Annulate lamellae in spermatogenous cells of Lycopodium obscurum

1995 ◽  
Vol 73 (4) ◽  
pp. 552-556
Author(s):  
John R. Palisano ◽  
Karen Sue Renzaglia ◽  
Angel Renee Maden ◽  
Dean P. Whittier
Keyword(s):  
Endoplasmic Reticulum ◽  
Key Words ◽  
Cross Section ◽  
Plant Tissue ◽  
Cell Lineage ◽  
Annulate Lamellae ◽  
Nuclear Pores ◽  
Spatial Associations ◽  
First Time ◽  
Spermatogenous Cells

The existence of annulate lamellae is detailed for the first time in the ultrastructure of a plant flagellated cell lineage. In early spermatogenous cells of Lycopodium obscurum, annulate lamellae are abundant and located adjacent to either the nucleus or plastid. Individual organelles consist of 1–11 parallel cisternae bearing tightly compacted pores that are similar in size and substructure to nuclear pores. In cross section, the pores measure 95–130 nm in diameter. Frequently, endoplasmic reticulum is continuous with the annulate lamellae cisternae. The existence of annulate lamellae in Lycopodium extends the known distribution of these organelles to rapidly proliferating spermatogenous tissue of seedless plants. Moreover, spatial associations between annulate lamellae and plastids are reported for the first time in any plant tissue. Key words: Annulate lamellae, Lycopodium, plastid, "pteridophyte," spermatogenesis, ultrastructure.

Monoplastidy in spermatogenesis of Lycopodium obscurum

1994 ◽  
Vol 72 (10) ◽  
pp. 1436-1444 ◽  
Author(s):  
Karen Sue Renzaglia ◽  
Angel R. Maden ◽  
Jeffrey G. Duckett ◽  
Dean P. Whittier
Keyword(s):  
Endoplasmic Reticulum ◽  
Key Words ◽  
Mother Cell ◽  
Annulate Lamellae ◽  
Microtubule Organizing Center ◽  
Microtubule Organizing Centers ◽  
Cell Divisions ◽  
Organizing Center ◽  
Spindle Microtubules ◽  
Spindle Development

Unlike Lycopodium laterale, which is polyplastidic during spermatogenesis, Lycopodium obscurum exhibits monoplastidy beginning in the early proliferative stages of antheridial development. Previous cell generations are polyplastidic and plastid fusion involving connective cylinders establishes the monoplastidic condition. Plastid and nuclear divisions are coordinated in L. obscurum with the plastids positioned at opposite poles prior to spindle development. Unlike monoplastidic cell divisions with morphogenetic plastid migration and polarity in other lycophytes, mosses, and hornworts, however, the spindles in L. obscurum do not originate from the plastid envelopes but from endoplasmic reticulum positioned against the plastid. In the final divisions, spindle microtubules emanate from structurally defined microtubule organizing centers that develop between the plastids and nucleus. Preceding the appearance of centrioles in the spermatid mother cell, the centrosomes comprise electron-dense granular matrices with associated vesicles and endoplasmic reticulum. Among archegoniate microtubule organizing centers, the discrete acentriolar centrosomes of Lycopodium most closely resemble the microtubule organizing centers in moss spore development and the polar organizer of liverwort mitosis. Key words: annulate lamellae, centrosome, Lycopodium, microtubule organizing center, monoplastidy, plastid dividing ring.

scholarly journals THE RABBIT ZYGOTE

1972 ◽  
Vol 55 (3) ◽  
pp. 533-541 ◽  
Author(s):  
Bela J. Gulyas
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Nuclear Envelope ◽  
Smooth Endoplasmic Reticulum ◽  
Annulate Lamellae ◽  
Nuclear Pores ◽  
Late Anaphase ◽  
Dense Nucleus

The formation of the blastomere nucleus was examined in the rabbit zygote with the electron microscope. In late anaphase the chromosomes are bare and vesicles of the smooth endoplasmic reticulum are numerous in the vicinity of the chromosomes. In early telophase individual chromosomes attain their own nuclear envelope and they are called karyomeres. The envelope of the karyomeres contains small gaps within it at several places where the chromatin is exposed to the cytoplasm. Nuclear pores are also observed. In the cytoplasm short annulate lamellae appear adjacent to the karyomeres, and clusters of punctate substance are also present. From early telophase onward the karyomeres extend pseudopod-like structures, called karyopods, which extend toward other karyomeres or karyopods, and consequently fuse together and serve as chromosomal bridges. Eventually all of the karyomeres fuse into a dense nucleus and decondensation of the chromosomes occurs.

