Architecture of the Inner Ear

Normal hearing is dependent upon a highly specialized structure in the inner ear called the tectorial membrane. How this precisely organized extracellular matrix is assembled had been unknown. However, Park and colleagues showed the inner ear membrane anchors to the cell surface during development and grows one layer at a time. Continue reading → Architecture of the Inner Ear

Cellular Origins of Pancreatic Cancer

Our pancreas has two main functions, endocrine control of blood sugar and exocrine production of the enzymes that digest our food. These enzymes are synthesized by pancreatic acinar cells and transported to the intestine through a network of pancreatic duct cells. Pancreatic cancer, the third deadliest cancer in the U.S., was previously assumed, based on histology and gene expression, to arise from duct cells. Continue reading → Cellular Origins of Pancreatic Cancer

Neuronal Circuits that Modulate Pain and Defensive Responses

Understanding pain-processing mechanisms and the neural circuits involved is central to developing new therapeutic strategies for the treatment of pain. The Douglass lab investigated brain regions that modulate behavioral responses to noxious stimuli in zebrafish. Continue reading → Neuronal Circuits that Modulate Pain and Defensive Responses

The Role of Cholesterol in Activating a Key Cellular Signaling Pathway

Hedgehog signaling promotes embryonic development and, when aberrant, can lead to malignancies. The seven-transmembrane transducer Smoothened (SMO) occupies a key node in this pathway and is activated by cholesterol. Continue reading → The Role of Cholesterol in Activating a Key Cellular Signaling Pathway

MicroRNA Regulation of Inflammation and Immunity

MicroRNAs provide a crucial level of control for cell development and function through their post-transcriptional regulation of gene expression. Their importance is highlighted by their diverse functions in a range of cell types, including immune cells. Continue reading → MicroRNA Regulation of Inflammation and Immunity

Diaphragm Development and Congenital Hernias

The diaphragm is an essential mammalian skeletal muscle, as it is required for respiration and serves as a barrier between the thoracic and abdominal cavities. The Kardon lab used sophisticated mouse genetic studies to establish that the diaphragm arises from multiple embryonic tissues. Continue reading → Diaphragm Development and Congenital Hernias

Mechanisms of Epigenetic Inheritance

A central issue in epigenetics is whether and how epigenetic information in gametes (sperm and egg) is inherited. Cairns and colleagues discovered that “Placeholder” nucleosomes, containing histone variants, occupy DNA regions lacking methylation in both sperm and early embryos. Continue reading → Mechanisms of Epigenetic Inheritance

Genes Responsible for Maintaining Embryonic Developmental Potential

A major question concerning early embryos involves how early cleavage-stage (two-cell) embryos establish unlimited developmental potential – termed totipotency. Cairns and colleagues identified the multicopy retrogene, DUX4 in humans or Dux in mice, as a transcription factor that is turned on in very early embryos and activates hundreds of genes and retroviral elements during cleavage stage. Continue reading → Genes Responsible for Maintaining Embryonic Developmental Potential