This article presents an update on the variable prognostic significance of different sperm pathologies in patients with severe male factor infertility due to morphology and motility disorders. Severe asthenozoospermia...This article presents an update on the variable prognostic significance of different sperm pathologies in patients with severe male factor infertility due to morphology and motility disorders. Severe asthenozoospermia is one of the leading causes of male infertility as spermatozoa cannot reach the oocyte and/or penetrate normally. Identifying structural causes of sperm immotility was of great concern before the advent of intracytoplasmic sperm injection （ICSI）, because immotility was the limiting factor in the treatment of these patients. In these cases, in vitro methods are used to identify live spermatozoa or stimulate sperm motility to avoid selection of non-viable cells. With these advances, fertilization and pregnancy results have improved dramatically. The identification of genetic phenotypes in asthenozoospermia is important to adequately inform patients of treatment outcomes and risks. The one sperm characteristic that seriously affects fertility prognosis is teratozoospermia, primarily sperm head and neck anomalies. Defects of chromatin condensation and acrosomal hypoplasia are the two most common abnormalities in severe teratozoospermia. The introduction of microscopic methods to select spermatozoa and the development of new ones to evaluate sperm quality before ICSI will assure that ultrastructural identification ofsperm pathologies will not only be of academic interest, but will also be an essential tool to inform treatment choice. Herein, we review the differential roles played by sperm components in normal fertilization and early embryo development and explore how assisted reproductive technologies have modified our concepts on the prognostic significance of sperm pathologies affecting the head, neck, mid-piece and tail.展开更多
During spermiogenesis,haploid spermatids undergo dramatic morphological changes to form slender sperm flagella and cap-like acrosomes,which are required for successful fertilization.Severe deformities in flagella caus...During spermiogenesis,haploid spermatids undergo dramatic morphological changes to form slender sperm flagella and cap-like acrosomes,which are required for successful fertilization.Severe deformities in flagella cause a male infertility syndrome,multiple morphological abnormalities of the flagella(MMAF),while acrosomal hypoplasia in some cases leads to sub-optimal embryonic developmental potential.However,evidence regarding the occurrence of acrosomal hypoplasia in MMAF is limited.Here,we report the generation of base-edited mice knocked out for coiled-coil domain-containing 38(Ccdc38)via inducing a nonsense mutation and find that the males are infertile.The Ccdc38-KO sperm display acrosomal hypoplasia and typical MMAF phenotypes.We find that the acrosomal membrane is loosely anchored to the nucleus and fibrous sheaths are disorganized in Ccdc38-KO sperm.Further analyses reveal that Ccdc38 knockout causes a decreased level of TEKT3,a protein associated with acrosome biogenesis,in testes and an aberrant distribution of TEKT3 in sperm.We finally show that intracytoplasmic sperm injection overcomes Ccdc38-related infertility.Our study thus reveals a previously unknown role for CCDC38 in acrosome biogenesis and provides additional evidence for the occurrence of acrosomal hypoplasia in MMAF.展开更多
Morphology of the spermatozoon of Octopus ocellatus was studied by light, scanning electron, and transmission electron microscopes. Sperm are 600-700 um long, with a large number of granules in diameter about 130 um. ...Morphology of the spermatozoon of Octopus ocellatus was studied by light, scanning electron, and transmission electron microscopes. Sperm are 600-700 um long, with a large number of granules in diameter about 130 um. Each spermatozoon is composed of a head, neck, and tail. The head is made up of an acrosomal complex anterior to the nucleus. The spiral acrosomal complex consists of an electron-lucent vesicle, lacuna, and an electron-dense acrosomal vesicle. Additionally, the spiral acrosomal vesicle has numerous equidistant striations, and is surrounded by many small granules （20 nm diameter）. A long straight nucleus, which is electron-densed, has a deep posterior concavity, the nuclear vacuole. At the terminal end of the nucleus is a sleeve-like structure with a concave posterior nuclear fossa （PNF）. The neck is short connecting the PNF. The basal body is located in the PNF and gives rise to the axoneme. This structure connects the head, neck, and tail. The tail is divided into a middle piece and a principal piece. The middle piece, having a 9＋9＋2 arrangement, is surrounded by a mitochondrial sheath and terminates by an electron-dense fibrous sheath. The principal piece is the longest part of the sperm with coarse fibers tapering posteriorly. The results of this study shall provide some useful information for artificial breeding of this species.展开更多
