Structure of the Leydig Cell in the African Sideneck Turtle (Pelusios castaneus)

Abstract

The African sideneck turtle (Pelusios castaneus) is a freshwater turtle of West African origin used in traditional medicine with
little consumption as meat. There have been documentations on the reproductive biology of the turtle with no report on the
structure of the Leydig cell of the animal. We described the structure of the Leydig cell of the adult African sideneck turtle using
histology, microstereology and transmission electron microscopy. The Leydig cell of the African sideneck turtle were elliptical
in shape when found proximal to blood vessels and elongated at other points within the testicular interstitium. Leydig cells
occurred in cords or clusters of varying sizes and numbers (3-5 cells) that appear to be random in distribution possessing round
to ovoid nuclei containing small amount of peripherally disposed heterochromatin with prominent nucleoli. The seminiferous
tubules of the turtle occupied about 85% of the total testicular parenchyma while the interstitium occupied 15% of it. Of this
15%, the Leydig cell occupied about 10% while the stromal elements, inclusive of blood vessels occupied the remaining 5%.
The cytoplasm of the Leydig cell was about 85% of the entire cell and comprised microfilaments, lipid droplets, smooth and
rough endoplasmic reticula as well as numerous mitochondria. In conclusion, the histological and ultrastructural features of the
Leydig cell of the African sideneck turtle bear close similarities with those of other reptiles with little variations. These variations
include interstitial location as well as in relation to blood vessels within the testicular interstitium. Information made available
by this study is expected to be useful in the comparative anatomy of the Leydig cell of turtles and reptiles.

Keywords: African sideneck turtle; Leydig cell; Testicular interstitium; Reptiles