Antonia Klein
PhD student


University of Regensburg

Biology I

Institute of Evolution, Behavior and Genetics

Phone: +49 (0)941 943 2259


Research Interests:

Cardiocondyla obscurior as model for eusocial traits
My work is part of the DFG-funded “Cardiocondyla genome project”, which investigates the subtropical Myrmicinae ant species Cardiocondyla obscurior, using a combination of behavioral, genetic and genomic (next generation sequencing) methods. The possibility of controlled crosses in the lab, the production of sexuals throughout the year and a peculiar male diphenism with ergatoid fighter males and normal Hymenopteran winged males make Cardiocondyla perfectly suited for the investigation of evolutionary questions dealing with eusocial traits (Heinze et al. 2006, Oettler et al. 2010).

Genetic Architecture as requirement for genomic work
It is important for future quantitative genomic work to improve the resolution of the genetic architecture. Hence I am constructing a genetic linkage map of C. obscurior, using a cross between two C. obscurior populations from Brazil and Japan. These two populations differ in phenotypic characters as well as in about 400,000 homologous SNPs on a genetic level. The SNPs will be located with help of the NGS method RADseq

(Restriction site Associated DNA sequencing). The big advantage of RADseq is the possibility of genotyping the same reduced representation of the genome in many individuals in parallel. Including a double digest (ddRADseq) in the protocol, allows for working with less than 200 ng of genomic DNA as input (Peterson et al. 2013).


Sex Determination in an haplodiploid Hymenopteran species
At first glance sex in Hymenoptera lacking sex chromosomes is determined by haplodiploidy: Fertilized eggs will become females, unfertilized eggs will develop into males. But more complex genetic mechanisms underly this simple rule. E. g. single locus sex determination (sld) of the csd locus in the Honeybee (Beye et al. 2003) or maternal imprinting in Nasonia (Verhulst et al. 2010a) are the beginning of a gene cascade involving the genes transformer (tra) and doublesex (dsx) (see review: Verhulst et al. 2010b).

The genetic mechanisms underlying haplodiploid sex determination in C. obscurior are unknown. As in C. obscurior despite many generations of inbreeding no diploid males could be detected using flow cytometry (Schrempf et al. 2006), single locus sex determination is unlikely. I am investigating sex determination mechanisms in C. obscurior using different approaches: Genotyping of offspring of controlled crosses with distinct genotypes, gene annotation of the known sex determination genes tra and dsx, and quantitative description of their expression using RT-qPCR in male and female individuals respectively.

Cited Literature:

Beye M., Hasselmann M., Fondrik M. K., Page R. E., Omholt S. W. (2003) The Gene csd is the Primary Signal for Sexual Development in the Honeybee and Encodes an SR-Type Protein. Cell 114: 419-429.

Heinze J., Cremer S., Eckl N., Schrempf A.  (2006) Stealthy invaders: the biology of Cardiocondlya tramp ants. Insectes Sociaux 53: (2006) 1–7.

Oettler J., Suefuji M., Heinze J. (2010) The Evolution of Alternative reproductive tactics in male Cardiocondlya Ants. Evolution 64: 3310–3317.

Peterson K. P., Weber J. N., Kay E. H., Fisher H. S., Hoekstra H. E. (2013) Double Digest RADseq: An Inexpensive Method for De Novo SNP Discovery and Genotyping in Model an Non-Model Species. PloS One 7: 5.

Schrempf A., Aron S., Heinze J. (2006) Sex determination and inbreeding depression in an ant with regular sib-mating. Heredity 97: 75-80.

Verhulst E. C., Beukeboom L. W., van de Zande L. (2010a) Maternal Control of Haplodiploid Sex Determination in the Wasp Nasonia. Science 328: 620-623.

Verhulst E. C., van de Zande L., Beukeboom L. W. (2010b) Insect sex determination: it all evolves around transformer. Current Opinion in Genetics & Development 20: 376-383.