Skin gland concentrations adapted to different evolutionary pressures in the head and posterior regions of the caecilian Siphonops annulatus
Skin gland concentrations adapted to different evolutionary pressures in the head and posterior regions of the caecilian Siphonops annulatus
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DOI：
10.1038/s41598-018-22005-5
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发表时间：
2018-02-23
影响因子：
4.6
通讯作者：
Antoniazzi, Marta Maria
中科院分区：
文献类型：
--
作者：
Jared, Carlos;Mailho-Fontana, Pedro Luiz;Antoniazzi, Marta Maria
两栖动物的皮肤上有丰富的粘液腺和毒腺，分泌对气体交换很重要的物质，在抵御捕食者和微生物的化学防御中起着重要作用。在无尾目的Siphonops annulatus（Mikan，1920）中，我们观察到头部区域有一个增大的粘液腺。在身体的后部区域，类似的浓度由扩大的毒腺组成。这些腺体的堆积在结构上类似于以前在无尾两栖类和蝾螈中报道的大腺体。这些区域中的皮肤腺体各自被形成蜂窝状结构的胶原蛋白壁包围。头部区域的胶原蛋白网络牢固地附着在头骨中的小坑上。身体的两个末端产生不同的分泌物，含有独特的分子。考虑到无尾目动物的穴居生活方式，头部和尾部区域的分泌物显然具有不同的功能。粘液腺的前部大腺，富含粘液/脂质分泌物，与漏斗形的头部结合，可以起到润滑身体和渗透土壤的作用，从而促进地下运动。钝的后端承载真皮中的毒腺的内化的大腺体，其可以在化学防御和/或通过阻断隧道的侵入中起作用。
Amphibian skin is rich in mucous glands and poison glands, secreting substances important for gas exchange and playing a fundamental role in chemical defense against predators and microorganisms. In the caecilian Siphonops annulatus (Mikan, 1920) we observed a concentration of enlarged mucous glands in the head region. In the posterior region of the body a similar concentration is made up of enlarged poison glands. These accumulations of glands structurally resemble the macroglands previously reported in anurans and salamanders. The skin glands in these regions are each surrounded by collagen walls forming a honeycomb-like structure. The collagen network in the head region firmly attaches to tiny pits in the bones of the skull. The two extremities of the body produce different secretions, containing exclusive molecules. Considering the fossorial lifestyle of caecilians, it seems evident that the secretions of the head and caudal region serve different functions. The anterior macrogland of mucous glands, rich in mucous/lipid secretion, in conjunction with the funnel-shaped head, may act to lubricate the body and penetrate the soil, thus facilitating locomotion underground. The blunt posterior end bearing an internalized macrogland of poison glands in the dermis may act in chemical defense and/or by blocking invasion of tunnels.