. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. COMPARATIVE SENSITIVITY OF SPERM AND EGGS TO ULTRAVIOLET RADIATIONS ARTHUR C. GIESE* Marine Biological Laboratory, Woods Hole, Mass, and Hopkins Marine Station, Pacific Grove, Calif, and Stanford University, California The sperm of the sea urchin are more sensitive to ultraviolet radiations than the eggs when the effectiveness of the rays is compared by the retardation of cleav- age of unexposed eggs fertilized with irradiated sperm on the one hand and of ir- radiated eggs fertilized with unexposed sperm on the other (Giese,
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. COMPARATIVE SENSITIVITY OF SPERM AND EGGS TO ULTRAVIOLET RADIATIONS ARTHUR C. GIESE* Marine Biological Laboratory, Woods Hole, Mass, and Hopkins Marine Station, Pacific Grove, Calif, and Stanford University, California The sperm of the sea urchin are more sensitive to ultraviolet radiations than the eggs when the effectiveness of the rays is compared by the retardation of cleav- age of unexposed eggs fertilized with irradiated sperm on the one hand and of ir- radiated eggs fertilized with unexposed sperm on the other (Giese, 1939c). It would be interesting to know whether sperm are generally more susceptible to these radiations than eggs; therefore, the experiments were repeated on a number of marine forms. It is also desirable to find an explanation for this differential sus- ceptibility in those cases where it occurs. Insight might be gained by determining action spectra for the sperm and egg, therefore the relative efficiency of action of different wave-lengths of ultraviolet light in retarding cleavage of irradiated eggs and of eggs fertilized with irradiated sperm was determined as described below. MATERIALS AND METHODS Arbacia punctulata, Nereis limbata, Chaetoptcrus pcrgamcntaccus, and Mactra sp. were studied at Woods Hole, Mass. Strongylocentrotus franciscaims and S. purpuratus, collected at Moss Beach, and Urcchis caiipo collected at Bolinas Bay, California, were used at Stanford University, and Dendrastcr and Pa- tcria miniata were studied at the Hopkins Marine Station, each type of egg being used during the active breeding season. The methods for studying the eggs were similar to those previously described (Giese, 1938). Except for the work on the action spectrum, the mercury argon discharge tube which emits about 85 per cent of its light at A 2537 A was used and the light intensity was measured with a Hanovia Ultraviolet Meter (No. 949). The dishes were kept in running sea
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
