Ultrastruktur und Bildungsweise penialer Hartstrukturen bei freilebenden Plathelminthen

Brüggemann, Jochen

doi:10.1007/bf00312155

Cited by 34 publications

(15 citation statements)

References 43 publications

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“…3 Haplopharynx: cranial protrusible proboscis; specialized male organ (see Doe 1986). 4 Macrostomida: female pore in front of male pore; special differentiation of penial structures (see Brüggemann 1985;Doe 1986); spermatozoon with two sets of cortical microtubules. 5 Microstomidae: gut with preoral blind sac; cranial ciliated sensory pits.…”

Section: Figmentioning

confidence: 99%

Ultrastructure of spermiogenesis and spermatozoa in Bradynectes sterreri and remarks on sperm cells in Haplopharynx rostratus and Paromalostomum fusculum: phylogenetic implications for the Macrostomorpha (Plathelminthes)

Sopott‐Ehlers¹,

Ehlers²

1999

Zoomorphology

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The fine structure of spermiogenesis and spermatozoa in three species of the Macrostomorpha was studied, with emphasis on Bradynectes sterreri. Two centrioles appear during the development of sperm cells, at least in B. sterreri and Paromalostomum fusculum. Initially these organelles have a perpendicular position, but later they come to lie in line with each other. In P. fusculum, the differentiation of rootlet structures inserting on both centrioles was found. However, ciliary axonemes do not grow out, either in B. sterreri or in P. fusculum. These two species, and also Haplopharynx rostratus, have aciliated spermatozoa. The mature male gametes of B. sterreri are characterized by a filiform nucleus, numerous mitochondria, dense bodies irregular in shape, membranous lacunae, a pair of electron-dense lateral ledges and two sets of cortical microtubules in addition to a closed ring of microtubules in the posterior segment of the cell. Both lateral ledges do not originate from the centrioles. 'Lateral ledges' or 'lateral bristles' were not observed in spermatozoa of H. rostratus and P. fusculum. Such structures cannot be considered autapomorphic for the Macrostomorpha. The known spermatological characteristics contribute to elucidating the interrelationships of the Macrostomorpha. Haplopharynx and Macrostomida are sister groups. Spermatozoa with cortical microtubules separated into two sets are hypothesized as an autapomorphy of the Macrostomida. The two lateral ledges found in spermatozoa of B. sterreri are discussed to correspond to the pair of 'lateral bristles' known from Macrostomum species, indicating a sister-group relationship of these two taxa. Apparently, the aciliated spermatozoa of Macrostomorpha species originated from biciliated male gametes. Hence, biciliated spermatozoa are not an evolutionary novelty of the Trepaxonemata, but of the Rhabditophora.& b d y :

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Section: Figmentioning

confidence: 99%

Ultrastructure of spermiogenesis and spermatozoa in Bradynectes sterreri and remarks on sperm cells in Haplopharynx rostratus and Paromalostomum fusculum: phylogenetic implications for the Macrostomorpha (Plathelminthes)

Sopott‐Ehlers¹,

Ehlers²

1999

Zoomorphology

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“…The intracellular (or intrasyncytial) formation of the stylet in P. busheki is like that of copulatory hard structures in most flatworms studied by TEM to date, including the stylets and accessory spines in Macrostomorpha (Doe , ,b; Brüggemann , ), stylets in Proseriata (Lanfranchi ; Ehlers & Ehlers ; Brüggemann ), cirri in Proseriata (Martens & Schockaert ; Martens ; Jouk et al. ; see also below), stylets in Kalyptorhynchia (Brüggemann ), and stylets in Dalytyphloplanoida (Brüggemann , , , ). Although there are variations in the details of intracellular stylet formation, the primitive condition in Rhabditophora is the production of penial hard structures inside syncytia (or cells) derived from the epithelium lining the ejaculatory duct (Fig.…”

mentioning

confidence: 86%

“…Although there are variations in the details of intracellular stylet formation, the primitive condition in Rhabditophora is the production of penial hard structures inside syncytia (or cells) derived from the epithelium lining the ejaculatory duct (Fig. E,F; Brüggemann ). Presently, the sole exception to this is found in the proseriate family Monocelididae ( sensu Curini‐Galletti et al.…”

mentioning

confidence: 99%

“…What is not clear is how the shape of the stylet is generated during its development. Brüggemann () describes internal “Füllzellen” and external “Hüllzellen” associated with the stylet during stylet formation. It is interesting that the Hüllzellen are elongated cells with axially arranged microtubules in V. pellucida , where the greatly elongated stylet is formed tip‐to‐base (Brüggemann ;—successive formation mode), suggesting that the Hüllzellen associated with the outer side of the stylet‐forming cell may be at least partly responsible for directing morphogenesis of the stylet.…”

mentioning

confidence: 99%

“…It is interesting that the Hüllzellen are elongated cells with axially arranged microtubules in V. pellucida , where the greatly elongated stylet is formed tip‐to‐base (Brüggemann ;—successive formation mode), suggesting that the Hüllzellen associated with the outer side of the stylet‐forming cell may be at least partly responsible for directing morphogenesis of the stylet. A particularly rich area for investigation of this process would be the genus Macrostomum , in which the stylet is relatively simple and is also formed in successive mode (Brüggemann ). Furthermore, in this genus there is a model organism ( M. lignano; Ladurner et al.…”

mentioning

confidence: 99%

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Structure of the male copulatory apparatus in Prognathorhynchus busheki (Platyhelminthes, Kalyptorhynchia)

Doe

Smith

2016

Invertebrate Biology

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Gnathorhynchidae is a diverse taxon of predatory eukalyptorhynch flatworms characterized by an armed proboscis. Their present taxonomy is not concordant with what we know of their phylogeny. Further progress in this area is hindered by a lack of information concerning their morphology. As recent studies have shown, a historical reliance on live observations for species descriptions has resulted in a number of errors and omissions. Here, we redescribe the anatomy of the male copulatory organ of Prognathorhynchus busheki using transmission-electron and confocal microscopy, correcting several errors in the original description. Furthermore, we use these results to update our understanding of the anatomy and evolution of male copulatory organs in Gnathorhynchidae and in Platyhelminthes more generally.

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Ultrastructural investigations on the differentiation of genital hard structures in free-living platyhelminths and their phylogenetic significance

Brüggemann

1986

Advances in the Biology of Turbellarians and Related Platyhelminthes

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Ultrastruktur und Bildungsweise penialer Hartstrukturen bei freilebenden Plathelminthen

Cited by 34 publications

References 43 publications

Ultrastructure of spermiogenesis and spermatozoa in Bradynectes sterreri and remarks on sperm cells in Haplopharynx rostratus and Paromalostomum fusculum: phylogenetic implications for the Macrostomorpha (Plathelminthes)

Ultrastructure of spermiogenesis and spermatozoa in Bradynectes sterreri and remarks on sperm cells in Haplopharynx rostratus and Paromalostomum fusculum: phylogenetic implications for the Macrostomorpha (Plathelminthes)

Structure of the male copulatory apparatus in Prognathorhynchus busheki (Platyhelminthes, Kalyptorhynchia)

Ultrastructural investigations on the differentiation of genital hard structures in free-living platyhelminths and their phylogenetic significance

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