摘要:

AbstractMouse oocytes were stained by antitubulin antibody and by an anti‐MAP1 antibody (JA2) during the first meiotic cell division. At germinal vesicle stage, JA2 antibody exclusively stains the nucleoplasm. When the nuclear envelope breaks down (GVBD) (2–3 h of culture), numerous foci of microtubules appear around the disrupting nuclear envelope; they are decorated by anti‐MAP1 antibody. After 10–12 h of culture, the antigen component detected with anti‐MAP1 antibody is present in the meiotic spindle.The antimitotic agent taxol (10 μm) induces microtubule formation, mainly at the periphery of the germinal vesicle. At GVBD, taxol provokes the formation of a large microtubular array stained with both antibodies, which is associated with the condensed chromosomes. Furthermore, numerous cytoplasmic asters become visible in the cytoplasm. At metaphases I and II, taxol induces an important enlargement of the metaphase spindles and increases the number of

ISSN:0148-7280    

DOI:10.1002/mrd.1120170102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThe present study was undertaken to determine the efficiency of HVJ treatment and electrofusion for pronuclear transplantation in the mouse. The output voltage and duration of the pulses were fixed to 200 μsec at 10 V or to 150 μsec at 15 V for electrofusion, because the maximum rates of blastomere fusion of 2‐cell embryos and development of fused embryos in vitro were obtained under these conditions. Although the proportion of eggs with fused karyoplast (78%) and the fused eggs developed to morulae or blastocysts (67%) was significantly lower than those obtained after HVJ treatment (94% and 94%), the proportion of pregnant recipients and young obtained after treatment of fused eggs was not significantly different between these two procedures.It is advised that electrofusion can be used as a fusogenic procedure for pronuclear transplantation in the mouse in some cases where HVJ cannot be appl

ISSN:0148-7280    

DOI:10.1002/mrd.1120170103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractTo investigate chromatin organization, we applied the spreading techniques to nuclei isolated fromScolopendriumspermatozoids.Well‐dispersed chromatin shows three types of fibers: beaded fibers corresponding to a nucleosomal filament with adjacent nucleosomes in close contact, smooth fibers (14 nm in diameter) associated in a complex network, and knobby fibers constituted by local supercoiling of a very thin (4 nm) smooth filament. Along the knobby fibers, beads of variable size are irregularly spaced.The knobby fibers lie parallel and coalesce in thick bundles. The sperms basic proteins identified by electrophoretic analysis probably promote the supercoiling and the side‐to‐side attachment of the knobby fibers, which are all the more abundant in spread preparations. These results indicate that knobby fibers are probably located in the outer part of the sperm nucleus in which the chromatin is densely packed. As for the nucleosomal and smooth filaments, they may be situated in the inner

ISSN:0148-7280    

DOI:10.1002/mrd.1120170104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractRabbit spermatozoa were labeled predominantely in their acrosomal glycoproteins by 1‐3H‐glucosamine during spermiogenesis. Ova fertilized in vivo by spermatozoa labeled 22 days earlier were analyzed by fine‐structure autoradiography for the localization of the label. The latter was found associated with 1) the fused membranes of the acrosomal cap remaining on the zona pellucida surface, 2) the material released on the zona surface after the acrosome reaction and possibly detectable after tannic acid fixation, 3) the equatorial segment of the sperm head and the preequatorial swellings, and 4) other sperm components, eg, the sperm tail. No labeling, on the other hand, was detected on the denuded leading edge of spermatozoa found either in the penetration slit or in the perivitelline space. Our observations suggest the involvement of acrosomal glycoproteins in different mechanisms of sperm/zona pellucida interaction but are not in favor of a major role of (enzymatic) glycoproteins bound to the inner acrosomal membrane during the penetration of the zona pell

