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 cells for nearly 60 years.   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.

The researchers concentrate on a structure in the nucleus called the Cajal body, so named because it was first described 100 years ago by the Spanish neurobiologist and Nobel laureate Ramon y Cajal. Until recently very little was known about the Cajal body, but modern microscopical techniques  have brought rapid progress. Cajal bodies are now known to contain many factors involved in transcribing and modifying both pre-messenger RNA and pre-ribosomal RNA. Gall thinks that the Cajal body is a site for assembly of factors required for transcription and RNA processing.

Much of the lab’s work is carried out with unlaid eggs removed from the female frog Xenopus. These eggs, called oocytes, are giant cells up to 1.5 millimeters (mm) in diameter with a nucleus, or germinal vesicle (GV), 0.4 mm in diameter. The large GV permits scientists to examine the contents and structure of the nucleus in unprecedented detail.

The lab also used the fruit fly Drosophila cells , which are much smaller than frog cells, but have the advantage that they permit genetic studies on Cajal body components. In Drosophila one can manipulate the genes that encode proteins and RNAs of the Cajal body, and follow the consequences in various embryonic, larval, and adult tissues.

Gall has received numerous awards in acknowledgment of his special contributions, including the Albert Lasker Special Achievement Award in Medical Research, and the Lifetime Achievement Award of the Society for Developmental Biology, among others.

From 1952 to 1964 Gall taught zoology at the University of Minnesota. From 1964 to1983 he was the Ross Granville Harrison Professor of Biology, Professor of Molecular Biophysics and Biochemistry, at Yale University. In1983 he joined the Carnegie Institution as a staff scientist. For more see the Gall lab

Explore Carnegie Science

Stephanie Hampton
August 12, 2022

Washington, DC— Aquatic ecologist Stephanie Hampton joined Carnegie as Deputy Director of Carnegie’s newly launched Division of Biosphere Sciences and Engineering at the end of July. She arrived from the National Science Foundation, where she was the director of the Division of Environmental Biology. She was also a professor and the former director of an interdisciplinary environmental research center at Washington State University.

“Stephanie’s experience leading the primary funder of basic ecological and evolutionary research in the U.S. has given her a 10-thousand-foot view of the field, which will help us as we implement a new, cross-disciplinary vision

Watercolor illustration of Drosophila, courtesy Carnegie Institution for Science
June 15, 2022

Baltimore, MD— Recent work from Carnegie’s Chenhui Wang and Allan Spradling reveals a surprising capability of renal stem cells in fruit flies—remodeling. Their work, which could eventually guide kidney stone treatments, was published by Science Advances.

Stem cells are the raw materials from which our bodies are formed.

The ultimate utility player, embryonic stem cells are capable of differentiating into any cell type to construct any organ or tissue in the body. Adult stem cells’ abilities are not quite so unlimited. They exist within a specific tissue—such as the skin or the intestinal lining—and are responsible for renewing it

Artist's conception by Navid Marvi
February 9, 2022

Baltimore, MD— The gut microbiome is an ecosystem of hundreds to thousands of microbial species living within the human body. These populations affect our health, fertility, and even our longevity. But how do they get there in the first place?

New collaborative work led by Carnegie’s William Ludington reveals crucial details about how the bacterial communities that comprise each of our individual gut microbiomes are acquired. These findings, published in the Proceedings of the National Academy of Sciences, have major implications for treatments such as fecal transplants and probiotic administration.

“There is a huge amount of variation in microbiome

Palm trees rise in front of the San Gabriel Mountains.
January 10, 2022

Washington, DC—California Governor Gavin Newsom on Monday announced $20 million in his 2023 fiscal year budget to support Carnegie’s new research facility in Pasadena. The proposed budget allocation still must clear the California State Senate and Assembly, which will begin to hold hearings in the coming weeks. It must be adopted by June 15. 

The new 135,000-square-foot, state-of-the-art campus will bring the institution’s life and environmental scientists together in a single location adjacent to Caltech—making a decisive investment in the global fight against climate change. The facility will house more than 200 new hires and relocated staff, who

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 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.

Ana Bonaca is Staff Member at Carnegie Observatories. Her specialty is stellar dynamics and her research aims to uncover the structure and evolution of our galaxy, the Milky Way, especially the dark matter halo that surrounds it. In her research, she uses space- and ground-based telescopes to measure the motions of stars, and constructs numerical experiments to discover how dark matter affected them.

She arrived in September 2021 from Harvard University where she held a prestigious Institute for Theory and Computation Fellowship. 

Bonaca studies how the uneven pull of our galaxy’s gravity affects objects called globular clusters—spheres made up of a million

Peter Gao's research interests include planetary atmospheres; exoplanet characterization; planet formation and evolution; atmosphere-surface-interior interactions; astrobiology; habitability; biosignatures; numerical modeling.

His arrival in September 2021 continued Carnegie's longstanding tradition excellence in exoplanet discovery and research, which is crucial as the field prepares for an onslaught of new data about exoplanetary atmospheres when the next generation of telescopes come online.

Gao has been a part of several exploratory teams that investigated sulfuric acid clouds on Venus, methane on Mars, and the atmospheric hazes of Pluto. He also

Anne Pommier's research is dedicated to understanding how terrestrial planets work, especially the role of silicate and metallic melts in planetary interiors, from the scale of volcanic magma reservoirs to core-scale and planetary-scale processes.

She joined Carnegie in July 2021 from U.C. San Diego’s Scripps Institution of Oceanography, where she investigated the evolution and structure of planetary interiors, including our own Earth and its Moon, as well as Mars, Mercury, and the moon Ganymede.

Pommier’s experimental petrology and mineral physics work are an excellent addition to Carnegie’s longstanding leadership in lab-based mimicry of the

Johanna Teske became the first new staff member to join Carnegie’s newly named Earth and Planets Laboratory (EPL) in Washington, D.C., on September 1, 2020. She has been a NASA Hubble Fellow at the Carnegie Observatories in Pasadena, CA, since 2018. From 2014 to 2017 she was the Carnegie Origins Postdoctoral Fellow—a joint position between Carnegie’s Department of Terrestrial Magnetism (now part of EPL) and the Carnegie Observatories.

Teske is interested in the diversity in exoplanet compositions and the origins of that diversity. She uses observations to estimate exoplanet interior and atmospheric compositions, and the chemical environments of their formation