Formation and Role of the Manchette Microtubules in the Poultry Spermatids

Abstract

Mar e t taM.: Formation and Role of the Manchette Microtubules in the Poultry Spermatids. Acta vet. Brno 1995,64: 000-000.Formation of the manchette microtubules and its disappearance in spermatids of cocks, drakes and Japanese quail was studied.The manchette in spermatid of three species examined was formed by a set of microtubules appearing close to the elongating spermatid nucleus. It assumed two shapes: in the first stage of development, it is helical-shaped, and in the second stage it has longitudinally-arranged microtubules. In both cases, microtubules are arranged in the shape of a cylinder, the integrity of which could be distorted, above all, in the region of the flagellum. At the helical arrangement, the manchette consists of one row of helically running microtubules that start in the forming acrosome region and terminate at the end of a distal centriole of developing flagellum. The manchette with its longitudinal-shaped microtubules also starts in the region of the acrosome, however, it encroaches the end compartment of the forming flagellum. Conversion of the helical-shaped microtubules into the longitudinal arrangement is very fast, and is likely to occur by reconstruction of original microtubules as well as synthesis of new ones. The manchette dissapp ears by disintegration of all microtubules without leaving any residue from the region of the head and anterior part of the flagellum, and by leaving the residue of electron-dense material in the cytoplasm of a maturing spermatid. The role of the manchette with helical-arranged microtubules is to model the nucleus from originally spherical shape to a long cylinder, and with longitudinal arrangement of microtubules, it displaces the cytoplasm from the anterior part of the head to the caudal part of the flagellum. The manchette is suggested to play also a role in formation of a mitochondrial sheath of the sperm flagellum. ' Microtubules, manchette,formation, role, spermatids, poultryThe manchette of the spennatid is a transient organelle composed of numerous microtubules located and running mostly unifonnly close to the nucleus. It appears just prior to the onset of chromatin condensation and in mammals it encircles the caudal pole of the nucleus and extends into the postnuclear cytoplasm. Bur go s and F a w c e t t (1955) observed the beginnings of the manchette development in the period of forming of the acrosomal cap and migration of the Golgi apparatus, when at the caudal pole of the nucleus a higher number of fine filaments appear in the surrounding cytoplasm. According to D 0 0 her and Ben net (1973), P 10 e n (1971), and Sic k 1 e sand He a t h (1986) the manchette tubules originate in a ring-shaped structure that appears just under the posterior margin of the acrosomal cap. B ro kelm ann (1963), Go 0 dro we andH e a th (1984), R us s ell et al. (1991) observed the same site from which the manchette microtubules originated.F a w c e t t et al. (1971) found that the manchette is embedded in dense fibrillar material that occupies the conca...

Spermiogenesis in birds

“…38,46,48 The development of the centriolar complex and flagellum of the spermatozoon is generally similar in mammals 7,10,96-98 and non-passerine birds. 23,24,26,27,29,30,38,42,48,50 Initially, in all the birds studied, except the quails, Coturnix japonica and probably C. chinensis 61 (see step 3, above), the centriolar pair, lying at right angle to each other, is closely associated with the Golgi apparatus, and, initially, lies mid-way between the cell membrane and the nucleus. The diplosome thereafter migrates gradually toward the nucleus, to which it eventually attaches, usually obliquely, in the region of the nucleus destined to become the caudal pole.…”

A novel transient structure with phylogenetic implications found in ratite spermatids

“…Although not based on cladistic evidence, the observation that the only non-passerine birds with this unique structural adaptation studied to date appear to be the emu, ostrich and rhea, would support the traditional view that the extant ratites form a monophyletic group [2,8,13,53-56]. This view is strengthened by the fact that studies on galliform birds such as the chicken [26,28,30]; personal observations], turkey [34], quail [32] and members of the anseriforms [33,57]; personal observations], two families closely linked phylogenetically to the ratites, have failed to reveal an equivalent structure. It would be essential to determine whether the remaining members of the Ratidae (cassowaries and kiwis) also reflect the “structure” during spermiogenesis and indeed whether it is present in developing spermatids of the tinamous, as recent molecular studies have placed the tinamou together with the ratites as a polyphyletic group [2,15,58,59].…”

Ultrastructural research of spermiogenesis in two sponges, Crellomima imparidens and Hymedesmia irregularis (Demospongiae): New evidence of sperms with acrosome in sponges

“…In C. imparidens the microtubules surround the nucleus and are arranged along its longer axis, similarly to the manchette microtubules in the sperms of some other metazoans (Buckland-Nicks et al, 1990;Kondo et al, 1988;Maretia, 1995;Russell et al, 1991). Such manchettelike structures have never been reported in Porifera before.…”