Chi-Yao Chang'Lab｜Institute of Cellular and Organismic Biology, Academia Sinica

To explore the regulatory mechanism of life and solve the aquaculture problems, we identify fish as the study organism.

In the study of aquatic environment, we found that zinc (Zn) is one of the major trace elements indispensable for fish embryonic development. Zn deprivation induces congenital malformations. However, excess Zn can be highly toxic to embryos. On the other hand, it was demonstrated that a low molecular weight, heavy metal binding protein – Metallothionein (MT) can provide protection against the lethal toxic dosage of Zn through sequestration. We are interested in the protein MT which involves in heavy metal ion homeostasis and detoxification. Through whole-mount in situ hybridization, we present the expression pattern of MT gene during embryonic and early larval stages. Besides, we also found that the expression of MT gene is induced by Zn through the MRE sequence on its promoter and transcription factor MTF-1(Metal-responsive transcription factor-1). The regulation ability of MT and MTF-1 on heavy metal ion homeostasis and their expression patterns in early embryonic development implies their important role in embryogenesis.

Recently, iridovirus and nervous necrosis virus have been considered as causative agents of the most severe damages in the industry of fin-fish aquaculture. To solve the problems, we conduct basic as well as applied researches on these two viruses. By using functional genomics, proteomics, transgenics and vaccine approaches, we investigate the interaction of virus and host to understand the viral infectious mechanisms and the host immune response. We have finished the complete DNA sequencing of grouper iridovirus (GIV) genome. The circular form genome was 139,793 bp in length with 120 predicted open reading frames (ORFs). The genomic sequence will offer useful information to develop novel approaches for iridovirus control. Interestingly, the GIV genome contains a purine nucleoside phosphorylase (PNP) gene, which is not found in any other viruses. GIV-PNP has the potential to develop cancer treatments gene-directed enzyme prodrug therapy. Yellow grouper nervous necrosis virus (YGNNV) is non-enveloped, icosahedral, single stranded RNA virus, belonging to the family Nodaviridae. We had developed inactivated YGNNV and GIV vaccines and conducted field trials. Besides, we also developed an immunoprophylactic DNA vaccine to effectively neutralize the nervous necrosis virus in vitro and in vivo. Recently, we have cloned three type of Mx genes from grouper, and demonstrated that grouper Mx proteins have efficient inhibitory activity against nervous necrosis virus.