温度胁迫下卵形鲳鲹仔鱼骨骼组织病理及分子表征

【目的】探究不同养殖水温对卵形鲳鲹仔鱼骨骼组织病理和分子表征的影响，为进一步阐明鱼类骨骼发育的分子机理和骨骼畸形发生可能的机制提供参考依据。【方法】采用苏木精—伊红（HE）染色技术对分别在24、28和32℃水温下养殖一周后的卵形鲳鲹仔鱼头部和脊柱的骨骼组织进行观察，并利用原位杂交技术探究不同温度处理下骨骼发育相关基因的表达规律。【结果】随着水温的升高，卵形鲳鲹仔鱼头部软骨的细胞增大，软骨基质增多；高温下更多仔鱼的脊索向脊柱转变，软骨组织增多增大。头部骨骼中BMP2、BMP4、RUNX2、MMP9、MMP13和OCN的原位杂交信号均随水温的升高而有所增强；而在脊柱中，BMP2和BMP4的原位杂交信号随水温的升高而增强，RUNX2、MMP9和OCN在不同处理组之间的差异不明显，MMP13的信号则先增强后减弱。【结论】水温的升高会影响一系列骨骼发育相关基因的表达，进而促进卵形鲳鲹仔鱼头部骨骼的发育，在促进脊柱软骨组织增殖肥大的同时抑制脊柱的矿化。

Histopathology and molecular characterization of the skeletal tissues of golden pompano(Trachinotus ovatus) larvae under temperature stress

【Objective】 This study was conducted to investigate the histopathological effects and molecular regulatory characterization of bone development of golden pompano(Trachinotus ovatus) larvae under different breeding temperatures, and to provide support for further elucidations of the internal molecular mechanisms of bone development and malformation in fish.【Method】 Skeletal tissues of the head and spine of the larvae were observed using hematoxylin-eosin (HE) staining after a week of farming at 24℃, 28℃, and 32℃. In situ hybridization was used to observe the expression of bone development-related genes.【Result】 With an increase in temperature, enlarged chondrocytes and increased cartilage matrix were observed in the head. At the highest temperature, 32℃, more larval notochords transformed into spine and more spinal cartilaginous tissues were formed. The in situ hybridization signals of BMP2, BMP4, RUNX2, MMP9, MMP13 and OCN in the head were enhanced with an increase in water temperature. In the spine, the in situ hybridization signals of BMP2 and BMP4 were enhanced with an increase in water temperature, while the differences of RUNX2, MMP9 and OCN were not obvious between the different treatment groups. The signal of MMP13 was the strongest in the middle temperature group.【Conclusion】 The increase in water temperature may promote the development of bone in the head of the larvae by changing the expression of bone-related genes, and inhibit the mineralization of the spine while promoting the development of the spinal cartilaginous tissues.