Newsome D A, Linsenmayer T F, Trelstad R L
J Cell Biol. 1976 Oct;71(1):59-67. doi: 10.1083/jcb.71.1.59.
Two different cells types have been shown to synthesize embryonic chick vitreous collagen (vitrosin) at different stages of development. Identification of vitrosin was established by labeling the embryos in ovo [3H]proline at stages 23 and 28 and separating the extracted vitreous collagen alpha-chains by carboxymethylcellulose chromatography. The labeled collagen consisted predominately of alpha 1 chains, indicating a molecule in the form of a trimer of identical chains designated (alpha 1)3. The molecular weight of the labeled chains measured approximately 95,000 daltons by molecular sieve chromatography, and contained 41% of their imino acid as 4-hydroxyproline. To establish which eye tissues synthesize vitrosine, the collagens produced in organ culture by the isolated neural retina, lens and vitreous body from stages 26-27, 29-30, and 40 were examined. At the two earlier stages, only the neural retina synthesized large quantities of (alpha 1)3 collagen whereas the lens and the cells within the vitreous body itself synthesized relatively small amounts of collagen characterized by an alpha 1:alpha 2 ratio of about 2:1. At stage 40, however, the cells of the vitreous body itself synthesized the greatest quantities of collagen, which now was predominantly an (alpha 1)3 type molecule. Stage 40 neural retina and lens synthesized lesser amounts of collagen with an alpha 1:alpha 2 ratio of 2 to 3:1. Chick vitrosin thus appears to be synthesized by the neural retina in early embryonic stages, whereas the major contribution derives from cells within the vitreous body in later development.
已证明两种不同类型的细胞在胚胎发育的不同阶段合成胚胎鸡玻璃体胶原蛋白（玻璃蛋白）。通过在胚胎发育的第23和28阶段对鸡胚进行卵内[³H]脯氨酸标记，并通过羧甲基纤维素色谱法分离提取的玻璃体胶原蛋白α链，确定了玻璃蛋白。标记的胶原蛋白主要由α1链组成，表明该分子为相同链三聚体形式，即(α1)₃。通过分子筛色谱法测得标记链的分子量约为95,000道尔顿，其亚氨基酸中41%为4-羟脯氨酸。为确定哪些眼组织合成玻璃蛋白，对从第26 - 27、29 - 30和40阶段分离出的神经视网膜、晶状体和玻璃体在器官培养中产生的胶原蛋白进行了检测。在较早的两个阶段，只有神经视网膜合成大量的(α1)₃胶原蛋白，而晶状体和玻璃体自身的细胞合成的胶原蛋白量相对较少，其α1:α2比例约为2:1。然而，在第40阶段，玻璃体自身的细胞合成的胶原蛋白量最大，此时主要是(α1)₃型分子。第40阶段的神经视网膜和晶状体合成的胶原蛋白量较少，α1:α2比例为2至3:1。因此，鸡玻璃蛋白似乎在胚胎早期由神经视网膜合成，而在后期发育中主要由玻璃体内的细胞合成。
