November 7, 2013 Inside every plant cell, a cytoskeleton provides an interior scaffolding to direct construction of the cell’s walls, and thus the growth of the organism as a whole....
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Baltimore, MD--Cells in the body wear down over time and die. In many organs, like the small intestine, adult stem cells play a vital role in maintaining function by replacing old cells with new ones...
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AudioBaltimore, MD—Proper tissue function and regeneration is supported by stem cells, which reside in so-called niches. New work from...
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Baltimore, MD—Mammalian females ovulate periodically over their reproductive lifetimes, placing significant demands on their ovaries for egg production. Whether mammals generate new eggs in adulthood...
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Baltimore, MD— Eggs take a long time to produce in the ovary, and thus are one of a body’s precious resources. It has been theorized that the body has mechanisms to help the ovary ensure that...
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Baltimore, MD— The ability of embryonic stem cells to differentiate into different types of cells with different functions is regulated and maintained by a complex series of chemical interactions,...
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Washington, D.C.—The Carnegie Institution for Science and the University of Massachusetts Medical School (UMMS) have been granted United States Patent 8,283,329, entitled, “Genetic inhibition of...
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Baltimore, MD —You may think you have dinner all to yourself, but you’re actually sharing it with a vast community of microbes waiting within your digestive tract. A new study from a team including...
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The Fan laboratory studies the molecular mechanisms that govern mammalian development, using the mouse as a model. They use a combination of biochemical, molecular and genetic approaches to identify and characterize signaling molecules and pathways that control the development and maintenance of...
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The thyroid gland secretes thyroxine (TH), a hormone essential for the growth and development of all vertebrates including humans. To understand TH action, the Donald Brown lab studies one of the most dramatic roles of the hormone, the control of amphibian metamorphosis—the process by which a...
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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...
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Frederick Tan holds a unique position at Embryology in this era of high-throughput sequencing where determining DNA and RNA sequences has become one of the most powerful technologies in biology. DNA provides the basic code shared by all our cells to program our development. While there are about 30...
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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...
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The Donald Brown laboratory uses  amphibian metamorphosis to study complex developmental programs such as the development of vertebrate organs. The thyroid gland secretes thyroxine (TH), a hormone essential for the growth and development of all vertebrates including humans. To understand TH,...
Meet this Scientist
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Baltimore, MD—A first-of-its-kind study on almost 20,000 K-12 underrepresented public school students shows that Project BioEYES, based at Carnegie’s Department of Embryology, is effective at...
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Explore Carnegie Science

Super-resolution image of fly gut crypts colonized by the native Lactobacillus (red) and Acetobacter (green) bacteria. Fly cell nuclei appear blue. Image is courtesy of Benjamin Obadia.
December 4, 2018

Baltimore, MD—The interactions that take place between the species of microbes living in the gastrointestinal system often have large and unpredicted effects on health, according to new work from a team led by Carnegie’s Will Ludington. Their findings are published this week in Proceedings of the National Academy of Sciences.

The gut microbiome is an ecosystem of hundreds to thousands of microbial species living within the human body.  The sheer diversity within the human gut presents a challenge to cataloging and understanding the effect these communities have on our health.

Biologists are particularly interested in determining whether or not the

November 1, 2018

Baltimore, MD—Since Carnegie Institution’s Barbara McClintock received her Nobel Prize on her discovery of jumping genes in 1983, we have learned that almost half of our DNA is made up of jumping genes—called transposons. Given their ability of jumping around the genome in developing sperm and egg cells, their invasion triggers DNA damage and mutations. This often leads to animal sterility or even death, threatening species survival. The high abundance of jumping genes implies that organisms have survived millions, if not billions, of transposon invasions. However, little is known about where this adaptability comes from. Now, a team of Carnegie researchers has

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

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



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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. 


In mammals, most lipids, such as fatty acids and cholesterol, are absorbed into the body via the small intestine. The complexity of the cells and fluids that inhabit this organ make it very difficult to study in a laboratory setting. The goal of the Farber lab is to better understand the cell and molecular biology of lipids within digestive organs by exploiting the many unique attributes of the clear zebrafish larva  to visualize lipid uptake and processing in real time.  Given their utmost necessity for proper cellular function, it is not surprising that defects in lipid metabolism underlie a number of human diseases, including obesity, diabetes, and atherosclerosis.

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 Gall laboratory studies all aspects of the cell nucleus, particularly the structure of chromosomes, the transcription and processing of RNA, and the role of bodies inside the cell nucleus, especially the Cajal body (CB) and the histone locus body (HLB).

Much of the work makes use of the giant oocyte of amphibians and the equally giant nucleus or germinal vesicle (GV) found in it. He is particularly  interested in how the structure of the nucleus is related to the synthesis and processing of RNA—specifically, what changes occur in the chromosomes and other nuclear components when RNA is synthesized, processed, and transported to the cytoplasm.

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

The Donald Brown laboratory uses  amphibian metamorphosis to study complex developmental programs such as the development of vertebrate organs. The thyroid gland secretes thyroxine (TH), a hormone essential for the growth and development of all vertebrates including humans. To understand TH, director emeritus Donald Brown studies one of the most dramatic roles of the hormone, the control of amphibian metamorphosis—the process by which a tadpole turns into a frog. He studies the frog Xenopus laevis from South Africa.

 Events as different as the formation of limbs, the remodeling of organs, and the resorption of tadpole tissues such as the tail are all directed by TH

Junior investigator Zhao Zhang joined Carnegie in November 2014. He studies how elements with the ability to “jump” around the genome, called transposons, are controlled in egg, sperm, and other somatic tissues in order to understand how transposons contribute to genomic instability and to mutations that lead to inherited disease and cancer. He particularly focuses on transposon control and its consequences in gonads compared to other tissues and has discovered novel connections to how gene transcripts are processed in the nucleus.To accomplish this work, Zhang frequently develops new tools and techniques, a characteristic of many outstanding Carnegie researchers.

The first step in gene expression is the formation of an RNA copy of its DNA. This step, called transcription, takes place in the cell nucleus. Transcription requires an enzyme called RNA polymerase to catalyze the synthesis of the RNA from the DNA template. This, in addition to other processing factors, is needed before messenger RNA (mRNA) can be exported to the cytoplasm, the area surrounding the nucleus.

Although the biochemical details of transcription and RNA processing are known, relatively little is understood about their cellular organization. Joseph G. Gall has been an intellectual leader and has made seminal breakthroughs in our understanding of chromosomes, nuclei and