温度对鳜体表黏液细胞及黏液免疫因子的影响

Effects of Water Temperature on Distribution and Type of Skin Mucus Cells and Mucus Immune Factors of Mandarinfish Siniperca chuatsi

鱼类体表黏液细胞分泌大量黏液,构成机体防御的第一道防线。为探明不同温度条件(10、20、30℃)对鳜体表黏液细胞类型和黏液免疫因子的影响,以体质量(19.0±3.2)g、体长(11.0±1.5)cm鳜为试验对象,利用阿辛蓝-过碘酸雪夫染色法观察试验开始72 h时3种温度对体表黏液细胞分布与类型变化的影响。结果显示:鳜体表黏液细胞含有4个类型,头部单位面积皮肤所含有的黏液细胞数量最多,躯干部黏液细胞数量次之,尾部数量最少;相较于10℃组,20℃组和30℃组体表Ⅱ型黏液细胞增幅最大,Ⅳ型次之,Ⅰ型呈略减趋势,Ⅲ型变化无规律。于试验开始后第0、36、72 h采集皮肤组织和体表黏液,分别通过实时荧光定量PCR和双抗体夹心酶联免疫法检测皮肤免疫因子IgM、IL-1β、Hepcidin基因表达量变化和体表黏液中酸性磷酸酶、溶菌酶、超氧化物歧化酶活性变化,结果显示:IgM、Hepcidin基因表达量均随温度升高而上调,相较于10℃组,20℃组IL-1β基因表达量显著上调,而30℃组表达量下调;30℃组中,酸性磷酸酶、溶菌酶和超氧化物歧化酶活性显著高于10℃组和20℃组。试验结果表明,环境温度显著影响鳜皮肤黏液细胞类型、数量及免疫相关因子的表达和活性。

In order to understand the effects of different temperatures on the surface mucus cell types and mucus immune factors of mandarinfish Siniperca chuatsi,the mandarinfish with body weight of(19.0±3.2)g and body length of(11.0±1.5)cm was placed in an aquarium with water temperature of 10,20 and 30℃,and at 0,36 and 72 h,the excess water on the body surface of the mandarin was gently wiped off with absorbent paper,the mucus on the trunk and tail was gently scraped with a glass slide,and the skins of head,trunk and caudal peduncle was immediately cut off from the mandarinfish anaesthetized with 1%MS-222 on ice,and fixed in Bonn′s fluid to observe the effects of three temperatures on the distribution and types of body surface mucus cells at 72 h after the experiment by AB-PAS staining method.The staining results showed that there were four types of mucus cells on the skin surface of mandarinfish.The maximal number of mucus cells per unit area was observed in skin of the head,followed by the trunk and the caudal peduncle.The typeⅡwas found to be increased the most in 20℃and 30℃groups,followed by typeⅣcompared with 10℃group,typeⅠshowing slightly decreasing trend,and typeⅢshowing irregular change.qRT-PCR and double-antibody sandwich enzyme-linked immunoassay revealed that the expression levels of IgM gene and Hepcidin gene were up-regulated with increasing temperature.The expression levels of IL-1βgene were significantly up-regulated in the 20℃group and down-regulated in the 30℃group compared with the 10℃group.There was significantly higher SOD activity in 30℃group than that in 10℃and 20℃groups,while the ACP and LYS activities were slightly higher than those in 10℃and 20℃groups.The findings indicate that the skin mucus cell types and number and immune-related factors of mandarinfish are significantly affected by ambient temperature.