Department of Biological Sciences, NUS
The origin and evolution of the eyespot gene network in Nymphalid butterflies
Speaker: Nesibe Ozsu (Graduate Student, Dept. of Biological Sciences, NUS)
Date: 23 May 2014, Friday
Venue: Seminar Room 1 (S2-04-14)
Supervisor: Assoc Prof Antonia Monteiro
The origin of the multiple life forms on our planet is essentially a history about the origin of novel traits; yet how these novel traits originate via modifications in development is largely unknown. In general, the development of any trait is dependent on an underlying gene regulatory network, so, identifying the origin of a novel trait should begin with the identification of the primitive and derived developmental gene networks. Butterfly eyespots are complex novel traits that originated once, from simpler coloured spots, within the family Nymphalidae, approximately 90 million years ego. Candidate gene approaches revealed that several genes gained a novel eyespot expression domain concurrently with eyespot origins, suggesting that eyespots may have originated via the co-option of a pre-existent gene network. However, the total number of genes associated with eyespot origins, and the identity of this co-opted network, remain unidentified. Here, Next-Gen sequencing and transciptome analyses will be used to identify the full set of genes associated with eyespot development at a particular stage in development. That set of genes with be compared with the set involved in the development of primitive spot patterns. First, the total set of genes involved in eyespot development will be identified in the model nymphalid, Bicyclus anynana using comparative transcriptomics of homologous small regions of wing tissue that either develop or don’t develop eyespots. Second, the transcriptome of the same wing sector from additional nymphalid species with eyespots and outgroup species with spots will be sequenced to identify a conserved set of genes shared across species with eyespots and across species with spots. The comparison of the two gene sets will allow the identification of genes that are unique to eyespots and that may have allowed spots to transform into eyespots. Finally, I will examine the function of an eyespot-specific candidate gene, wingless, expressed in eyespot centres in the early pupal stage, using an RNAi approach.
All are welcome