Guest lecture by Professor James Marden, Penn State University
Dr. James Marden, entomologist with interests in the areas of physiological
ecology, functional genomics, evolutionary ecology, and behaviour, is visiting
Institute of biology on Thursday 1st September. Prof. Marden will give a guest
lecture entiteled: “Intraspecific variation in hypoxia signaling: a hot-spot for life
history variation including tracheogenesis, mitochondrial health, dispersal and
metapopulation dynamics in an ecological model insect”.
Time and place: Thursday 1st September, 14.30 p.m. in room K1/K2 in Bioblock A.
Abstract for the talk (kan dette kanskje lages som link? F.eks med ordet
Abstract): Aerobic metabolism requires matching of oxygen delivery and
consumption rates. The hypoxia inducible pathway, a conserved feature of
eukaryotes, senses and responds to intracellular oxygen and metabolite
concentrations by controling gene expression affecting the development and
dynamics of oxygen delivery networks. Research on this pathway has
concentrated on describing its fundamental features and how major
disruptions cause disease. Largely overlooked is the likelihood that the
hypoxia inducible pathway is a common mutational target for alleles subtly
affecting life history and fitness, since changes in oxygen availability and
metabolism have developmental, performance, and longevity phenotypes. I
will address this hypothesis by examining allelic variation in a metabolic gene,
succinate dehydrogenase d (Sdhd), which acts on metabolites known to affect
hypoxia signaling and the development of vascularized tumors. The
ecologically well characterized Glanville fritillary butterfly contains a
polymorphism in Sdhd that appears to have large effects on fitness and
ecological dynamics. Our transcriptome study revealed associations between
an insertion-deletion (indel) polymorphism in the 3’ UTR of Sdhd and
metabolic rate, dispersal ability, population growth rate and metapopulation
dynamics. I will present physiological data showing how these Sdhd
alleles are associated with differences in hypoxia signaling and tracheal
development that relate to flight metabolic capacity and mitochondrial integrity,
likely arising from the way SDH metabolites affect development of the oxygen
delivery network and ultimately oxygen availability during peak demand.