Université de Fribourg

Evolution of gene expression during a transition from environmental to genetic sex determination

Molinier, Cécile ; Reisser, Céline M O ; Fields, Peter D ; Ségard, Adeline ; Galimov, Yan ; Haag, Christoph R

In: Molecular Biology and Evolution, 2019, vol. 36, no. 7, p. 1551–1564

Genetic sex determination (GSD) can evolve from environmental sex determination (ESD) via an intermediate state in which both coexist in the same population. Such mixed populations are found in the crustacean Daphnia magna, where non-male producers (NMP, genetically determined females) coexist with male producers (MP), in which male production is environmentally inducible and can also...

Université de Fribourg

Identification of general patterns of sex-biased expression in Daphnia, a genus with environmental sex determination

Molinier, Cécile ; Reisser, Céline M.O. ; Fields, Peter ; Ségard, Adeline ; Galimov, Yan ; Haag, Christoph R.

In: G3& Genes|Genomes|Genetics, 2018, vol. 8, no. 5, p. 1523–1533

Daphnia reproduce by cyclic-parthenogenesis, where phases of asexual reproduction are intermitted by sexual production of diapause stages. This life cycle, together with environmental sex determination, allow the comparison of gene expression between genetically identical males and females. We investigated gene expression differences between males and females in four genotypes of Daphnia...

Université de Fribourg

Uncovering cryptic asexuality in Daphnia magna by RAD sequencing

Svendsen, Nils ; Reisser, Celine M. O. ; Dukić, Marinela ; Thuillier, Virginie ; Ségard, Adeline ; Liautard-Haag, Cathy ; Fasel, Dominique ; Hürlimann, Evelin ; Lenormand, Thomas ; Galimov, Yan ; Haag, Christoph R.

In: Genetics, 2015, vol. 201, no. 3, p. 1143–1155

The breeding systems of many organisms are cryptic and difficult to investigate with observational data, yet they have profound effects on a species’ ecology, evolution, and genome organization. Genomic approaches offer a novel, indirect way to investigate breeding systems, specifically by studying the transmission of genetic information from parents to offspring. Here we exemplify this method...

Université de Fribourg

Frequency and inheritance of non-male producing clones in Daphnia magna: evolution towards sex specialization in a cyclical parthenogen?

Galimov, Yan ; Walser, Barbara ; Haag, Christoph R.

In: Journal of Evolutionary Biology, 2011, vol. 24, no. 7, p. 1572–1583

In Daphnia (Cladocera, Crustacea), parthenogenetic reproduction alternates with sexual reproduction. Individuals of both sexes that belong to the same parthenogenetic line are genetically identical, and their sex is determined by the environment. Previously, non-male producing (NMP) genotypes have been described in species of the Daphnia pulex group. Such genotypes can only persist through phases...