Fine structure of the spermatozoon of Tubularia larynx (Hydrozoa, coelenterata)

Afzelius, Björn A.

doi:10.1016/s0022-5320(71)80031-x

Cited by 38 publications

(12 citation statements)

References 17 publications

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“…The alignment of the two centrioles on the major axis of the cell, as observed in C. marsupialis, is also typical of some hydrozoan sperm, as in Tubularia larinx (Afzelius, 1971), Eudendrium ramosum (Summer, 1972) and Clytia hemispherica (CarrC and Carre, 1992). The same alignment is encountered in some Anthozoa, as in Scleractinia and in Corallimorpharia, where, however, they are connected to each other by a fibrillar intercentriolar ligament absent in C. marsupialis.…”

Section: Discussionmentioning

confidence: 82%

“…moreover, the vesicles are located on the apex of the nucleus and have a roundish shape, whereas in C. marsupialis these structures are often lengthened and, in the majority of the cases, they are located antero-laterally to the nucleus. An anterolateral disposition of the vesicles was found by some authors in various Hydrozoa, as in Tubularia larinx (Afzelius, 1971), Cladonema uchidai (Yamashita, 1987), Campanularia frexuosa (O' Rand and Miller, 1974) and Clytia hemispherica (Carre and Carre, 1992). In these species the vesicles are homogeneus electron-dense structures.…”

Section: Discussionmentioning

confidence: 82%

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The spermatozoon ofCarybdea marsupialis(Cubozoa, Cnidaria)

Corbelli

Avian

Marotta

et al. 2003

Invertebrate Reproduction & Development

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The spermatozoon of Carybdea marsupialis (Cnidaria, Cubozoa, Carybdeidae) is a primitive sperm with a short pear-shaped head and a long tail. The head contains a pyriform nucleus, six mitochondria, two centrioles aligned on the major axis of the sperm, and an anchoring apparatus formed by a complex pericentriolar system and a pyramid-like appendix (spur). The pericentriolar system is formed by three different and concentric orders of pericentriolar processes located around the distal centriole from which they, together with the spur, originate. Anterolaterally to the nucleus and scattered in the midpiece, we have found several pro-acrosomal vesicles with two concentric regions with a different electron density. The tail has a conventional 9+2 axoneme. In the transition zone between the anchoring apparatus and the tail, the central axonemal doublet is not yet present, but there is an electron-dense cylinder internal and adhering to the nine peripheral doublets, and the latter are connected to the plasma membrane by the classical Y-links. The spermatozoa are probably released through ruptures of the endodermal layer of the testes, as in other cnidarian species. The spermatozoon of C. marsupialis is very different from the modified anthozoan sperm, and shares characters with both the Hydrozoa and the Scyphozoa. The shape of the spur, its striations, the shape of the tertiary pericentriolar processes and the presence of the intersecondary processes of the anchoring apparatus are new for the whole phylum and are considered autapomorphic characteristics.

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Section: Discussionmentioning

confidence: 82%

Section: Discussionmentioning

confidence: 82%

The spermatozoon ofCarybdea marsupialis(Cubozoa, Cnidaria)

Corbelli

Avian

Marotta

et al. 2003

Invertebrate Reproduction & Development

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“…6,7 In several kinds of sperm, such as those in the Coelenterata Tubularia laryn, there are connective structures, called Y-link, between the doublet microtubules and plasma membrane. 8 The morphology of sperm cell varies among organisms and atypical axonemal structures are observed in sperm of some organisms: 9 + 9 + 2 (caddis fly, Neuronia sp. ), 9 + 9 + 3 (black fly, Odagmia pontina), 9 + 3 (spider, Pholcus phalangioides), 9 + 7 (caddisfly, Polycentropus sp.…”

Section: Diversity Of Axonemal Structuresmentioning

confidence: 99%

Molecular Basis of Sperm Flagellar Axonemes

Inaba

2007

Annals of the New York Academy of Sciences

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The axonemes serve as motile machineries in sperm flagella. Although atypical axonemal structures are observed in some cases, 9 + 2 microtubule structure of the axoneme is predominant in many organisms. Several structures are bound to these microtubules and comprise a highly organized protein network. Extensive proteomic analysis of the axonemes has led to find several repeats, domains, and motifs in axonemal proteins. Molecular comparison of subunit composition of axonemal substructures between the ascidian Ciona intestinalis and the green algae Chlamydomonas reinhardtti leads to an intriguing molecular aspect concerning the evolution of intracellular functional complex: The architecture of the axonemes has been well conserved through evolution, but the molecular structure of each axonemal component is not always conserved. In light of domain structure in the axonemal proteins, substructures like outer arm dynein and radial spoke contain a set of domain structures, although some domain-containing subunits are different between these two organisms. Thus, conservation of protein domains within a substructure seems to take precedence over that of each protein ("module-dominant conservation"), which may ultimately result in morphological and functional conservation of the axonemes through evolution.

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“…anterior tip of the nucleus (Afzelius, 1971). Apical vesicles are absent from mature sperm of the freshwater hydroid Hydra (Moore and Dixon, 1972;Stagni and Lucci, 1970) and in anthozoans.…”

Section: Types Of Spermmentioning

confidence: 99%

“…(Kleve, M.G., and Clark, W.H., Jr., Journal of Cell Biology, 86:87-95 (1980) by copyright permission from the Rockefeller University Press.) anterior tip of the nucleus (Afzelius, 1971). Apical vesicles are absent from mature sperm of the freshwater hydroid Hydra (Moore and Dixon, 1972;Stagni and Lucci, 1970) and in anthozoans.…”

Section: Fig 7 Longitudinal Section Of a Spermatozoan Of The Hydrozoanmentioning

confidence: 99%

Ultrastructure of sperm, spermiogenesis, and sperm‐egg interactions in selected invertebrates and lower vertebrates which use external fertilization

Koch

Lambert

1990

J. Elec. Microsc. Tech.

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This review discusses the ultrastructure of sperm with reference to their development, the surface morphology of the egg, and the processes of sperm binding and penetration during fertilization. These topics are treated for selected invertebrates and lower vertebrates which live in aquatic environments and fertilize their eggs externally. Specifically, sperm eggs from cnidarians, echinoderms, decapod crustaceans, ascidians, lampreys, bony fishes, and amphibians are discussed. Sperm from the majority of these groups exhibit the classical head-midregion-tail configuration characteristic of primitive sperm. Specific variations within this general morphology have been described. The notable exceptions to the primitive-sperm paradigm are the sperm of decapod crustaceans and amphibians. Eggs from all of the animals considered are covered by complex vitelline envelopes except those of cnidarians. In general, the ultrastructural analysis of these egg envelopes shows that they are composed of fibrous subunits. Sperm bind to the vitelline envelope and then penetrate through it to fertilize the egg in all groups reviewed except fishes. In sperm ultrastructure which occur during penetration of the egg envelopes in both flagellated and non-flagellated sperm. These changes, which involve membrane fusion and reorganization as well as movement of membranous organelles, aid the sperm in reaching the actual site of gamete fusion.

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Fine structure of the spermatozoon of Tubularia larynx (Hydrozoa, coelenterata)

Cited by 38 publications

References 17 publications

The spermatozoon ofCarybdea marsupialis(Cubozoa, Cnidaria)

The spermatozoon ofCarybdea marsupialis(Cubozoa, Cnidaria)

Molecular Basis of Sperm Flagellar Axonemes

Ultrastructure of sperm, spermiogenesis, and sperm‐egg interactions in selected invertebrates and lower vertebrates which use external fertilization

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