Meeting Abstract

P1.14  Wednesday, Jan. 4  The mangrove killifish as a model for environmental embryology MOURABIT, S*; KUDOH, T; Univ. of Exeter, Exeter, UK

The mangrove killifish, Kryptolebias marmoratus, is a self-fertilizing vertebrate offering vast potential as a model species in many biological disciplines. Previous studies have defined developmental stages but lacked visual representations of the various embryonic structures. We offer detailed photographic images of K. marmoratus development with revised descriptions. An improved dechorionation method was developed to provide high resolution photographs, as well as a microinjection technique enabling cell marking. Using K. marmoratus in conjunction with the zebrafish, a popular model species, we examined the differential stress response of embryos exposed to high temperatures. In situ hybridisation was performed for oxidative stress related genes (hmox1, gstp, fth1), and regulation of these genes in response to heat stress was compared between both species. In addition, microinjections of two constructs were carried out allowing for visualisation of promoter activity, via fluorescent proteins, for the heat-shock protein 70 and the electrophile responsive element (which activates gene expression in response to oxidative stress). The comparative data allows us to discuss the conserved and species specific mechanisms of the heat-shock response in different fish species from different thermal habitats. Our data also suggest that K. marmoratus embryos are easily used and manipulated, supporting the use of this hermaphroditic vertebrate as a strong comparative model system in embryology, evolution, genetics, environmental and medical biology.