Fujihira Takuma, Kinoshita Mikio, Sasaki Motoki, Ohnishi Masao, Ishikawa Hajime, Ohsumi Seiji, Fukui Yutaka
Laboratory of Animal Reproduction, Obihiro University of Agriculture and Veterinary Medicine, Japan.
J Reprod Dev. 2004 Oct;50(5):525-32. doi: 10.1262/jrd.50.525.
The present study was conducted to clarify the difference in the color of the cytoplasm in immature follicular oocytes from prepubertal and adult minke whales. The four lipid contents (triglyceride, total cholesterol, phospholipids and non-esterified fatty acids) in vitrified immature oocytes from prepubertal and adult minke whales, and also in fresh and vitrified immature porcine oocytes, were measured. The lipid contents in vitrified-warmed minke whale oocytes were similarly high compared with those in vitrified-warmed porcine oocytes. In particular, the total cholesterol and phospholipid contents in the vitrified immature oocytes from prepubertal and adult minke whales were significantly (P<0.05) higher than those from prepubertal pigs. Furthermore, the distribution of lipid droplets in fresh and vitrified immature oocytes was observed in transmission electron microscopy. Lipid droplets in the prepubertal minke whale oocytes were distributed throughout the cytoplasm. In contrast, adult minke whales had larger lipid droplets which were distributed mainly in the central portion of the cytoplasm. The lipid droplets of immature oocytes from prepubertal pigs were larger than those in minke whale oocytes. These results indicated that the difference in the distribution of the cytoplasmic lipid droplets may result in the difference in the color tone of both prepubertal and adult whale oocyte cytoplasm.
本研究旨在阐明未成年和成年小须鲸未成熟卵泡卵母细胞细胞质颜色的差异。测定了未成年和成年小须鲸玻璃化未成熟卵母细胞以及新鲜和玻璃化未成熟猪卵母细胞中的四种脂质含量（甘油三酯、总胆固醇、磷脂和非酯化脂肪酸）。与玻璃化复温猪卵母细胞相比，玻璃化复温小须鲸卵母细胞中的脂质含量同样较高。特别是，未成年和成年小须鲸玻璃化未成熟卵母细胞中的总胆固醇和磷脂含量显著高于未成年猪（P<0.05）。此外，通过透射电子显微镜观察了新鲜和玻璃化未成熟卵母细胞中脂滴的分布。未成年小须鲸卵母细胞中的脂滴分布在整个细胞质中。相比之下，成年小须鲸的脂滴更大，主要分布在细胞质的中央部分。未成年猪未成熟卵母细胞的脂滴比小须鲸卵母细胞中的脂滴大。这些结果表明，细胞质脂滴分布的差异可能导致未成年和成年鲸卵母细胞细胞质色调的差异。
