Wolf Rainer, Nuss Elke
Zoologisches Institut (I), University of Würzburg, Röntgenring 10, D-8700, Würzburg, Germany.
Wilehm Roux Arch Dev Biol. 1976 Sep;179(3):197-202. doi: 10.1007/BF00848645.
Time-lapse photomicrographs of eggs from the Ichneumonid waspPimpla and from the gall midgeWachtliella reveal that during fixation the ooplasm performs excessive streaming movements when conventional fluids such as Bouin's or Dubosq-Brasil's are used. InWachtliella, intravitelline cleavage may continue for two mitotic cycles during fixation. The cytoplasm of individual egg regions may become displaced up to 45% of the egg's length inPimpla, and up to 14% of the egg's length inWachtliella. Therefore fixed preparations may grossly misrepresent the distribution of egg components in the living state. The changes can be traced back by microkymographic registration of movements during fixation. Microkymograms for this purpose were obtained by projecting a time-lapse film through a slit onto photosensitive material mounted on a rotating drum.The shifting of egg components and the mitotic activity of nuclei fail to occur when the egg is treated with a buffered solution of OsO (1%, 1 min). Subsequent fixation with glutaraldehyde results in satisfactory preservation of microtubules.
姬蜂科黄蜂扁股小蜂属的卵以及瘿蚊科的瓦氏瘿蚊的卵的延时显微照片显示，在固定过程中，当使用诸如波因氏液或杜博斯克-巴西氏液等传统固定液时，卵质体会出现过度的流动运动。在瓦氏瘿蚊中，卵黄内分裂在固定过程中可能会持续两个有丝分裂周期。在扁股小蜂属中，单个卵区域的细胞质可能会移位至卵长的45%，在瓦氏瘿蚊中则可达卵长的14%。因此，固定后的标本可能会严重歪曲卵成分在活体状态下的分布。这些变化可以通过固定过程中运动的微记录片来追溯。为此目的的微记录片是通过将延时电影通过狭缝投射到安装在旋转鼓上的感光材料上获得的。当用1%的四氧化锇缓冲溶液处理卵1分钟时，卵成分的移位和细胞核的有丝分裂活动不会发生。随后用戊二醛固定可使微管得到满意的保存。
