An in vitro approach reveals molecular mechanisms underlying endocrine disruptor-induced epimutagenesis.

Endocrine disrupting chemicals (EDCs) such as bisphenol S (BPS) are xenobiotic compounds that can disrupt endocrine signaling due to steric similarities to endogenous hormones. EDCs have been shown to induce disruptions in normal epigenetic programming (epimutations) and differentially expressed genes (DEGs) that predispose disease states. Most interestingly, the prevalence of epimutations following exposure to many EDCs persists over multiple generations.

Endocrine disruptor-induced epimutagenesis : Insight into molecular mechanisms.

Endocrine disrupting chemicals (EDCs) such as bisphenol S (BPS) are xenobiotic compounds that can disrupt endocrine signaling following exposure due to steric similarities to endogenous hormones within the body. EDCs have been shown to induce disruptions in normal epigenetic programming (epimutations) that accompany dysregulation of normal gene expression patterns that appear to predispose disease states. Most interestingly, the prevalence of epimutations following exposure to many different EDCs often persists over multiple subsequent generations, even with no further exposure to the causative EDC.

Source cell-type epigenetic memory persists in induced pluripotent cells but is lost in subsequently derived germline cells.

Retention of source cell-type epigenetic memory may mitigate the potential for induced pluripotent stem cells (iPSCs) to fully achieve transitions in cell fate . While this may not preclude the use of iPSC-derived somatic cell types for therapeutic applications, it becomes a major concern impacting the potential use of iPSC-derived germline cell types for reproductive applications. The transition from a source somatic cell type to iPSCs and then on to germ-cell like cells (GCLCs) recapitulates two major epigenetic reprogramming events that normally occur during development -embryonic reprogramming in the epiblast and germline reprogramming in primordial germ cells (PGCs).

Accelerating the alignment processing speed of the comprehensive end-to-end whole-genome bisulfite sequencing pipeline, wg-blimp.

Analyzing whole-genome bisulfite and related sequencing datasets is a time-intensive process due to the complexity and size of the input raw sequencing files and lengthy read alignment step requiring correction for conversion of all unmethylated Cs to Ts genome-wide. The objective of this study was to modify the read alignment algorithm associated with the whole-genome bisulfite sequencing methylation analysis pipeline (wg-blimp) to shorten the time required to complete this phase while retaining overall read alignment accuracy. Here, we report an update to the recently published pipeline wg-blimp achieved by replacing the use of the bwa-meth aligner with the faster gemBS aligner.

Differential susceptibility to endocrine disruptor-induced epimutagenesis.

There is now considerable evidence indicating the potential for endocrine disrupting chemicals to alter the epigenome and for subsets of these epigenomic changes or "epimutations" to be heritably transmitted to offspring in subsequent generations. While there have been many studies indicating how exposure to endocrine disrupting chemicals can disrupt various organs associated with the body's endocrine systems, there is relatively limited information regarding the relative susceptibility of different specific organs, tissues, or cell types to endocrine disrupting chemical-induced epimutagenesis. Here we review available information about different organs, tissues, cell types, and/or cell lines which have been shown to be susceptible to specific endocrine disrupting chemical-induced epimutations.

The Mammalian Spermatogenesis Single-Cell Transcriptome, from Spermatogonial Stem Cells to Spermatids.

Spermatogenesis is a complex and dynamic cellular differentiation process critical to male reproduction and sustained by spermatogonial stem cells (SSCs). Although patterns of gene expression have been described for aggregates of certain spermatogenic cell types, the full continuum of gene expression patterns underlying ongoing spermatogenesis in steady state was previously unclear. Here, we catalog single-cell transcriptomes for >62,000 individual spermatogenic cells from immature (postnatal day 6) and adult male mice and adult men.

Tertiary Epimutations - A Novel Aspect of Epigenetic Transgenerational Inheritance Promoting Genome Instability.

Exposure to environmental factors can induce the epigenetic transgenerational inheritance of disease. Alterations to the epigenome termed "epimutations" include "primary epimutations" which are epigenetic alterations in the absence of genetic change and "secondary epimutations" which form following an initial genetic change. To determine if secondary epimutations contribute to transgenerational transmission of disease following in utero exposure to the endocrine disruptor vinclozolin, we exposed pregnant female rats carrying the lacI mutation-reporter transgene to vinclozolin and assessed the frequency of mutations in kidney tissue and sperm recovered from F1 and F3 generation progeny.