Ultrastructural features of ovarian interstitial tissue in a wild mouse, Apodemus flavicollis, at various reproductive stages, with a note on its histochemistry at the onset of the breeding period

1983 ◽  
Vol 61 (7) ◽  
pp. 1560-1567 ◽  
Author(s):  
Margareta Eriksson ◽  
Erik Nyholm

In Apodemus flavicollis caught at the onset of the breeding season, interstitial tissue of the ovaries showed weak to moderate 3β-hydroxysteroid dehydrogenase and glucose-6-phosphate dehydrogenase activity. Interstitial cells were found to be actively secretory among females with open vaginas. The active cells were characterized by round nuclei and well-developed cytoplasmic organelles. The mitochondria were sometimes associated with smooth endoplasmic reticulum and had mainly tubular cristae. Lipid droplets were few and contained electron-dense material. A Golgi complex with associated vesicles was conspicuous, as were endo- or exo-cytotic vesicles. It is concluded that in A. flavicollis interstitial tissue is actively secretory in connection with ovulation or early pregnancy.

1972 ◽  
Vol 20 (12) ◽  
pp. 1006-1023 ◽  
Author(s):  
ALEX B. NOVIKOFF ◽  
PHYLLIS M. NOVIKOFF ◽  
CLEVELAND DAVIS ◽  
NELSON QUINTANA

A modification of the Novikoff-Goldfischer alkaline 3,3'-diaminobenzidine medium for visualizing peroxisomes is described. It makes possible light microscopic as well as electron microscopic studies of a recently described class of peroxisomes, the microperoxisomes. Potassium cyanide (5 x 10–3 M) is included in the medium to inhibit mitochondrial staining, the pH is 9.7 and there is a high concentration of H2O2 (0.05%). Two cell types have been chosen to illustrate the advantages of the new procedure for demonstrating the microperoxisomes: the absorptive cells in the human jejunum and the distal tubule cells in the guinea pig kidney. Suggestive relations of microperoxisomes and lipid are described in the human jejunum. The microperoxisomes are strategically located between smooth endoplasmic reticulum that radiates toward the organelles and contains lipid droplets and "central domains" of highly specialized endoplasmic reticulum which do not show the lipid droplets. The microperoxisomes are also present at the periphery of large lipid-like drops. In the guinea pig kidney tubule there is a striking difference between the thick limb of Henle and distal tubule. The distal tubule has a population of cells with large numbers of microperoxisomes readily visible by light microscopy; these cells are not present in the thick limb of Henle. Other differences between the two are also described.


Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 320 ◽  
Author(s):  
Małgorzata Kozieradzka-Kiszkurno ◽  
Daria Majcher ◽  
Emilia Brzezicka ◽  
Joanna Rojek ◽  
Justyna Wróbel-Marek ◽  
...  

The suspensor in the majority of angiosperms is an evolutionally conserved embryonic structure functioning as a conduit that connects ovule tissues with the embryo proper for nutrients and growth factors flux. This is the first study serving the purpose of investigating the correlation between suspensor types and plasmodesmata (PD), by the ultrastructure of this organ in respect of its full development. The special attention is paid to PD in representatives of Crassulaceae genera: Sedum, Aeonium, Monanthes, Aichryson and Echeveria. The contribution of the suspensor in transporting nutrients to the embryo was confirmed by the basal cell structure of the suspensor which produced, on the micropylar side of all genera investigated, a branched haustorium protruding into the surrounding ovular tissue and with wall ingrowths typically associated with cell transfer. The cytoplasm of the basal cell was rich in endoplasmic reticulum, mitochondria, dictyosomes, specialized plastids, microtubules, microbodies and lipid droplets. The basal cell sustained a symplasmic connection with endosperm and neighboring suspensor cells. Our results indicated the dependence of PD ultrastructure on the type of suspensor development: (i) simple PD are assigned to an uniseriate filamentous suspensor and (ii) PD with an electron-dense material are formed in a multiseriate suspensor. The occurrence of only one or both types of PD seems to be specific for the species but not for the genus. Indeed, in the two tested species of Sedum (with the distinct uniseriate/multiseriate suspensors), a diversity in the structure of PD depends on the developmental pattern of the suspensor. In all other genera (with the multiseriate type of development of the suspensor), the one type of electron-dense PD was observed.


