Limits...
First spermatological study in the Atractotrematidae (Digenea, Haploporoidea): the case of Atractotrema sigani, intestinal parasite of Siganus lineatus.

Bakhoum AJ, Quilichini Y, Justine JL, Bray RA, Miquel J, Feliu C, Bâ CT, Marchand B - Parasite (2015)

Bottom Line: However, the mature spermatozoon of A. sigani has some specific characters such as the morphology of its anterior region and the submembranous electron-dense material.Although similar structures have been reported in some digenean species, the presence of a submembranous electron-dense material describing a complete ring is reported here for the first time in the mature spermatozoon of A. sigani.In addition, sperm characteristics are compared between the Haploporoidea and their supposed close superfamilies, and possible phylogenetic implications of these findings for the Digenea are discussed.

View Article: PubMed Central - PubMed

Affiliation: CNRS-Università di Corsica, UMR 6134-SPE, SERME Service d'Étude et de Recherche en Microscopie Électronique, Corte 20250, Corsica, France - Laboratory of Evolutionary Biology, Ecology and Management of Ecosystems, Cheikh Anta Diop University of Dakar, BP 5055, Dakar, Senegal.

No MeSH data available.


A–I. Mature spermatozoon of Atractotrema sigani in regions IV–V. (A) Cross-section in proximal part of region IV exhibiting the second mitochondrion (M2). Cm, cortical microtubules. Note the decrease in the maximum number of cortical microtubules (about 9) compared to region III. (B–D) Consecutive cross-sections showing the simultaneous presence of the second mitochondrion and the nucleus (N) which increases progressively in size. (E) Disorganization of the first axoneme resulting into doublets of microtubules. D, doublet of microtubules. (F) Distal part of region IV with only the second axoneme, the second mitochondrion and few cortical microtubules (about 4). (G, H) Cross-section showing only the second axoneme, the nucleus and its progressive reduction in size. (I) Cross-section of the posterior spermatozoon tip, where the nucleus disappears and only one axoneme is still observed. Scale in μm: (A–I), 0.3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4609001&req=5

Figure 2: A–I. Mature spermatozoon of Atractotrema sigani in regions IV–V. (A) Cross-section in proximal part of region IV exhibiting the second mitochondrion (M2). Cm, cortical microtubules. Note the decrease in the maximum number of cortical microtubules (about 9) compared to region III. (B–D) Consecutive cross-sections showing the simultaneous presence of the second mitochondrion and the nucleus (N) which increases progressively in size. (E) Disorganization of the first axoneme resulting into doublets of microtubules. D, doublet of microtubules. (F) Distal part of region IV with only the second axoneme, the second mitochondrion and few cortical microtubules (about 4). (G, H) Cross-section showing only the second axoneme, the nucleus and its progressive reduction in size. (I) Cross-section of the posterior spermatozoon tip, where the nucleus disappears and only one axoneme is still observed. Scale in μm: (A–I), 0.3.

Mentions: Region IV (Figs. 2A–F and 4IV) is mainly distinguished by the appearance of the second mitochondrion in its anterior part and the nucleus in its middle and posterior part. The anterior part contains only the second mitochondrion, both axonemes and cortical microtubules of which the maximum number (about 9) (Fig. 2A) is lower than in region III. When the nucleus appears in the middle part of this region IV, the axonemes, the second mitochondrial and the two fields of cortical microtubules are still present. However, the maximum number of cortical microtubules progressively diminishes from 9 (Fig. 2B), 8 (Fig. 2C) to 7 (Fig. 2D). Cross-sections in the posterior part of region IV exhibit the posterior extremity of the first axoneme with disorganized doublets of microtubules (Fig. 2E). Consequently, only one axoneme accompanied by the second mitochondrion, nucleus and few cortical microtubules (about 5) are observed (Figs. 2F and 4IV).


First spermatological study in the Atractotrematidae (Digenea, Haploporoidea): the case of Atractotrema sigani, intestinal parasite of Siganus lineatus.

Bakhoum AJ, Quilichini Y, Justine JL, Bray RA, Miquel J, Feliu C, Bâ CT, Marchand B - Parasite (2015)

A–I. Mature spermatozoon of Atractotrema sigani in regions IV–V. (A) Cross-section in proximal part of region IV exhibiting the second mitochondrion (M2). Cm, cortical microtubules. Note the decrease in the maximum number of cortical microtubules (about 9) compared to region III. (B–D) Consecutive cross-sections showing the simultaneous presence of the second mitochondrion and the nucleus (N) which increases progressively in size. (E) Disorganization of the first axoneme resulting into doublets of microtubules. D, doublet of microtubules. (F) Distal part of region IV with only the second axoneme, the second mitochondrion and few cortical microtubules (about 4). (G, H) Cross-section showing only the second axoneme, the nucleus and its progressive reduction in size. (I) Cross-section of the posterior spermatozoon tip, where the nucleus disappears and only one axoneme is still observed. Scale in μm: (A–I), 0.3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4609001&req=5

Figure 2: A–I. Mature spermatozoon of Atractotrema sigani in regions IV–V. (A) Cross-section in proximal part of region IV exhibiting the second mitochondrion (M2). Cm, cortical microtubules. Note the decrease in the maximum number of cortical microtubules (about 9) compared to region III. (B–D) Consecutive cross-sections showing the simultaneous presence of the second mitochondrion and the nucleus (N) which increases progressively in size. (E) Disorganization of the first axoneme resulting into doublets of microtubules. D, doublet of microtubules. (F) Distal part of region IV with only the second axoneme, the second mitochondrion and few cortical microtubules (about 4). (G, H) Cross-section showing only the second axoneme, the nucleus and its progressive reduction in size. (I) Cross-section of the posterior spermatozoon tip, where the nucleus disappears and only one axoneme is still observed. Scale in μm: (A–I), 0.3.
Mentions: Region IV (Figs. 2A–F and 4IV) is mainly distinguished by the appearance of the second mitochondrion in its anterior part and the nucleus in its middle and posterior part. The anterior part contains only the second mitochondrion, both axonemes and cortical microtubules of which the maximum number (about 9) (Fig. 2A) is lower than in region III. When the nucleus appears in the middle part of this region IV, the axonemes, the second mitochondrial and the two fields of cortical microtubules are still present. However, the maximum number of cortical microtubules progressively diminishes from 9 (Fig. 2B), 8 (Fig. 2C) to 7 (Fig. 2D). Cross-sections in the posterior part of region IV exhibit the posterior extremity of the first axoneme with disorganized doublets of microtubules (Fig. 2E). Consequently, only one axoneme accompanied by the second mitochondrion, nucleus and few cortical microtubules (about 5) are observed (Figs. 2F and 4IV).

Bottom Line: However, the mature spermatozoon of A. sigani has some specific characters such as the morphology of its anterior region and the submembranous electron-dense material.Although similar structures have been reported in some digenean species, the presence of a submembranous electron-dense material describing a complete ring is reported here for the first time in the mature spermatozoon of A. sigani.In addition, sperm characteristics are compared between the Haploporoidea and their supposed close superfamilies, and possible phylogenetic implications of these findings for the Digenea are discussed.

View Article: PubMed Central - PubMed

Affiliation: CNRS-Università di Corsica, UMR 6134-SPE, SERME Service d'Étude et de Recherche en Microscopie Électronique, Corte 20250, Corsica, France - Laboratory of Evolutionary Biology, Ecology and Management of Ecosystems, Cheikh Anta Diop University of Dakar, BP 5055, Dakar, Senegal.

No MeSH data available.