Main Article Content
The transgenic medaka rankl:HSE:CFP expressing Rankl, a stimulator for osteoclastogenesis - the formation and activation of osteoclasts, bone “eating” cells, under control of a heat inducible promotor has been established as a model for osteoporosis to evaluate antiosteoporosis effects of substances. Transgenic larvae were usually heat-shocked for 90 minutes at 39oC when they were at 9 days post fertilization (dpf) and osteoporosis-like phenotype was analysed when they were at 11 dpf. In this study we investigated whether osteoporosis-like phenotype could be induced in the transgenic larvae when heat-shock was applied at earlier time points, when larvae were at 1, 2, 3, 4, 5, or 6 dpf. Results showed that heat-shocks from the time point of 3 dpf onwards resulted in osteoporosis-like phenotype while heat-shock at 1 or 2 dpf did not affect mineralized bone matrix in 11 dpf larvae. These provide important evidence for study on onset of Rankl induced osteoclasts in fish and help improving experimental procedures using this fish model for osteoporosis.
 J. A. Cauley, Osteoporosis: Fracture Epidemiology Update 2016, Curr, Opin, Rheumatol, Vol. 29, No. 2, 2017, pp. 150-156.
 T. Komori, Animal Models for Osteoporosis, Eur, J. Pharmacol, Vol. 759, 2015, pp. 287-294.
 P. E. Witten, M. P. Harris, A. Huysseune, C. WinklerS, Mall Teleost Fish Provide New Insights into Human Skeletal Diseases, Methods Cell Biol, Vol. 38, 2017, pp. 321-346.
 C. V. Pham, T. T. Pham, T. T. Lai, D. C. Trinh, H. V. M. Nguyen, T. T. M. Ha et al., Icariin Reduces Bone Loss in a Rankl-induced Transgenic Medaka (Oryzias Latipes) Model for Osteoporosis, J. Fish Biol, Vol. 98, No. 4, 2021, pp. 1039-1048.
 T. T. To, P. E. Witten, J. Renn, D. Bhattacharya, A. Huysseune, C. Winkler et al., Rankl-induced Osteoclastogenesis Leads to Loss of Mineralization in a Medaka Osteoporosis Model, Vol. 139, No. 1, 2012, pp. 141-150.
 K. Naruse, M. Tanaka, H. Takeda, Medaka - A Model for Organogenesis, Human Disease, and Evolution, Science, 2011, pp. 132.
 C. Y. Lin, C. Y. Chiang, H. J. Tsai, Zebrafish and Medaka: New Model Organisms for Modern Biomedical Research, J. Biomed, Sci, Vol. 23, 2016, pp. 19.
 M. Chatani, Y. Takano, A. Kudo, Osteoclasts in Bone Modeling, as Revealed by in Vivo Imaging, are Essential for Organogenesis in Fish, Dev, Biol, Vol. 360, No. 1, 2011, pp. 96-109.
 A. Büttner, T. T. To, C. Winkler, S. J. H. Chan, J. Renn, A Col10a1_nlGFP Transgenic Line Displays Putative Osteoblast Precursors at the Medaka Notochordal Sheath Prior to Mineralization, Dev, Biol, Vol. 381, No. 1, 2013, pp. 134-143.
 T. T. To, P. E. Witten, A. Huysseune, C. Winkler, An Adult Osteopetrosis Model in Medaka Reveals the Importance of Osteoclast Function for Bone Remodeling in Teleost Fish, Comp, Biochem, Physiol, Part - C Toxicol, Pharmacol., Vol. 178, 2015, pp. 68-75.
 M. Kasahara, K. Naruse, S. Sasaki, Y. Nakatani, W. Qu, B. Ahsan et al., The Medaka Draft Genome and Insights into Vertebrate Genome Evolution, Nature, Vol. 447, 2007, pp. 714-719.
 T. Yu, P. E. Witten, A. Huysseune, A. Buettner, T. T. To, C. Winkler, Live imaging of Osteoclast Inhibition by Bisphosphonates in a Medaka Osteoporosis Model, Dis, Model, Mech, Vol. 9, No. 2, 2016, pp. 155-163.
 Q. T. Phan, W. H. Tan, R. Liu, S. Sundaram, A. Buettner, S. Kneitz et al., Cxcl9l and Cxcr3.2 Regulate Recruitment of Osteoclast Progenitors to Bone Matrix in a Medaka Osteoporosis Model, Proc, Natl, Acad, Sci, USa, Vol. 117, No. 32, 2020, pp. 19276-19286.
 V. C. Pham, T. T. Pham, T. H. Nguyen, D. L. Tran, T. T. To, Segregation of rankl:HSE:CFP Medaka Transgenic Fish Line for Use as Osteoporosis Models, VNU Journal of Science: Natural Sciences and Technology, Vol. 31, No. 4S, 2015, pp. 24-34 (in Vietnamese).
 T. N. Lai, T. T. Pham, V. C. Pham, D. L. Tran, T. T. To, Stability of the Transgene Rankl in the rankl:hse:cfp Transgenic Medaka Fish Used as a Model for Osteoporosis, Vietnam J. Physiol, Vol. 19, No. 2, 2015, pp. 10-17 (in Vietnamese).
 A. Apschner, S. Schulte-Merker, P. E. Witten, Not All Bones are Created Equal - Using Zebrafish and Other Teleost Species in Osteogenesis Research, Methods Cell Biol, Vol. 105, No. 239, 2011, pp. 255.
 T. T. Pham, V. C. Pham, D. L. Tran, T. T. To, Bone Mineralization Development in Medaka (Oryzias Latipes) I, Vietnam J. Physiol, Vol. 19, No. 3, 2015, pp. 8-16 (in Vietnamese).