SỰ PHÁT TRIỂN XƯƠNG CỦA CÁ MEDAKA (ORYZIAS LATIPES) I

Abstract

Medaka, Oryzias latipes, a small fresh water teleost fish originated
from Japan and southest Asia has been widely used as an experimental model for
research in biomedicine, especially in bone biology and diseases. To obtain better data for
bone research, we analyzed the process of bone mineralization in medaka, from the
embryonic stage until the fish reached 2 months of age. Bone mineralization was
visualized by alizarin red staining that was also confirmed by green fluorescent calcein
staining. The results showed that bone mineralization in medaka began from early
embryonic stages with the formation of some head bone structures that followed by the
formation of vertebral column and the fin rays. Here we describe bone minerilazation in
medaka from early develoment up to 10 days of age. Otholiths are the head bone
structures that were mineralized first when the embryo was at 3 days post fertilization
(3dpf). During the following stages of development (4-7dpf), other head bone structures
were formed, such as parasphenoid, supraoccipital, basilar plate, pharyngeal jaw... The

vertebral column consiting of about 30 vertebrae at adult stage was mineralized first in 5-6
anterior vertebrae, from the 2nd vertebra onwards at 6dpf. Interestingly the first vertebra
was formed latter, at 7dpf. At 9dpf, mineralization of some caudal fin rays were visualized
while that of other fin rays such as pectoral, pelvic, dorsal, anal fins was not yet appeared
until the fish reached 10 days of age.