2001 ◽  
Vol 170 (1) ◽  
pp. 99-111 ◽  
Author(s):  
K Toda ◽  
K Takeda ◽  
T Okada ◽  
S Akira ◽  
T Saibara ◽  
...  

Aromatase P450 (CYP19) is an enzyme catalysing the conversion of androgens into oestrogens. We generated mice lacking aromatase activity (ArKO) by targeted disruption of Cyp19 and report the characteristic features of the ArKO ovaries and uteri as revealed by histological and biochemical analyses. ArKO females were totally infertile but there were as many developing follicles in their ovaries at 8 weeks of age as in wild-type ovaries. Nevertheless, no typical corpus luteum was observed in the ArKO ovaries. Electron microscopy revealed the presence of well-developed smooth endoplasmic reticulum, few lipid droplets and mitochondria with less organized tubular structures in the ArKO luteinized interstitial cells. These ultrastructural features were different from those of the wild-type interstitial cells, where there are many lipid droplets and mitochondria with well-developed tubular structures, characteristic of steroid-producing cells. When ArKO mice were supplemented with 17beta-oestradiol (E(2); 15 microg/mouse) every fourth day from 4 weeks of age for 1 month, increased numbers of follicles were observed in the ovaries as compared with those of untreated ArKO mice, although no typical corpus luteum was detectable. Ultrastructural analysis revealed the disappearance of the accumulated smooth endoplasmic reticulum in the luteinized interstitial cells after E(2 )supplementation. Transcripts of pro-apoptotic genes such as p53 and Bax genes were markedly elevated in the ArKO ovaries as compared with those of wild-type mice. Although E(2) supplementation did not cause suppression of the elevated expression of p53 and Bax mRNAs, it caused marked enhancement of expression levels of lactoferrin and progesterone receptor mRNAs in the uteri as well as increases in uterine wet weight. At 8 months of age, ArKO mice developed haemorrhages in the ovaries, in which follicles were nearly depleted, while age-matched wild-type females still had many ovarian follicles. Furthermore, macrophage-like cells were occasionally observed in the ArKO ovarian follicles. These results suggested that targeted disruption of Cyp19 caused anovulation and precocious depletion of ovarian follicles. Additionally, analysis of mice supplemented with E(2) demonstrated that E(2) apparently supports development of ovarian follicles, although it did not restore the defect in ovulation.


2010 ◽  
Vol 391 (1) ◽  
Author(s):  
Silvia Senesi ◽  
Miklos Csala ◽  
Paola Marcolongo ◽  
Rosella Fulceri ◽  
Jozsef Mandl ◽  
...  

Abstract Hexose-6-phosphate dehydrogenase (H6PD) is a luminal enzyme of the endoplasmic reticulum that is distinguished from cytosolic glucose-6-phosphate dehydrogenase by several features. H6PD converts glucose-6-phosphate and NADP+ to 6-phosphogluconate and NADPH, thereby catalyzing the first two reactions of the pentose-phosphate pathway. Because the endoplasmic reticulum has a separate pyridine nucleotide pool, H6PD provides NADPH for luminal reductases. One of these enzymes, 11β-hydroxysteroid dehydrogenase type 1 responsible for prereceptorial activation of glucocorticoids, has been the focus of much attention as a probable factor in the pathomechanism of several human diseases including insulin resistance and the metabolic syndrome. This review summarizes recent advances related to the functions of H6PD.


1979 ◽  
Vol 27 (6) ◽  
pp. 1017-1028 ◽  
Author(s):  
B S Weakley

Osmium-pyroantimonate solutions for the precipitation of cations are unsuitable for use with delicate mammalian oocytes. A variant of the pyroantimonate technique employing a mixture of pyroantimonate and glutaraldehyde has been found to give successful and repeatable results if a fixation time of 4 hr is used. Calcium-containing antimonate precipitates were localized principally in nuclei, smooth endoplasmic reticulum, Golgi apparatus, mitochondria, and cytoplasmic processes of both oocytes and follicle cells, and along the plasma membrane in small oocytes. Deposits were also concentrated around the periphery of lipid droplets in the follicle cells. The presence of calcium in the precipitates was confirmed by x-ray microprobe analysis.


