New data on spermatogenic cyst formation and cellular composition of the testis in a marine gastropod, Littorina saxatilis

• Published in: International journal of molecular sciences Vol. 21; no. 11; p. 3792
• Main Authors: Demin, Sergei Iu, Bogolyubov, Dmitry S, Granovitch, Andrey I, Mikhailova, Natalia A
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 27-05-2020; MDPI AG
• Subjects: Animals; cyst cells; Gastropoda - cytology; Littorina saxatilis; Male; marine snails; spermatocysts; spermatogenesis; Spermatogonia - ultrastructure; testes; Testis - cytology; spermatogenesis; spermatocysts; cyst cells; Littorina saxatilis; marine snails; testes
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21113792

Knowledge of the testis structure is important for gastropod taxonomy and phylogeny, particularly for the comparative analysis of sympatric
species. Observing fresh tissue and squashing fixed tissue with gradually increasing pressure, we have recently described a peculiar type of cystic spermatogenesis, rare in mollusks. It has not been documented in most mollusks until now. The testis of adult males consists of numerous lobules filled with multicellular cysts containing germline cells at different stages of differentiation. Each cyst is formed by one cyst cell of somatic origin. Here, we provide evidence for the existence of two ways of cyst formation in
. One of them begins with a goniablast cyst formation; it somewhat resembles cyst formation in
testes. The second way begins with capture of a free spermatogonium by the polyploid cyst cell which is capable to move along the gonad tissues. This way of cyst formation has not been described previously. Our data expand the understanding of the diversity of spermatogenesis types in invertebrates.