Category Archives: Human Genetics

Guest Post from John Rawls Ph.D., associate professor of molecular genetics and microbiology

Illustration by Timothy Cook

Recent advances in genomic technology have led to spectacular insights into the complexity and ubiquity of microbial communities (the microbiome) throughout our planet, including on and within the human body.

The microbiome is now known to contribute significantly to human health and disease, regulate global biogeochemistry, and harbor much of our planets genetic diversity.

On November 21, 2014, more than 200 scientists, clinicians, engineers, and students gathered in the Trent Semans Center at the Duke University Medical Center to learn about cutting-edge microbiome research in an interdisciplinary symposium entitled The Human and Environmental Microbiome.

Reflecting the interdisciplinary nature of this exciting field, symposium participants represented a broad range of basic and clinical science departments at Duke and other institutions across North Carolinas Research Triangle.

The symposium showcased microbiomes in a wide diversity of habitats, including the body surfaces of humans and other animals, plant roots, soil, dust, freshwater streams, coastal waters, and in vitro systems.

Despite the diversity of their experimental systems, participants shared many of the same experimental approaches and methodologies. For instance, microbial genomic sequencing was highlighted as a tool for understanding the life cycle of the parasites that cause malaria, as well as for identifying useful genes in symbiotic bacteria residing in the intestine.

Several abstracts presented at the symposium highlighted innovative new genetic and genomic approaches to understanding how microbial communities assemble and function, which could be widely applicable to other microbiomes.

In addition to shared methodologies, participants also reported on shared themes emerging from analysis of different microbiomes. For example, analysis of a marine environment in response to acute weather perturbation revealed many of the same ecological patterns observed in the human gut microbiome during a cholera outbreak.

Originally posted here:
Microbiome Researchers Find Common Ground

Published on January 7th, 2015 | by LedgerOnline

By Diana Burmistrovich/JNS.org

One in four Jews is a carrier of one or more of the 19 known preventable Jewish genetic diseases, according to the Center for Jewish Genetics. Although Sephardic Jews and non-Jews can carry these diseases, they appear twice as often for Ashkenazi Jews as they do for the rest of the population. When both spouses are carriers for a particular genetic disease, the couple has a 25 percent chance of passing the disease on to their children.

Launched in September through the Emory University School of Medicines Department of Human Genetics, the goal of the JScreen not-for-profit health initiative is to make those statistics appear less daunting.

A carrier-screening program for Jewish genetic diseases, JScreen aims to give families with Jewish ancestry easy access to information and to provide convenient testing. Employing an easy-to-use kit, JScreen allows individuals to test for the 19 known preventable Jewish genetic diseaseswhich among others include Tay-Sachs, Canavan, and Gaucherin their own homes.

While testing for genetic disorders is nothing new, JScreens accessibility is. The kit is easily acquired through the initiatives website atwww.JScreen.org, and the test allows a saliva sample to be sentdirectly for analysis. Theprogram works closely with the individual,obtaining doctors orders when needed andproviding updates on the status of the sample until results are sent out approximately four weeks later.

Touting the initiative as community-oriented, JScreens website provides resources that aim to make couples feel comfortable in proceeding with their family-planning efforts. This includes explaining the reasons for getting tested, as well as statistics.

JScreen hopes to act as a resource for the community to do genetic testing and make a big impact in growing healthy families, JScreen spokesperson Patricia Page told JNS.org.

The program grew out of the work of Randy and Caroline Gold, who were surprised to find out that their daughter, Eden, had the genetic disease Mucolipidosis Type IV (ML4), despite their having both undergone genetic testing before starting a family.

When they learned that their genetic test had screened for less than half the conditions common in people of Jewish descent, the Golds made it their mission to spread the word about expanded Jewish genetic disease screening. They launched the Atlanta Jewish Gene Screen, an organization thatpartneredwith the Victor Center for Prevention of Jewish Genetic Diseases at Einstein Medical Center in Philadelphia, and Emory Geneticsfrom 2010 to 2012.

Link:
Jewish genetic screening becomes more accessible through at-home testing kits

Oxford University scientists begin to immunise volunteers Hope to immunise 72 adults by the end of the month to trial the new jab A prime injection is followed by a booster to strengthen immune response The vaccine wassuccessfulin protecting primates against Ebola There are now at least three Ebola vaccines being trialled for safety

By Madlen Davies for MailOnline

Published: 10:08 EST, 6 January 2015 | Updated: 16:10 EST, 6 January 2015

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The first human trials of a new Ebola vaccine are today underway, the latest step in attempts to halt the spread of the virus in West Africa.