2010 ◽  
Vol 70 (2) ◽  
pp. 341-350 ◽  
Author(s):  
GD Moraes ◽  
M. Achaval ◽  
MM Dal Piva ◽  
MC Faccioni-Heuser ◽  
GF Wassermann ◽  
...  

The ultrastructure of the reproductive gland, dorsal body (DB), of Megalobulimus abbreviatus was analysed. Electron microscope immunohistochemistry was used to detect FMRFamide-like peptides in the nerve endings within this gland. Nerve backfilling was used in an attempt to identify the neurons involved in this innervation. In M. abbreviatus, the DB has a uniform appearance throughout their supraesophageal and subesophageal portions. Dorsal body cells have several features in common with steroid-secreting gland cells, such as the presence of many lipid droplets, numerous mitochondria with tubular cristae and a developed smooth endoplasmic reticulum cisternae. Throughout the DB in M. abbreviatus numerous axonal endings were seen to be in contact with the DB cells exhibiting a synaptic-like structure. The axon terminals contained numerous electron-dense and scanty electron-lucid vesicles. In addition, the DB nerve endings exhibited FMRFamide immunoreactive vesicles. Injection of neural tracer into the DB yielded retrograde labelling of neurons in the metacerebrum lobe of the cerebral ganglia and in the parietal ganglia of the subesophageal ganglia complex. The possibility that some of these retrograde-labelled neurons might be FMRFamide-like neurons that may represent a neural control to the DB in M. abbreviatus is discussed.


1999 ◽  
Vol 5 (S2) ◽  
pp. 1092-1093
Author(s):  
Gurdip S. Sidhu ◽  
Nicholas D. Cassai

TRS and CCC are endoplasmic reticulum membrane-derived structures seen in HIV-infected individuals in a variety of cell types. TRS (synonym: tubuloreticular inclusions) are 24-25 nm in diameter, branching tubules which are short or long and associated with the granular or smooth endoplasmic reticulum, the Golgi complex, the perinuclear cistern, and annulate lamellae (Fig. 1-3, 8). The tubules are noticeably more stretched out in Kaposi's sarcoma endothelial cells, presumably by an increase of matrix material within the reticulum sac (Fig. 3). TRS consist of membranous components, including polypeptides, but lack nucleic acid.CCC (test tube and ring-shaped forms; curvilinear membranes) are formed by a concentric stacking of two or three cisterns of endoplasmic reticulum resembling nuclear membrane in mitosis (Fig. 7), but with the interposition between the opposing membranes of a layer of electron-dense material that is resistant to lipid solvents (Fig. 4,5,8).


1997 ◽  
Vol 34 (6) ◽  
pp. 575-584 ◽  
Author(s):  
S. Kennedy ◽  
S. McConnell ◽  
H. Anderson ◽  
D. G. Kennedy ◽  
P. B. Young ◽  
...  

Many cobalt-deficient sheep develop liver lesions known as ovine "white liver" disease, but the etiology of these changes is controversial. It has been suggested that cofactors are required for development of liver damage in cobalt-deficient sheep. In this study, one group of lambs ( n=5) was fed a diet low in cobalt (4.5 μg/kg) while a group of control lambs ( n=4) received the same diet after it had been supplemented with cobalt (1000 μg/kg). All cobalt-depleted lambs had reduced growth rate, anorexia, lacrimation, and alopecia, and they eventually became emaciated (mean body weight at end of study: 83% of initial body weight). Plasma concentrations of bilirubin and serum activity of glutamate-oxaloacetate transferase were elevated in these animals, while plasma concentrations of vitamin B12 were reduced (less than 220 pmol/L from day 42). Fatty degeneration of the liver associated with reduced concentrations of vitamin B12 (14.5 pmol/g) was seen in these animals at necropsy at 196 days. Microscopic liver lesions included accumulation of lipid droplets and lipofuscin particles in hepatocytes, dissociation and necrosis of hepatocytes, and sparse infiltration by neutrophils, macrophages, and lymphocytes. Ultrastructural hepatocytic alterations included swelling, condensation and proliferation of mitochondria, hypertrophy of smooth endoplasmic reticulum, vesiculation and loss of arrays of rough endoplasmic reticulum, and accumulation of lipid droplets and lipofuscin granules in cytoplasm of hepatocytes. No liver lesions were seen in control lambs. The results of this study indicate that cofactors are not a prerequisite to development of hepatic damage in cobalt-deficient sheep. Reduced activities of the vitamin B12-dependent enzymes, methylmalonyl CoA mutase and methionine synthase, and lipid peroxidation are of likely pathogenetic importance in the development of the lesions.


