Spatiotemporal expression of foxo4, foxo6a, and foxo6b in the developing brain and retina are transcriptionally regulated by PI3K signaling in zebrafish.
The forkhead box subclass O (FoxO) family of proteins is a group of highly evolutionary conserved transcription factors that regulate various cellular processes and embryonic development. Dysregulated expressions of FOXO genes have been identified in numerous tumors and genetic disorders. The expression of FOXO/Foxo, particularly FOXO4/Foxo4 and FOXO6/Foxo6, in the developing nervous system has not been fully characterized. Here, we identified zebrafish foxo4, foxo6a, and foxo6b homologs and demonstrated that all three genes were expressed in the developing nervous system. foxo4, foxo6a, and foxo6b displayed ubiquitous expression in the brain and later in distinct brain tissues. In addition, these three genes were expressed in different retinal layers in a time-dependent manner. Furthermore, the mRNA expression of all three genes was significantly downregulated after treatment with a selective PI3-kinase (PI3K) inhibitor, LY294002. Our results suggest that foxo4, foxo6a, and foxo6b play important roles in the developing brain and retina and that the transcriptional levels of these genes are regulated by PI3-kinase signaling.
Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
Sheng-Jia
SJ
Lin
Department of Life Science, College of Science and Engineering, Fu Jen Catholic University, New Taipei City, Taiwan.
Ming-Chang
MC
Chiang
Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
Hung-Yu
HY
Shih
General Surgery Department, Chang Gung Memorial Hospital, Keelung, Taiwan.|Zebrafish center of Keelung Chang Gung Memorial Hospital, Keelung, Taiwan.
Kun-Chun
KC
Chiang
Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan. yccheng@mail.cgu.edu.tw.|Neuroscience Research Center, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan, Taiwan. yccheng@mail.cgu.edu.tw.
Yi-Chuan
0000-0002-4772-2380
YC
Cheng
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D051858:Forkhead Transcription Factors / Q000235:genetics*; D005786:Gene Expression Regulation; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010802:Phylogeny; D012160:Retina / Q000378:metabolism*; D016415:Sequence Alignment; D015398:Signal Transduction; D014158:Transcription, Genetic; D015027:Zebrafish / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics*
D051858:Forkhead Transcription Factors; C000621432:Foxo4 protein, zebrafish; C000621433:Foxo6a protein, zebrafish; C000621434:Foxo6b protein, zebrafish; D000081082:Phosphoinositide-3 Kinase Inhibitors; D029961:Zebrafish Proteins
Brain; Foxo; Neural development; PI3K; Retina