Lectins have been used to analyze variations in the distribution and density of exposed saccharides of the sperm plasma membrane during physiologic maturation and after ejaculation. Studies have been conducted in a number of nonprimate species but have been conducted to only a limited extent in nonhuman primates. In this study, pure suspensions of chimpanzee sperm from the caput and cauda epididymis and from the ejaculate were labeled with lectins conjugated to fluorescein isothiocyanate in order to visualize changes in the distribution of exposed membrane glycocomponents. The lectins used were Con A, DBA, RCA-I, and WGA. Con A binding showed minimal change during epididymal transit, with an increased binding to the flagellum after ejaculation. DBA binding was relatively constant in all specimens. RCA-I showed distinct changes in binding pattern between epididymal and ejaculated sperm. On ejaculated sperm strong fluorescence was limited to the posterior head and to the midpiece. WGA binding increased during epididymal passage and decreased after ejaculation. There appears to be a wide variety of saccharide groups available for lectin binding on the surface of epididymal and ejaculated chimpanzee sperm. The general similarity in binding patterns of caput and cauda epididymal chimpanzee sperm exposed to Con A and DBA might reflect the fact that sperm morphology does not change during epididymal transit in this species, thus implying a more stable membrane structure than is present in other primates so far studied.
{"title":"Lectin binding sites on the plasma membrane of epididymal and ejaculated chimpanzee sperm","authors":"L. Young, K. Gould, B. T. Hinton","doi":"10.1002/MRD.1120140109","DOIUrl":"https://doi.org/10.1002/MRD.1120140109","url":null,"abstract":"Lectins have been used to analyze variations in the distribution and density of exposed saccharides of the sperm plasma membrane during physiologic maturation and after ejaculation. Studies have been conducted in a number of nonprimate species but have been conducted to only a limited extent in nonhuman primates. In this study, pure suspensions of chimpanzee sperm from the caput and cauda epididymis and from the ejaculate were labeled with lectins conjugated to fluorescein isothiocyanate in order to visualize changes in the distribution of exposed membrane glycocomponents. The lectins used were Con A, DBA, RCA-I, and WGA. Con A binding showed minimal change during epididymal transit, with an increased binding to the flagellum after ejaculation. DBA binding was relatively constant in all specimens. RCA-I showed distinct changes in binding pattern between epididymal and ejaculated sperm. On ejaculated sperm strong fluorescence was limited to the posterior head and to the midpiece. WGA binding increased during epididymal passage and decreased after ejaculation. There appears to be a wide variety of saccharide groups available for lectin binding on the surface of epididymal and ejaculated chimpanzee sperm. The general similarity in binding patterns of caput and cauda epididymal chimpanzee sperm exposed to Con A and DBA might reflect the fact that sperm morphology does not change during epididymal transit in this species, thus implying a more stable membrane structure than is present in other primates so far studied.","PeriodicalId":12668,"journal":{"name":"Gamete Research","volume":"40 1","pages":"75-87"},"PeriodicalIF":0.0,"publicationDate":"1986-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78766935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nucleolar ultrastructural changes occurring in vivo in bovine oocytes during follicular growth were analyzed by electron microscopy. The rates of in vitro incorporation of 3H-uridine by oocytes of the same size class were evaluated by autoradiography. One to two large fibrillogranular, vacuolated nucleoli were present in oocytes from small to medium antral follicles 0.5–3 mm in diameter. These oocytes showed intense hnRNA and rRNA synthesis. The homogeneous, agranular nucleoli in oocytes from follicles 3–4 mm in diameter were composed of a compact fibrillar material. This morphological change was accompanied by an impairment of nucleolar transcriptional activity as well as by a decrease in hnRNA synthesis.
