The Melanogenic System of Xenopus laevis.

The melanogenic system of Xenopus laevis.

Melanin pigments in lower vertebrates are often found in locations other than the skin, thus forming an extracutaneous pigmentary system of unknown function. The cellular and biochemical structure of this system is still poorly characterized. This paper deals with the ultrastructural and biochemical features of the melanogenic system of Xenopus laevis. Melanin containing cells were identified i...

The spatio-temporal framework of melanogenic induction in pigmented retinal cells of Xenopus laevis.

Using methods involving transplantation of neuroectoderm and eye rudiments between ap/ap mutants and +/+ embryos of Xenopus laevis, new aspects of melanogenic induction have been ascertained. The possibility of separate induction of a melanocyte cell type and of the product of terminal differentiation in it-melanosomes, has been demonstrated. Melanogenic induction starts at the late gastrula st...

ترتیب اعصای جانبی در دم لارو of Xenopus laevis

Development of the lateral line system in Xenopus laevis

During development of Xenopus laevis, the supraorbital lateral line system (i.e. the parietal and supraorbital lines of organs and the anterior auditory group of organs) is all derived from a single primordium located in the ear region of the epidermis. The primordium elongates first by active movement along the dorsal margin of the eye. Individual primary organs are then formed by progressive ...

The lateral line system at metamorphosis in Xenopus laevis (Daudin).

Marked changes in the anatomy of the lateral line system occur during the metamorphosis of Xenopus. The distribution of rows differs in larva and adult and the orientation and number of organs are modified at metamorphosis. Larval plaques are functional, as shown by recording from their nerves. Two classes of cells with polarized cilia are present in the tadpole well before the orientation of i...