Morphological analyses of the retinal photoreceptor cells in the nocturnally adapted owl monkeys

The Journal of Veterinary Medical Science

Takeshi KURAISHI¹  Yasuo KISO¹  Shin-ichi YOKOTA¹  Tomohiro KONDO¹  Chieko KAI²  Nobue KUNIYOSHI³  Ken Takeshi KUSAKABE³  Midori YOSHIZAWA⁴  Yuji YOSHIDA⁵  Yoshiki ITOH⁶  Shosaku HATTORI⁷ 

[1] Amami Laboratory of Injurious Animals, Institute of Medical Science, The University of Tokyo, Kagoshima 894-1531, Japan;Graduate School of Agricultural Science, Utsunomiya University, Tochigi 321-8505, Japan;Laboratory of Basic Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi 753-8515, Japan;Laboratory of Laboratory Animal Science, Division of Veterinary Science, Graduate School of Life and Environmental Science, Osaka Prefecture University, Osaka 598-8531, Japan;Laboratory of Veterinary Anatomy, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan;Laboratory of Veterinary Radiology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan;Present affiliation: HAMURI Co., Ltd., Ibaraki 306-0101, Japan

关键词: evolution;    owl monkey;    photoreceptor cell;    retina;    squirrel monkey;   

DOI  :  10.1292/jvms.17-0418

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

Owl monkeys are the only one species possessing the nocturnal lifestyles among the simian monkeys. Their eyes and retinas have been interested associating with the nocturnal adaptation. We examined the cellular specificity and electroretinogram (ERG) reactivity in the retina of the owl monkeys by comparison with the squirrel monkeys, taxonomically close-species and expressing diurnal behavior. Owl monkeys did not have clear structure of the foveal pit by the funduscope, whereas the retinal wholemount specimens indicated a small-condensed spot of the ganglion cells. There were abundant numbers of the rod photoreceptor cells in owl monkeys than those of the squirrel monkeys. However, the owl monkeys’ retina did not possess superiority for rod cell-reactivity in the scotopic ERG responses. Scanning electron microscopic observation revealed that the rod cells in owl monkeys’ retina had very small-sized inner and outer segments as compared with squirrel monkeys. Owl monkeys showed typical nocturnal traits such as rod-cell dominance. However, the individual photoreceptor cells seemed to be functionally weak for visual capacity, caused from the morphological immaturity at the inner and outer segments.

【 授权许可】

Unknown