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Lecture Summaries
Lecture 1 — From Venoms to Drugs, by Baldomero M. Olivera, Ph.D.
Natural selection has produced an astounding array of venoms for prey capture. Marine cone snails are among the most dangerous venomous creatures. Cone snail venoms are potent, deadly to fish and people, and each species makes a venomous cocktail of up to 200 different toxins. One of these toxins has been developed into a drug called Prialt--a pain killer that prevents the spinal cord from relaying pain information to the brain. With over 700 living species of cone snails, each having up to 200 unique toxins, there are potentially more than 140,000 novel molecules with drug potential.
Lecture 2 — Shedding Light on an Invisible World, by Bonnie L. Bassler, Ph.D.
Bacteria live in and on us in complex communities that outnumber the cells and genes of our own tissues. These bacteria possess a communication mechanism that allows them to coordinate their activities. This mechanism, called quorum sensing, was first described in bacteria living symbiotically in a squid. The bacteria produce bioluminescence which simulates moonlight and camouflages the squid. The key to quorum sensing is a molecular signal released by the bacteria that is monitored by receptors, which in turn modulate gene expression. Bioluminescence genes are only turned on when the population density--and therefore the signal concentration--is high.
Lecture 3 —Biodiversity at a Snail's Pace, by Baldomero M. Olivera, Ph.D.
Cone snail venoms have a wide variety of effects, ranging from convulsive shock, to paralysis, to sedation. The venoms contain a mixture of peptide toxins that simultaneously attack different molecular targets of the nervous system. The evolution of such a diversity of toxins is made possible by multiple gene superfamilies containing hypervariable sequences. The research and medical value of a group of animals like the cone snails is a powerful reminder of what we can learn from biodiversity. Venomous relatives of the cone snails--the turrid snails--number over 10,000 known species, representing a million compounds of potential pharmacological value.
Lecture 4 — Eavesdropping on Tiny Conspiracies, by Bonnie L. Bassler, Ph.D.
Pathogenic bacteria use quorum sensing to launch a simultaneous attack when in sufficient numbers. Bacteria possess at least two systems of quorum sensing. They sense their own species’ numbers by monitoring their species-specific quorum sensing signal. Bacteria also sense a signal that is shared between different species to obtain information about the bacterial community. Manipulating quorum sensing is a promising approach for developing new antibiotics against pathogens, or probiotics for industrial applications.
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