Histological variation along and ultrastructural organization of the epithelium of the ductus epididymidis of the fan‐throated lizard Sitana ponticeriana Cuvier

Abstract

 Abstract Akbarsha, M.A., Kadalmani, B. and Tamilarasan, V. 2006. Histological variation along and ultrastructural organization of the epithelium of the ductus epididymidis of the fan-throated lizard Sitana ponticeriana Cuvier. -Acta Zoologica (Stockholm) 87 : 181-196The epididymis of the fan-throated lizard Sitana ponticeriana was subjected to light and transmission electron microscopic analysis to find the histological variation along the ductus epididymidis, describe the various cell types in the epithelium and compare the resulting descriptions with what is known for other reptiles and for amniotes. The ductus epididymidis of this lizard is differentiated along its length into four histologically distinct zones, initial segment, caput, corpus and cauda. The first three zones appear to be associated with secretion and absorption/endocytosis whereas the cauda appears to be concerned with absorption/endocytosis and storage. The epithelium consists of six different cell types, principal, narrow, apical, clear, basal and intraepithelial leucocytes as in the mammals. Principal cells, basal cells and intraepithelial leucocytes are present along the entire length. Narrow cells and apical cells are confined to the initial segment whereas clear cells occur in the cauda only. The principal cells from the initial segment to the corpus produce biphasic secretion granules measuring 1-2 µ m in diameter. This paper reports on four histologically distinct zones along the length of the ductus epididymidis of the lizard S. ponticeriana and six different cell types in the lining epithelium.

Proximal Testicular Ducts of the Mediterranean Gecko (Hemidactylus turcicus)

“…A single tubule emerges from the external tunic of the testes, signifying the extra-testicular rete testis as described by Sever (2010) in his synonomizing of the terminology for reptiles. Although the number of extratesticular rete tubules varies (Table 1), the presence of a single rete testis tubule in H. turcicus is the same as in a diverse assemblage of lizards: Sitana ponticeriana (Akbarsha et al, 2006a), Eumeces fasciatus, (Reynolds, 1943), Lacerta vivipara (Martin-Saint-Ange, 1854), and Sceloporus undulatus (Forbes, 1941). Thus, this character may not have any phyletic significance.…”

“…Akbarsha et al (2006a) correctly identified these halo cells as intraepithelial leukocytes, and Hermo and Robaire (2002) consider these leukocytes are either monocytes or T lymphocytes. We are unaware of other reports of intraepithelial leukocytes in the rete testis of vertebrates, and we did not encounter these cells in the ductuli efferentes or epididymis of H. turcicus.…”

“…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.…”

The reproductive cycle of the male house gecko, Hemidactylus flaviviridis, in relation to plasma steroid concentrations, progesterone receptors, and steroidogenic ultrastructural features, in Oman

“…The spermatogenic activities leading to spermiation and mating behavior were the main emphasis in these investigations (Flemming, 1993;Gribbins et al, 2011;Nkosi et al, 2004;Ramírez-Bautista et al, 1996). In addition, some of the morphological studies have attempted to link specific features related to testicular activities such as the development of specific histological and ultrastructural features of the testicular tissues (including germ cells, Sertoli and Leydig cells) in relation to the seasonal activities (Akbarsha et al, 2006;Rheubert et al, 2009;Prasad, 1966, 1967). Other studies emphasized the relationship between plasma steroid concentrations and testicular activities such as spermiation relative to courtship and mating behavior (Amey and Whittier, 2000;Ando et al, 1990Ando et al, , 1992Johnson et al, 2011;Radder et al, 2001;Schuett et al, 1997).…”

Hormones and the Sex Ducts and Sex Accessory Structures of Reptiles

“…The most abundant cell type in the reptilian epididymis, accounting for > 80% of the epithelium, is variously identified as a principal (Akbarsha et al, 2006a), vesicular (Holmes & Gist, 2004), columnar (Guerrero et al, 2004), or secretory cell (Desantis, Labate, M., Labate, G., & Cirillo, 2002). The shape of principal cells changes from columnar in the caput epididymis to cuboidal distally; they possess microvilli and appear to have tight junctions.…”