Genetics in the News Homework Assignment Biol 136 60 Due: March 29, 2018 (60 poi
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Genetics in the News Homework Assignment Biol 136 60 Due: March 29, 2018 (60 points) Background: Everyday we hear stories in the news related to genetics. New discoveries about cancer treatments, gene therapy, claims that refute or support GMOs, new genetic tests that are available directly to consumers, to name a few. Some of these stories are based on sound research studies, while others are loosely based on science. The accompanying handout explains the differences between science and pseudoscience and how you can evaluate the difference. One of the best ways to evaluate scientific claims is to consider the source of the information. A primary source is original material presented for the first time by the person(s) who performed the research. (Examples include peer reviewed journal articles, technical reports and dissertations) A secondary source is a description or review of the primary source. (Examples include summary websites like Wikipedia, WebMD, many government websites, books, newspaper and magazine articles). Different sources of information have different degrees of reliability, so when reading news articles about scientific claims, you should always maintain skepticism regarding the claims of evidence. To be reliable, news stories need to be based on reproducible scientific research, not loosely based on science. News stories that report on research published in peer reveiwed journals (primary resources) are the most reliable, as compared to articles citing websites that may describe a scientific breakthrough (a secondary source) without citing the research behing the news Instrueti For this homework assignment you need to 1. 2. Find a recent article in the news about a topic related to genetics that interests you. Read the article. Write a 3-5 paragraph essay summarizing the main points of the article and evaluating whether the report is reliable or you should be cautious about the conclusions of the story. 3. 4. In your essay, answer the following questions: What interests you about the article you chose? Why did you pick the article? How does your article relate to a topic that we have or will be studying in class? What are the main points of the article? Use your OWN WORDS. DO NOT PARAPHRASE! Evaluate the reliability of the information reported in the article by answering these questions: o o o o Is the information current (within the last 2-3 years?) Is the information reported in the article based on a primary or secondary source? Does your article refer to a particular peer reviewed research study? If so, who did the research, where and how was it done? Are references cited? . . " Does the author of your article lack potential conflicts of interest with the information presented? Is the information reported unbiased? Is the intent of the source of the news article known and valid? . . What is your conclusion regarding the reliability of the article? Is the ne reliable or should you be cautious about its conclusions? o ws reportExplanation / Answer
An article published in The Scientist Magazine entitled “Environment, Not Genetics, Primarily Shapes Microbiome Composition” on 28th February 2018 attracted my interest. The article is about a genetic association study, “Environment dominates over host genetics in shaping human gut microbiota” published in nature on the same day.
Human gastrointestinal tract (GIT) contain bacterial cells that outnumber the host’s cells by a factor of 10 and the genes encoded by the bacteria resident within the GIT outnumber their host’s genes by more than 100 times. These human digestive-tract associated microbes are referred to as the gut microbiome. Human gut microbiome has strong genetic diversity as well as functional potential in it. The human gut microbiome and its role in both health and disease has been the subject of extensive research, establishing its involvement in human metabolism, nutrition, physiology, and immune function. There are several previous studies regarding the role of genetic makeup of the host in stabilizing the human gut microbiome. The aforementioned article quotes Professor Jack Gilbert’s opinion about the major role of environment in driving the composition of human gut microbiome. This original research is carried out by researchers from Weizmann Institute of Science – Israel and University of Groningen, University Medical Centre Groningen.
In this study, they demonstrate that genetic ancestry, and that host genetics have a minor role in human gut microbiome. As a proof of concept, they analyse metagenome-sequenced and 16S rRNA gene-sequenced gut microbiomes, genotypes, anthropometric and blood measurements, and dietary habits data from 1,046 healthy Israeli individuals with several distinct ancestral origins who share a relatively common environment and genetically unrelated individual living in similar environmental conditions have significant similarities in microbiome composition. Over 20% of the inter-person microbiome variability is associated with factors related to diet, drugs and anthropometric measurements. On the same line, this study questions the statistical significance of a recent study, that identified 42 SNPs that together explained 10% of the variance of microbiome ?-diversity. They have compared the power of microbiome and host-genetics to predict the host phenotype. For this, they defined a new term ‘microbiome-association index’ (b2) (h2 - analogy with genetic heritability), quantifies the overall association between the microbiome and a host phenotype after accounting for host genetics. As a result, there were significant b2 levels of 22–36% for body mass index (BMI; 25%), fasting glucose levels (22%), glycaemic status (25%), levels of high-density lipoprotein (HDL) cholesterol (36%), waist circumference (29%), hip circumference (27%), waist–hip ratio (WHR; 24%) and lactose consumption (36%) which strongly support the observation. As an addition, they mentioned that using microbiome data together with human genetic data considerably improves the accuracy with which human phenotypes can be predicted.
To make sure the observation is unbiased, they have replicated the analyses using a cohort of 836 Dutch individuals from the LLD cohort8, with metagenome-sequenced gut microbiomes, genotypes and the same covariates that we used in our analysis of the Israeli cohort. Final conclusion was that there is significant harmony between the results obtained in the two cohorts.
Original Research: https://www.nature.com/articles/nature25973
MLA format: Environmental Factors Dominate Over Host Genetics in Shaping Human Gut Microbiota Composition
Daphna Rothschild-Omer Weissbrod-Elad Barkan-Tal Korem-David Zeevi-Paul Costea-Anastasia Godneva-Iris Kalka-Noam Bar-Niv Zmora-Meirav Pevsner-Fischer-David Israeli-Noa Kosower-Gal Malka-Bat Wolf-Tali Avnit-Sagi-Maya Lotan-Pompan-Adina Weinberger-Zamir Halpern-Shai Carmi-Eran Elinav-Eran Segal - 2017
Online Article: https://www.the-scientist.com/?articles.view/articleNo/51949/title/Environment--Not-Genetics--Primarily-Shapes-Microbiome-Composition/
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