New data on spermiogenesis and trepaxonematan axoneme in basal tapeworms (Cestoda, Caryophyllidea, Lytocestidae) parasitizing cyprinid fishes

0520177 - BC 2020 RIV GB eng J - Journal Article
Matoušková, M. - Bílý, Tomáš - Bruňanská, M. - Oros, M. - Kostič, B. - Nebesářová, Jana
New data on spermiogenesis and trepaxonematan axoneme in basal tapeworms (Cestoda, Caryophyllidea, Lytocestidae) parasitizing cyprinid fishes.
Scientific Reports. Roč. 9, SEP 9 2019 (2019), č. článku 12881. ISSN 2045-2322. E-ISSN 2045-2322
R&D Projects: GA MŠMT(CZ) LM2015062
Grant - others:AV ČR(CZ) SAV-18-21
Program: Bilaterální spolupráce
Institutional support: RVO:60077344
Keywords : glaridacris-catostomi cooper * wenyonia-virilis woodland * spermatological characters * spermatozoon ultrastructure * sperm ultrastructure * 1st data * platyhelminthes * pallas * spermatogenesis * tomography
OECD category: Genetics and heredity (medical genetics to be 3)
Impact factor: 3.998, year: 2019
Method of publishing: Open access
https://www.nature.com/articles/s41598-019-49312-9.pdf

Monozoic caryophyllidean cestodes, intestinal parasites of cyprinid fishes, represent a group of tapeworms with an unclear evolutionary history. As spermatology may provide phylogenetically important data, the spermiogenesis and ultrastructure of the mature spermatozoon have been investigated using an integrative approach combining transmission electron microscopy, cytochemistry and electron tomography in Khawia rossittensis (Szidat, 1937). The process of spermatid formation is accompanied by the presence of ultrastructural characters not described in traditional models of spermiogenesis, e.g., apical electron-dense material, the two striated roots situated unusually opposite each other, branching of typical striated roots, an intercentriolar body comprising five electron-dense and four electron-lucent layers, rotation of both free flagella and flagellar buds to the median cytoplasmic process at 90 degrees, and a complete proximodistal fusion. The synchronous rotation of both flagellar buds and growing free flagella is an evolutionarily linked pattern favouring the hypothesis that the Caryophyllidea are not ancestral but are secondarily derived from polyzoic forms. Electron tomography analysis has revealed a unique feature of two helicoidal tubular structures in the central electron-dense core of the axoneme of mature spermatozoon. These data provide new insights into the architecture of the 9 + '1' axoneme, which is shared by male gametes of all trepaxonematan Platyhelminthes.
Permanent Link: http://hdl.handle.net/11104/0304866