Immunohistochemical localization of cyclic AMP during normal and abnormal chick and mouse limb development.

This paper describes the immunohistochemical localization of cAMP during limb chondrogenesis in talpid3 chick, brachypod mouse, and normal embryos. Comparisons were made between chick wing buds at Stages 22, 25, and 30, and mouse hind limb buds at Days 11, 12.5 and 14. At Stage 22, the normal mesenchyme in the chick displayed areas of bright fluorescence compared to a lesser intense and more evenly distributed fluorescence in talpid3. Sections of the central region from normal Stage 25 limb buds exhibited an intense fluorescence that was uniformly distributed, whereas, in talpid3 staining was more mosaic with some areas fluorescing brightly and others showing little fluorescence. At Stage 30 the staining pattern was similar between normal and talpid3, with the fluorescence being brighter in the cartilage tissue than in the surrounding soft tissue. Difference in the staining patterns of normal and brachypod limb tissue were not detectable. At Days 11 and 12.5, tissue from both genotypes displayed a very bright, uniform fluorescence. In the 14-day hind limb buds, the staining patterns were comparable to those observed in Stage 30 chick wing buds. However, under in vitro conditions conducive for the expression of the chondrogenic phenotype, differences in the intensity and extensiveness of fluorescent staining were detectable in cultures derived from 12-day normal and brachypod hind limb mesenchyme. Compared to the control, the uneven distribution of immunofluorescence in the talpid3 limb buds and the differences in intensity and extensiveness of fluorescence in the brachypod cultures support the hypothesis that cAMP is involved in limb cartilage differentiation.

本文描述了在短肢畸形3型鸡、短足小鼠以及正常胚胎肢体软骨发生过程中，环磷腺苷（cAMP）的免疫组织化学定位。对鸡在22、25和30期的翅芽以及小鼠在11、12.5和14天的后肢芽进行了比较。在22期，与短肢畸形3型中较弱且分布更均匀的荧光相比，鸡的正常间充质显示出明亮荧光区域。正常25期肢体芽中心区域的切片呈现出均匀分布的强烈荧光，而在短肢畸形3型中，染色更呈马赛克状，一些区域荧光明亮，其他区域则几乎没有荧光。在30期，正常和短肢畸形3型之间的染色模式相似，软骨组织中的荧光比周围软组织更亮。正常和短足肢体组织的染色模式差异无法检测到。在11天和12.5天，两种基因型的组织都显示出非常明亮、均匀的荧光。在14天的后肢芽中，染色模式与在30期鸡翅芽中观察到的相似。然而，在有利于软骨生成表型表达的体外条件下，从12天正常和短足后肢间充质培养物中可以检测到荧光染色强度和范围的差异。与对照相比，短肢畸形3型肢体芽中免疫荧光的不均匀分布以及短足培养物中荧光强度和范围的差异支持了cAMP参与肢体软骨分化这一假设。