To in teract with the egg, the spermatozo on must un dergo several biochemical and motility modifications in the female reproductive tract, collectively called capacitation. Only capacitated sperm can undergo acrosoma...To in teract with the egg, the spermatozo on must un dergo several biochemical and motility modifications in the female reproductive tract, collectively called capacitation. Only capacitated sperm can undergo acrosomal exocytosis, near or on the egg, a process that allows the sperm to penetrate and fertilize the egg. In the present study, we investigated the invoIvement of cyclic adenosine monophosphate (cAMP)-dependent processes on acrosomal exocytosis. Inhibition of protein kinase A (PKA) at the end of capacitation induced acrosomal exocytosis. This process is cAMP-dependent;however, the addition of relatively high concentration of the membrane-permeable 8-bromo-cAMP (8Br-cAMP, 0.1 mmol l^-1) analog induced significant inhibition of the acrosomal exocytosis. The induction of acrosomal exocytosis by PKA inhibition was significantly inhibited by an exchange protein directly activated by cAMP (EPAC) ESI09 inhibitor. The EPAC selective substrate activated AE at relatively low concentrations (0.02-0.1 μmol l^1), whereas higher concerttrations (>5 pmol l^-1) were inhibitory to the AE induced by PKA inhibition. Inhibition of PKA revealed about 50% increase in intracellular cAMP levels, conditions under which EPAC can be activated to induce the AE. Induction of AE by activating the actin severing?protein, gelsolin, which causes F-actin dispersion, was inhibited by the EPAC inhibitor. The AE induced by PKA inhibition was mediated by phospholipase C activity but not by the Ca^2+-channel, CatSper. Thus, inhibition of PKA at the end of the capacitation process induced EPAC/phospholipase C-dependent acrosomal exocytosis. EPAC mediates F-actin depolymerization an d/or activation of effectors down stream to F-actin breakdown that lead to acrosomal exocytosis.展开更多
A membrane protein was isolated from mouse sperm heads that had undergone acrosomal reaction induced by C2+ ionophore, A 23187, which, with a molecular weight of 77.6 kd, shows capability to block egg-sperm fusion. As...A membrane protein was isolated from mouse sperm heads that had undergone acrosomal reaction induced by C2+ ionophore, A 23187, which, with a molecular weight of 77.6 kd, shows capability to block egg-sperm fusion. As revealed by analysis usintg isotopic markers, this protein is one of the chief membrane proteins of inner acrosomal membrane or the outer membrane of equatorial segment and Post-acrosomal region; treatment of mouse sperms with 0.6 μg/ml of the Purified protein for 30 minutes reduced the sperm-egg fusion index by 51%.The above results led us to the conclusion that the protein is an active participant in sperm-egg fusion. The possible existence of sperm receptor on egg plasma membrane was discussed.展开更多
To investigate into the mechanisms underlying the irreversible sterility induced by gossypol, we studied the relationship between its inhibitory action on acrosomal enzymes and its antifertility effect.As shown by our...To investigate into the mechanisms underlying the irreversible sterility induced by gossypol, we studied the relationship between its inhibitory action on acrosomal enzymes and its antifertility effect.As shown by our result, after exposure to gossypol (l.25-60 μg/ml) for 15 min. in vitro,the sperms' ability to penetrate bovine cervical mucus and the fertility rate were significantly reduced. Also, following administration of gossypol (12.5 mg/kg/day) for six weeks, the rate of fertilization in vitro by hamster sperm was significantly decreased. In the gossypol-treated group, extracts of testis sperm delayed dispersion of cumulus cells, suggesting inhibition of hyaluronidase and other acrosomal enzymes. Furthermore, the acrosin and arylsulfatase activities were shown to be markedly inhibited. Thus, a parallelism was displayed between the reduction of fertility and the decreasc in acrosin and arylsulfatase activities in epididymis sperms.Besides, the inhibition was reversible and was dosage-and durationdependent. In conclusion, the assay of acrosin activity might serve as a useful tool for monitoring the irreversible sterility induced by gossypol,展开更多
