Evolution and adaptation of sperm in marine organisms
This is a suggestion for a Degree Project for Bachelor's and Master's levels at the Department of Marine Sciences. Degree projects at the Department of Marine Sciences are done independently and must be written and assessed individually.
Subject: Marine Biology
Level: Bachelor and Master
Location: Projects will be based mostly at Tjärnö, but if there is a co-supervisor in Gothenburg or Kristineberg, the project may take place there.
Supervisor: Erica Leder. Other co-supervisors will be involved depending on taxa and approach.
Background
Sperm cells are one of the most varied cell types across the animal kingdom which is surprising giving their universal function of fertilization of an egg. Many organisms, especially crustaceans, have vastly different morphology than what we typically think of as a sperm cell – the tadpole-like mammalian sperm (in the figure, a-d and h-j are crustaceans, from Pitnick et al. 2009).
Additionally, in the marine environment, many organisms have external fertilization, so the gametes can be affected by the external environment (salinity, pH, pollutants). Sperm are produced in the testes through the process of spermatogenesis, and germ cells proceed through several sequential steps before becoming a functional sperm cell.
Due to the complexity of varied cell types that are present in testis tissue, very little is known about the cell biology and genetics of this process except in model organisms.
Project Suggestions
There are many interesting questions still to be addressed concerning spermatogenesis and sperm evolution in fish and marine invertebrates. Projects in this area can focus on histology and characterization of cell types during spermatogenesis, on gene expression in testis, on sperm performance or testis development in response to environmental changes.
I currently have access to samples of fish (gobies & sticklebacks) originating from different salinities to examine sperm adaptation to salinity, but other experiments can be designed, for example, exposure to chemicals or temperature differences.
Access to other taxa for other questions can be accomplished through collaborators or by sampling from the wild.
Contact
Erica Leder is an evolutionary geneticist with broad interests in the genomic basis for evolution and adaptation, particularly with respect to reproduction and mating systems in response to environmental changes. However, the projects need not involve genetics.
Please get in touch if you are interested in developing a project in this area.
Erica Leder
Email: erica.leder@gu.se