Fine-structural studies of the gametes and embryo of Fucus vesiculosus L. (Phaeophyta). III. Cytokinesis and the multicellular embryo

1977 ◽  
Vol 24 (1) ◽  
pp. 275-294
Author(s):  
S.H. Brawley ◽  
R.S. Quatrano ◽  
R. Wetherbee
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Daughter Cell ◽  
Fucus Vesiculosus ◽  
Complete Disappearance ◽  
Annulate Lamellae ◽  
Nuclear Pores ◽  
Cell Stage ◽  
Golgi Bodies ◽  
Daughter Cells

Condensation of the chromosomes during the first cell division following fertilization of the brown alga Fucus vesiculosus L. is accompanied by the almost complete disappearance of the nuclear envelope. Golgi vesicles and other small vesicles appear within the spindle, which has paired centrioles at each end. A large amount of rough endoplasmic reticulum is in the surrounding cytoplasm during mitosis, and many vesicles at the spindle margin are encircled by stacks of endoplasmic reticulum. Annulate lamellae are observed during mitosis. The envelope which initially reforms around the chromatin in telophase has unevenly spaced nuclear pores. Cytokinesis results primarily by vesicle addition to a centripetal furrow. Mitochondria and chloroplasts concentrate around the partition site, possibly in association with microfilaments. Fibrillar material is added rapidly to the space between the daughter cells from vesicle discharge of both cells and seems to spread into the older cell wall surrounding the embryo. The rhizoid daughter cell contains numerous mitochondria and hypertrophied Golgi bodies whose vesicles increasingly pack the cell. The thallus daughter cell is packed with a variety of vesicles, and the nucleus is surrounded by many dilated cisternae of rough endoplasmic reticulum. By the four-cell stage, chloroplasts of the rhizoid cells have weakly staining lamellae, while chloroplasts of the thallus cells are actively dividing with deeply staining lamellae.

Annulate lamellae in the Sertoli cells of guinea pig testis after unilateral torsion of the spermatic cord

1984 ◽  
Vol 42 ◽  
pp. 196-197
Author(s):  
J. Chakraborty ◽  
A. P. Sinha Hikim ◽  
J. S. Jhunjhunwala
Keyword(s):  
Sertoli Cells ◽  
Guinea Pigs ◽  
Spermatic Cord ◽  
Present Report ◽  
Cell Types ◽  
Annulate Lamellae ◽  
Spermatogenic Cells ◽  
Electron Microscopic ◽  
Structural Details ◽  
First Time

Although the presence of annulate lamellae was noted in many cell types, including the rat spermatogenic cells, this structure was never reported in the Sertoli cells of any rodent species. The present report is based on a part of our project on the effect of torsion of the spermatic cord to the contralateral testis. This paper describes for the first time, the fine structural details of the annulate lamellae in the Sertoli cells of damaged testis from guinea pigs.One side of the spermatic cord of each of six Hartly strain adult guinea pigs was surgically twisted (540°) under pentobarbital anesthesia (1). Four months after induction of torsion, animals were sacrificed, testes were excised and processed for the light and electron microscopic investigations. In the damaged testis, the majority of seminiferous tubule contained a layer of Sertoli cells with occasional spermatogonia (Fig. 1). Nuclei of these Sertoli cells were highly pleomorphic and contained small chromatinic clumps adjacent to the inner aspect of the nuclear envelope (Fig. 2).

An effectiveness of training program on COVID-19 among healthcare students: A cross section study

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 1250-1254
Author(s):  
Kurvatteppa Halemani ◽  
Merlin Cheema ◽  
Shabana Khatun ◽  
Yadidya ◽  
Bhumika Singh ◽  
...  
Keyword(s):  
Nursing Students ◽  
Training Program ◽  
Cross Section ◽  
Sampling Technique ◽  
Teaching Session ◽  
Post Intervention ◽  
Post Test ◽  
College Of Nursing ◽  
Novel Coronavirus ◽  
First Time

