Wellcome Trust Sir Henry Dale fellowship pre-application: Chih-Jen Lin
Title: Acquisition of competence in the oocytes: epigenetic regulation of ribosomal RNA transcription.
Background: The Oocyte, a highly differentiated cell type, has the remarkable capacity to reprogram cells (from sperm to even somatic cells) to that of totipotent embryonic cells. Understanding how oocyte-derived factors contribute to developmental competence will not only impact the fields of stem cell biology/cellular reprogramming but also benefit to infertile patients directly. I have recently shown that Hira mediated histone variant H3.3 incorporation is involving the nucleosome assembly in the male genome to form a male pronucleus. Moreover, I demonstrated that maternal H3.3 is required for zygotic cleavage to 2-cells by regulating the function of RNA Polymerase I (ribosomal RNA, rRNA, transcription). This serendipity overturned a long-lasting dogma that transcription of the mouse zygotic genome is minor and not required for development. However, the molecular mechanisms remain to be elucidated. RRNAs are transcribed using rDNA gene array, which is an epigenetically regulated repeated gene locus. My overall hypothesis is that unique epigenetic regulatory mechanisms of ribosome RNA transcription occur during oogenesis is critical for zygote development. To prove this, I will continue explore how Hira complex and H3.3 regulate rDNA transcription. I will next explore the upstream processes of ribosome
Thesis: Individuals that have experienced traumatic events or are put into high stress environments are prone to having their epigenetics modified which can be passed down to offspring. The altered genes can induce people to becoming much more vulnerable to depression and anxiety as a result. While there isn't a way to “cure” intergenerational trauma there are ways to cope with it.
Epigenetics can be defined as a way of turning on and off certain genes in your body, which as evidence has shown, we have a lot more control of than we thought. The video on epigenetics was so great, I did not have a clear idea of what epigenetics was. Watching the video really enlightens how far we have come in research of the human body. I find the advancements that have been made using epigenetics with cancer to be one of the best sections of the thirteen minute video. Just knowing the fact that half of the patients that complied with the research whom had cancer to begin with are now in remission is a great accomplishment. I also found the fact that we have more control over our epigenes, we are to modify our own genes by just following
Epigenetics is a field where advances are being made daily. Epigenetics is defined as “heritable changes in gene expression that occur without a change in DNA sequence,” as stated by Dr. Alan Wolffe. A way in which we can understand this definition is by taking the analogy of a card game. The cards, the DNA sequence, have been dealt and will not change, however we need to understand how to play the cards, the rules, which is epigenetics. The guidelines can vary and completely change the way the card game is played and who comes out on top. The rules that are studied and understood through this research paper are those of DNA methylation and chromatin. These changes can produce
The most compelling piece of information that I read from the article "Epigenetics: Its What Turns You On...and Off" (Schardt, 2013) is how children born from the same mother, before gastric bypass surgery and after the surgery, had different patterns of epigenetic marks than their siblings. It would not have crossed my mind that being overweight would actually have an affect on your genes, that could be passed down to your offspring. Researchers have also reported that the gene IGF2 was more turned on in those born to obese fathers, which might increase the risk of becoming overweight in adulthood (Schardt, 2013). So they chances that a child becomes overweight is on both parents and not just one.
I took a semester off in the Spring of 2012 and 2013. In 2012, I helped care for my grandfather, who suffered from lung cancer and passed away that April. During my time off, I volunteered in the pediatric department of the hospital where he was staying. The inoperable nature of his cancer spurred me to shadow Dr Cheng, a radiation oncologist. In 2013, my mother was told that she might have breast cancer. With my father working in China, I took time off to be with her. I decided to transfer schools because Columbia dramatically decreased my financial aid for the upcoming year, while Brandeis offered me a full scholarship. With my mother’s health issues, I did not want to further burden her financially. I shadowed Dr Anderson, a pediatric geneticist at UT Genetic Center and validated a plasma cell enrichment procedure for the diagnosis of Multiple Myeloma.