Scientists at Oxford University have immunised the first healthy volunteers with a new drug, which they hope will protect people against the disease.

The World Health Organisation said today more than 8,100 people have now lost their lives to the virus, the majority in Guinea, Sierra Leone and Liberia.

In September a separate trial was launched at the university, to test the effects of another potential vaccine.

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First human trial of new experimental Ebola vaccine begin

How genetics is helping us understand Parkinson #39;s disease
The last twenty years have seen huge advances in our understanding of human genetics. In this webinar, I #39;ll talk about how looking at genetics is helping us to learn more about what causes...

By: Patrick Lewis

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How genetics is helping us understand Parkinson's disease - Video

human genetics documentary

By: sermin kaya

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human genetics documentary - Video

Human Genetics I

By: McIntoshBiology

Original post:
Human Genetics I - Video

A group of scientists has created artificial human sperm and eggs using human embryonic stem cells and skin cells. While researchers have already previously accomplished this using rodents, this is the first time they were able to replicate the process with human cells.

Their final products were not actually working sperm and eggs, but rather germ cells that potentially could mature and become viable for fertility. The study's findings were published Wednesday in the journal Cell.

"Germ cells are 'immortal' in the sense that they provide an enduring link between all generations, carrying genetic information from one generation to the next," Azim Surani, PhD, professor of physiology and reproduction at the University of Cambridge, said in a press release.

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Sperm wear hard hats and live for days? It's true, and that's just the beginning...

When an egg is fertilized by a sperm, it begins to divide into a group of cells called a blastocyst, which is the stage right before the embryo is formed. Some of the cells inside this blastocyst cluster will develop into a fetus, while others eventually become the placenta.

Some cells are set up to become stem cells, which will then have the potential to develop into any type of cell in the body. And some cells in the fetus become primordial germ cells and eventually evolve into the cells of either sperm or eggs, which will allow this offspring to pass their genes on to a future generation.

In the study, the researchers identified a single gene known as SOX17, which is directly responsible for ordering human stem cells to become the cells that will turn into sperm and eggs. The scientists say this discovery on its own is surprising, because this gene is not involved in the creation of primordial cells in rodents. In humans, the SOX17 gene is also involved in helping to develop cells of the lungs, gut and pancreas.

The scientists harvested these cells by culturing human embryonic stem cells for five days. They then showed that the same process could be replicated using adult skin cells.

This doesn't mean men and women will soon be donating skin cells rather than sperm and egg at fertility clinics. Eventually, however, the findings could open the door to more intensive research on human genetics and certain cancers, and could impact fertility treatments sometime in the future.

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Scientists create artificial human eggs and sperm

CAMBRIDGE, England, Dec. 25 (UPI) -- The first time in history, researchers have successfully used human embryonic stem cells to create primordial germ cells, cells that divide and mature into egg and sperm. Previously, the feat had been accomplished using rodent stem cells -- not those from a human embryo.

"Researchers have been attempting to create human primordial germ cells (PGCs) in the petri dish for years," leader author Jacob Hanna, a researcher in the Institute's Molecular Genetics Department, said in a released statement.

Stem cells are undifferentiated biological cells capable of dividing and transforming into specialized cells. They are the most basic of biological building blocks.

"The creation of primordial germ cells is one of the earliest events during early mammalian development," study co-author Naoko Irie, researcher at the Wellcome Trust/Cancer Research UK Gurdon Institute at the University of Cambridge, said in a press release.

"It's a stage we've managed to recreate using stem cells from mice and rats, but until now few researches have done this systematically using human stem cells," Irie added.

Researchers say the newly realized feat has revealed differences between embryo development in humans and rodents -- discrepancies that could undermine studies that extrapolate mice and rat-based evidence to human-related conclusions.

"Having the ability to create human PGCs in the petri dish will enable us to investigate the process of differentiation on the molecular level," Hanna said.

The research was published this week in the journal Cell.

2014 United Press International, Inc. All Rights Reserved. Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.

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Scientists create human primordial cells in the lab

Human Genetics II

By: McIntoshBiology

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Human Genetics II - Video

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Newswise Groups at the Weizmann Institute of Science and Cambridge University have jointly managed the feat of turning back the clock on human cells to create primordial germ cells the embryonic cells that give rise to sperm and ova in the lab. This is the first time that human cells have been programmed into this early developmental stage. The results of their study, which were published December 24 in Cell, could help provide answers as to the causes of fertility problems, yield insight into the earliest stages of embryonic development and potentially, in the future, enable the development of new kinds of reproductive technology.

