Efferent ductules of the fan‐throated lizardSitana ponticerianaCuvier: light and transmission electron microscopy study

Abstract

Akbarsha, M.A., Kadalmani, B. and Tamilarasan, V. 2007. Efferent ductules of the fan-throated lizard Sitana ponticeriana Cuvier: light and transmission electron microscopy study. -Acta Zoologica (Stockholm) 88 : 265-274.Light microscopy histology of efferent ductules and the ultrastructural organization of their epithelium were studied in the fan-throated lizard Sitana ponticeriana Cuvier. The ductules of this lizard are extra-testicular and arise from an extra-testicular rete testis. A major portion of the ductules is intraepididymal and occupies the cephalic end of the epididymis. The ductules differentiate histologically into proximal and distal portions. The epithelium is formed of two major tall columnar cell types, the non-ciliated and ciliated, and one minor cell type, the basal cells. Dark cells were also identified. The non-ciliated cells possess microvilli towards the luminal end, tubular coated pits at the bases of the microvilli, coated vesicles in the apical cytoplasm and multivesicular bodies, lysosomes and mitochondria in the supranuclear and perinuclear cytoplasm, which reflects their role in the uptake of the material they are processing. These cells also participate in spermiophagy. The ciliated cells reflect their role in mixing the luminal content and/or its transport to the distal parts of the male tract. The lizard efferent ductules share many features in common with those of mammals and a crocodile and several other features with birds and a turtle. Spermiophagy by the efferent ductules is reported here for the first time in a reptile.

Proximal Testicular Ducts of the Mediterranean Gecko (Hemidactylus turcicus)

“…The ductuli efferentes of H. turcicus are lined by a cuboidal epithelium that consists of ciliated and nonciliated cells consistent with reports in mammals (Ilio and Hess, 1994), birds (Aire, 2007), and other reptiles (Guerrero et al, 2004;Akbarsha et al, 2007;Sever, 2010). In addition to being a conduit for sperm, the ductuli efferentes have been ascribed roles in fluid resorption, secretion, and spermiophagy (Hess, 2002).…”

“…In amniotes the rete testis is composed of a simple squamous epithelium with bifurcated or irregular shaped nuclei and ciliated and nonciliated (principal) cells (Djakiew and Jones, 1981;Jones, 2002;Holmes and Gist, 2004;Aire, 2007;Akbarsha et al, 2007;Sever, 2010). Ciliated cells are not numerous in the rete testes of H. turcicus and more than one cilium projects into the lumen from a single cell unlike the ciliated rete cells described in mammals (Dym, 1976;Jones, 2002).…”

“…Aside from the 10-18 tubules of the ductuli efferentes mentioned for Lacerta by Alverdes (1926), Reynolds (1943) reported 11 in the skink Eumeces fasciatus, Averal et al (1992) observed 7-8 in the agamid Calotes versicolor, and Akbarsha et al (2007) found 6-8 in another agamid, Sitana ponticeriana. Some workers, such as Forbes (1941) apparently considered the ductuli efferentes to comprise the initial segment of the ductus epididymis.…”

“…From the seminiferous tubules of squamate reptiles (i.e., lizards and snakes), sperm sequentially pass through the rete testis, ductuli efferentes, ductus epididymis, ductus deferens, and ampulla ductus deferentis (Akbarsha et al, 2006a(Akbarsha et al, , 2007Sever 2010). MartinSaint-Ange ( Fig.…”

“…Some workers, such as Forbes (1941) apparently considered the ductuli efferentes to comprise the initial segment of the ductus epididymis. The only ultrastructural study on the ductuli efferentes in a lizard is by Akbarsha et al (2007) on S. ponticeriana.…”