December 9, 2013 In researching neural pathways, it helps to establish an analogous relationship between a region of the human brain and the brains of more-easily studied animal species. New work...
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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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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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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...
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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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Allan Spradling is a Howard Hughes Medical Institute Investigator and director of the Department of Embryology. His laboratory studies the biology of reproduction particularly egg cells, which are able to reset the normally irreversible processes of differentiation and aging that govern all somatic...
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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...
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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...
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Baltimore, MD— As we age, the function and regenerative abilities of skeletal muscles deteriorate, which means it is difficult for the elderly to recover from injury or surgery. New work from...
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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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New work led by Carnegie’s Steven Farber, with help from Yixian Zheng’s lab, sheds light on how form follows function for intestinal cells responding to high-fat foods that are rich in...
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Explore Carnegie Science

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

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

April 24, 2019

Butterflies are well known for the beautiful colors and patterns that decorate their wings. They function to attract mates, provide camouflage, or ward off predators. Many colors are created by pigments within the scales, but others, especially blues and greens, are produced by a remarkable phenomenon known as structural coloration.

In structural coloration, nanostructures, which are smaller than the wavelength of light, amplify certain colors and diminish others to create dazzling hues. On April 24th, Dr. Nipam Patel will describe a number of butterfly species that use structural coloration, and recent genetic and cellular insights into how scale cells generate the necessary

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 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.

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 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 tadpole turns into a frog. He studies the frog Xenopus laevis, from South Africa, because it is easy to rear. 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. How can a simple molecule control so many different developmental changes? The hormone works by regulating the expression of groups of

Yixian Zheng is Director of the Department of Embryology. Her lab has a long-standing interest in cell division. In recent years, their findings have broadened their research using animal models, to include the study of stem cells, genome organization, and lineage specification—how stem cells differentiate into their final cell forms. They use a wide range of tools, including genetics in different model organisms, cell culture, biochemistry, proteomics, and genomics.

Cell division is essential for all organisms to grow and live. During a specific time in a cell’s cycle the elongated apparatus consisting of string-like micro-tubules called the spindle is assembled to

Integrity of hereditary material—the genome —is critical for species survival. Genomes need protection from agents that can cause mutations affecting DNA coding, regulatory functions, and duplication during cell division. DNA sequences called transposons, or jumping genes (discovered by Carnegie’s Barbara McClintock,) can multiply and randomly jump around the genome and cause mutations. About half of the sequence of the human and mouse genomes is derived from these mobile elements.  RNA interference (RNAi, codiscovered by Carnegie’s Andy Fire) and related processes are central to transposon control, particularly in egg and sperm precursor cells.  

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 30,000 human genes, 98% of DNA sequences are comprised of repetitive and regulatory sequences within and between genes. Measuring the specific set of DNA sequences that are transcribed into RNA helps reveal what and how our tissues are doing by showing which genes are active.

Modern sequencing platforms, such as the Illumina HiSeq 2000, generate only short, ordered sequences, usually 100

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.