Approximately half of the gene sequences of human and mouse genomes comes from so-called mobile elements—genes that jump around the genome. Much of this DNA is no longer capable of moving, but is likely “auditioning”  perhaps as a regulator of gene function or in homologous recombination, which is a type of genetic recombination where the basic structural units of DNA,  nucleotide sequences, are exchanged between two DNA molecules to  repair  breaks in the DNA  strands. Modern mammalian genomes also contain numerous intact movable elements, such as retrotransposon LINE-1, that use RNA intermediates to spread about the genome. 

Given the crucial role of the precursor cells to egg and sperm, called germ cells, to continue a species, their genomes represent a particularly attractive target for mobile elements. One lab looks at the uncontrolled activity of retrotransposons, which causes new mutations and even kill germ cells, which is countered by specialized defensive mechanisms regulating LINE-1 elements through the analysis of function of Maelstrom, a protein found in many species, which is implicated in silencing jumping genes in flies and mice by means of specialized small RNAs known as Piwi-interacting RNAs (or piRNAs).  The group is trying to uncover and understand how LINE-1 elements impact germ cells during normal development.

Scientific Area: 
Genetics & Developmental Biology
Reference to Person: 
Alex Bortvin

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Steven Farber Awarded $3.3-Million NIH Grant To Identify New Pharmaceuticals To Fight Cardiovascular Disease
October 10, 2018

Carnegie’s Department of Embryology scientist Steven Farber and team have been awarded a 5-year $3.3-million NIH grant to identify novel pharmaceuticals for combating a host of diseases associated with altered levels of lipoproteins like LDL (“bad cholesterol”). Obesity, diabetes, cardiovascular disease, fatty liver disease, and metabolic syndrome have all been linked to changes in plasma lipoproteins. 

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Former Carnegie Postdoctoral Fellow Tasuku Honjo Shares Nobel Prize
October 1, 2018

Tasuku Honjo, a postdoctoral fellow in the Brown Lab at the Department of Embryology 1971-1973, shares the 2018 Nobel Prize in Physiology or Medicine.

The AsianScientist quoted Honjo as saying: "After I moved to the US as a postdoctoral researcher in the 70s, I met my mentor, Dr. Donald Brown, at the Carnegie Institution for Science in Baltimore. He told me that the major question of immunology at the time was, how do we create such an enormous diversity of antibodies? That question is now ready to be tackled using a molecular strategy." Read the official Nobel press release. Image courtesy Nobel.org

 

 

 
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Intestines modify their cellular structure in response to diet
September 20, 2018

Baltimore, MD— Body organs such as the intestine and ovaries undergo structural changes in response to dietary nutrients that can have lasting impacts on metabolism, as well as cancer susceptibility, according to Carnegie’s Rebecca Obniski, Matthew Sieber, and Allan Spradling.

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Ethan Greenblatt Receives 11th Postdoctoral Innovation and Excellence Award
September 18, 2018

Ethan Greenblatt, a senior postdoctoral associate in Allan Spradling’s lab at the Department of Embryology, has been awarded the eleventh Postdoctoral Innovation and Excellence Award. Greenblatt has made a major impact on biological science, particularly with his research identifying genetic factors underlying fragile X syndrome, the most common cause of autism.

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The Zheng lab studies cell division including the study of stem cells, genome organization, and lineage specification. They study the mechanism of genome organization in development, homeostasis—metabolic balance-- and aging; and the influence of cell morphogenesis, or cell shape and steructure,  on cell fate decisions. They use a wide range of tools and systems, including genetics in model organisms, cell culture, biochemistry, proteomics, and genomics.

 
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The biology of reproduction studying ovarian stem cells of the fruitfly

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The mechanics of stem cell development

Stem cells make headline news as potential treatments for a variety of diseases. But undertstanding the nuts and bolts of how they develop from an undifferentiated cell  that gives rise to cells that are specialized such as organs, or bones, and the nervous system, is not well understood. 

The Lepper lab studies the mechanics of these processes. overturned previous research that identified critical genes for making muscle stem cells. It turns out that the genes that make muscle stem cells in the embryo are surprisingly not needed in adult muscle stem cells to regenerate muscles after injury. The finding challenges the current course of research into muscular dystrophy, muscle

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Left and right side differences of the developing brain

The Marnie Halpern laboratory studies how left-right differences arise in the developing brain and discovers the genes that control this asymmetry. Using the tiny zebrafish, Danio rerio, they explores how regional specializations occur within the neural tube, the embryonic tissue that develops into the brain and spinal cord.

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William Ludington

The Ludington lab investigates complex ecological dynamics from microbial community interactions using the fruit fly  Drosophila melanogaster. The fruit fly gut carries numerous microbial species, which can be cultured in the lab. The goal is to understand the gut ecology and how it relates to host health, among other questions, by taking advantage of the fast time-scale and ease of studying the fruit fly in controlled experiments. 
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Nick Konidaris

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Michael Walter, Director

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Guoyin Shen

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