IAS-Research Seminar by Guglielmo Militello: “Harnessing energy production: functional integration in symbiotic relationships”

Date and time: November 14, Tuesday, 11:30 a.m.

Location: Carlos Santamaría Building, Room B14.

Speaker: Guglielmo Militello


Functional integration is broadly defined in life sciences as the causal interdependence among the subsystems forming an organism. However, this characterisation is vague and not able to describe the different degrees of functional integration in living beings (Pradeau 2010). From an organizational perspective, functional integration is interpreted as the mutual dependence of the constitutive constraints that collectively maintain the whole organisation (Moreno and Mossio 2015; Bich 2016). Therefore, organisational closure (i.e. the closure of constitutive constraints) implies functional integration (Moreno and Mossio 2015).

This talk aims to investigate some important organisational requirements for the functional integration of two (or more) symbionts.

Two case-studies will be analysed and compared: the first one is the endosymbiotic relationship between an α-proteobacterium (the ancestor of mitochondrion) and the proto-eukaryotic cell; the second one is the set of mutualistic relationships that mixotricha paradoxa establishes with its ectosymbionts (essential for the locomotion of mixotricha) and with its endosymbionts (crucial for the bioenergetics of mixotricha).

The analysis supports the thesis that a necessary, but not sufficient, condition for integrated symbionts is the ability of harnessing energy production (namely the synthesis of ATP molecules) through a number of metabolic and genetic constraints that are mutually dependent.