281+ LIMB F lELD OPERATIONS 



XENOPLASTIC LIMB TRANSPLANTATIONS 



These are transplantations 'between different genera and even more distantly related 

 ^ or separated) species. Using Amblystoma donors, such transplants may te attempted to 

 Bufo, Hyla, and Sana. In using Triturus donors, the student should first consult the work 

 of Twitty (1957), and others, which indicates that Triturus embryos produce a toxin (from 

 yolk) that paralyzes emhryos of other genera. Depending upon the availability of material, 

 the following are suggested: 



a. Anuran belly ectoderm transplanted over the limb-field of a Urodele. 



b. Urodele limb-field ( ecto- and mesoderm) transplanted to the post-gill region an 

 Anuran embryo in the tail- bud stage. 



c. Anuran belly ectoderm (stage #l6-#17) transplanted for 2k hours over Urodele 

 limb-field mesoderm; then re-transplanted along with the urodele mesoderm, to 

 the flank region of Urodele embryos. This would clearly demonstrate the rela- 

 tion of foreign (xenoplastic) ectoderm and limb mesoderm in the formation of an 

 heterotopic limb. 



BECOED OF XENOPLASTIC LIMB TEANSPLANTATIONS 