ISSN:0148-7280    

DOI:10.1002/mrd.1120170105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractTo better understand, to optimize, and to validate the technique of intratesticular (i.t.) injection, several parameters related to i.t. injection were examined. Volumes exceeding 50 μl could be injected i.t.; however, testes frequently became excessively turgid and backflow of injected fluids occurred. Thus, a volume of 50 μl or less was deemed optimal for injection. To determine the rate of distribution of substances throughout the testis, trypan blue was injected i.t. near the caudal pole of the testis, and the movement of dye was monitored. Within 2 min, the dye had spread approximately 1 cm from the site of injection, and in 5 min it had spread twice that distance. In 2 h, the dye had become distributed throughout the testis except at its extreme cranial pole. Seminiferous tubules did not take up dye, indicating that the spread of dye was via peritubular lymphatics. Seminiferous tubule histology appeared virtually unaffected by i.t. injection, even at regions adjacent to the site of injection, when a sterile 26‐gauge or smaller bore needle was utilized. To determine disappearance from the testis, radiolabeled inulin was injected i.t. Half time for absorption was achieved at 1.75 h. Potential vehicles were expolored in which compounds with a variety of physical properties could be injected. Gum tragacanth, normal saline, ethylene glycol, dimethyl sulfoxide (DMSO) mixed 1:1 with normal saline, sesame oil, and propylene glycol were found to be suitable injection vehicles, whereas ethanol, dissolved in normal saline in concentrations as low as 0.5% was found unsuitable. To assess vehicle efficiency, various vehicles were utilized with a known testicular toxin (taxol) and injected into one testis, and the histology was compared with the contralateral testis injected with vehicle alone. All vehicles, found suitable above, allowed dispersion of taxol to influence areas distant from the site of injection. Intratesticular injection assesses the potential of agents to directly affect the testis, and systemic metabolism is avoided. Their rapid spread throughout the lymphatics of the testes allows seminiferous tubules to be exposed to agents in innocuous vehicles more rapidly and in higher concentration than is often possible when using systemic injecti

ISSN:0148-7280    

DOI:10.1002/mrd.1120170106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractMicrodrops of medium under either paraffin or silicone oil are commonly used for culture of early mammalian embryos. Radiolabeled estradiol, progesterone, and androstenedione in drops of medium under oil decreased by 51, 89, and 77%, respectively, after 24‐hr incubation. Up to 14% of labeled estradiol moved to another drop of medium by passing through the oil. Several other substances tested (FSH, leucine, glucose, lactate, sodium ion, PGE2, PGF2α) did not pass into the oil. Both paraffin and silicone oils can alter the composition of culture medium by absorbing and transferring certain types of compoun

ISSN:0148-7280    

DOI:10.1002/mrd.1120170107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractAt fertilization, the sea urchin egg vitelline envelope (VE) elevates, and a subset of released cortical granule proteins, paracrystalline protein fraction (PCF), associates with the VE to form the fertilization envelope (FE). Cortical granule peroxidase cross‐links FE polypeptides by phenolic coupling of tyrosyl residues. We have used an immunological approach to determine which polypeptides are linked together in the hardened FE ofStrongylocentrotus purpuratus. Soluble polypeptides were extracted from hardened FEs, and antibodies were prepared in rabbits against the insoluble envelope matrix (FE ghost). Whole immune serum and purified IgGs each reacted with FE ghosts when using an enzyme‐linked immunosorbent assay. VEs isolated by means of three published procedures cross‐reacted with the immune serum and purified IgGs. Soluble FE polypeptides also cross‐reacted with whole immune serum and IgGs owing to the presence of VE polypeptides. Hyalin, a protein not found in FEs, and PCF did not cross‐react with antiserum against FE ghosts. To determine which VE polypeptides were cross‐linked in the hardened FE, VE polypeptides were immunoblotted by using antiserum against FE ghosts. Most of the VE polypeptides that ranged from 68,000 to 283,000 molecular weight cross‐reacted with

ISSN:0148-7280    

DOI:10.1002/mrd.1120170108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractWe describe a protocol to isolate a highly enriched fraction of outer acrosomal membrane from guinea pig spermatozoa and present new data on the ultrastructure of this membrane domain. Cauda epididymal spermatozoa were suspended into a low ionic strength buffer and subjected to brief homogenization; this stripped the plasma membrane from the spermatozoa and severed the acrosomal apical segment from the spermatozoon. The crescent‐shaped apical segments retained the outer acrosomal membrane and specific components of the acrosomal matrix. Enriched fractions of apical segments were isolated on discontinuous sucrose gradients and the outer acrosomal membrane purified by subsequent centrifugation onto Percoll density gradients. The isolated outer acrosomal membrane did not form vesicles, but instead rolled up into spiral sheets. Both thin section and negatively stained specimens revealed a paracrystalline arrangement of filaments associated with the luminal surface of the membrane. The isolated outer acrosomal membrane revealed a limited number of polypeptides by SDS‐PAGE, and the polypeptide pattern was distinct from the plasma membrane fraction. The isolated acrosomal membranes possessed no oubain sensitive Na+, K+‐ATPase activity, whereas about 20% of the ATPase activity of the plasma membrane enriched fraction was inhibited by oubain. The potential function of the structural differentiations of the outer acrosomal membrane in the membrane fusion events of the acrosome reaction is disc

ISSN:0148-7280    

DOI:10.1002/mrd.1120170109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

ISSN:0148-7280    

DOI:10.1002/mrd.1120170113

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

ISSN:0148-7280    

DOI:10.1002/mrd.1120170101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY