Disputas og prøveforelesning: Silje Larsen Rekdal

Silje Larsen Rekdal ved Naturhistorisk museum vil forsvare sin avhandling "Major histocompatibility complex and mate choice in two passerine birdsfor ph.d.-graden.

Foto: Karsten Sund

Foto: Karsten Sund

Tittel prøveforelesning

The evolution of sex - a review of hypotheses.

 

Bedømmelseskomité

  • Professor Manfred Milinski, Max-Planck-Institute for Evolutionary Biology, Germany
  • Professor Elizabeth MacDougall-Shackleton, University of Western Ontario, Canada
  • Professor Torsten Hugo Struck, Natural History Museum, University of Oslo

Veiledere

Leder av disputasen

Professor Hans Arne Nakrem

Conferral summary / Kreeringssammendrag

Denne doktorgraden tar for seg partnervalg hos sangfugler basert på et immunologisk viktig og svært variabelt gen-kompleks, med bruk av nye sekvenseringsmetoder. Hovedresultatene viser at blåstrupehunner velger kompatible hanner som gir avkom med en intermediær diversitet i én kategori av disse genene, og at dette er optimalt. Det samme mønsteret ble ikke funnet hos løvsangere i en annen kategori av gen-komplekset, noe som tyder på forskjeller mellom arter og/eller kategorier.

Main research findings / Hovedfunn 

All organisms constantly need to fight pathogens to avoid infectious diseases. In vertebrates, two classes of polymorphic genes from what is known as the major histocompatibility complex (MHC) are crucial for triggering immune responses against specific intracellular (MHC class I; MHCI) and extracellular (MHC class II; MHCII) pathogens. Whenever possible, females should choose mates that render an optimal MHC constitution in the offspring. Such genetic effects of mate choice can be elucidated by studying species where females engage in mating outside the social pair, which occurs frequently in songbirds. The hypervariable songbird MHC has been difficult to genotype, but new methodology offers great improvements. This thesis explores MHC-based extra-pair mate choice in two songbirds, using new sequencing technology. For the bluethroat (Luscinia svecica), evidence for non-random, self-referential female choice of extra-pair males based on an intermediate optimum in MHCII diversity was found. For the willow warbler (Phylloscopus trochilus), two different female mating strategies were implied, where females with few MHCI variants were more likely to engage in extra-pair mating. This sheds light on the variation in MHC-based mate choice across species and MHC classes, and demonstrate an adaptive benefit of female extra-pair mating in songbirds.

 

 

Følg med på disputasen her / follow the disputation

Last ned Zoom / Download Zoom

 

The University of Oslo is closed. Rekdal's PhD defense will, therefore, be fully digital and streamed directly using Zoom. The host of the session will moderate the technicalities while the chair of the defense will moderate the disputation.

Ex auditorio questions: the chair of the defense will invite the audience to ask ex auditorio questions either written or oral. This can be requested by clicking 'Participants -> Raise hand'. 

 

Kontakt

Elisabeth Aronsen

Arrangør

Naturhistorisk museum
Publisert 13. apr. 2020 12:55 - Sist endret 30. apr. 2020 12:02