文摘This article presents an update on the variable prognostic significance of different sperm pathologies in patients with severe male factor infertility due to morphology and motility disorders. Severe asthenozoospermia is one of the leading causes of male infertility as spermatozoa cannot reach the oocyte and/or penetrate normally. Identifying structural causes of sperm immotility was of great concern before the advent of intracytoplasmic sperm injection （ICSI）, because immotility was the limiting factor in the treatment of these patients. In these cases, in vitro methods are used to identify live spermatozoa or stimulate sperm motility to avoid selection of non-viable cells. With these advances, fertilization and pregnancy results have improved dramatically. The identification of genetic phenotypes in asthenozoospermia is important to adequately inform patients of treatment outcomes and risks. The one sperm characteristic that seriously affects fertility prognosis is teratozoospermia, primarily sperm head and neck anomalies. Defects of chromatin condensation and acrosomal hypoplasia are the two most common abnormalities in severe teratozoospermia. The introduction of microscopic methods to select spermatozoa and the development of new ones to evaluate sperm quality before ICSI will assure that ultrastructural identification ofsperm pathologies will not only be of academic interest, but will also be an essential tool to inform treatment choice. Herein, we review the differential roles played by sperm components in normal fertilization and early embryo development and explore how assisted reproductive technologies have modified our concepts on the prognostic significance of sperm pathologies affecting the head, neck, mid-piece and tail.
基金supported by the National Key Research and Development Program of China(2021YFC2701400)in part by the National Natural Science Foundation of China(32000393 and 32288101).
文摘During spermiogenesis,haploid spermatids undergo dramatic morphological changes to form slender sperm flagella and cap-like acrosomes,which are required for successful fertilization.Severe deformities in flagella cause a male infertility syndrome,multiple morphological abnormalities of the flagella(MMAF),while acrosomal hypoplasia in some cases leads to sub-optimal embryonic developmental potential.However,evidence regarding the occurrence of acrosomal hypoplasia in MMAF is limited.Here,we report the generation of base-edited mice knocked out for coiled-coil domain-containing 38(Ccdc38)via inducing a nonsense mutation and find that the males are infertile.The Ccdc38-KO sperm display acrosomal hypoplasia and typical MMAF phenotypes.We find that the acrosomal membrane is loosely anchored to the nucleus and fibrous sheaths are disorganized in Ccdc38-KO sperm.Further analyses reveal that Ccdc38 knockout causes a decreased level of TEKT3,a protein associated with acrosome biogenesis,in testes and an aberrant distribution of TEKT3 in sperm.We finally show that intracytoplasmic sperm injection overcomes Ccdc38-related infertility.Our study thus reveals a previously unknown role for CCDC38 in acrosome biogenesis and provides additional evidence for the occurrence of acrosomal hypoplasia in MMAF.
基金Supported by the Doctor's Fund Item of Shandong Province (No.2006BS06010)National High Technology Research and Development Program of China (863 Program) (No.2007AA09Z433)
文摘Morphology of the spermatozoon of Octopus ocellatus was studied by light, scanning electron, and transmission electron microscopes. Sperm are 600-700 um long, with a large number of granules in diameter about 130 um. Each spermatozoon is composed of a head, neck, and tail. The head is made up of an acrosomal complex anterior to the nucleus. The spiral acrosomal complex consists of an electron-lucent vesicle, lacuna, and an electron-dense acrosomal vesicle. Additionally, the spiral acrosomal vesicle has numerous equidistant striations, and is surrounded by many small granules （20 nm diameter）. A long straight nucleus, which is electron-densed, has a deep posterior concavity, the nuclear vacuole. At the terminal end of the nucleus is a sleeve-like structure with a concave posterior nuclear fossa （PNF）. The neck is short connecting the PNF. The basal body is located in the PNF and gives rise to the axoneme. This structure connects the head, neck, and tail. The tail is divided into a middle piece and a principal piece. The middle piece, having a 9＋9＋2 arrangement, is surrounded by a mitochondrial sheath and terminates by an electron-dense fibrous sheath. The principal piece is the longest part of the sperm with coarse fibers tapering posteriorly. The results of this study shall provide some useful information for artificial breeding of this species.