{"title":"Nucleolar fine structure and RNA synthesis in bovine oocytes from antral follicles","authors":"N. Crozet, J. Kanka, J. Motlík, J. Fulka","doi":"10.1002/MRD.1120140108","DOIUrl":"https://doi.org/10.1002/MRD.1120140108","url":null,"abstract":"Nucleolar ultrastructural changes occurring in vivo in bovine oocytes during follicular growth were analyzed by electron microscopy. The rates of in vitro incorporation of 3H-uridine by oocytes of the same size class were evaluated by autoradiography. \u0000 \u0000 \u0000 \u0000One to two large fibrillogranular, vacuolated nucleoli were present in oocytes from small to medium antral follicles 0.5–3 mm in diameter. These oocytes showed intense hnRNA and rRNA synthesis. The homogeneous, agranular nucleoli in oocytes from follicles 3–4 mm in diameter were composed of a compact fibrillar material. This morphological change was accompanied by an impairment of nucleolar transcriptional activity as well as by a decrease in hnRNA synthesis.","PeriodicalId":12668,"journal":{"name":"Gamete Research","volume":"71 1","pages":"65-73"},"PeriodicalIF":0.0,"publicationDate":"1986-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85888302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The form that rat spermatozoa assume when swelling in hyposmotic media depends on the position of the cytoplasmic droplet, previous exposure to hypertonic media, and the stiffness of the flagellum. Bending at the end of the midpiece occurs when the swelling droplet is situated at this site; this occurs in midcaput cells, but sperm from more proximal sites do not bend in this fashion. Stiffening of caput sperm stored in vitro reduces the incidence of such midpiece bending but looping at the tip of the tail still occurs, and previous exposure of caput spermatozoa to hypertonic media also prevents hairpin bend formation. Mature sperm from the cauda are too stiff to form hairpin loops when placed in hypotonic media unless first treated with a penetrating disulphydryl-reducing agent, after which swollen spherical vesicles can result from very flexible flagella confined within an intact membrane. Long-chain acylcarnitines are more potent lytic agents than acylcholines, but, for both, chain lengths of 16 carbon atoms is optimal for preventing the swelling of rat caput sperm.
{"title":"Osmotic swelling of maturing rat spermatozoa and Lysis of caput spermatozoa by acylcarnitines and acylcholines","authors":"T. Cooper","doi":"10.1002/MRD.1120140106","DOIUrl":"https://doi.org/10.1002/MRD.1120140106","url":null,"abstract":"The form that rat spermatozoa assume when swelling in hyposmotic media depends on the position of the cytoplasmic droplet, previous exposure to hypertonic media, and the stiffness of the flagellum. Bending at the end of the midpiece occurs when the swelling droplet is situated at this site; this occurs in midcaput cells, but sperm from more proximal sites do not bend in this fashion. Stiffening of caput sperm stored in vitro reduces the incidence of such midpiece bending but looping at the tip of the tail still occurs, and previous exposure of caput spermatozoa to hypertonic media also prevents hairpin bend formation. Mature sperm from the cauda are too stiff to form hairpin loops when placed in hypotonic media unless first treated with a penetrating disulphydryl-reducing agent, after which swollen spherical vesicles can result from very flexible flagella confined within an intact membrane. Long-chain acylcarnitines are more potent lytic agents than acylcholines, but, for both, chain lengths of 16 carbon atoms is optimal for preventing the swelling of rat caput sperm.","PeriodicalId":12668,"journal":{"name":"Gamete Research","volume":"38 1","pages":"47-56"},"PeriodicalIF":0.0,"publicationDate":"1986-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73402633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cauda boar sperm but not caput sperm bind to isolated porcine oocytes, and several cauda sperm plasma membrane proteins (PMPs) with high affinity for isolated zonae have been identified. These PMPs migrate with apparent molecular weights near 70, 45 and 30 K [Peterson et al, Gamete Res 12: 91–100, 1985]. When caput plasma membranes (PM) were fractionated on dextran sulfate (DS) agarose and compared to cauda PM similarly fractionated, less protein with high affinity for DS bound to the column, and significant differences in the PMPs eluted with increasing concentration of NaCl were observed. The PMPs at ∼70, ∼45, and ∼30 K, noted above, and two bands near ∼20K were present in fractions from cauda PM but were absent or present in only small quantities in caput PM. Cauda PM fraction eluted at high salt were effective in blocking the binding of sperm to isolated oocytes; caput PM fractions were not. Antibodies to the cauda PMPs eluted at high salt, which blocks the binding of capacitated sperm to eggs and fertilization in vitro, were absorbed by cauda PMV but not by caput PMV. These findings suggest that the ability of boar sperm to attach to porcine oocytes develops as the result of the addition of one or more of these PMPs to sperm during epididymal transit.
