The correlation between bismuth and uranyl staining and phosphorus content of intracellular structures as determined by electron spectroscopic imaging

Four groups of intracellular structures can be recognized according to bismuth and uranyl staining and phosphorus content. (1) Those which contain phosphorus and stain strongly with uranyl acetate but not with bismuth (ribosomes, heterochromatin and mature ribosomal precursor granules), presumably because of their nucleic acid content. (2) Those which contain phosphorus and stain with uranyl acetate and bismuth (interchromatin granules, immature ribosomal precursor granules and mitochondrial granules), presumably because at least some of their phosphate is available to react with bismuth. (3) Those which contain little phosphorus but which stain strongly with bismuth and weakly with uranyl acetate (Golgi complex beads), perhaps because some ligand in addition to phosphate reacts with bismuth, and (4) those which do not contain phosphorus and stain with neither uranyl acetate nor bismuth (portasomes). Uranyl staining correlates strongly with the phosphorus content of nucleic acids, proteins and inorganic deposits. Bismuth will stain some phosphorylated molecules but not all. Thus only some phosphates stain with bismuth.     

Isolation of 3-(2-carboxyethyl)thymine following in vitro reaction of β-propiolactone with calf thymus DNA

3-(2-Carboxyethyl)thymine (3-CET) was synthesized from β-propiolactone (BPL) and dThd5′P at pH 9.0–9.5 via the intermediate 3-(2-carboxyethyl)thymidine-5′-monophosphoric acid (3-CEdThd5′P). 3-CEdThd5′P was converted to 3-CET by hydrolysis in 1.5 N HCl at 100°C for 2 h. The structure of 3-CET was assigned on the basis of UV spectra, electron impact (EI) and isobutane chemical ionization mass spectra and the EI mass spectrum of a trimethylsilyl derivative of 3-CET. BPL was reacted in vitro with calf thymus DNA at pH 7.5. 100 A units of BPL-reacted DNA yielded, following perchloric acid hydrolysis and preparative paper chromatography, 3 A units of 3-CET. Reaction of BPL with the phosphodiester thymidylyl-(3′-5′)thymidine gave 3-(2-carboxyethyl)thymidylyl-(3′-5′)-3-(2-carboxyethyl)thymidine (～3%). Phosphotriester formation was not detected.     

Fate of spermatozoa that do not participate in fertilization in the domestic fowl

Summary The fate of spermatozoa that do not participate in fertilization was investigated by electron microscopy. After artificial insemination, we observed several spermatozoa between the fibers of the outer layer of the vitelline membrane of the ovum. One or more spermatozoa were also found in a phagocytic vesicle of macrophages located in the intercellular space of the mucosal epithelium of the infundibulum or in the outer layer of the vitelline membrane.From these observations, we assume that the superfluous spermatozoa in the lumen of the anterior part of the oviduct might be removed by inclusion into the outer layer of the vitelline membrane and by phagocytosis by macrophages.The authors are greatly indebted to Assoc. Prof. Osamu Koga for his invaluable advice. The authors also wish to thank Mr. Takayuki Mri for his helpful suggestions and technical advice. This investigation was supported by a grant from the Ministry of Education of Japan (156185)     

Scanning electron microscopic study of spermatozoa from gossypol-treated rats

Summary Spermatozoa from the cauda epididymidis of gossypol-treated rats exhibit distinctive departures from the morphology of spermatozoa from control rats: wrinkled and disorganized cell membrane in the head and tail regions, cell membrane missing from segments of the tail midpiece and principal piece regions, malformed heads, decapitate spermatozoa, retention of a cytoplasmic droplet at variable loci along tail midpieces, and looped tails. The observations suggest that gossypol exerts its contraceptive effect during spermatocytogenesis and spermiogenesis, including the posttesticular development and maturation of spermatozoa in the epididymis.     

The structure and distribution of satellite cells of cardiac muscles in decapod crustaceans

Summary The structure and distribution of satellite cells of cardiac muscles were examined in twenty-one species of animals chosen from each tribe within the order Decapoda (Arthropoda, Crustacea). The satellite cells were found in all animals observed. Most of them are morphologically identical with those described in different striated muscles of other species, but some cells have unusual features. The decapod satellite cell occasionally lies right over the region corresponding to the intercalated disc between the apposed cardiac muscle cells. The cell sends cytoplasmic processes into the adjacent muscle cells, enabling the plasma membrane to make close contact with the cleft opening of the intercalated disc, and with the myofibril at the level of the Z-line. Another characteristic feature is the presence of paired cells. Such cells are clearly separated from each other over most of the contact area by the respective plasma membranes, which are smooth in appearance and devoid of specialized regions. The significance of the presence of satellite cells in decapod cardiac muscle and its possible role are discussed and compared with those described for other species.     

