摘要
为探讨猫儿山小鲵(Hynobius maoershanensis)和瑶山肥螈(Pachytriton intexpectatus)消化道结构的异同及5-羟色胺(5-HT)细胞的分布特征与食性、生活环境之间的关系,运用常规组织染色及免疫组织化学染色法对其消化道进行研究。结果显示,猫儿山小鲵和瑶山肥螈的消化道均包括食道、胃、十二指肠、回肠和直肠,但瑶山肥螈消化道长于猫儿山小鲵。猫儿山小鲵和瑶山肥螈的比肠长(即肠道长与头体长的比值)分别为0.57±0.03(n=5)和0.84±0.03(n=5)。两者消化道组织结构均由黏膜层、黏膜下层、肌层和外膜组成,主要差异在消化道黏膜层和肌层厚度。猫儿山小鲵的消化道黏膜层以胃体部最厚,达(712.82±37.67)μm(n=5),而瑶山肥螈则胃贲门部最厚,为(403.24±55.81)μm(n=5);二者消化道肌层均以胃幽门部最厚,但瑶山肥螈胃幽门部的肌层厚度比猫儿山小鲵的厚。二者消化道均有开放型和闭合型的5-HT细胞,但5-HT细胞的分布特征不同:猫儿山小鲵分布密度高峰位于直肠,低谷位于食道;瑶山肥螈则在十二指肠部位分布密度最高,直肠最低。综上所述,猫儿山小鲵和瑶山肥螈消化道形态学和组织学结构相似,二者肠道长占头体长的比值均不超过1,符合肉食性动物消化道短的特征。二者消化道5-HT细胞都具有内、外分泌功能,分布密度具有自身的特点,可能与它们的食物组成和生活环境不同有关。
Hynobius maoershanensis and Pachytriton intexpectatus are endemic to Guangxi Maoershan National Nature Reserve,China.Their living environments and distribution altitudes are different.H.maoershanensis is inhabited in an alpine swamp at an altitude of 2000 m with small population size,but P.intexpectatus lives in mountain streams with gentle currents at an altitude of 1140﹣1800 m.This study was designed to explore the differences of digestive tracts between H.maoershanensis and P.intexpectatus,and how the 5-hydroxytryptamine cells of digestive tract adapt to their feeding habits and living environments.Anatomical,histological and envision two-step immunohistochemistry staining techniques were used.The total length,head length,body weight,snout-vent length,digestive tract length,and the thickness of mucosa and muscle layers were measured.Statistical analysis and inspection were performed using the Kolmogorov-Simirnov test,Kruskal-Wallis test and Mann-Whitney U test(Microsoft Excel 2016 and SPSS 26.0 software).Results showed that the digestive tracts of H.maoershanensis and P.intexpectatus were composed of esophagus,stomach,duodenum,ileum and rectum(Fig.1).The digestive tract of P.intexpectatus was longer than that of H.maoershanensis.The ratios of intestine length and snout-vent length in H.maoershanensis and P.intexpectatus were 0.57±0.03(n=5)and 0.84±0.03(n=5),respectively.The histological structure of the digestive tracts in H.maoershanensis and P.intexpectatus could be divided into mucosa,submucosa,muscularis and adventitia(Fig.2).There were many glands,such as pyloric glands(Fig.2e﹣h).The thicknesses of mucosa layer in the stomach body of H.maoershanensis was the highest(712.82±37.67μm,n=5),while that of P.intexpectatus was in the cardia(403.24±55.81μm,n=5).The thickness of muscular layer of the digestive tract was the highest in the pylorus,with that of P.intexpectatus thicker than in H.maoershanensis.Both open and closed 5-HT cells were distributed in the digestive tracts of H.maoershanensis and P.intexpectatus(Fig.3),while the distributional patterns of 5-HT cells along the digestive tracts were different.5-HT cells showed the highest density in the rectum and the least density in the esophagus of H.maoershanensis.But in P.intexpectatus,the highest count was found in the duodenum but the least count in the rectum.In conclusion,the morphological and histological structures of the digestive tracts of H.maoershanensis and P.intexpectatus are similar.The ratios of intestine length to snout-vent length of both were not more than 1,which is consistent with the characteristics of the short digestive tract of carnivorous animals.The 5-HT cells in the digestive tracts of both have endocrine and exocrine functions,but the distributive patterns of these cells have their own characteristics,which may be related to their different feeding habits and living environments.
作者
陈毓
崔甄甄
杨波
宁梅红
武正军
叶建平
黄华苑
CHEN Yu;CUI Zhen-Zhen;YANG Bo;NING Mei-Hong;WU Zheng-Jun;YE Jian-Ping;HUANG Hua-Yuan(Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection(Guangxi Normal University),Ministry of Education,Guangxi Normal University,Guilin 541004;Bureau of Guangxi Mao'er Mountain National Nature Reserve,Guilin 541000,China)
出处
《动物学杂志》
CAS
CSCD
北大核心
2021年第4期597-607,共11页
Chinese Journal of Zoology
基金
国家自然科学基金项目(No.31860609)
广西研究生教育创新计划项目(No.XYCSZ 2020058)。
关键词
猫儿山小鲵
瑶山肥螈
消化道
组织形态学
5-羟色胺细胞
Hynobius maoershanensis
Pachytriton intexpectatus
Digestive tract
Histomorphology
5-hydroxytryptamine cells
作者简介
第一作者:陈毓,女,硕士研究生,研究方向:动物学,E-mail:cheny-117@163.com;通讯作者:黄华苑,E-mail:hhy-121@163.com。
