Ultrastructural investigations on the morphology and genesis of sperms in Archaeogastropoda

Kohnert, R.; Storch, V.

doi:10.1007/bf01995797

Cited by 26 publications

(33 citation statements)

References 6 publications

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“…The glycogen piece of A. ancilla does not diVer in any respect from the conWguration shown to exist in many other caenogastropods (Healy 1983a;Kohnert and Storch 1984;Koike 1985), showing the typical microtubular pattern (9 + 2) associated with glycogen granules for each pair. The junction between the midpiece and glycogen piece presents a complex of ring elements attached to the plasma membrane, as in many caenogastropods (Buckland-Nicks and Chia 1973;Buckland-Nicks et al 1982a, b;Healy 1986Healy , 1988Healy and Jamieson 1993;Giménez et al 2008).…”

Section: Euspermatozoamentioning

confidence: 66%

“…Many neogastropods and some mesogastropods, like Potamididae, show the mitochondrial elements uniformly electron-dense (Kohnert and Storch 1984;Koike 1985) or present a non-helical arrangement of mitochondrial elements (Suwanjarat and Suwaluk 2003), respectively. In A. ancilla we found the outer layer of each mitochondrial element considerably more electron-dense than the remainder of the matrix component (which shows a U-shape in longitudinal section proWle), the number of mitochondria was taken from previous stages of spermatogenesis (data unpublished) and there was a spiraling of the mitochondrial elements, as in Z. dufresnei and P. mirabilis (Giménez et al 2008).…”

Section: Euspermatozoamentioning

confidence: 99%

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Ultrastructure of euspermatozoa and paraspermatozoa in the volutid snail Adelomelon ancilla (Mollusca: Caenogastropoda)

2009

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The ultrastructure of the euspermatozoa and the paraspermatozoa is investigated in Adelomelon ancilla, through histological section observed by transmission electron microscopy. Euspermatozoa of A. ancilla consists of: (1) a conical acrosomal vesicle (with a short basal invagination, constricted anteriorly) which is Xattened at the apex and associated with an axial rod, a centrally perforated basal plate and a short accessory membrane, (2) a rodshaped, solid and highly electron-dense nucleus (with a short basal fossa containing a centriolar complex and a initial portion of a 9 + 2 axoneme), (3) an elongate midpiece consisting of the axoneme sheathed by 5-6 helical mitochondrial elements each exhibiting a dense U-shaped outer layer, (4) an elongate glycogen piece (where the axoneme is sheathed by nine tracts of glycogen granules), (5) a dense annulus at the junction of the midpiece and glycogen piece, and (6) a short free tail region (where the axoneme is surrounded only by plasma membrane). We observed a parasperm in A. ancilla. This is vermiform in shape and is composed of multiple axonemes and extensive cytoplasm with numerous vesicles, and mitochondria are scattered inside the axonemes. Sperm of A. ancilla is characterized by the euspermatozoa type 2 and the paraspermatozoa morphology belongs to type 5. The U shaped electrodense mitochondrial element in the midpiece of the eusperm and the constriction in the acrosomal vesicle present in A. ancilla are exclusive. We suggest that these characteristics could have taxonomic importance, because these was observed in other volutids and have not been observed in the rest of caenogastropods studies. We consider that the morphology of paraspermatozoa in A. ancilla corresponds to the "lancet" type.

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Section: Euspermatozoamentioning

confidence: 66%

Section: Euspermatozoamentioning

confidence: 99%

Ultrastructure of euspermatozoa and paraspermatozoa in the volutid snail Adelomelon ancilla (Mollusca: Caenogastropoda)

2009

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“…Nuclear lamellae such as those occurring during late spermiogenesis in many internally fertilizing gastropods (Walker & MacGregor, 1968;Eckelbarger & Eyster, 1981;Healy, 1982aHealy, , b, 1988Kohnert & Storch, 1984;Koike, 1985) have not been observed in…”

Section: ~!Ilmentioning

confidence: 99%

Ultrastructure of spermiogenesis inVampyroteuthis infernalis Chun — a relict cephalopod mollusc

