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Background & objectives: The detailed assessment of sperm morphology is important in the semen of infertile men because there is a low proportion of normal spermatozoa. One of the parameters of such sperm morphology is the acrosome, and its effect on assisted reproductive outcomes is controversial. This study was undertaken to evaluate the association between different forms of acrosome on the chromatin status and the assisted reproductive outcomes. Methods: A total of 1587 unstained sperms from 514 infertile men were captured and analyzed for different acrosome forms (normal, large, small, skew, amorphous acrosome and without acrosome) in real time during intracytoplasmic sperm injection into oocytes. The association between the percentage of sperms with atypical acrosome and head shapes and the sperm chromatin status was studied. Fertilization, zygote and embryo quality and clinical pregnancy rates were calculated for different groups of sperms. Results: The highest frequency of irregular shapes of acrosomes, such as small, large and amorphous, was observed in abnormal ellipticity, anteroposterior symmetry and angularity parameters, respectively (P <0.05). The fertilization rate of injected sperms with large (P <0.01) and small (P=0.001) acrosomes and without acrosome (P=0.001) was significantly lower in comparison with normal acrosomes. The quality of zygotes (Z3, P=0.05), embryos (grade C, P <0.05) and the pregnancy rate (P=0.001) from injected sperms with large acrosomes were significantly lower compared with normal acrosomes. Interpretation & conclusions: Our findings showed that the different sperm acrosome morphologies (e.g., large, small, and without acrosome) might negatively relate with chromatin integrity and decrease the sperm's fertility potential and pregnancy rate during intracytoplasmic sperm injection (ICSI) cycles.
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Objective@#To explore the expression and regulatory function of sperm-associated antigen 6 (SPAG6) in the formation of the sperm acrosome in mice.@*METHODS@#The expression of SPAG6 during the first wave of spermatogenesis on postnatal days (PN) 8, 12, 16, 20, 24, 28, 30 and 35 was examined by Western blot and the localization of SPAG6 in the testicular germ cells was determined by immunofluorescence. The expression plasmids of SPAG6 and serine protease inhibitor Kazal-type 2 (SPINK2) were constructed, the interaction between SPAG6 and SPINK2 in the AH109 and CHO cells examined by yeast two-hybrid and co-localization assays, and the expression and localization of SPINK2 in the testicular germ cells of the SPAG6-knockout (SPAG6 KO) mice detected by immunofluorescence.@*RESULTS@#SPAG6 was highly expressed between PN 16 and 28 and localized in the acrosome of the round spermatids. Yeast two-hybrid assay showed the growth of SPAG6 and SPINK2 in the selective culture medium SD/-Leu/-Trp/-His, and the transfection of the CHO cells revealed the co-localization of SPAG6 and SPINK2 around the nuclei. The expression and acrosomal localization of SPINK2 were not found in the testicular germ cells of the SPAG6-KO mice.@*CONCLUSIONS@#SPAG6 interacts with SPINK2 and probably participates in the formation of the sperm acrosome by stabilizing the expression of SPINK2 during spermatogenesis.
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Vasectomy has been increased as a popular method of birth control because it is simpler than other methods for men. But the vasectomy results in several problems such as relation to effect changes on the structure and function of the reproductive organ. The fate of non-ejaculated spermatozoa is postulated by some authors that those are disappeared by a progress of dissolution and reabsorption in the epididymis, and we have attempted to prove the true state of sperm-acrosome on the fine structure in vasectomized rats. The results were as follows: 1. Apical segments of the acrosome were swollen similar to the shape of club in many spermatozoa. 2. Discontinuities of the outer and inner acrosomal membranes were occasionally noted and there were complete losses of acrosomes in the certain places. 3. There was no evidence of significant changes in the nuclear structure, nor dilatation of the subacrosomal space. 4. Vasectomy might effect destructive changes in the acrosomes of the non-ejaculated spermatozoa in situ.