Sex Chromosome Evolution in a Hermaphrodite : Genetic and phenotypic relationships between sex roles
Author
Summary, in English
Here, I show that additive genetic variance for female fitness is three times larger than male fitness in stock populations of M. lignano. I also found that additive genetic variance was environment-specific, and the difference depended on the sex-role. The relationship between male and female fitness was weak both on the genetic and phenotypic level, and it did not seem to change across environments. This indicates that male and female fitness function can evolve independently from each other, and that there was no sexual antagonism between sex roles. Despite this, we could show evidence of a genetically-based trade-off in the sex-limited experimental evolution, indicating that we might have reinforced a negative intersexual genetic correlation between sex roles during the course of the experiment. Gene expression analysis also revealed that the largest number of differentially expressed genes was between the male- and female-limited selection treatments, but there was no expression difference between treatments in the sex-specific organs (antrum and prostate gland). In any case, we could show proof of concept that the early stages of sex chromosome evolution are observable in real time.
Department/s
Publishing year
2017-11
Language
English
Full text
Document type
Dissertation
Publisher
Lund University, Faculty of Science, Department of Biology
Topic
- Natural Sciences
- Biological Sciences
- Genetics
- Evolutionary Biology
Keywords
- Sex chromosome evolution
- Hermaphrodite
- Inter-sexual genetic correlation
- Quantitative genetics
- Macrostomum lignano
- Experimental evolution
- Sexual conflict
Status
Published
Supervisor
ISBN/ISSN/Other
- ISBN: 978-91-7753-474-7
- ISBN: 978-91-7753-473-0
Defence date
24 November 2017
Defence time
09:30
Defence place
Lecture hall “Blå hallen”, Ecology building, Sölvegatan 37, Lund
Opponent
- Mike Ritchie (Prof.)