MORPHOLOGICAL CHANGES OF YOLK LYOTROPIC LIQUID CRYSTALS DURING FOLLICULAR ATRESIA OF TILAPIA MOSSAMBICA
莫桑鼻给非鲫滤泡闭锁中卵黄溶致液晶的形变特征

Using ultrathin section and freeze-etching replica techniques the morphological changes of yolk lyotropic liquid crystals (YLLQ) during follicular atresia of Tilapia mossambica were observed with transmission electron microscope.The YLLQ formed by granulosa cells, which phagocytosized and digested yolk spheres of abnormal oocytes, were liposome-like structures with tightly lamellar layers, or pilled -up lamellar structures without distinct circular centre, or irregular concentric lamellar structres. These YLLQ in the cells were unstable state. After liberated from granulosa cells, YLLQ by themselves, in the enlargement of space and the increase of water, swelled to form a stable and regular liposome-like structure with wide intervals between lamellar layers.The YLLQ can move intercellularly with body liquid and eventually enter the capillary lumen through the fenestrae of endothelia cells. According to the behaviour of morphological changes of YLLC, it is considered that the follicular atresia of teleosts come into operation as a resorption process of yolk materials and does not take part in the steroid synthesis.