1991 ◽  
Vol 69 (7) ◽  
pp. 1880-1888 ◽  
Author(s):  
Carter T. Atkinson

Mature oocysts of Haemoproteus meleagridis developed in specimens of Culicoides edeni within 3–6 days after the midges took a blood meal from an infected domestic turkey. Approximately 50 sporozoites budded from the surface of a single sporoblast body. Sporogonic development was similar to that of reptilian, avian, and mammalian haemoproteids that are transmitted by ceratopogonid and tabanid flies, but unlike that of hippoboscid-transmitted species in birds, which form large, slowly developing oocysts with multiple sporoblast bodies. Ultrastructural features of developing oocysts included nuclei with prominent nucleoli, mitochondria, and sandwich-like arrays of crystalloid particles and smooth endoplasmic reticulum (ER) that were present on the outer surface of developing lipid droplets during early stages of sporogony. During budding of sporozoites, crystalloid particles measuring 30–40 nm in diameter were associated with the inner membrane complex of the sporozoite pellicle, arranged in rows between subpellicular microtubules. Mature sporozoites contained an apical complex composed of a polar ring with two anterior apical rings, from two to eight elongate rhoptries, 22 evenly spaced subpellicular microtubules, and a small anterior crystalloid body. Morphological similarities between the ER–crystalloid arrays and the ER–microperoxisome arrays that have been described in cells actively engaged in lipid biosynthesis suggest that the crystalloid body contains enzymes important in lipid metabolism.


Zygote ◽  
2014 ◽  
Vol 23 (4) ◽  
pp. 583-593 ◽  
Author(s):  
E.M.V. Bettencourt ◽  
C.M.V. Bettencourt ◽  
J.N. Chagas e Silva ◽  
P. Ferreira ◽  
E. Oliveira ◽  
...  

SummaryThe ultrastructure of in vivo-produced ovine embryos, at the morula, early blastocyst and late blastocyst stages, was evaluated using transmission electron microscopy. Embryonic cells were characterized by the presence of intact intercellular junctions, numerous mitochondria, smooth endoplasmic reticulum cisternae and light vesicles. Polyribosomes, rough endoplasmic reticulum cisternae, secondary lysosomes, Golgi complexes and lipid droplets were also observed in the cytoplasm. The nucleus was well defined and organized, with an intact envelope rich in nuclear pore complexes, and one or more reticular nucleoli. Microvilli were present in external blastomeres of morulae and became more abundant in trophectoderm cells of early and late blastocysts. Light vesicles seemed to be associated with small cisternae of Golgi and endoplasmic reticulum origin. These cisternae fused and created light vesicles with engulfed heterogeneous cytosolic structures, small cisternae and vesicles. Their labile membrane enabled them to rapidly coalesce into medium-sized vesicles that began to engulf mitochondria and lipid droplets, forming giant vacuoles mostly filled with fat. Incomplete matured secretory vesicles were observed to exocytose into the perivitelline space of morulae, whereas fully matured secretory vesicles appeared only in trophectoderm cells, being exocytosed into the blastocoelic cavity. These observations suggested that these endoplasmic-/Golgi-derived vesicles behave as active autophagic organelles presenting probably a maturation process from compact morulae to blastocyst.


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