文摘To in teract with the egg, the spermatozo on must un dergo several biochemical and motility modifications in the female reproductive tract, collectively called capacitation. Only capacitated sperm can undergo acrosomal exocytosis, near or on the egg, a process that allows the sperm to penetrate and fertilize the egg. In the present study, we investigated the invoIvement of cyclic adenosine monophosphate (cAMP)-dependent processes on acrosomal exocytosis. Inhibition of protein kinase A (PKA) at the end of capacitation induced acrosomal exocytosis. This process is cAMP-dependent;however, the addition of relatively high concentration of the membrane-permeable 8-bromo-cAMP (8Br-cAMP, 0.1 mmol l^-1) analog induced significant inhibition of the acrosomal exocytosis. The induction of acrosomal exocytosis by PKA inhibition was significantly inhibited by an exchange protein directly activated by cAMP (EPAC) ESI09 inhibitor. The EPAC selective substrate activated AE at relatively low concentrations (0.02-0.1 μmol l^1), whereas higher concerttrations (>5 pmol l^-1) were inhibitory to the AE induced by PKA inhibition. Inhibition of PKA revealed about 50% increase in intracellular cAMP levels, conditions under which EPAC can be activated to induce the AE. Induction of AE by activating the actin severing?protein, gelsolin, which causes F-actin dispersion, was inhibited by the EPAC inhibitor. The AE induced by PKA inhibition was mediated by phospholipase C activity but not by the Ca^2+-channel, CatSper. Thus, inhibition of PKA at the end of the capacitation process induced EPAC/phospholipase C-dependent acrosomal exocytosis. EPAC mediates F-actin depolymerization an d/or activation of effectors down stream to F-actin breakdown that lead to acrosomal exocytosis.
文摘A membrane protein was isolated from mouse sperm heads that had undergone acrosomal reaction induced by C2+ ionophore, A 23187, which, with a molecular weight of 77.6 kd, shows capability to block egg-sperm fusion. As revealed by analysis usintg isotopic markers, this protein is one of the chief membrane proteins of inner acrosomal membrane or the outer membrane of equatorial segment and Post-acrosomal region; treatment of mouse sperms with 0.6 μg/ml of the Purified protein for 30 minutes reduced the sperm-egg fusion index by 51%.The above results led us to the conclusion that the protein is an active participant in sperm-egg fusion. The possible existence of sperm receptor on egg plasma membrane was discussed.
文摘To investigate into the mechanisms underlying the irreversible sterility induced by gossypol, we studied the relationship between its inhibitory action on acrosomal enzymes and its antifertility effect.As shown by our result, after exposure to gossypol (l.25-60 μg/ml) for 15 min. in vitro,the sperms' ability to penetrate bovine cervical mucus and the fertility rate were significantly reduced. Also, following administration of gossypol (12.5 mg/kg/day) for six weeks, the rate of fertilization in vitro by hamster sperm was significantly decreased. In the gossypol-treated group, extracts of testis sperm delayed dispersion of cumulus cells, suggesting inhibition of hyaluronidase and other acrosomal enzymes. Furthermore, the acrosin and arylsulfatase activities were shown to be markedly inhibited. Thus, a parallelism was displayed between the reduction of fertility and the decreasc in acrosin and arylsulfatase activities in epididymis sperms.Besides, the inhibition was reversible and was dosage-and durationdependent. In conclusion, the assay of acrosin activity might serve as a useful tool for monitoring the irreversible sterility induced by gossypol,