猪尾精子与分离的猪卵母细胞结合，但不与头精子结合，并且已经鉴定出几种对分离带具有高亲和力的尾精子质膜蛋白(pmp)。这些pmp迁移的表观分子量在70,45和30k附近[Peterson et, Gamete Res 12: 91 - 100,1985]。用硫酸葡聚糖(dextran sulfate, DS)琼脂糖对头质膜(caput质膜，PM)进行分离，并与同样分离的尾质膜(尾质膜)进行比较，发现附着在柱上的对DS有高亲和力的蛋白较少，且随着NaCl浓度的增加，洗脱的PM有显著差异。如上所述，在~ 70、~ 45和~ 30 K处的PMPs和在~ 20K附近的两个谱带存在于尾部PM的组分中，但在头部PM中不存在或仅少量存在。高盐洗脱的尾根PM组分能有效阻断精子与离体卵母细胞的结合;caput PM分数则没有。在高盐条件下洗脱的尾端PMPs抗体可阻断获能精子与卵子的结合和体外受精，被尾端PMV吸收，而不被头端PMV吸收。这些发现表明，猪精子附着于猪卵母细胞的能力是在附睾运输过程中向精子中添加一种或多种pmp的结果。
{"title":"Interaction of boar spermatozoa with porcine oocytes: Increase in proteins with high affinity for the zona pellucida during epididymal transit","authors":"R. Peterson, W. Hunt, L. Henry","doi":"10.1002/MRD.1120140107","DOIUrl":"https://doi.org/10.1002/MRD.1120140107","url":null,"abstract":"Cauda boar sperm but not caput sperm bind to isolated porcine oocytes, and several cauda sperm plasma membrane proteins (PMPs) with high affinity for isolated zonae have been identified. These PMPs migrate with apparent molecular weights near 70, 45 and 30 K [Peterson et al, Gamete Res 12: 91–100, 1985]. When caput plasma membranes (PM) were fractionated on dextran sulfate (DS) agarose and compared to cauda PM similarly fractionated, less protein with high affinity for DS bound to the column, and significant differences in the PMPs eluted with increasing concentration of NaCl were observed. The PMPs at ∼70, ∼45, and ∼30 K, noted above, and two bands near ∼20K were present in fractions from cauda PM but were absent or present in only small quantities in caput PM. Cauda PM fraction eluted at high salt were effective in blocking the binding of sperm to isolated oocytes; caput PM fractions were not. Antibodies to the cauda PMPs eluted at high salt, which blocks the binding of capacitated sperm to eggs and fertilization in vitro, were absorbed by cauda PMV but not by caput PMV. These findings suggest that the ability of boar sperm to attach to porcine oocytes develops as the result of the addition of one or more of these PMPs to sperm during epididymal transit.","PeriodicalId":12668,"journal":{"name":"Gamete Research","volume":"7 1","pages":"57-64"},"PeriodicalIF":0.0,"publicationDate":"1986-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75184835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Salts of transition elements that alter the rate of sperm cell movement act at or near calcium-binding sites. After living bull sperm cells had been preincubated in VO43−, Ni2+, Zn2+, Mn2+, and also La3+, they were then fixed. Crisply defined organelles and the absence of particulate deposits in the morphological controls contrasted sharply with the treated specimens; the latter contained regions of increased electron density, the nature and distribution of which depended on the test substance, reflecting the differential affinities of the specific ions. La3+ formed fine dense areas, mainly at the exocytic surface of the plasma membrane. VO43− marks the cell surface but also left particulate densities within the cell. Ni2+ caused a nearly uniformly dense deposit at the surface and on the satellite fibers and axonemal microtubules. Zn2+ formed less uniform but coarser deposits, while in Mn2+ the distribution was similar to that in Zn2+ but much denser in the axonemal matrix and on the satellite fibers. Verapamil restricted the size and number of the opacities, while procaine permitted a similar distribution of slightly larger size reaction product. The differences in size and distribution of the enhanced densities were consistent and replicable for the individual assay substances. Vanadate, which specifically inhibits Na, K-ATPase, bound to ouabain-sensitive enzyme loci, however, completely disrupting the axonemal complex. This suggests that an important role of dynein in flagellar motion may relate to intracellular transport of Ca2+.
