Human sperm head vacuoles are physiological structures formed during the sperm development and maturation process

2012 ◽  
Vol 98 (2) ◽  
pp. 315-320 ◽  
Author(s):  
Atsushi Tanaka ◽  
Motoi Nagayoshi ◽  
Izumi Tanaka ◽  
Hiroshi Kusunoki
2020 ◽  
Vol 22 (4) ◽  
pp. 401
Author(s):  
MaríaPaz Herráez ◽  
Silvia González-Rojo ◽  
Cristina Fernández-Díez ◽  
Marta Lombó

2021 ◽  
pp. 177-191
Author(s):  
Natalia V. Revollo ◽  
G. Noelia Revollo Sarmiento ◽  
Claudio Delrieux ◽  
Marcela Herrera ◽  
Rolando González-José

1998 ◽  
Vol 70 (5) ◽  
pp. 883-891 ◽  
Author(s):  
Nabil Aziz ◽  
Simon Fear ◽  
Clare Taylor ◽  
Charles R Kingsland ◽  
D.Iwan Lewis-Jones

2017 ◽  
Vol 84 ◽  
pp. 205-216 ◽  
Author(s):  
Violeta Chang ◽  
Laurent Heutte ◽  
Caroline Petitjean ◽  
Steffen Härtel ◽  
Nancy Hitschfeld

Author(s):  
Tongguang Ni ◽  
Yan Ding ◽  
Jing Xue ◽  
Kaijian Xia ◽  
Xiaoqing Gu ◽  
...  

Morphological classification of human sperm heads is a key technology for diagnosing male infertility. Due to its sparse representation and learning capability, dictionary learning has shown remarkable performance in human sperm head classification. To promote the discriminability of the classification model, a novel local constraint and label embedding multi-layer dictionary learning model called LCLM-MDL is proposed in this study. Based on the multi-layer dictionary learning framework, two dictionaries are built on the basis of Laplacian regularized constraint and label embedding term in each layer, and the two dictionaries are approximated to each other as much as possible, so as to well exploit the nonlinear structure and discriminability features of the morphology of human sperm heads. In addition, to promote the robustness of the model, the asymmetric Huber loss is adopted in the last layer of LCLM-MDL, which approximates the misclassification error by using the absolute error function. Finally, the experimental results on HuSHeM dataset demonstrate the validity of the LCLM-MDL.


Author(s):  
Marvin Ferrer

CRES is an inhibitor of a specific member of an enzyme family called serine proteases.  It is thus thought to play a role in enzymatic regulation.  It has been shown to be expressed only in the testes, epididymis, sperm, and gonadotropic cells of the anterior pituitary gland.  Localization of CRES in sperm is an important step in determining its role within sperm.  Previous studies have shown CRES to be localized in the mouse acrosomal cap: a vesicle on the tip of the sperm head which releases its contents upon initial sperm‐egg contact.  The present study shows that developmental analysis of spermatogenesis via immunohistochemistry is incompatible with the conclusion that CRES is localized in the acrosomal cap.   CRES expression begins in the elongating spermatid stage of sperm development; by this point, the acrosomal cap has been completed and it has never been shown that further additions to it can occur.   Western blot and immunogold electron microscopy shows that CRES is localized in the sperm tail.  It is also  possible that further CRES is placed on the outer sperm membranes on the head as it travels through the epididymis, which is a part of the male reproductive tract.


Andrologia ◽  
2009 ◽  
Vol 25 (2) ◽  
pp. 67-70 ◽  
Author(s):  
M. C. Ou ◽  
H. T. Ng ◽  
B. N. Chiang ◽  
C. Y. Hong ◽  
C. T. Hsu

1995 ◽  
Vol 43 (4) ◽  
pp. 439-445 ◽  
Author(s):  
M Kalina ◽  
R Socher ◽  
R Rotem ◽  
Z Naor

We localized protein kinase C (PKC) in human sperm cells at the ultrastructural level by the immunogold technique. The sperm head PKC was localized in the acrosome, equatorial segment, and post-acrosomal region. In the flagellum, PKC was associated with the segmented column of the neck and was distributed along the mid, principal, and end pieces. Immunoreactive sites were observed in patches along the axoneme and outer dense fibers and were evenly distributed between these regions. Pre-absorption of the antibody used with rat brain PKC (alpha and beta) eliminated gold labeling of the sperm head but only reduced labeling of the sperm tail. The co-localization of PKC with various cytoskeletal and other structural elements suggests that the proteins involved are potential substrates for sperm PKC subspecies. The localization of PKC in distinct structures of the human sperm (head, neck, and tail) strongly suggests a role for this enzyme in various aspects of sperm physiology.


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