Healy

1990

Helgolander Meeresunters

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Spermiogenesis in the relict deep-sea cephalopod Vampyroteutln's infemah's Chun is examined using transmission electron microscopy (TEM), and the results compared with available data on other cephalopods. Early spermatids of Vampyroteuthis exhibit an ovoid nucleus (with dense irregular patches), numerous mitochondria and a pair of triplet substructure centrioles (arranged parallel to each other). Subsequently, the following morphological changes take place: (1) nuclear contents condense into a fibrous reticulum, then into thick fibres; (2) the acrosomal vesicle (presumably Golgi-derived) positions itself in a shallow depression at the nuclear apex; (3) the flagellum forms from one of the two centrioles; (4) mitochondria cluster around the flagellum at the base of the nucleus; (5) a dense, fibrous plug forms within the basal invagination of the nucleus. Microtubules surround the acrosome and condensing nucleus of spermatids. The dense plug is of special systematic importance since it also occurs in spermatids and spermatozoa of Octopus spp., but not in any investigated species of the Sepiida, Sepiolida or Teuthida. Late spermatids and mature spermatozoa of Vampyroteuthis strongly resemble developing spermatids of Octopus, suggesting a close phylogenetic relationship between Vampyroteuthis (and the Vampyromorpha) and octopods.

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“…Comparative sperm structure -Campanile euspermatozoa The true conical shape of the acrosomal cone of Campanile euspermatozoa occurs in most other mesogastropods (including some cerithiaceans), and neogastropods, the primitive spermatozoa of archaeogastropods, bivalves and scaphopods (for references see Popham, 1979;Franz6n, 1983;Kohnert & Storch, 1983;Healy, 1983a), and in fact many invertebrate groups (see Dan, 1970;Baccetti, 1979 for references). In contrast, the acrosomal cones of some cerithiaceans (cerithiids, some potamidids, Australaba; cf.…”

Section: Recurvature Of Euspermatozoamentioning

confidence: 99%

Euspermatozoa and paraspermatozoa of the relict cerithiacean gastropod,Campanile symbolicum (prosobranchia, mesogastropoda)

Healy

1986

Helgolander Meeresunters

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Euspermatozoa and paraspermatozoa of Campanile symbolicum Iredale, 1917 -a large, relict cerithiacean from Western Australia -have been examined using transmission electron microscopy and phase-contrast light microscopy. The euspermatozoa resemble those of many other mesogastropods with the important exception that the midpiece region exhibits unusual and possibly unique features. These include possession of seven or eight straight, periaxonemal elements (each containing scattered cristae) and a closely associated sheath composed of electrondense segments which are semicylindrical in shape and longitudinally aligned. This sheath -here termed the 'accessory midpiece sheath'-surrounds only one half of the periaxonemal midpiece elements and lies outside the mitochondrial membrane (but nevertheless within the plasma membrane). Two types of paraspermatozoa occur in Campanile:(1) those with a nuclear core within the mosaic sheath of the head (nucleate paraspermatozoa) and (2} those lacking a nuclear core (dense blocks of mosaic sheath surrounding one to three axonemes -anucleate paraspermatozoa). An acrosome-like structure forms the apex of the head in both types of paraspermatozoa, while beyond the head region, electron-dense glycogen deposits are associated with each of the multiple tails. While the form of Campanile paraspermatozoa suggests links with families such as the Cerithiidae, Potamididae and Turritellidae, the highly unusual morphology of the euspermatozoan midpiece indicates that the Campanilidae should occupy an isolated position within the superfamily Cerithiacea.

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Ultrastructural investigations on the morphology and genesis of sperms in Archaeogastropoda

Cited by 26 publications

References 6 publications

Ultrastructure of euspermatozoa and paraspermatozoa in the volutid snail Adelomelon ancilla (Mollusca: Caenogastropoda)

Ultrastructure of euspermatozoa and paraspermatozoa in the volutid snail Adelomelon ancilla (Mollusca: Caenogastropoda)

Ultrastructure of spermiogenesis inVampyroteuthis infernalis Chun — a relict cephalopod mollusc

Euspermatozoa and paraspermatozoa of the relict cerithiacean gastropod,Campanile symbolicum (prosobranchia, mesogastropoda)

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