Renn Joerg, Winkler Christoph
Department of Biological Sciences, National University of Singapore, Singapore.
Dev Dyn. 2009 Jan;238(1):241-8. doi: 10.1002/dvdy.21836.
Intramembranous and chondral bone formation by osteoblasts is found in all vertebrates. The genetic network controlling osteoblast differentiation is highly conserved and regulated by a small number of key factors, including the zinc-finger transcription factor Osterix. Expression analysis of osterix in the teleost model medaka revealed a highly restricted expression in skeletal regions. For in vivo imaging, we generated transgenic medaka expressing mCherry under control of the osterix promoter. We show that the transgene becomes expressed in early osteoblasts, which have not yet mineralized bone matrix, and remains high in matured and mineralizing osteoblasts. Life imaging of transgenic larvae provided insight into the appearance and behavior of early osteoblasts during development of the teleost cranium, vertebrae, and caudal fin. In summary, osterix-mCherry transgenic medaka enable us to analyze osteoblasts during different maturation phases in vivo and represent a unique tool to study osteoblast behavior in vertebrate embryos and adults.
成骨细胞进行的膜内成骨和软骨内成骨在所有脊椎动物中均有发现。控制成骨细胞分化的基因网络高度保守，并受包括锌指转录因子osterix在内的少数关键因子调控。在硬骨鱼模型青鳉中对osterix进行的表达分析显示，其在骨骼区域的表达受到高度限制。为了进行体内成像，我们构建了在osterix启动子控制下表达mCherry的转基因青鳉。我们发现，该转基因在尚未矿化骨基质的早期成骨细胞中表达，并在成熟和矿化的成骨细胞中保持高表达。对转基因幼虫的活体成像为硬骨鱼头骨、脊椎和尾鳍发育过程中早期成骨细胞的出现和行为提供了深入了解。总之，osterix-mCherry转基因青鳉使我们能够在体内分析不同成熟阶段的成骨细胞，是研究脊椎动物胚胎和成年个体中成骨细胞行为的独特工具。
