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Status: Ongoing
Project Contact: José Fonseca (jmf@uninova.pt)

Financing: FCT/MCTES

Project Summary

A bacterium appears to be functionally immortal as it perpetuates itself by dividing into cells with a genotype identical to the mother cell. Recent evidence suggests that this strategy has costs and requires mechanisms to deal with them. These included the accumulation of unwanted substances and degradation of internal structures. It is poorly understood how these problems were solved by the evolutionary process of these organisms.

The objective of this project is to study the kinetics of segregation to the poles and the partitioning in division of aggregates in live bacteria, one event at a time with single molecule resolution, various environmental and stress conditions. Also, it will be established the correlation between this and aging, i.e., loss of reproductive vitality across lineages.

A major component of this work is the development of image processing and segmentation techniques to extract the information from time series of microscope images. With these tools, we will characterize the kinetics of segregation at the single event level over time and its adaptability to less favorable conditions. In particular, we will:

  • Establish methods for image segmentation of cells and aggregates from temporal images by confocal microscopy;

  • Establish automated methods to track cells and aggregates in time from temporal images by confocal microscopy and characterize the kinetics of the aggregates.

  • Develop methods to detect cell divisions and characterize the partitioning of aggregates by the daughter cells;

  • Study the kinetics of segregation of unwanted fluorescently tagged aggregates in various conditions. Study how the kinetics changes when the cells are subject to different temperatures and stress, e.g., by starvation and heat shock;

  • Establish, in the various conditions, the correlation between segregation and aging in bacteria. From this, draw conclusions on kinetics of process and its adaptability and robustness.