The Effect of Ultracentrifuging on the respiration Activity of Developing and Blocked Embryonic Cell

Bodine, Joseph Hall

Boell, Edgar J.

English

University of Northern Iowa

Proceedings of the Iowa Academy of Science Volume 43 Annual Issue Article 141 1936 The Effect of Ultracentrifuging on the Respiration Activity of Developing and Blocked Embryonic Cells Joseph Hall Bodine State University of Iowa Edgar J. Boell State University of Iowa Copyright ©1936 Iowa Academy of Science, Inc. Follow this and additional works at: https://scholarworks.uni.edu/pias Recommended Citation Bodine, Joseph Hall and Boell, Edgar J. (1936) "The Effect of Ultracentrifuging on the Respiration Activity of Developing and Blocked Embryonic Cells," Proceedings of the Iowa Academy of Science, 43(1), 391-392. Available at: https://scholarworks.uni.edu/pias/vol43/iss1/141 This Research is brought to you for free and open access by the Iowa Academy of Science at UNI ScholarWorks. It has been accepted for inclusion in Proceedings of the Iowa Academy of Science by an authorized editor of UNI ScholarWorks. For more information, please contact scholarworks@uni.edu. EFFECTS OF ROENTGEN RAYS ON DEVELOPMENT AND RESPIRATION OF GRASSHOP-PER EMBRYOS TITus C. Ev ANS Roentgen rays have been found to have many and varied effects on the development of the grasshopper, JV! elanoplus differentialis. Development may he completely inhibited, partly injured, or only temporarily retarded by proper dosages of Roentgen rays. Irradia-tion at a certain stage ( 5 to 6 clays, 25 ° C) results in the formation of aberrant growths and the occasional duplication of formed parts. The most rapidly growing parts, and embryos developing rapidly, are more quickly affected by irradiation. The appearance of injury may be prolonged by stopping development either by cold ( 5 ° C) or by means of the natural block ( diapause). \Vhen development is stopped by irradiation, the rate of respiration fails to increase with time as does that of the controls. If the nuclear end of the one day egg is protected with lead and the yolk thus irradiated with more than enough to kill the nuclei had they been exposed, the rate of oxygen consumption is not retarded at all and in some ·cases it is even increased. During diapause the respiration does not respond quantitatively to irradiation. It appears that the re-tardation of oxygen consumption rate noted when developing eggs are irradiated is due to the decrease in embryonic material rather than to a direct effect on the respiratory mechanism. DEPARTMENT OF ZOOLOGY, STA1'I~ UNIVERSITY oF low A, IowA CITY, IowA. THE EFFECT OF ULTRACE~TRIFUGING ON THE RESPIRATORY ACTIVITY OF DEVELOPING AND BLOCKED EMBRYO='JIC CELLS JosEPH HALL BomNJ·: AND EnGAR J. BoELL The effects of high rotational speeds as obtained through the use of the ultracentrifuge have been studied on the oxygen uptake of the eggs of the grasshopper, },f elanoplus differentialis. The 391 1Bodine and Boell: The Effect of Ultracentrifuging on the Respiration Activity of DePublished by UNI ScholarWorks, 1936392 IOWA ACADEMY OF SCIENCE [VoL. XLIII respiration of actively developing eggs is profoundly depressed after centrifugation by forces ranging from 1500 to 400,000 times gravity. The respiration of blocked eggs (in a state of physiolog-ical quiescence of diapause) remains unaffected after centrifugation by forces of the magnitude indicated. Complete stratification of the egg contents occurs in all eggs, regardless of their physiological state, with rotational forces in excess of 1800 times gravity. Re-covery of the eggs from the effects of centrifugation (as evidenced by hatching) occurs after exposure to dosages of 20,000 times gravity or less. DEPARTMENT OF ZOOLOGY, STATE UNIVERSITY OF low A, IowA CITY, IowA. RESPIRATORY ACTIVITY OF GRASSHOPPER EM-BRYO AS CONTRASTED WITH INTACT EGG J os:ern HALL BODINE AND EDGAR J. BoELL An attempt has been made to localize the important respiring components of the grasshopper egg and to estimate the relative respiratory intensity of each. Prior to the process of blastokinesis or yolk engulfment, the. differentiated embryo is responsible for only one-third of the oxy-gen uptake shown by the intact whole egg. This figure remains approximately the same in the blocked or diapause state, where development is at a standstill, as well as in pre- and post-diapause states where cell division and differentiation are actively occurring. Respiration of the whole egg in developmental states is 4 - S times greater than during diapause, and the same general difference in magnitude of 02 uptake is exhibited by the embryos. In terms of unit mass of respiring material, the respiratory activity of the embryonic cells is 10 times greater than that of the extra embry-onic material. During blastokinesis the extra embryonic materials in the egg are engulfed by the embryo where they are gradually incorporated into differentiated embryonic structures. At the completion of this process the respiration of the embryo is the same as that of the intact egg. In the remaining days of development before hatching the embryos show an O~ uptake in excess of that of the whole eggs. This is due to the fact that in such older embryos vigorous appendicular and abdominal movements are possible after the 2Proceedings of the Iowa Academy of Science, Vol. 43 [1936], No. 1, Art. 141https://scholarworks.uni.edu/pias/vol43/iss1/141

The Effect of Ultracentrifuging on the Respiration Activity of Developing and Blocked Embryonic Cells

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The Effect of Ultracentrifuging on the Respiration Activity of Developing and Blocked Embryonic Cells

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