改变精子运动速率的过渡元素盐在钙结合位点或附近起作用。在VO43−、Ni2+、Zn2+、Mn2+和La3+中预孵育活公牛精细胞后，将其固定。形态学对照组的细胞器清晰，没有颗粒沉积，与处理过的标本形成鲜明对比;后者含有电子密度增加的区域，其性质和分布取决于测试物质，反映了特定离子的不同亲和力。La3+主要在质膜的胞外表面形成细小的致密区。VO43 -标记细胞表面，但也在细胞内留下颗粒密度。Ni2+在表面、卫星纤维和轴突微管上形成几乎均匀致密的沉积。Zn2+的沉积不均匀但较粗，而Mn2+的分布与Zn2+相似，但在轴突基质和卫星纤维上密度更大。维拉帕米限制了混浊物的大小和数量，而普鲁卡因允许类似的稍大尺寸的反应产物分布。增强密度的大小和分布的差异对于单个测定物质是一致的和可复制的。然而，钒酸盐特异性抑制Na, k - atp酶，结合到瓦苦素敏感酶位点，完全破坏轴突复合体。这表明动力蛋白在鞭毛运动中的重要作用可能与细胞内Ca2+的运输有关。
{"title":"Cationic probes: Specificity of distribution of metal-binding sites in bovine sperm","authors":"Leonard Nelson, M. E. Gardner","doi":"10.1002/MRD.1120130408","DOIUrl":"https://doi.org/10.1002/MRD.1120130408","url":null,"abstract":"Salts of transition elements that alter the rate of sperm cell movement act at or near calcium-binding sites. After living bull sperm cells had been preincubated in VO43−, Ni2+, Zn2+, Mn2+, and also La3+, they were then fixed. Crisply defined organelles and the absence of particulate deposits in the morphological controls contrasted sharply with the treated specimens; the latter contained regions of increased electron density, the nature and distribution of which depended on the test substance, reflecting the differential affinities of the specific ions. La3+ formed fine dense areas, mainly at the exocytic surface of the plasma membrane. VO43− marks the cell surface but also left particulate densities within the cell. Ni2+ caused a nearly uniformly dense deposit at the surface and on the satellite fibers and axonemal microtubules. Zn2+ formed less uniform but coarser deposits, while in Mn2+ the distribution was similar to that in Zn2+ but much denser in the axonemal matrix and on the satellite fibers. Verapamil restricted the size and number of the opacities, while procaine permitted a similar distribution of slightly larger size reaction product. The differences in size and distribution of the enhanced densities were consistent and replicable for the individual assay substances. Vanadate, which specifically inhibits Na, K-ATPase, bound to ouabain-sensitive enzyme loci, however, completely disrupting the axonemal complex. This suggests that an important role of dynein in flagellar motion may relate to intracellular transport of Ca2+.","PeriodicalId":12668,"journal":{"name":"Gamete Research","volume":"77 1","pages":"339-351"},"PeriodicalIF":0.0,"publicationDate":"1986-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80008614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A detailed chronology of the cytological events related to maturation that take place within the reproduction molt cycle has been established. It has been shown that oocytes, initially arrested at prophase I, resume meiosis when approaching stage D1‴ of the molt cycle, ie, 4–5 days before molting. The following steps characterize this premolt period of oocyte maturation: nuclear envelope folding, nucleolar dissociation, condensation of the chromosomes, and beginning of the breakdown of the nuclear envelope (GVBD). At the ultrastructural level, it has been confirmed that GVBD actually takes place at the D1‴−D2 stage transition, when the germinal vesicle still occupies a central position in the oocyte. The migration of the chromosome takes only a few hours and begins approximately 4 hr before molting. It is only 1–2 hr before molting that the divalent chromosomes that are not yet organized in a metaphase plate become visible at the surface of the oocyte. They lay in a nucleoplasmic area no longer limited by the nuclear envelope. Metaphase I is reached a few minutes after molting. A second meiotic block appears at this stage, which persists until spawning, ie, for about 24 hr. Fertilization occurs at the moment of spawning. In vitro fertilization experiments demonstrated that fertilization normally triggers the release of the second meiotic block. Extrusion of the two polar bodies can be easily observed using a method for clearing and staining the oocytes in toto.
