Schärer Group
Evolutionary Biology
Zoological Institute
University of Basel
Vesalgasse 1
CH-4051 Basel
Switzerland

Kiyono Sekii

email: kiyono.sekii-at-unibas.ch
phone: +41 61 267 03 61

I am a PhD student in the group of Dr. Lukas Schärer and I am performing experimental tests of sex allocation theory using an RNAi knockdown approach.

Current research

In nature, we can see various types of sexual systems such as gonochorists (separate sex), sequential hermaphrodites and simultaneous hermaphrodites. In addition to these typical systems, there are also mixed type such as gynodioecy and androdioecy. This reproductive diversity has fascinated many evolutionists, including C. Darwin, R. Fischer, W.D. Hamilton and E. Charnov, and these people formulated sex allocation theory in order to explain why and how these sexual systems have evolved (Darwin 1859; Fisher 1930; Hamilton 1967; Charnov 1979; Charnov 1982). Thus sex allocation theory describes, based on the concept of resource allocation and fitness return, how organisms should behave in order to maximize their reproductive success, for example, what kind of sex ratio should be produced in gonochorists, at which time sex should be change in sequential hermaphrodites and how many pollen and ovules (or sperm and eggs) should be produced in simultaneous hermaphrodites. However, the empirical examination of sex allocation theory is so far limited, especially in simultaneously hermaphrodite animals. Therefore I propose to approach this intriguing question experimentally, using molecular techniques such as RNA interference (RNAi) of sex specific genes. This should allow for direct manipulation of resource allocation and microsatellite parentage analyses will then be used to examine the fitness consequecnes of such a manipulation.

In situ hybridization expression patterns of two candidate genes that are either specifically expressed in the testis (left) or ovary (right) of Macrostomum lignano