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.
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.
The mouse is a traditional model organism for understanding physiological processes in humans. Chen-Ming Fan uses the mouse to study the underlying mechanisms involved in human development and genetic diseases. He concentrates on identifying and understanding the signals that direct the musculoskeletal system to develop in the mammalian embryo.
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 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.
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.
Staff associate Christoph Lepper, with colleagues, 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.
Ecosystems fluctuate over time. For example, in a forest trees fall, seeds grow, and sometimes forest fires burn it all down. Microbial ecosystems experience similar fluctuations but on a much faster time scale. Taking advantage of the fast time scale and ease of setting up a controlled experiment, we study complex ecological dynamics that arise from microbial community interactions.
Allan Spradling is a Howard Hughes Medical Institute Investigator and former 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 cells—those that turn into non-reproductive tissues.
My research in yeast focuses on the fundamental question: What factors make a given molecule a “good substrate” for homologous recombination? Such factors determine how often non-allelic repetitive DNA recombines to produce chromosomal aberrations associated with cancer and hereditary diseases.
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.
Yixian Zheng is the Director of the Department of Embryology. Yixian Zheng’s 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.
