Salk Institute promotes latest generation of extraordinary scientists

E. J. Chichilnisky
Promoted to professor
Systems Neurobiology Laboratories
Chichilnisky is working on deciphering how the retina, the tissue lining the back of the eye, encodes visual information so the brain can use it to produce visual experience. Employing a microscopic electrode array to record the activity of retinal ganglion cells—each of which views the world only through a small, jagged window called a receptive field—he was able to show that receptive fields fit together like pieces of a puzzle, preventing blind spots and excessive overlap that could blur our perception of the world. Most recently, he was able to trace for the first time the neuronal circuitry that connects individual photoreceptors with retinal ganglion cells, shedding light on the neural code used by the retina to relay color information to the brain.

Andrew Dillin
Promoted to professor
Molecular and Cell Biology Laboratory
A Howard Hughes Medical Institute investigator and director of the Glenn Center for Aging, Dillin uses the tiny roundworm Caenorhabditis elegans to study the genetic and molecular pathways that regulate aging and aging-related diseases. His lab discovered the mechanisms that clear away toxic proteins in young, healthy brains— mechanisms that, he found, break down with age and lead to protein aggregate build-up, the hallmark of age-related neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's. Most recently, he identified a molecular switch flipped by hunger, which links caloric restriction and longevity and that could identify drug targets for patients with age-related diseases such as type 2 diabetes or cancer.

Martin W. Hetzer
Promoted to Hearst Endowment professor
Molecular and Cell Biology Laboratory
Hetzer explores how the organization of the nucleus influences gene activity and how disruption of its three-dimensional architecture can cause developmental defects, cancer and aging. Work from the Hetzer lab has established nuclear pore proteins as a new class of gene regulators and shown that nuclear membrane integrity declines with age and during the formation or production of tumors. Nuclear membrane irregularities are a hallmark of many diseases, including cancer and neurodegenerative disorders, and thus his work is relevant for many diverse aspects of human health.

Leanne Jones
Promoted to associate professor
Laboratory of Genetics
Jones uses the fruit fly Drosophila melanogaster to establish paradigms for how stem cell behavior is controlled and how the relationship between stem cells and their environment changes during development, aging and tumorigenesis. Using the fly intestine and testis as model systems, Jones discovered that during the aging process, the level of support from a stem cell's specialized environment, also known as the stem cell niche, drops off, diminishing stem cells' ability to selfrenew and adequately maintain tissues. In a separate study, she also found that stem cells adjust their numbers depending on the availability of nutrients to coordinate tissue maintenance with environmental conditions.

Jan Karlseder
Promoted to professor
Molecular and Cell Biology Laboratory
Karlseder studies how cells keep tabs on their telomeres—the protective ends of chromosomes—and prevent catastrophic meltdowns to gain a better understanding of the interrelationship of aging and cancer. For example, he found that the telomere dysfunction observed in cells from patients with the premature aging disease known as Werner syndrome is a major cause of genomic instability and could explain the high incidence of cancer seen in this disease. In a finding with direct implications for the treatment of cancer, he discovered that telomeres, which commonly end in a string of DNA rich in the base guanine (G), can also terminate with a different motif, a strand abundant in the base cytosine (C).

Satchidananda Panda
Promoted to associate professor
Regulatory Biology Laboratory
Panda seeks to understand how our brain clock keeps track of time in all seasons and time zones and tells our body when to sleep, when to wake up and when to eat. His work focuses mostly on melanopsin, a photopigment he discovered before he joined the Salk Institute. His research in the Laboratory of Regulatory Biology has revealed that melanopsin not only reports the intensity of incoming light to the circadian clock but also to regular visual centers in the brain. In a different set of experiments, he discovered that the daily waxing and waning of thousands of genes in the liver—the body's metabolic clearinghouse—is mostly controlled by food intake and not, as conventional wisdom had it, by the body's circadian clock.