According to Rachael Rettner, Epigenetics is defined as, “external modifications to DNA that turn genes on or off. These modifications to DNA do not change the DNA sequence, but instead, they affect how cells read genes.” (Rettner 2013) Epigenetics is thought to possibly have a role in the development of some cancers. Since epigenetics modifies DNA, they can hide a growth, so to speak, or it can play a role in repairing the DNA’s damage. (Rettner 2013) If the changes are in the person’s sperm or egg cells, there is a possibility of that person’s children, or they’re children’s children, getting the modified DNA. (Rettner 2013) In a process called reprogramming, when the sperm and egg combine it allows the fetus to make its own epigenetic changes,
Researchers first thought the genes you receive from your parents are set in stone since they are made of a genetic code set in our DNA sequence;however, they are discovering that there is a second layer of structure that combines with DNA to decide whether or not a gene is active or not, called the epigenome. The epigenome consists of the DNA, histones, a protein DNA is wrapped around, and chemical tags. The epigenome alters the genetic code by directing signals. The signals come from the environment, which are reacted upon by epigenetic tags to turn a gene either on or off without affecting the DNA sequence. Certain things from our environment that send signals to epigenetic tags to change our genes in the epigenome includes the following:
The PBS video called “Epigenetics” brought to light some very interesting views. Through rats scientist have been able to see the works of epigenetics and believe that the finding have led to the idea that the change in genetics has the same effect on humans. The most interesting part of the video was that younger pairs of twins have very similar genes, but the older pairs of twin have more epigenetic difference in their genes. This validates the idea that the epigenetic difference in old twins is caused by environmental factors such as lifestyle choices. The idea also alludes to the idea that our parents and grandparents healthy and epigenetics may affect my heath and my children’s health. This leads to the inclination that my child’s health
For years, scientists believed DNA, deoxyribonucleic acid, was the end-all-be-all: a mould for our cells to be created from. Which does not sound far-fetched since DNA contains all of the information needed for replication, differentiation, growth, and development, in addition to the countless cellular fates, as described in Waddington’s landscape. Instead, DNA is a guide for our cells, and Epigenetics is the tool that coerces them into their final cellular form. The Epigenetics Revolution: How Modern Biology Is Rewriting Our Understanding of Genetics, Disease, and Inheritance written by Nessa Carey, outlines the process of DNA versus Epigenetics, and the developments they have had within the scientific field. This paper will examine the fundamental distinction constructed by Nessa Carey between DNA as a script versus a template. This analogy of DNA as a script.
A roadmap to our future is predetermined by our genetical makeup. However, can external influences such as environment and lifestyle unlock who we are? The study to understand heritable changes in genetical expression is called Epigenetics. Héctor González-Pardo and Marino Pérez Álvarez(2013) describes Epigenetics as the examination of the heritable complex genetical alterations that are shaped by environmental factors which don’t cause changes to the DNA Sequence. In other words, different cell/organism must use the same script in different ways. The study of epigenetics explores the idea that DNA is a script and not a manual. Accordingly, we can positively influence our lives as well as the lives of our offspring by leading a healthy lifestyle.
As of late there has been more of a focus on the Epigenetics component of mental illness.
Every human being possesses their own unique genetic code, called DNA. A person’s individual DNA structure is something that they are born with and will remain constant and unchanging throughout their lifetime. DNA is passed down from each of our parents, and is combined to form our own personal, specific inherited genetic information. This makes it seem like that every characteristic (physical and mental) a person possesses is in direct result of inheritance, unchangeable and unyielding. This is not the case, however. Epigenetics are different factors/circumstances/experiences that play a major role in influencing a person’s gene expression without actually changing their DNA/genetic code. A gene that exists in a person’s genotype is
The research of epigenetics has evolved from the twentieth century from two scientists including Conrad H. Waddington and Ernst Hadorn who combined genetics and biology. There was an interest in this study in the 1990s. Research has evolved trying to figure out the changes caused by epigenetic mechanisms. This field is growing as researchers are unraveling environmental and lifestyle influences on genes (Epigenetics, n.d.). This paper will discuss differences in epigenetics and genetics, current research of epigenetics, and diseases associated with epigenetics.
A series of pronuclear transfer studies using mice provided experimental evidence that the sex of the parental derive genome directly affects the developing embryo (McGrath and Solter, 1984; Surani et al., 1984). The results of these experiments showed that if an oocyte devoid of its pronucleus is injected with either two oocytes or two sperm pronuclei and then implanted the resulting cellular development was the same as that observed in respective human germ cell tumors. Conversely when the empty oocyte was injected with the pronuclei from an oocyte and a sperm a normal embryo developed. While it may not be surprising that for the development of a viable embryo it is necessary to have both a maternal and paternal genome it does raise the question how are these genomes differentiated such that parent of origin is read. These finding provided evidence that not only is one of each parental germ cell is import for proper development but additional the manner in which a genome (i.e. either maternally or paternally) is packaged has a direct influence on differentiation of specific cell
The deadly disease of IPF is one the major frontiers that medical science has had a hard time tackling. The complex genetic and matrix nature of IPF makes it even harder to pinpoint the true cradle of this menace. As mentioned above, there are multiple genes and epigenetic factors that tend to express differently in IPF patients. While MUC5B has been found out to be the gene associated with IPF, only 38% patients with IPF have been found to be associated with it. Though the current research is not very well defined, epigenetic factors like smoking and gastrointestinal issues have been shown to be a possible cause of IPF. In relation to this the idea of epigenetic inheritance needs to be studied further in detail. If it can be identified that