Evolution of the endoplasmic reticulum during spermiogenesis of the rooster: An electron microscopic study

Abstract

The endoplasmic reticulum (ER) of rooster's spermatids was analyzed during spermiogenesis, which was subdivided into eight distinct steps on the basis of changes observed with the electron microscope in the nucleus, acrosome-perforatorium system, manchette, and flagellum. In steps 1 and 2, spermatids' ER cisternae presented the following specializations: A loose network of tubular cisternae was distributed throughout the cytoplasm. Six to eight tight networks of anastomosed tubular cisternae parallel to each other were closely stacked to form a discoid body (1.5-2.5 microns in diameter and 0.5-0.8-micron thick) in which spheroidal vesicles (0.4 micron in diameter) were inserted. Close to and connected with this body, called the alveolar body, there was a stack of annulate lamellae. Large, flattened ER cisternae were seen singly or in piles of two or three running parallel to the nuclear surface. A collection of tubular ER cisternae faced plaques of thickened plasma membranes. These elements of the ER system appear continuous with each other. During steps 3-5 of spermiogenesis, no modification of the alveolar body-annulate lamellae complex was noted; the large flattened ER cisternae disappeared, however, and the broad network of tubular cisternae developed markedly. During steps 6 and 7, the latter network of tubular cisternae fragmented into vesicles that swelled to give a vacuolated appearance to the cytoplasm. The alveolar body-annulate lamellae complex remained visible until late step 7, when it disintegrated just before spermiation. Thus the system of ER cisternae underwent marked structural modifications during spermiogenesis.

Spermiogenesis in Soft‐Shelled Turtle, Pelodiscus sinensis

“…Between the stages of the circular and longitudinal manchettes, the microtubules are arranged obliquely (Asa and Phillips, 1988). In the ostrich spermatid, the longitudinal manchette is far better developed than the circular one, and shows a similar structure to that observed in the chicken spermatid (Nagano, 1962;McIntosh and Porter, 1967;Okamura and Nishiyama, 1976;Xia et al, 1986). In reptiles, to the best of our knowledge, only a few species have a similarly well organized array of perinuclear microtubules.…”

Ultrastructural study of spermiogenesis in the turkey,Meleagris gallopavo

“…However, Soley (1994) is of the view that the structure referred to as a chromatoid body in the chicken by Gunawardana and Scott (1977) is, in fact, the granulated body described in the ostrich (Soley, 1994) and rat (Clermont et al, 1990). Xia et al (1986) have described aggregations of endoplasmic reticulum, referred to as alveolar bodies in the spermatid of the rooster. As in the ostrich (Soley, 1994), the chromatoid body of the turkey lies in the region of the proximal centriole and alongside the cranial part of the distal centriole.…”

“…The categorisation and description of spermatid differentiation in birds has been reported, using the 4-phase system (Gunawardana and Scott, 1977;Xia et al, 1986;Soley, 1997) or the step-wise system (Clermont, 1958;Aire et al, 1980;Xia et al, 1986;Lin and Jones, 1993). It appears that both methods of spermatid evaluation have merits and disadvantages.…”

“…That is where the 4-phase system may be more consistent, albeit imprecise, with regard to subtle developmental processes that take place in one segment or part of the spermatid. In one of the few ultrastructural studies, in birds, using the step-wise system, Xia et al (1986) in the domestic fowl subdivided spermiogenesis into 8 steps. He had collapsed a number of steps described by Lin and Jones (1993) in the Japanese quail.…”

Spermiogenesis in birds

“…However, only a few reports detailing spermiogenesis in birds are to be found in the literature. 1,4,5,6,8,9,14,15, Most of these publications are, understandably, on the more economic domestic species of birds, such as the domestic fowl, turkey, duck and quail, [21][22][23][24][25]27,29,30,42,[47][48][49][50][51] and even much fewer on other species of birds, including passerines and the Paleognathae. 22,33,35,37,41,42,[44][45][46]49,52 However, most of these publications are based upon individual or fragmentary organelle development 30,[37][38][39][40]45,46 rather than the non-fragmentary method of spatiotemporal, in-tandem, development of the early spermatid in the Japanese quail, 49 in the Turkey, 42 in the House Sparrow, 41 in the parrot, 45 in the Ostrich, 37 in the European nightjar (Caprimulgus europaeus) …”