Investigating the functionality of papaver s-determinants in highly diverged heterologous systems

Flores Ortiz, Carlos Alberto (2015). Investigating the functionality of papaver s-determinants in highly diverged heterologous systems. University of Birmingham. Ph.D.

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Abstract

Self-incompatibility (SI) is an important genetic mechanism that angiosperms utilize to reject "self' pollen. In Papaver rhoeas (poppy) Sl is controlled in an allele-specific manner by a single locus with multiple haplotypes; each haplotype encodes male (PrpS) and female (PrsS) S-determinants. PrsS-PrpS interaction triggers Sl, stimulating cation channel activity and increases in cytosolic free Ca2+ ([Ca2+]i), triggering a signalling network involving actin cytoskeleton alterations and programmed cell death (PCD). PrpS was recently functionally transferred into self-compatible, highly diverged Arabidopsis thaliana. Transgenic Arabidopsis pollen expressing PrpS-GFP was shown to undergo a "Papaver-SI-Iike response", involving actin and PCD when challenged by recombinant PrsS.
Here we investigated function of PrpS in several other heterologous model systems, including Arabidopsis mesophyll protoplasts, yeast, barley and mammalian HeLa cells. Although more work is needed on some of these systems, data were obtained suggesting that PrpS is functional in mammalian HeLa cells. A key finding was that HeLa cells expressing PrpS , when exposed to cognate PrsS, exhibited transient increases in [Ca2+]i and inward cation currents; actin reorganization and decrease in cell adherence. These data suggest that: PrsS-PrpS interaction can recruit endogenous components in HeLa cells to achieve a biological response.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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