Altered expression of CG5961, a putative Drosophila melanogaster homologue of FBXO9, provides a new model of Parkinson disease
GENETICS AND MOLECULAR RESEARCH
Authors: Merzetti, E. M.; Staveley, B. E.
Abstract
F-box proteins act as the protein recognition component of the Skp-Cul-F-box class of ubiquitin ligases. Two members of a gene sub-family encoding these proteins, FBXO7 and FBXO32, have been implicated in the onset and progression of degenerative disease. FBXO7 is responsible for rare genetic forms of Parkinson disease, while FBXO32 has been implicated in muscle wasting. The third gene in this family, FBXO9, is related to growth signaling, but the role of this gene in degenerative disease pathways has not been thoroughly investigated. Characterizing the putative Drosophila melanogaster homologue of this gene, CG5961, enables modeling and analysis of the consequence of targeted alteration of gene function and the effects on the overall health of the organism. Comparison of the protein domains of Homo sapiens FBXO9 and the putative D. melanogaster homologue CG5961 revealed a high degree of conservation between the protein domains. Directed expression of CG5961 (via CG5961(EP)) and inhibition of CG5961 (through a stable RNAi transgene) in the developing D. melanogaster eye caused abnormalities in adult structures (ommatidia and inter-ommatidial bristles). Directed expression of either CG5961 or CG5961-RNAi in the dopaminergic neurons led to a reduced lifespan compared to that in lacZ controls. We showed that protein structures of CG5961 and FBXO9 are highly similar and studied the effects of altered expression of CG5961 in neuron-rich tissues. Our results suggest that CG5961 activity is necessary for the proper formation of neuronal tissue and that targeted alteration of gene expression in dopaminergic neurons leads to a reduced lifespan.
Common deregulated gene expression profiles and morphological changes in developing zebrafish larvae exposed to environmental-relevant high to low concentrations of glucocorticoids
CHEMOSPHERE
Authors: Chen, Qiyu; Li, Caixia; Gong, Zhiyuan; Chan, Eric Chun Yong; Snyder, Shane A.; Lam, Siew Hong
Abstract
Synthetic glucocorticoids have been detected in environmental waters and their biological potency have raised concerns of their impact on aquatic vertebrates especially fish. In this study, developing zebrafish larvae exposed to representative glucocorticoids (dexamethasone, prednisolone and triamcinolone) at 50 pM to 50 nM from 3 h post-fertilisation to 5 days post-fertilisation were investigated. Microarray analysis identified 1255,1531, and 2380 gene probes, which correspondingly mapped to 660, 882 and 1238 human/rodent homologs, as deregulated by dexamethasone, prednisolone and triamcinolone, respectively. A total of 248 gene probes which mapped to 159 human/rodent homologs were commonly deregulated by the three glucocorticoids. These homologs were associated with over 20 molecular functions from cell cycle to cellular metabolisms, and were involved in the development and function of connective tissue, nervous, haematological, and digestive systems. Glucocorticoid receptor signalling, NRF2-mediated oxidative stress response and RAR signalling were among the top perturbed canonical pathways. Morphological analyses using four transgenic zebrafish lines revealed that the hepatic and endothelial-vascular systems were affected by all three glucocorticoids while nervous, pancreatic and myeloid cell systems were affected by one of them. Quantitative real-time PCR detected significant change in the expression of seven genes at 50 pM of all three glucocorticoids, a concentration comparable to total glucocorticoids reported in environmental waters. Three genes (cry2b, fbxo32, and klhl38b) responded robustly to all glucocorticoid concentrations tested. The common deregulated genes with the associated biological processes and morphological changes can be used for biological inference of glucocorticoid exposure in fish for future studies. (C) 2017 Elsevier Ltd. All rights reserved.