Nucleic Acid 



and Protein Changes 



in Budding Hydra Uttoralis 



Yu-YiNG Fu Li 



AND 



Howard M. Lenhoff 



Laboratories of Biochemistnj, Howard Hughes Medical Insiitute, and Departments 

 of Biochemistnj and Zoology, University of Miami, Miami, Florida 



Budding in hydra has excited biologists since it was first discov- 

 ered over 250 years ago by Leeuwenhoek and Trembley. As one step 

 toward understanding the mechanisms involved in the initiation 

 and growth of a l^ud, we have been searching for means to charac- 

 terize chemical differences between parent and bud tissues (2). 

 Some of our preliminary observations concern changes in the amount 

 and distribution of DNA, RNA, and protein in budding Hydra. 



Experiments involving the chemical analyses of cellular compo- 

 nents required large number of Hydro in the same stages of bud- 

 ding. These were obtained by carefully controlling the time at 

 which they were fed, while keeping all other growth conditions 

 constant. In these experiments, Hydra having one bud were removed 

 from a mass culture (3). The animals were then allowed to starve 

 4-6 days, during which time the original bud and one or two latent 

 buds completed their development, detached, and were discarded. 

 On the sixth day of starvation the animals were fed once with excess 

 Artemia nauplii. As shown in Figure 1, nearly all of the Hydra 

 initiated a small bud within the first day after feeding. 



The developmental stages of the budding Hydra are presented 

 in Figure 2. First, the 6-day starved animal enters the "small bud" 



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