Researchers have been attempting to create human primordial germ cells (PGCs) in the petri dish for years, says Dr. Jacob Hanna of the Weizmann Institutes Department of Molecular Genetics, who led the study together with research student Leehee Weinberger. PGCs arise within the early weeks of embryonic growth, as the embryonic stem cells in the fertilized egg begin to differentiate into the very basic cell types. Once these primordial cells become specified, they continue developing toward precursor sperm cells or ova pretty much on autopilot, says Dr. Hanna. The idea of creating these cells in the lab took off with the 2006 invention of induced pluripotent stem (iPS) cells adult cells that are reprogrammed to look and act like embryonic stem cells, which can then differentiate into any cell type. Thus several years ago, when researchers in Japan created mouse iPS cells and then got them to differentiate into PGCs, scientists immediately set about trying to replicate the achievement in human cells. But until now, none had been successful.

Previous research in Dr. Hannas lab pointed to new methods that could take human cells to the PGC state. That research had focused on the question of how human iPS cells and mouse embryonic cells differ: The mouse embryonic cells are easily kept in their stem cell state in the lab, while human iPS cells that have been reprogrammed a technique that involves the insertion of four genes have a strong drive to differentiate, and they often retain traces of priming. Dr. Hanna and his group then created a method for tuning down the genetic pathway for differentiation, thus creating a new type of iPS cell that they dubbed nave cells. These nave cells appeared to rejuvenate iPS cells one step further, closer to the original embryonic state from which they can truly differentiate into any cell type. Since these nave cells are more similar to their mouse counterparts, Dr. Hanna and his group thought they could be coaxed to differentiate into primordial germ cells.

Working with nave human embryonic stem and iPS cells, and applying the techniques that had been successful in the mouse cell experiments, the research team managed to produce cells that, in both cases, appeared to be identical to human PGCs. Together with the lab group of Prof. Azim Surani of Cambridge University, the scientists further tested and refined the method jointly in both labs. By adding a glowing red fluorescent marker to the genes for PGCs, they were able to gauge how many of the cells had been programmed. Their results showed that quite a high rate up to 40% had become PGCs; this quantity enables easy analysis.

Dr. Hanna points out that PGCs are only the first step in creating human sperm and ova. A number of hurdles remain before labs will be able to complete the chain of events that move an adult cell through the cycle of embryonic stem cell and around to sperm or ova. For one, at some point in the process, these cells must learn to perform the neat trick of dividing their DNA in half before they can become viable reproductive cells. Still, he is confident that those hurdles will one day be overcome, raising the possibility, for example, of enabling women who have undergone chemotherapy or premature menopause to conceive.

In the meantime, the study has already yielded some interesting results that may have significant implications for further research on PGCs and possibly other early embryonic cells. The team managed to trace part of the genetic chain of events that directs a stem cell to differentiate into a primordial germ cell, and they discovered a master gene, Sox17, that regulates the process in humans, but not in mice. Because this gene network is quite different from the one that had been identified in mice, the researchers suspect that more than a few surprises may await scientists who study the process in humans.

According to Dr. Hanna, Having the ability to create human PGCs in the petri dish will enable us to investigate the process of differentiation on the molecular level. For example, we found that only fresh nave cells can become PGCs; but after a week in conventional growth conditions they lose this capability once again. We want to know why this is. What is it about human stem cell states that makes them more or less competent? And what exactly drives the process of differentiation once a cell has been reprogrammed to its more nave state? It is the answers to these basic questions that will, ultimately, advance iPS cell technology to the point of medical use.

Dr. Jacob Hannas research is supported by Pascal and Ilana Mantoux, France/Israel; the New York Stem Cell Foundation; the Flight Attendant Medical Research Institute (FAMRI), the Israel Cancer Research Fund (ICRF); the Helen and Martin Kimmel Award for Innovative Investigation; the Benoziyo Endowment Fund for the Advancement of Science; the Leona M. and Harry B. Helmsley Charitable Trust; the Sir Charles Clore Research Prize; Erica A. Drake and Robert Drake; the Abisch Frenkel Foundation for the Promotion of Life Sciences; the European Research Council; the Israel Science Foundation, and the Fritz Thyssen Stiftung. Dr. Hanna is a New York Stem Cell Foundation-Robertson Investigator.

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In a First, Weizmann Institute and Cambridge University Scientists Create Human Primordial Germ Cells