脑红蛋白在赛加羚羊主要内脏器官中的表达与定位

赛加羚羊(Saiga tatarica)属于我国一级重点保护野生动物，其原产地主要为高寒低氧地区，现存种群则主要栖息于中亚地区的荒漠及半荒漠草原上。脑红蛋白是一种存在于脊椎动物体内具有运输和储存血氧能力的球蛋白，在动物适应低氧过程中具有重要的生理功能。为了初步探究赛加羚羊对低氧环境的耐受性机制，运用免疫组织化学染色法与实时荧光定量PCR技术，对脑红蛋白及脑红蛋白基因(NGB)在赛加羚羊的心、肝、脾、肺、肾等5种主要内脏器官中的分布规律与表达情况进行了探究。免疫组织化学染色结果显示，脑红蛋白在赛加羚羊的心、肝、脾、肺、肾中均有分布，阳性表达主要分布在其心肌细胞、肝细胞、脾白髓区中的淋巴细胞、肺泡细胞以及肾小球内皮细胞。实时荧光定量PCR结果显示，脑红蛋白基因在赛加羚羊心、肝、脾、肺、肾中的表达量不同，脾的表达量最高，心的表达量次之，两者均显著高于肝、肺和肾(P < 0.05)；其后依次为肝、肾、肺，其中，肝的表达量显著高于肾和肺(P < 0.05)，肾和肺之间表达量差异不显著(P > 0.05)，肺的表达量最低。上述研究表明，脑红蛋白在赛加羚羊的主要内脏器官中均有阳性表达，不同内脏器官中的表达量不同，这表明脑红蛋白可能参与了这些内脏器官的氧利用过程，具体机制有待进一步探讨。

The Expression and Localization of Neuroglobin in Major Visceral Organs of Saiga Antelope

Objectives] Saiga Antelope (Saiga tatarica) is a class I wildlife in China and a world-class endangered species. Its origin is mainly in high cold and low oxygen areas, while the existing population mainly inhabits the desert and semi desert grassland in Central Asia. Neuroglobin is a kind of globulin with the ability of blood oxygen transport and storage in vertebrates, which plays an important physiological role in the process of animal adaptation to hypoxia. Methods] In order to explore the mechanism of tolerance to hypoxia in Saiga Antelope, the distribution and expression of neuroglobin in the heart, liver, spleen, lung and kidney of Saiga Antelope were studied by Immunohistochemistry and qRT-PCR. Results] The results of Immunohistochemistry showed that NGB protein was distributed in heart, liver, spleen, lung and kidney of Saiga Antelope, and the positive expression of NGB protein was mainly distributed in the cardiomyocytes, liver cells, lymphocytes, alveolar cells and glomerular endothelial cells in the white pulp area of the spleen (Fig. 1). The results of qRT-PCR showed that the expression of NGB in heart, liver, spleen, lung and kidney of Saiga Antelope was different. The expression of spleen was the highest, and the expression of heart was the second, both of which were significantly higher than that of liver, lung and kidney (P < 0.05). The expression of liver was higher than that of kidney and lung (P < 0.05), the difference between the expression of kidney and lung was not significant (P > 0.05), and the expression of lung was the lowest (Fig. 2). Conclusion] The above studies showed that NGB was positive in the main organs of Saiga Antelope, and the expression of NGB in different viscera organs was different, which indicated that NGB might be involved in the oxygen utilization process of these visceral organs. The specific mechanism will need to be further explored.