Beck D P, Greenawalt J W
J Gen Microbiol. 1976 Jan;92(1):97-110. doi: 10.1099/00221287-92-1-97.
The ultrastructural characteristics of Neurospora cells during dedifferentiation and redifferentiation of conidiospores into vegetative cells have been determined. This germination process occurs between 2 and 5 h after inoculation; by 3-5 h, approximately 50% of the cells have germinated. The cells enter the exponential phase of dry-weight gain between 4 and 5 after inoculation. Several unusual structures are observed in Neurospora cells during germination. Whorled structures are frequently seen in the cytoplasm during germination, and occasionally at other times. They appear to be derived from the cytoplasmic membrane. Whorled structures of different appearance were observed in the mitochondria between 2 and 4 h after inoculation. Their number was related to the level of metabolizable carbohydrate, and was higher in 15% glucose-than in 2% sucrose-supplemented medium, and very low in medium containing 15% mannitol, or 2% sucrose +13% 2-deoxyglucose, or no added carbohydrate. The mitochondrial inclusions were osmiophilic and could be removed by treatment with 90% aqueous acetone in the cold, indicating that they were composed at least in part of lipid. The strong dependence of the number of mitochondrial inclusions on time and on carbohydrate supplementation, suggests that there is a physiological basis for these structures and that they reflect changes occurring in the mitochondria at times significant to cellular differentiation.
已经确定了链孢霉分生孢子去分化和再分化为营养细胞过程中细胞的超微结构特征。这种萌发过程在接种后2至5小时内发生;到3至5小时时,约50%的细胞已经萌发。接种后4至5小时,细胞进入干重增加的指数期。在链孢霉细胞萌发过程中观察到几种异常结构。在萌发过程中,细胞质中经常可见涡旋状结构,其他时候偶尔也会出现。它们似乎源自细胞质膜。接种后2至4小时,线粒体中观察到外观不同的涡旋状结构。它们的数量与可代谢碳水化合物的水平有关,在添加15%葡萄糖的培养基中比添加2%蔗糖的培养基中更高,而在含有15%甘露醇、或2%蔗糖 + 13% 2-脱氧葡萄糖或未添加碳水化合物的培养基中非常低。线粒体内含物嗜锇,可在低温下用90%丙酮水溶液处理去除,这表明它们至少部分由脂质组成。线粒体内含物数量对时间和碳水化合物添加的强烈依赖性表明,这些结构存在生理基础,并且它们反映了线粒体在对细胞分化具有重要意义的时刻发生的变化。