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The social life of bacteria: collapse of a culture

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Air date: Wednesday, January 20, 2016, 3:00:00 PM
Time displayed is Eastern Time, Washington DC Local
Views: Total views: 328 (122 Live, 206 On-demand)
Category: WALS - Wednesday Afternoon Lectures
Runtime: 01:06:52
Description: Wednesday Afternoon Lecture Series

Dr. Greenberg is interested in how and why individual cells communicate with each other. In particular, he has studied the bacterial communication system—called quorum sensing—and how it controls cooperation in groups of bacteria. In his lecture, he will focus on a human pathogen, Pseudomonas aeruginosa, which uses a transcription factor called LasR to activate dozens of genes in response to the LasI-produced quorum-sensing signal 3OC12-HSL. The most overrepresented LasR-controlled genes code for the synthesis of exoproducts. Exoproducts are common goods that are made by individuals and shared within the group. Members of quorum-sensing groups are thus thought of as cooperators. Quorum-sensing cooperators, however, are susceptible to invasion by social cheaters—LasR mutants that benefit from cooperator-derived common goods without incurring a production cost. Greenberg will discuss three questions related to this bacterial social activity: 1) If social cheaters have a fitness advantage over cooperators, then how can cooperation be evolutionarily stable (Darwin’s dilemma)? He will describe one molecular mechanism that restrains cheating; 2) Why do cooperators and cheaters reach an equilibrium and co-exist with each other in some situations? He will describe how cooperators police cheaters; and 3) Can we manipulate conditions to induce a breakdown in cooperation and a catastrophic population crash? He will show that this crash can occur when the cost of cooperation is increased or when policing is eliminated. He will discuss the implications of this sociobiology view of P. aeruginosa population ecology in the context of chronic infections and general cell-cell interactions.

For more information go to https://oir.nih.gov/wals
NLM Title: The social life of bacteria : collapse of a culture / E. Peter Greenberg.
Author: Greenberg, E Peter.
National Institutes of Health (U.S.),
Publisher:
Abstract: (CIT): Dr. Greenberg is interested in how and why individual cells communicate with each other. In particular, he has studied the bacterial communication system--called quorum sensing--and how it controls cooperation in groups of bacteria. In his lecture, he will focus on a human pathogen, Pseudomonas aeruginosa, which uses a transcription factor called LasR to activate dozens of genes in response to the LasI-produced quorum-sensing signal 3OC12-HSL. The most overrepresented LasR-controlled genes code for the synthesis of exoproducts. Exoproducts are common goods that are made by individuals and shared within the group. Members of quorum-sensing groups are thus thought of as cooperators. Quorum-sensing cooperators, however, are susceptible to invasion by social cheaters--LasR mutants that benefit from cooperator-derived common goods without incurring a production cost. Greenberg will discuss three questions related to this bacterial social activity: 1) If social cheaters have a fitness advantage over cooperators, then how can cooperation be evolutionarily stable (Darwin's dilemma)? He will describe one molecular mechanism that restrains cheating; 2) Why do cooperators and cheaters reach an equilibrium and co-exist with each other in some situations? He will describe how cooperators police cheaters; and 3) Can we manipulate conditions to induce a breakdown in cooperation and a catastrophic population crash? He will show that this crash can occur when the cost of cooperation is increased or when policing is eliminated. He will discuss the implications of this sociobiology view of P. aeruginosa population ecology in the context of chronic infections and general cell-cell interactions.For more information go to https://oir.nih.gov/wals.
Subjects: Bacterial Physiological Phenomena
Pseudomonas aeruginosa--physiology
Quorum Sensing
Publication Types: Lecture
Webcast
 
NLM Classification: QW 52
NLM ID: 101676588
CIT Live ID: 17658
Permanent link: https://videocast.nih.gov/watch=17658

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