Laterally Asymmetric Development of Duck Syrinx: Inhibition of Growth and Chondrogenesis of the Right Syringeal Half by the Left Half: (duck syrinx/lateral asymmetry/tissue interaction/growth and chondrogenesis).

Abstract

For determination of whether position-related tissue interaction is involved in the laterally asymmetric development of the male duck syrinx, a cartilaginous vocal organ, the syrinxes from 10-day embryos were cut into right and left halves and cultured organotypically. The lateral halves developed equally when cultured separately, but their developments were unequal when they were cultured together in the same culture medium: that is, the right half developed less than the left half in terms of increase in size and chondrogenesis. When the right half from a normal or estrogen-treated embryo was cultured with the left half from a normal embryo, it accumulated less sulfated proteoglycans than when it was cultured with a left half from an estrogen-treated embryo. These results suggest that a soluble inhibitor that is susceptible to estrogen in the left half of the male syrinx inhibits the intrinsic increase in size and chondrogenesis of the right half and plays an important role in the laterally asymmetric development of the male duck syrinx.