Fluorescence Transients as Indicator for the Existence of Regulatory Mechanisms in Photosynthetic Electron Transport

In green algae several characteristic differences in the slope of the fast 685 nm fluorescence transient indicate the existence of different mechanisms for the regulation of the photosynthetic electron transport in vivo with respect to the requirements for ATP and NADPH. Autotrophically cultivated Chlamydobotrys stellata exhibits a normal time curve of the fluorescence yield. Anaerobiosis and C0₂-deficiency raise the O-, I- and S-level, whereas the P- level is lowered and the I-D-decay disappears. The readdition of oxygen increases the fluorescence significantly. Supplementation of aerobic cells with CO₂ restores the normal fluorescence transients. The replacement of carbon dioxide by acetate as a carbon source in the light lowers the overall fluorescence emission and abolishes the D-P-increase and the P-S-decline. The presence of DCMU increases fluorescence only at high intensities of incedent light. Anaerobiosis in these photoheterotrophic algae lowers the fluorescence emission. In this case DCMU increases fluorescence even at low light intensities. In Gonium multicoccum, which shows a normal fluorescence transient when cultivated autotrophically, CO₂-deficiency abolishes the O-level and increases the I- and S-niveau. Additional anaerobiosis in CO₂-deficient cells raises the steady state emission. Readdition of oxygen to these cells raises the I- and S-level even more and prevents the build up of the P-level. In Gonium     

Possible sites of ultrafiltration in Tubifex tubifex Müller (Annelida,Oligochaeta)

Summary The endothelia of Tubifex tubifex Müller consist of myoendothelial cells, chloragocytes, or podocytes. The latter seem to occur only as windows on the ventral vessel which has an endothelium of myoendothelial cells elsewhere. The podocytes are large cells, with several processes on the inner side which ramify into several pedicels. These are aligned upon the outside of the basement membrane which lines the inside of the endothelium. The gaps between adjacent pedicels are about 40 nm wide. In capillaries fenestrated endothelia occur with irregular spacings measuring up to 0.4–1 m. A diaphragm in podocytes or capillary fenestrations do not seem to exist. The basement membrane is the only continuous layer lining the blood vessels and capillaries of Tubifex with a rather uniform diameter in the range of 50 nm. It is the only permeability barrier between blood and coelomic fluid.     

The hypothalamo-choroidal tract

Summary Light and electron microscopic examination of choroid plexuses from lateral ventricles of water-deprived and subcutaneously or intravenously vasopressin administered rats reveal morphologic changes typical for vasopressin responsive fluid transporting epithelia during hormonal stimulation. Ultrastructural changes noted in both dehydrated and vasopressin treated animals included: the frequent occurrence of choroidal dark cells, dilatation of the lateral and basal intercellular spaces, increased vacuolization of the apical cytoplasm, and a change in microvillar conformation from the normal clavate type to those with a filiform shape. On the basis of the ultrastructural changes observed it is proposed that the choroid plexus be regarded as a target tissue for vasopressin. These findings indicated that a vasopressinmediated transchoroidal cerebrospinal fluid absorption capability exists.Supported by U.S.P.H.S. Grant HD-08867This work submitted as partial requirement for the Master of Science degree in the Department of Anatomy, Colorado State University     

Secretion in the rat coagulating gland (Anterior Prostate) after copulation

Summary The effect of copulation on the rat coagulating gland (anterior prostate) was studied. At 4 to 6 h after the beginning of copulation the coagulating glands of rats that had produced copulatory plugs were nearly empty of secretion. Ultrastructurally, the coagulating gland has large cisternae of rough endoplasmic reticulum (RER) and few condensing vacuoles or secretion granules. After copulation the number of secretion granules and the frequency of their expulsion into the lumen increased. Also in the lumen were fragmentation vesicles (50–100 nm diameter) that were bounded by a unit membrane and appeared to arise from microvilli. At 4, 6, and 7h after the beginning of copulation there was an increase in apical blebbing. Blebbing was found in both perfusion and immersion-fixed tissue. Also, after copulation there was an increase in light cells that were characterized by reduced RER cisternae, an electron lucent cytoplasm, and atrophic Golgi apparatus. The luminal ground substance, secretion granules, and some Golgi elements, contained polysaccharides as seen with the periodic acid-thiocarbohydrazide-silver proteinate method.