. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. \. Figure 6. Behavior of injected droplets of fluids. Droplets of fluids were injected into unfertilized eggs, which were parthenogenetically ac- tivated by the injection. The egg in (A) was oriented with its animal pole uppermost; all others had vegetal pole uppermost. In all four eggs, the droplets of injected fluid (arrowheads) moved toward the animal pole of the egg and came to rest in the blastodisc at the boundary between the blastodisc and the yolk vacuole. (A) Mineral oil stained with Sudan black B, (B) FC-77, (C) FC
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. \. Figure 6. Behavior of injected droplets of fluids. Droplets of fluids were injected into unfertilized eggs, which were parthenogenetically ac- tivated by the injection. The egg in (A) was oriented with its animal pole uppermost; all others had vegetal pole uppermost. In all four eggs, the droplets of injected fluid (arrowheads) moved toward the animal pole of the egg and came to rest in the blastodisc at the boundary between the blastodisc and the yolk vacuole. (A) Mineral oil stained with Sudan black B, (B) FC-77, (C) FC-3275. (D) sihcone fluid. Scale bar. 250 pm. predominant wavelength emitted by the lamps was about 254 nm. Moreover, an action spectrum of the effects of UV irradiation on the inactivation of components re- quired for neural induction in the amphibian egg showed a peak at 280 nm and a decline toward both 250 and 320 nm (Youn and Malacinski, 1980). However, irradia- tion of cells with high-intensity near-UV light (360 nm, mW cm :, about 5-fold higher than that used in the present study) disrupts f-actin in epithelial cells (Rafferty el (//.. 1993). Although we saw an inhibition of segregation at such a high UV light intensity in preliminary experi- ments, UV light intensities sufficient to regenerate micro- tubules and normal oil droplet movement had no appar- ent effect on ooplasmic segregation in the medaka egg. That we could regenerate microtubules and oil droplet movement near the animal pole by irradiating this region en face is not surprising, given the apparent presence of a microtubule-organizing center there (Abraham et a!.. 1993b). More interesting is the observation that we could regenerate microtubules and oil droplet movement near the equator region and could regenerate microtubules at the vegetal pole. This result is consistent with Sakai's ob- servation (1964) that oil droplets will segregate toward the vegetal pole in vegetal halves of eggs that have been sur
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
