Moritomo Y, Koga O, Miyamoto H, Tsuda T
Department of Animal Science, School of Agriculture, Kyushu Tokai University, Kumamoto, Japan.
J Vet Med Sci. 1995 Aug;57(4):693-6. doi: 10.1292/jvms.57.693.
Anophthalmia and caudal vertebral anomalies such as taillessness or wry tail were morphologically examined in ten Japanese Brown calves obtained in Kumamoto Prefecture. The anomalous calves lacked eyeball bilaterally or unilaterally but had small-sized eyelids and narrow palpebral fissures. A small cystic, solid or spot-like remnant of eyeball (REB) was buried in the mixture of vestigial extraocular muscles, lacrimal gland and adipose tissue of the orbit. The REB was composed of irregularly arranged elements of ocular wall such as sclera, choroid and retina. The retina was often dysplastic and connected to the hypoplastic optic nerve. These morphological changes might represent the defective processes after the formation of the optic vesicle or cup. Therefore, this eye defect may be defined as degenerative anophthalmia. The defects of the vertebral body such as wedge vertebra, hemivertebra, and sagittal cleft vertebra seen in the lumbar, sacral, and coccygial regions and the meandering of the axial line of abnormal vertebrae may suggest the failure of notochord formation in the early fetal period. From the embryological point of view, it seemed possible that the calves were exposed to teratogen at the critical time of optic organogenesis and notochordal formation. The cause of anomalies could not be determined in this study.
对在熊本县获得的10头日本褐牛犊进行了无眼症和尾椎异常（如无尾或歪尾）的形态学检查。异常牛犊双侧或单侧缺少眼球，但有小尺寸的眼睑和狭窄的睑裂。一个小的囊性、实性或点状眼球残余物（REB）埋在眼眶残留的眼外肌、泪腺和脂肪组织的混合物中。REB由眼球壁的不规则排列成分组成，如巩膜、脉络膜和视网膜。视网膜通常发育异常，并与发育不全的视神经相连。这些形态学变化可能代表视泡或视杯形成后的缺陷过程。因此，这种眼缺陷可定义为退行性无眼症。在腰椎、骶椎和尾椎区域出现的椎体缺陷，如楔形椎体、半椎体和矢状裂椎体，以及异常椎骨轴线的弯曲，可能提示胎儿早期脊索形成失败。从胚胎学角度来看，这些牛犊在视器官发生和脊索形成的关键时期接触致畸剂似乎是有可能的。本研究无法确定异常的原因。
