Kristina M. Sefc
Kristina M. Sefc



Institute of Zoology
University of Graz
Universitätsplatz 2
A-8010 Graz
Tel. +43 (0) 316 380-5601
Fax +43 (0) 316 380-9875
kristina.sefc@uni-graz.at
Tropheus, by A. Konings Vidua camerunensis, photo by M. D. Sorenson Grapevines

1999 Ph.D., Centre for Applied Genetics, Universität für Bodenkultur Wien, Austria Grapes
1999 Post Doc, Department of Agricultural Sciences, University of the Azores, Portugal
2000-2003 Post Doc, Department of Biology, Boston University, MA, USA (Sorenson Lab) Indigobirds
2003- Assistant Professor, Institute of Zoology, Karl Franzens University Graz, Austria Cichlids


Publications

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FWF project information - P17380-B06


Cichlid diversity in Lake TanganyikaPhotos from Konings 1998 arranged by Nina Duftner

I am interested in diversification at the population level, including incipient speciation. In the early stages of divergence, environmental, ecological and behavioral factors are far more important than postzygotic mechanisms for maintaining and driving differentiation. Studies of population structure, mating systems and mate preferences can yield information on how diversification is launched or, in other cases, prevented.

Cichlid fishes of the African Rift Lakes are excellent model systems for this kind of research, because they are closely related to each other, but highly diversified in morphological, ecological and behavioral respects. My group is studying the phylogenetic relationship among cichlid species in Lake Tanganyika, as well as the population genetic structure and mating systems of different species in the southern part of Lake Tanganyika.

One particularly interesting case is represented by the color morphs of the genus Tropheus in Lake Tanganyika (see figure to the right), which have a common ancestor about 800,000 years ago. The absence of sexual dimorphism and the establishment of temporary pair bonds for spawning distinguishes Tropheus from other colorful cichlids, whose biology is more consistent with the action of strong sexual selection. We study the evolution of the extant wealth of color variants in Tropheus by investigating the mating system, the role of color variation in mating behavior, and the genetic structure of populations and color morphs.

Past and current group members are:
Bernd Egger (PhD), Eva Eigner (Ms), Beate Obermüller (Ms), Caroline Hermann (Ms), Karin Mattersdorfer (Ms), Bernd Steinwender (Ms), and Stephan Koblmüller (Postdoc).


Sympatric speciation in brood parasitic indigobrids

As a Postdoc in Michael Sorenson's lab at Boston University, I joined his research on speciation in a group of African finches, the indigobirds. Indigobirds (genus Vidua) are obligate, but benign, brood parasites with strict specificity to particular host species. The parasitic chicks mimic the mouth markings of their hosts and learn the host song, which they later on use as a mate recognition cue. Mating is assortative among associates of the same host, and females lay their eggs into nests of the same species that they were raised by. Host switches result in immediate reproductive isolation between birds reared by novel hosts and their former conspecifics, thus setting the stage for rapid sympatric speciation. Although the extant indigobird species are of very recent origin, genetic data confirm the reproductive isolation between associates of different hosts.

 

Genetic analysis of grapevine cultivars

In my PhD work at the Center for Applied Genetics, Universität für Bodenkultur Wien, I used microsatellite markers to build a database for the identification of grapevine and rootstock cultivars. Based on the cultivar's genotypes, I reconstructed ancient crosses that gave rise to some of our extant cultivars. The genetic contribution of local wild vines to European grapevine cultivars was inferred from the genetic structure of grapevines from different wine producing regions.

 

 

from Sefc et al. 1998, Theor. Appl. Genet. 97

 

 


Updated March 2008