Number and distribution of Leydig cells (LC) in the epidermis of the growing axolotl, Ambystoma mexicanum (Amphibia: Urodela)

作者：Gerling Sonja; D' Haese Jochen; Greven Hartmut^*

来源：Vertebrate Zoology, 2012, 62(1): 97-111.

• Ambystoma mexicanum. Epidermis
• Leydig cells
• uneven distribution
• amplification
• crowding

The epidermal Leydig cells (LC) of larval and paedomorphic Urodela (= Caudata) are highly specialized cells, which are characterized by a complex peripheral cytoskeleton (Langerhans%26apos; net) and numerous inclusions usually named secretory granules. We studied number, distribution and development of these cells in larvae up to 100 days after hatching and in some adults of the paedomorphic axolotl (Ambystoma mexicanum). With the exception of a short period after hatching, relation between age and total length of larvae was linear. The tail grew positively, the width of the head negatively allometric. Keeping larvae in groups resulted in a somewhat slower growth, in deviations from a strict linearity of some morphological parameters, and in a delayed increase of the number of LC, which is interpreted as crowding effect. LC could be identified already before hatching and developed first in the head, then in the trunk, and finally in the tail. Number of LC increased highly disproportionally during larval growth. Within 6 months, LC differentiated from relatively small cells (20 x 10 mu m) with a vacuolated appearance to large round cells (diameter ca. 65 mu m) with distinct and stainable granules and a prominent Langerhans%26apos; net forming several layers within the epidermis. LC neither rested directly upon the basal lamella nor reached the epidermal surface. They showed a moderate mitotic activity in all age groups examined. Number of mitoses appeared too small to explain the high number of LC in the epidermis and to guarantee continuous replacement. Mature, most superficially located LC appear to be shed.

• 出版日期2012