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 I–III. (A) Longitudinal section of anterior spermatozoon extremity (Ase) with a sharp tip. Sdm, submembranous electron-dense material; Ax1 first axoneme. (B) Cross-section showing the anterior extremity of the first axoneme (Aae1) and the submembranous electron-dense material describing a complete ring. (C) Cross-section in region I exhibiting the first axoneme and the anterior extremity of the second axoneme (Aae2). Note also the submembranous electron-dense material surrounding both axonemes. (D) Detail of submembranous electron-dense material of A. sigani. Pm, plasma membrane; Sdm, submembranous electron-dense material. (E) Cross-section in posterior part of region I with the axonemes and the submembranous electron-dense material located laterally. (F, G) Consecutive cross-sections in region II characterized by the presence of external ornamentation of the plasma membrane (Eo), the first mitochondrion (M1) and spine-like body (Sb). Note the cortical microtubules (Cm) associated with the external ornamentation and the residual submembranous electron-dense material not associated with cortical microtubules. (H) Detail showing the simultaneous presence of external ornamentation, spine-like body and submembranous electron-dense material. (I) Cross-section in the transitional area prior to the nuclear region, showing the axonemes and cortical microtubules distributed into two fields and their maximum number varies between 14 and 17. Scale in μm: (A, B, C, E, F, G, I), 0.3; (D), 0.2; (H), 0.1.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: A–I. Mature spermatozoon of Atractotrema sigani in regions I–III. (A) Longitudinal section of anterior spermatozoon extremity (Ase) with a sharp tip. Sdm, submembranous electron-dense material; Ax1 first axoneme. (B) Cross-section showing the anterior extremity of the first axoneme (Aae1) and the submembranous electron-dense material describing a complete ring. (C) Cross-section in region I exhibiting the first axoneme and the anterior extremity of the second axoneme (Aae2). Note also the submembranous electron-dense material surrounding both axonemes. (D) Detail of submembranous electron-dense material of A. sigani. Pm, plasma membrane; Sdm, submembranous electron-dense material. (E) Cross-section in posterior part of region I with the axonemes and the submembranous electron-dense material located laterally. (F, G) Consecutive cross-sections in region II characterized by the presence of external ornamentation of the plasma membrane (Eo), the first mitochondrion (M1) and spine-like body (Sb). Note the cortical microtubules (Cm) associated with the external ornamentation and the residual submembranous electron-dense material not associated with cortical microtubules. (H) Detail showing the simultaneous presence of external ornamentation, spine-like body and submembranous electron-dense material. (I) Cross-section in the transitional area prior to the nuclear region, showing the axonemes and cortical microtubules distributed into two fields and their maximum number varies between 14 and 17. Scale in μm: (A, B, C, E, F, G, I), 0.3; (D), 0.2; (H), 0.1.

Mentions: Region I (Figs. 1A–E and 4I) constitutes the anterior part of the spermatozoon showing in longitudinal section a sharp tip (Fig. 1A). In cross-section, the anterior spermatozoon extremity is characterized by the presence of the anterior extremity of the first axoneme and the submembranous electron-dense material which forms a complete ring (Figs. 1A and 4I). Consecutive cross-sections towards the posterior part of region I show the anterior extremity of the second axoneme accompanied by the first axoneme and the submembranous electron-dense material. This latter is reduced and located laterally when both axonemes are completely formed (Figs. 1C–E and 4I).


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 I–III. (A) Longitudinal section of anterior spermatozoon extremity (Ase) with a sharp tip. Sdm, submembranous electron-dense material; Ax1 first axoneme. (B) Cross-section showing the anterior extremity of the first axoneme (Aae1) and the submembranous electron-dense material describing a complete ring. (C) Cross-section in region I exhibiting the first axoneme and the anterior extremity of the second axoneme (Aae2). Note also the submembranous electron-dense material surrounding both axonemes. (D) Detail of submembranous electron-dense material of A. sigani. Pm, plasma membrane; Sdm, submembranous electron-dense material. (E) Cross-section in posterior part of region I with the axonemes and the submembranous electron-dense material located laterally. (F, G) Consecutive cross-sections in region II characterized by the presence of external ornamentation of the plasma membrane (Eo), the first mitochondrion (M1) and spine-like body (Sb). Note the cortical microtubules (Cm) associated with the external ornamentation and the residual submembranous electron-dense material not associated with cortical microtubules. (H) Detail showing the simultaneous presence of external ornamentation, spine-like body and submembranous electron-dense material. (I) Cross-section in the transitional area prior to the nuclear region, showing the axonemes and cortical microtubules distributed into two fields and their maximum number varies between 14 and 17. Scale in μm: (A, B, C, E, F, G, I), 0.3; (D), 0.2; (H), 0.1.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: A–I. Mature spermatozoon of Atractotrema sigani in regions I–III. (A) Longitudinal section of anterior spermatozoon extremity (Ase) with a sharp tip. Sdm, submembranous electron-dense material; Ax1 first axoneme. (B) Cross-section showing the anterior extremity of the first axoneme (Aae1) and the submembranous electron-dense material describing a complete ring. (C) Cross-section in region I exhibiting the first axoneme and the anterior extremity of the second axoneme (Aae2). Note also the submembranous electron-dense material surrounding both axonemes. (D) Detail of submembranous electron-dense material of A. sigani. Pm, plasma membrane; Sdm, submembranous electron-dense material. (E) Cross-section in posterior part of region I with the axonemes and the submembranous electron-dense material located laterally. (F, G) Consecutive cross-sections in region II characterized by the presence of external ornamentation of the plasma membrane (Eo), the first mitochondrion (M1) and spine-like body (Sb). Note the cortical microtubules (Cm) associated with the external ornamentation and the residual submembranous electron-dense material not associated with cortical microtubules. (H) Detail showing the simultaneous presence of external ornamentation, spine-like body and submembranous electron-dense material. (I) Cross-section in the transitional area prior to the nuclear region, showing the axonemes and cortical microtubules distributed into two fields and their maximum number varies between 14 and 17. Scale in μm: (A, B, C, E, F, G, I), 0.3; (D), 0.2; (H), 0.1.
Mentions: Region I (Figs. 1A–E and 4I) constitutes the anterior part of the spermatozoon showing in longitudinal section a sharp tip (Fig. 1A). In cross-section, the anterior spermatozoon extremity is characterized by the presence of the anterior extremity of the first axoneme and the submembranous electron-dense material which forms a complete ring (Figs. 1A and 4I). Consecutive cross-sections towards the posterior part of region I show the anterior extremity of the second axoneme accompanied by the first axoneme and the submembranous electron-dense material. This latter is reduced and located laterally when both axonemes are completely formed (Figs. 1C–E and 4I).

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.