The pandemic COVID-19 is a highly infected disease caused by a novel coronavirus or SARS-Cov-2. The virus was reported for the first time  December 2019 in, China's Wuhan province. Later the virus has broken down into the world and claimed millions of lives. In India, the disease was reported for the first time in Kerala on 30th January 2020. a cross-section one group pre-test & post-test research design was used among the 40 final year BSc nursing students, College of Nursing SGPGIMS, Lucknow India. Samples were selected based on purposive sampling technique and sample criteria. An instrument, the first tool included demographic characteristics Similarly, second instrument used for knowledge assessment. After pre-test assessment, a teaching session was held at the seminar room, college of nursing SGPGIMS Lucknow, India. Subsequently post assessment was held after intervention.  A total of 40 participants responded to the study. Demographic variables like 30(75%) participants had less than 22 years of age, 22(55%) were girls, 14(35%) families income found INR 10000-15000, and the majority of participants obtained COVID-19 related knowledge from news paper16(40%). A gender was found significant with pretest knowledge, and other variables weren't found significant (P=0.05). Knowledge mean & standard deviation in pre & post-intervention, 11.90±2.16 vs15.82±1.39. The mean difference was found in a pre-test & post-test-1 &post-test-2, 3.9, 5.02, & 1.1, respectively. The effectiveness of the training program was checked by paired t-test -10.20 & -13.93, P=0.00.  The study revealed that the teaching session was efficient in the COVID-19 program among BSc nursing students.

RESULTS OF INTRALESIONAL TRIAMCINOLONE ACETONIDE FOR CHALAZION TREATMENT

2011 ◽  
pp. 100-104
Author(s):  
Thi Thu Nguyen ◽  
Viet Hien Vo ◽  
Thi Em Do
Keyword(s):  
Success Rate ◽  
Key Words ◽  
Triamcinolone Acetonide ◽  
Lower Eyelid ◽  
Upper Eyelid ◽  
Interventional Trial ◽  
The Mean ◽  
First Time

The study use intralesional triamcinolone acetonide injection proceduce for chalazion treatment.1. Objectives: To evaluate results of intralesional triamcinolone acetonide injection for chalazion treatment. 2. Method: This noncomparative prospective interventional trial included 72 chalazions of 61 patients. 3. Results: 61 patients (72 chalazions) with 19 males (31.1%) và 42 females (68.9%), the mean age was 24 ± 9,78 years. 31.1% patients was the first time chalazion and 68.9% patients was more than one times chalazion including 78.6% patients was recurrent at the first position and 21.4% patients occur at new position. 72 chalazions with 16 (22.2%) chalazions was treated before and 56 (77.8%) chalazions wasn’t done that. 72 chalazions with 49 chalazions (68.1%) are local in upper eyelid and 23 chalazions (31.9%) are local in lower eyelid. The mean of chalazion diameter is 6.99 ± 3.03mm. Intralesional triamcinolone acetonide is injected to treat 72 chalazions with 16 (22.2%) chalazions are injected through the route of skin and 56 (77.8%) chalazions are injected through the route of conjunctiva. After 2 weeks follow-up, the success rate was 93.1% and 6.9% failed. 4. Conclusion: intralesional triamcinolone acetonide injection for chalazion treatment is really effective. Key words: chalazion, intralesional triamcinolone acetonide.

scholarly journals On the shape of cicada’s wing leading-edge cross section

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rachel M. Starkweather ◽  
Svetlana V. Poroseva ◽  
David T. Hanson
Keyword(s):  
Cross Section ◽  
Insect Flight ◽  
Leading Edge ◽  
Flight Performance ◽  
Cross Section Shape ◽  
Section Shape ◽  
First Time

AbstractAn important role that the leading-edge cross-section shape plays in the wing flight performance is well known in aeronautics. However, little is known about the shape of the leading-edge cross section of an insect’s wing and its contribution to remarkable qualities of insect flight. In this paper, we reveal, in the first time, the shape of the leading-edge cross section of a cicada’s wing and analyze its variability along the wing. We also identify and quantify similarities in characteristic dimensions of this shape in the wings of three different cicada species.

scholarly journals Structure of the Lectin Mannose 6-Phosphate Receptor Homology (MRH) Domain of Glucosidase II, an Enzyme That Regulates Glycoprotein Folding Quality Control in the Endoplasmic Reticulum

2013 ◽  
Vol 288 (23) ◽  
pp. 16460-16475 ◽  
Author(s):  
Linda J. Olson ◽  
Ramiro Orsi ◽  
Solana G. Alculumbre ◽  
Francis C. Peterson ◽  
Ivan D. Stigliano ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Three Dimensional ◽  
Binding Pocket ◽  
Dimensional Structure ◽  
Mannose Residue ◽  
Glucosidase Ii ◽  
Mannose 6 Phosphate ◽  
First Time ