Programa de Pós-Graduação em Saúde e Produção Animal na Amazônia, Universidade Federal Rural da Amazônia, Av. Presidente Tancredo Neves 2501, Montese, Belém, PA, 66077-530, Brazil.
Institute of Animal Health and Production, Universidade Federal Rural da Amazônia, Av. Presidente Tancredo Neves 2501, Montese, Belém, PA, 66077-530, Brazil.
Anat Rec (Hoboken). 2020 May;303(5):1489-1500. doi: 10.1002/ar.24247. Epub 2019 Oct 3.
Fossil evidence suggests that scent glands are basal features of Testudines. However, we know little about the structure of these glands in the Brazilian Kinosternidae. In this study, we described the macroscopic anatomy, histology, and histochemistry of the scent glands of three males and three females of Kinosternon scorpioides scorpioides from the Marajó mesoregion, Pará State, Brazil. In all of the specimens analyzed, regardless of sex, we found four scent glands, including two axillary and two inguinal glands that were structurally similar to each other. Each gland consisted of a single holocrine secretory lobule, a large lumen surrounded by relatively thin glandular secretory epithelium, an adjacent narrow layer of loose connective tissue, and a thick layer of skeletal striated muscle tissue surrounded by a serous tunic. The secretory epithelium produced a characteristic malodorous yellowish substance that was passed via a single duct through a bone channel in the bridge connecting the carapace to the plastron and excreted through an outer pore in the plate of each respective gland. Histologically, the secretory epithelium presented cells with two types of secretory vacuoles. Type 1 vacuoles stained red were the largest and most frequently found, and stained positively with Periodic acid-Schiff (PAS), suggesting they contained glycoproteic complexes. Type 2 vacuoles were translucent, smaller in size and fewer in number, and negative for PAS staining. Because they are very primitive structures, scent glands must play important roles in the lives of chelonians, but their real function remains unknown. Several hypotheses suggest that they can act as protection against ectoparasites, as a repellent of predators, in addition to attracting mates and eliciting other pheromonal responses. In this study, all animals reacted by exuding malodorous substances when handled, as a form of defense. However, these are just assumptions that need to be clarified with additional studies on animal behavior. Anat Rec, 303:1489-1500, 2020. © 2019 American Association for Anatomy.
化石证据表明，气味腺是龟鳖目动物的基本特征。然而，我们对巴西鳖科动物的这些腺体结构知之甚少。在这项研究中，我们描述了来自巴西马拉若地区的 3 只雄性和 3 只雌性 Kinosternon scorpioides scorpioides 的气味腺的宏观解剖结构、组织学和组织化学。在所有分析的标本中，无论性别如何，我们都发现了 4 个气味腺，包括 2 个腋腺和 2 个腹股沟腺，它们在结构上彼此相似。每个腺体由单个全分泌的分泌小叶组成，一个大腔室被相对较薄的腺体分泌上皮包围，一个相邻的窄层疏松结缔组织，以及一个厚层的骨骼肌组织，被浆膜被膜包围。分泌上皮产生一种特征性的恶臭的黄色物质，通过单个导管穿过连接背甲和腹甲的桥中的一个骨道，并通过每个腺体的板上的一个外孔排出。组织学上，分泌上皮呈现出两种类型的分泌空泡的细胞。1 型空泡染色呈红色，是最大和最常见的，对过碘酸雪夫（PAS）染色呈阳性，表明它们含有糖蛋白复合物。2 型空泡是半透明的，体积较小，数量较少，对 PAS 染色呈阴性。由于它们是非常原始的结构，气味腺在龟鳖类的生活中一定扮演着重要的角色，但它们的真正功能仍然未知。一些假说表明，它们可以作为对寄生虫的保护，作为对捕食者的驱避剂，以及吸引配偶和引发其他信息素反应。在这项研究中，所有的动物在被处理时都会通过分泌恶臭物质来反应，作为一种防御方式。然而，这些只是假设，需要通过对动物行为的额外研究来澄清。解剖记录，303：1489-1500，2020。©2019 美国解剖学会。
