There is a lot of folklore about left-brain, right-brain differences—the right side of the brain is supposed to be the creative side, while the left is the logical half. But it’s much more complicated than that. Marnie Halpern studies how left-right differences arise in the developing brain and discovers the genes that control this asymmetry.

Using the tiny zebrafish, Danio rerio, Halpern explores how regional specializations occur within the neural tube, the embryonic tissue that develops into the brain and spinal cord. The zebrafish is ideal for these studies because its basic body plan is set within 24 hours of fertilization. By day five, young larvae are able to feed and swim, and within three months they are ready to reproduce. They are also prolific breeders. Most importantly the embryos are transparent, allowing scientists to watch the nervous system develop and to identify mutants easily.

In the course of studying a mutation that produced fused eyes analogous to those of the mythological Cyclops, Halpern and a team from Vanderbilt University discovered that the affected gene codes for a protein signal that acts in the early embryo, then later reappears on the left side of the neural tube. This unexpected finding led her to explore where in the larval brain the molecular asymmetry resided and to determine its purpose.

Notable structural specializations are found within a precise region of the fish forebrain, and Halpern found that the signal influences whether they end up on the left or the right side. Remarkably, a member of the very same protein family had previously been shown to control the left and right differences in our internal organs, such as the characteristic rightward looping and left positioning of the heart, the counterclockwise coiling of the intestines, and the placement of the pancreas on the left and the gall bladder and liver on the right side of the body.

The Halpern laboratory has studied diverse problems using this versatile fish and its powerful genetics, initiating new projects to understand the basis of neural tube defects, to study patterning of the skeleton, and to visualize digestive physiology, projects that have enabled former trainees to establish unique research directions in their own laboratories. Other current interests of the Halpern group include the genetic regulation of myelination—the process of myelin synthesis. Myelin is the insulating material that forms around the axons of neurons to expedite their electrical activity and that is compromised in multiple sclerosis.

Halpern is also very involved in outreach. Among her activities she runs a speakers program with the Baltimore public schools, Women Serious About Science, which encourages girls from diverse backgrounds to pursue careers in science. She received her B.Sc. in biology from McMaster University and her master’s at the McMaster University Medical Centre. She then went on to Yale for her Ph.D. and did postdoctoral work at the Institute of Neuroscience, University of Oregon. She joined the Carnegie staff in 1994. For more see the Halpern lab

Explore Carnegie Science

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. 

Lab efforts, led by graduate student Jay Thierer, started by creating zebrafish that have been genetically engineered to produce glowing lipoproteins, a technique they call “LipoGlo”. This was achieved by attaching DNA encoding NanoLuc (a relative of the protein that makes

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

 

 

 

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.

Their work, published by Developmental Cell, used fruit flies, which are currently the most-sensitive experimental system for such detecting diet-induced cellular changes that are likely to be similar in mammals.

There are three major types of cells in fruit fly (and mammalian) intestines: Stem cells, hormone-producing cells, and nutrient-handling cells. Think of the stem cells as blanks, which are

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.

Recipients of these postdoctoral awards are given a cash prize for their exceptionally creative approaches to science, strong mentoring, and contributing to the sense of campus community. A celebration is also held in their honor. These awards are made through nominations from the departments and are chosen by the Office

No content in this section.

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.

 

The Spradling laboratory studies the biology of reproduction. By unknown means eggs reset the normally irreversible processes of differentiation and aging. The fruit fly Drosophila provides a favorable multicellular system for molecular genetic studies. The lab focuses on several aspects of egg development, called oogenesis, which promises to provide insight into the rejuvenation of the nucleus and surrounding cytoplasm. By studying ovarian stem cells, they are learning how cells maintain an undifferentiated state and how cell production is regulated by microenvironments known as niches. They are  also re-investigating the role of steroid and prostaglandin hormones in controlling the

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

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.

The zebrafish is ideal for these studies because its basic body plan is set within 24 hours of fertilization. By day five, young larvae are able to feed and swim, and within three months they are ready to reproduce. They are also prolific breeders. Most importantly the embryos are transparent, allowing scientists to watch the nervous system develop and to

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. 

Nick Konidaris is a staff scientist at the Carnegie Observatories and Instrument Lead for the SDSS-V Local Volume Mapper (LVM). He works on a broad range of new optical instrumentation projects in astronomy and remote sensing. Nick's projects range from experimental to large workhorse facilities. On the experimental side, he recently began working on a new development platform for the 40-inch Swope telescope at Carnegie's Las Campanas Observatory that will be used to explore and understand the explosive universe.

 Nick and his colleagues at the Department of Global Ecology are leveraging the work on Swope to develop a new airborne spectrograph that will be used to provide a direct

Experimental petrologist Michael Walter became director of the Geophysical Laboratory beginning April 1, 2018. His recent research has focused on the period early in Earth’s history, shortly after the planet accreted from the cloud of gas and dust surrounding our young Sun, when the mantle and the core first separated into distinct layers. Current topics of investigation also include the structure and properties of various compounds under the extreme pressures and temperatures found deep inside the planet, and information about the pressure, temperature, and chemical conditions of the mantle that can be gleaned from mineral impurities preserved inside diamonds.

Walter had been at

Guoyin Shen's research interests lie in the quest to establish and to examine models for explaining and controlling the behavior of materials under extreme conditions. His research activities include investigation of phase transformations and melting lines in molecular solids, oxides and metals; polyamorphism in liquids and amorphous materials; new states of matter and their emergent properties under extreme conditions; and the development of enabling high-pressure synchrotron techniques for advancing compression science. 

He obtained a Ph.D. in mineral physics from Uppsala University, Sweden in 1994 and a B.S. in geochemistry from Zhejiang University, China in 1982. For more