Physiological and ecological investigation of mouse deer and their conservation in Southeast Asia.

鼠鹿较早地从干祖先分化出来，保存着原始反刍动物的遗迹。本研究对鼠鹿的生理生态特性进行了研究。尽管它们是反刍动物，但它们表现出非反刍动物的特征，并进一步表现出以下非偶蹄动物的特征。向偶蹄动物脑部供血的通道是颈动脉外动脉，是替代颈内动脉的特殊动脉系统。通常偶蹄趾有颈动脉网无颈内动脉或颈动脉网和内陷动脉都有。鼠鹿是偶蹄动物中唯一没有颈动脉网的动物。我们不能说在反刍动物的进化过程中，颈动脉网的缺失是同形还是同形的特征。与其他反刍动物不同，鼠鹿的胎盘不是子叶状的，而是弥漫性的。在所有反刍动物中，滋养细胞双核细胞（BNC）扮演着核心角色。然而，由BNC和母体组织融合形成的合胞体斑块在小鼠鹿中是短暂的，不像绵羊和山羊的持久斑块。鼠鹿的母母亲缘关系似乎是由基本的内膜胎盘或血膜胎盘发展到联皮绒毛膜胎盘的遗迹。与大梅花鹿和中国麂相比，鼠鹿后肢肌肉集中在近端外侧和远端颅侧。距骨和后肢肌肉的近端关节表明，鼠鹿保留了原始反刍动物适应跳跃的运动方式，而不是行走。反刍动物Peyer's斑块具有不同的免疫功能，殖民地斑块和回肠斑块分别表现为B细胞分化和次生免疫组织。鼠鹿具有与其他反刍动物相似的群体斑块和回肠斑块。它们似乎有功能上的差异，比如牛和山羊。少

Mouse deer were diverged early from the stem ancestor and conserve the relics of primitive ruminants. In this research, we examined physiological and ecological characteristics of mouse deer. Despite ruminant group, they exhibit non-ruminant features, further more non-artiodactyl features as follows.1. Blood to artiodactyl brain is supplied through carotid rete mirabile, specific arterial system replacing internal carotid artery. Usual artiodactyls have rete mirabile without internal carotid artery or both rete mirabile and involuted artery. The mouse deer is only animal having no carotid rete among artiodactyls. We are unable to say whether absence of the caroid rete is plesimorphic feature or apomorphic during the evolution of ruminants.2. Unlike other ruminants, the placenta of mouse deer is not cotyledonary, but diffuse one. Histological interrelation between feto-maternal tissues is synepitheliochorial, and trophoblast binucleated cells (BNC) play the central role as in all other … More ruminants. However, syncytial plaques formed by fusion of BNC and maternal tissues are transient in mouse deer, unlike persistent plaques of sheep and goat. Feth-maternal interrelation in mouse deer seems to be relics of development of synepitheliochorial placenta from basic endo-or hemo-chorial placenta.3. Comparing with large Sika deer and Chinese muntjac, the muscles of hind limb in mouse deer concentrate in the lateral side of proximal area and in the cranial side of distal area. The proximal articulation of talus and the muscles of hind limb suggest that the mouse deer preserve locomotion pattern of primitive ruminants adapting for saltation more than cursoriality.4. Peyer's patches of ruminants serve different immune functions in colonial and ileal patches showing B cell differentiation and secondary immunue tissue, respectively. Mouse deer have colonial and ileal patches similar histological features in other ruminants. They seems to have functional difference such as in bovine and goat. Less