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

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June 17, 2019

Meredith Wilson, a postdoctoral associate in Steve Farber’s lab at the Department of Embryology, has been awarded Carnegie’s thirteenth Postdoctoral Innovation and Excellence Award. These prizes are given to postdocs for their exceptionally creative approaches to science, strong mentoring, and contributing to the sense of campus community. The nominations are made by the departments and are chosen by the Office of the President. The recipients receive a cash prize and are celebrated at an event at their departments.  

Wilson came to Carnegie in 2014 from the University of Pennsylvania with a background in cell biology investigating how motor proteins position

Illustration of a thymus in a human chest courtesy of Navid Marvi.
May 29, 2019

Washington, DC—Aging-related inflammation can drive the decline of a critical structural protein called lamin-B1, which contributes to diminished immune function in the thymus, according to research from Carnegie’s Sibiao Yue, Xiaobin Zheng, and Yixian Zheng published in Aging Cell.

Each of our cells is undergirded by a protein-based cellular skeleton. And each of our tissues is likewise supported by a protein matrix holding the cells that comprise it together. These protein scaffolds or structures are necessary for organs and tissues to be constructed during development.

“Since organ building and maintenance require this protein-based structural support

Steve Farber photo by Navid Marvi, courtesy of the Carnegie Institution for Science
May 1, 2019

Baltimore, MD—This week Carnegie’s Steve Farber will be recognized by New England Biolabs Inc. with its Passion in Science Award in the category of Mentorship and Advocacy. The company, which supplies research tools for sequencing, synthetic biology, and cellular and molecular research, launched the prize in 2014.  

The 12 honorees were chosen for their “innovative work that goes above and beyond the boundaries of pure science to make a profound impact on other fields.”

In announcing the 2019 class, CEO Jim Ellard described them as individuals “who are enriching lives in ways that go well beyond the traditional definition of success for a

Michael Diamreyan with Yixian Zheng, Frederick Tan, and Minjie Hu courtesy of Navid Marvi, Carnegie Embryology.
March 21, 2019

Baltimore, MD—Michael Diamreyan, a Johns Hopkins University undergraduate biophysics student with a Carnegie connection, has been awarded two prestigious research grants to further his independent investigations.  He is a member of Carnegie Embryology Director Yixian Zheng’s laboratory team, in collaboration with the department’s bioinformatician, Frederick Tan.

Diamreyan received an ASPIRE Grant (formerly called DURA grants), which recognizes “exceptional undergraduate students” from the Krieger School of Arts and Sciences at Johns Hopkins University (JHU) with funding for independent research projects. He was also named an Amgen Scholar, which

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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.

 

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

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,

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

Evolutionary geneticist Moises Exposito-Alonso joins the Department of Plant Biology as a staff associate in the summer of 2019. He investigates whether and how plants will evolve to keep pace with climate change by conducting large-scale ecological and genome sequencing experiments. He also develops computational methods to derive fundamental principles of evolution, such as how fast natural populations acquire new mutations and how past climates shaped continental-scale biodiversity patterns. His goal is to use these first principles and computational approaches to forecast evolutionary outcomes of populations under climate change to anticipate potential future

Staff Associate Kamena Kostova joined the Department of Embryology in November 2018. She studies ribosomes, the factory-like structures inside cells that produce proteins. Scientists have known about ribosome structure, function, and biogenesis for some time. But, a major unanswered question is how cells monitor the integrity of the ribosome itself. Problems with ribosomes have been associated with diseases including neurodegeneration and cancer. The Kostova lab investigates the fundamental question of how cells respond when their ribosomes break down using mass spectrometry, functional genomics methods, and CRISPR genome editing.

Kostova received a B.S. in Biology from the

Sally June Tracy applies cutting-edge experimental and analytical techniques to understand the fundamental physical behavior of materials at extreme conditions. She uses dynamic compression techniques with high-flux X-ray sources to probe the structural changes and phase transitions in materials at conditions that mimic impacts and the interiors of terrestrial and exoplanets. She is also an expert in nuclear resonant scattering and synchrotron X-ray diffraction. She uses these techniques to understand novel behavior at the electronic level.  Tracy received her Ph.D. from the California Institute of

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.