Environmental Epigenetics Symposium Inaugural Webinar Primer:
Early Germline Events in the Heritable Etiology of Autism Spectrum Disorders
October 1, 2015, 1-3pm EST
This webinar concerns complicated questions of molecular genetics that may be challenging for many webinar attendees. This page provides background scientific concepts to assist with comprehension of the subject matter.
Epigenetics: Genes (about 20,000 in humans) provide the set of basic instructions for the creation of proteins that make the cells, tissues, and organs of an organism. Genes do not operate in solitude, however. An elaborate "epigenome" provides many layers of complex molecular instruction to our genes, turning them on or off at different times and in different tissues. Our genes can not and do not function without the epigenetic instruction book telling them when, where, and how to work. Our genome is essentially identical in all of our cell types—blood cells, brain cells, muscle cells, skin cells, etc . — but the epigenome programs each cell type to operate differently, to read different genes, to increase or downgrade or even silence gene expression.
The epigenome is particularly vulnerable to environmentally induced perturbations, particularly during critical windows of development, which includes early gamete development, the focus of this webinar. Mutagenesis of the core genome may be precipitated by environmentally induced destabilizing events in the epigenomic scaffold. Additionally, epigenetic disruptions apart from outright mutagenesis may result in pathology.
The primary epigenetic mechanism to be discussed in this webinar is called "DNA methylation." In DNA methylation, groups of small molecules, as directed by certain enzymes, attach to the DNA, regulating function of underlying genes.
Autism genetics: Autism genetics has yielded intriguing findings regarding scattered de novo mutations in autism subjects. This means the genetic changes did not descend from the parents but rather occurred at the germline (sperm or egg) level. The literature has often presumed the de novo events to be "spontaneous" or "random," but autism research has not yet broached the question of the distinct environmental vulnerability of the germline during early gametogenesis, when the DNA is stripped of its methylation marks and undergoes dynamic and highly conserved reprogramming.
Purpose: This interdisciplinary online symposium bridges the worlds of germline biology (Clark) and autism genetics (Yuen) in a preliminary attempt to look for potential connections between early germline events (for example, increased risks for mutagenesis via destabilization, de-repressed transposons, laying of imprints, and "escapee" genes (news article) linked to neurodevelopment) and de novo alterations in human germline, including those found in a subset of ASDs. What implications does early germline susceptibility to environmental stressors have for research into autism etiology? What interdisciplinary work should lie ahead?
Epigenetics: Genes (about 20,000 in humans) provide the set of basic instructions for the creation of proteins that make the cells, tissues, and organs of an organism. Genes do not operate in solitude, however. An elaborate "epigenome" provides many layers of complex molecular instruction to our genes, turning them on or off at different times and in different tissues. Our genes can not and do not function without the epigenetic instruction book telling them when, where, and how to work. Our genome is essentially identical in all of our cell types—blood cells, brain cells, muscle cells, skin cells, etc . — but the epigenome programs each cell type to operate differently, to read different genes, to increase or downgrade or even silence gene expression.
The epigenome is particularly vulnerable to environmentally induced perturbations, particularly during critical windows of development, which includes early gamete development, the focus of this webinar. Mutagenesis of the core genome may be precipitated by environmentally induced destabilizing events in the epigenomic scaffold. Additionally, epigenetic disruptions apart from outright mutagenesis may result in pathology.
The primary epigenetic mechanism to be discussed in this webinar is called "DNA methylation." In DNA methylation, groups of small molecules, as directed by certain enzymes, attach to the DNA, regulating function of underlying genes.
Autism genetics: Autism genetics has yielded intriguing findings regarding scattered de novo mutations in autism subjects. This means the genetic changes did not descend from the parents but rather occurred at the germline (sperm or egg) level. The literature has often presumed the de novo events to be "spontaneous" or "random," but autism research has not yet broached the question of the distinct environmental vulnerability of the germline during early gametogenesis, when the DNA is stripped of its methylation marks and undergoes dynamic and highly conserved reprogramming.
Purpose: This interdisciplinary online symposium bridges the worlds of germline biology (Clark) and autism genetics (Yuen) in a preliminary attempt to look for potential connections between early germline events (for example, increased risks for mutagenesis via destabilization, de-repressed transposons, laying of imprints, and "escapee" genes (news article) linked to neurodevelopment) and de novo alterations in human germline, including those found in a subset of ASDs. What implications does early germline susceptibility to environmental stressors have for research into autism etiology? What interdisciplinary work should lie ahead?