{"title":"Study on oocyte maturation and activation of the common prawn palaemon serratus (Pennant): Relationship between oocyte maturation and the molt cycle cytological aspects","authors":"P. Clédon","doi":"10.1002/MRD.1120130409","DOIUrl":"https://doi.org/10.1002/MRD.1120130409","url":null,"abstract":"A detailed chronology of the cytological events related to maturation that take place within the reproduction molt cycle has been established. It has been shown that oocytes, initially arrested at prophase I, resume meiosis when approaching stage D1‴ of the molt cycle, ie, 4–5 days before molting. The following steps characterize this premolt period of oocyte maturation: nuclear envelope folding, nucleolar dissociation, condensation of the chromosomes, and beginning of the breakdown of the nuclear envelope (GVBD). At the ultrastructural level, it has been confirmed that GVBD actually takes place at the D1‴−D2 stage transition, when the germinal vesicle still occupies a central position in the oocyte. The migration of the chromosome takes only a few hours and begins approximately 4 hr before molting. It is only 1–2 hr before molting that the divalent chromosomes that are not yet organized in a metaphase plate become visible at the surface of the oocyte. They lay in a nucleoplasmic area no longer limited by the nuclear envelope. Metaphase I is reached a few minutes after molting. A second meiotic block appears at this stage, which persists until spawning, ie, for about 24 hr. Fertilization occurs at the moment of spawning. In vitro fertilization experiments demonstrated that fertilization normally triggers the release of the second meiotic block. Extrusion of the two polar bodies can be easily observed using a method for clearing and staining the oocytes in toto.","PeriodicalId":12668,"journal":{"name":"Gamete Research","volume":"5 1","pages":"353-362"},"PeriodicalIF":0.0,"publicationDate":"1986-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90175099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Movement characteristics of rhesus monkey spermatozoa were analyzed using high-speed cinemicrography. In the first experiment, spermatozoa were studied at 100 frames/sec in diluted semen near a surface, and after entering ovulatory cervical mucus from a bonnet monkey. In mucus, the spermatozoa swam more slowly, with reduced flagellar beat frequencies. The beat shape was altered, and there was less lateral yawing of the sperm head. In the second experiment, spermatozoa in diluted semen were studied at 500 frames/sec in deep preparations, while swimming near a surface or when in the midplane of these preparations. Those sperm in the midplane swam faster, but with lower beat frequencies than those near the surface, and exhibited much more pronounced yawing motions. Such distinctions in sperm motion are probably hydromechanical in origin and may be significant during transport in the female.
{"title":"The response of rhesus monkey sperm motility to cervical mucus and solid surfaces","authors":"D. Katz, D. Phillips","doi":"10.1002/MRD.1120130306","DOIUrl":"https://doi.org/10.1002/MRD.1120130306","url":null,"abstract":"Movement characteristics of rhesus monkey spermatozoa were analyzed using high-speed cinemicrography. In the first experiment, spermatozoa were studied at 100 frames/sec in diluted semen near a surface, and after entering ovulatory cervical mucus from a bonnet monkey. In mucus, the spermatozoa swam more slowly, with reduced flagellar beat frequencies. The beat shape was altered, and there was less lateral yawing of the sperm head. In the second experiment, spermatozoa in diluted semen were studied at 500 frames/sec in deep preparations, while swimming near a surface or when in the midplane of these preparations. Those sperm in the midplane swam faster, but with lower beat frequencies than those near the surface, and exhibited much more pronounced yawing motions. Such distinctions in sperm motion are probably hydromechanical in origin and may be significant during transport in the female.","PeriodicalId":12668,"journal":{"name":"Gamete Research","volume":"3 1","pages":"231-239"},"PeriodicalIF":0.0,"publicationDate":"1986-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90838523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The structure of pig oocytes after in vivo and in vitro fertilization and following treatment with the ionophore A23187 with differing levels of calcium are described, with particular reference to the cortical granules. Fertilization in vivo and in vitro resulted in cortical granule exocytosis. Sperm penetration in vivo was more rapid than in vitro and resulted in the dispersal of the cortical granules' contents in the perivitelline space following exocytosis. The contents of the granules remained adjacent to the plasmalemma after in vitro fertilization and suboolemmar vesicles were less numerous than after in vivo fertilization. High calcium levels were necessary to induce the dispersal of the cortical granule contents following treatment with ionophore. The observations are discussed regarding their relevance to the blockage to polyspermy.
