research in the Pilsner lab since 2018. Says Pilsner, “Amos excels in both wet- and dry-bench science by his ability to integrate knowledge and tools from different scientific disciplines. This publication showcases his potential as a leader in our field.”
In the paper, Oluwayiose and colleagues show that male mice exposed to phthalates before conception resulted in changes in sperm DNA methylation that were transferred to the next generation as altered gene expression in embryos. DNA methylation occurs when a chemical compound, called a methyl group, attaches to DNA, affecting whether a gene is turned on or off.
In the study, the researchers exposed male mice to either a low or high level of phthalates for two sperm production cycles. Following exposure, they mated the mice with unexposed females. They then assessed genome-wide methylation in sperm, embryos, and extra-embryonic tissues, which support the developing embryo.
Compared with unexposed controls, paternal preconception exposure altered methylation in 29 gene regions that overlapped between sperm and embryonic tissues. The researchers also identified changes in gene expression in embryos in both exposure groups compared with controls. Many of the altered genes were related to pathways important in development.
Their findings suggest that preconception is a sensitive window in which phthalate exposure alters sperm methylation and embryo gene expression in ways that may influence offspring health and development.