Marotta Roberto, Uggetti Andrea, Ricci Claudia, Leasi Francesca, Melone Giulio
Dipartimento di Biologia, Università degli Studi di Milano, 20133 Milano, Italy.
J Morphol. 2012 Jan;273(1):1-7. doi: 10.1002/jmor.11000. Epub 2011 Aug 25.
Bdelloid rotifers survive desiccation and starvation by halting activity and entering a kind of dormancy. To understand the mechanisms of survival in the absence of food source, we studied the anatomical and ultrastructural changes occurring in a bdelloid species, Macrotrachela quadricornifera Milne 1886, after starvation for different periods. The starved rotifers present a progressive reduction of body size accompanied with a consistent reduction of the volume of the stomach syncytium, where lipid inclusions and digestive vacuoles tend to fade with prolonged starvation. Similar reduction occurs in the vitellarium gland, in which yolk granules progressively decrease in number and size. The changes observed in the syncytia of the stomach and the vitellarium suggest that during starvation M. quadricornifera uses resources diverted from the stomach syncytium first and from the vitellarium syncytium later, resources that are normally allocated to reproduction. The fine structure of starved bdelloids is compared with that of anhydrobiotic bdelloids, revealing that survival during either forms of dormancy is sustained by different physiological mechanisms.
蛭形轮虫通过停止活动并进入一种休眠状态来在脱水和饥饿中存活。为了了解在没有食物来源的情况下的生存机制，我们研究了一种蛭形轮虫物种——四棘巨管轮虫（Macrotrachela quadricornifera Milne 1886）在饥饿不同时期后发生的解剖学和超微结构变化。饥饿的轮虫身体大小逐渐减小，同时胃合胞体的体积持续减小，随着饥饿时间延长，其中的脂质内含物和消化液泡趋于消失。卵黄腺也出现类似的减小，其中卵黄颗粒的数量和大小逐渐减少。在胃和卵黄腺合胞体中观察到的变化表明，在饥饿期间，四棘巨管轮虫首先利用从胃合胞体转移的资源，随后利用从卵黄腺合胞体转移的资源，这些资源通常分配用于繁殖。将饥饿蛭形轮虫的精细结构与脱水生物蛭形轮虫的精细结构进行比较，结果表明，在两种休眠形式下的存活是由不同的生理机制维持的。