{"title":"The cortical reaction in pig oocytes during in vivo and in vitro fertilization","authors":"D. G. Cran, W. Cheng","doi":"10.1002/MRD.1120130307","DOIUrl":"https://doi.org/10.1002/MRD.1120130307","url":null,"abstract":"The structure of pig oocytes after in vivo and in vitro fertilization and following treatment with the ionophore A23187 with differing levels of calcium are described, with particular reference to the cortical granules. \u0000 \u0000 \u0000 \u0000Fertilization in vivo and in vitro resulted in cortical granule exocytosis. Sperm penetration in vivo was more rapid than in vitro and resulted in the dispersal of the cortical granules' contents in the perivitelline space following exocytosis. The contents of the granules remained adjacent to the plasmalemma after in vitro fertilization and suboolemmar vesicles were less numerous than after in vivo fertilization. High calcium levels were necessary to induce the dispersal of the cortical granule contents following treatment with ionophore. The observations are discussed regarding their relevance to the blockage to polyspermy.","PeriodicalId":12668,"journal":{"name":"Gamete Research","volume":"54 1","pages":"241-251"},"PeriodicalIF":0.0,"publicationDate":"1986-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85800481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Comparative ultrastructural observations reveal that cytoplasmic deletion during spermatogenesis in Sphagnum and other mosses (Bryopsida) has two distinct phases. In young spermatids, Golgi-derived vesicles produce the mucopolysaccharide sheaths in which the gametes are liberated. Golgi bodies, however, play no part in removal of cytoplasm during gamete maturation. Rounding off of the cells during this process results in a 50% reduction in volume. Mid-spermatid stages in Sphagnum are characterised by the sequential loss of Golgi bodies and endoplasmic reticulum (ER) but no further diminution of the cytoplasm. The final stages of nuclear metamorphosis and chromatin condensation, in late spermatids, are marked by the sudden appearance, in the otherwise featureless central cytoplasm, of a membrane vesicle complex (MVC) comprising cisternae, tubules, and smooth and coated vesicles. Following repositioning of the MVC beneath the plasma membrane, rapid shrinkage of the cytoplasm is associated with the presence of vesicle fusion profiles at the cell surface. The MVC is considered to be intimately involved in cytoplasmic breakdown and loss. Acid phosphatase activity can be detected throughout spermatogenesis. Spermatogenous cells and young spermatids possess relatively low levels of the enzyme, restricted to the ER and perinuclear space, but particularly high levels occur in the MVC region of late spermatids of Sphagnum. The deletion process in Bryopsida is much more gradual than that of Sphagnum. Mid-spermatids contain sheets of ER, Golgi with small vesicles, and irregular cisternae associated with coated vesicles. Vacuoles derived either from dilation of the ER or the coated vesicle complexes gradually increase in size and number at the expense of the cytoplasm. During the early stages of chromatin condensation, a large central vacuole opens onto the anterior face of the gametes. Further discharge of vesicles continues throughout gamete maturation. A comparative survey of spermatogenesis in land plants indicates that cytoplasmic deletion is achieved in different ways in different groups. We speculate that the spermatozoids of the common ancestor of archegoniate plants probably possessed large amounts of cytoplasm. The deletion mechanisms may have originated from a contractile vacuole apparatus.
