Anatomy and Embryology Department, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44519, El-Sharkia, Egypt.
Department of Surgery, Anesthesiology, and Radiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44519, El-Sharkia, Egypt.
BMC Vet Res. 2023 Aug 25;19(1):133. doi: 10.1186/s12917-023-03649-6.
The purpose of this study was to explore whether domestication could lead to evolutionary changes towards flightlessness in the domestic duck (Anas platyrhynchos domesticus) compared to the cattle egret (Bubulcus ibis) as a nonflying and flying biological model, respectively. Bones of the pectoral girdle (scapula, clavicle, and coracoid) and the foramen triosseum were comparatively assessed using anatomical, radiographic, and 3D computed tomographic (CT) studies. Additionally, the muscles pectoralis and the supracoracoideus were histologically and immunohistochemically assessed.
Among the differences observed, radiographically, the distance between the paired clavicles was significantly wider (p < 0.05) in the domestic duck (mean ± SD 1.43 ± 0.23 cm) compared with the cattle egret (0.96 ± 0.13 cm). Unlike cattle egrets, there was no connection between the sternum and the hypocladium of furcula in domestic ducks. The scapula, clavicle, coracoid, sternum, and humerus were considerably longer in domestic ducks than in cattle egrets. The foramen triosseum appeared significantly (p < 0.01) wider in domestic ducks (0.7 ± 1.17 cm) compared to cattle egrets (0.49 ± 0.03 cm). Histologically, compared to cattle egrets, the muscle fibers in domestic ducks were loosely connected and contained fewer nuclei and perimysial/endomysial spaces. A higher myoglobin expression was evident in cattle egrets compared with domestic ducks.
Results of this study indicate that the bones and muscles of the pectoral girdle generally show specific morphological and structural changes reflective of the loss of prerequisites associated with flight behavior in domestic ducks due to domestication effects compared to cattle egrets.
本研究旨在探索驯化是否会导致家鸭（Anas platyrhynchos domesticus）在飞行能力丧失方面发生进化变化，与牛背鹭（Bubulcus ibis）作为非飞行和飞行的生物模型进行比较。使用解剖学、影像学和 3D 计算机断层扫描（CT）研究比较评估了胸带骨骼（肩胛骨、锁骨和喙突）和三骨孔。此外，还对胸肌和上胸肌进行了组织学和免疫组织化学评估。
在观察到的差异中，影像学上，配对锁骨之间的距离在家鸭（平均±标准差 1.43±0.23 厘米）中明显更宽（p<0.05），而在牛背鹭中为 0.96±0.13 厘米。与牛背鹭不同，在家鸭中胸骨和胸骨叉的锁骨没有连接。肩胛骨、锁骨、喙突、胸骨和肱骨在家鸭中明显比牛背鹭长。三骨孔在家鸭中明显更宽（p<0.01），为 0.7±1.17 厘米，而在牛背鹭中为 0.49±0.03 厘米。组织学上，与牛背鹭相比，家鸭的肌肉纤维连接松散，核和肌外膜/肌内膜空间较少。牛背鹭的肌红蛋白表达明显高于家鸭。
本研究结果表明，与牛背鹭相比，由于驯化的影响，家鸭的胸带骨骼和肌肉通常表现出与飞行行为相关的先决条件丧失的特定形态和结构变化。