{"title":"Cytoplasmic deletion processes during spermatogenesis in mosses","authors":"C. Miller, J. Duckett","doi":"10.1002/MRD.1120130308","DOIUrl":"https://doi.org/10.1002/MRD.1120130308","url":null,"abstract":"Comparative ultrastructural observations reveal that cytoplasmic deletion during spermatogenesis in Sphagnum and other mosses (Bryopsida) has two distinct phases. In young spermatids, Golgi-derived vesicles produce the mucopolysaccharide sheaths in which the gametes are liberated. Golgi bodies, however, play no part in removal of cytoplasm during gamete maturation. Rounding off of the cells during this process results in a 50% reduction in volume. \u0000 \u0000 \u0000 \u0000Mid-spermatid stages in Sphagnum are characterised by the sequential loss of Golgi bodies and endoplasmic reticulum (ER) but no further diminution of the cytoplasm. The final stages of nuclear metamorphosis and chromatin condensation, in late spermatids, are marked by the sudden appearance, in the otherwise featureless central cytoplasm, of a membrane vesicle complex (MVC) comprising cisternae, tubules, and smooth and coated vesicles. Following repositioning of the MVC beneath the plasma membrane, rapid shrinkage of the cytoplasm is associated with the presence of vesicle fusion profiles at the cell surface. The MVC is considered to be intimately involved in cytoplasmic breakdown and loss. Acid phosphatase activity can be detected throughout spermatogenesis. Spermatogenous cells and young spermatids possess relatively low levels of the enzyme, restricted to the ER and perinuclear space, but particularly high levels occur in the MVC region of late spermatids of Sphagnum. \u0000 \u0000 \u0000 \u0000The deletion process in Bryopsida is much more gradual than that of Sphagnum. Mid-spermatids contain sheets of ER, Golgi with small vesicles, and irregular cisternae associated with coated vesicles. Vacuoles derived either from dilation of the ER or the coated vesicle complexes gradually increase in size and number at the expense of the cytoplasm. During the early stages of chromatin condensation, a large central vacuole opens onto the anterior face of the gametes. Further discharge of vesicles continues throughout gamete maturation. \u0000 \u0000 \u0000 \u0000A comparative survey of spermatogenesis in land plants indicates that cytoplasmic deletion is achieved in different ways in different groups. We speculate that the spermatozoids of the common ancestor of archegoniate plants probably possessed large amounts of cytoplasm. The deletion mechanisms may have originated from a contractile vacuole apparatus.","PeriodicalId":12668,"journal":{"name":"Gamete Research","volume":"21 1","pages":"253-270"},"PeriodicalIF":0.0,"publicationDate":"1986-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81531052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An electron microscope study was carried out on Hypselodoris tricolor spermatids to describe the development of the nuclear morphogenesis and investigate the possible cause(s) of the change in the shape of the spermatid nucleus during spermiogenesis. Three different stages may be distinguished in the course of the nuclear morphogenesis on the basis of the morphology and inner organization of the nucleus. Stage 1 spermatid nuclei are spherical or ovoid in shape and the nucleoplasm finely granular in appearance. Stage 2 nuclei exhibit a disc- or cup-shaped morphology, and the chromatin forms short, thin filaments. During stage 3, a progressive nuclear elongation takes place, accompanied by chromatin rearrangement, first into fibers and then into lamellae, both formations helically oriented. A row of microtubules attached to the nuclear envelope completely surrounds the nucleus. Interestingly, the microtubules always lie parallel to the chromatin fibers adjacent to them. Late stage 3 spermatids show the highest degree of chromatin condensation and lack the manchette at the end of spermiogenesis. Our findings indicate the existence of a clear influence exerted on the chromatin by the manchette microtubules, which appear to be involved in determining the specific pattern of chromatin condensation in Hypselodoris tricolor.
{"title":"Nuclear morphogenesis during spermiogenesis in the nudibranch molluscHypselodoris tricolor (Gastropoda, opisthobranchia)","authors":"A. Medina, J. Moreno, J. López-Campos","doi":"10.1002/MRD.1120130209","DOIUrl":"https://doi.org/10.1002/MRD.1120130209","url":null,"abstract":"An electron microscope study was carried out on Hypselodoris tricolor spermatids to describe the development of the nuclear morphogenesis and investigate the possible cause(s) of the change in the shape of the spermatid nucleus during spermiogenesis. Three different stages may be distinguished in the course of the nuclear morphogenesis on the basis of the morphology and inner organization of the nucleus. Stage 1 spermatid nuclei are spherical or ovoid in shape and the nucleoplasm finely granular in appearance. Stage 2 nuclei exhibit a disc- or cup-shaped morphology, and the chromatin forms short, thin filaments. During stage 3, a progressive nuclear elongation takes place, accompanied by chromatin rearrangement, first into fibers and then into lamellae, both formations helically oriented. A row of microtubules attached to the nuclear envelope completely surrounds the nucleus. Interestingly, the microtubules always lie parallel to the chromatin fibers adjacent to them. Late stage 3 spermatids show the highest degree of chromatin condensation and lack the manchette at the end of spermiogenesis. Our findings indicate the existence of a clear influence exerted on the chromatin by the manchette microtubules, which appear to be involved in determining the specific pattern of chromatin condensation in Hypselodoris tricolor.","PeriodicalId":12668,"journal":{"name":"Gamete Research","volume":"26 1","pages":"159-171"},"PeriodicalIF":0.0,"publicationDate":"1986-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77166385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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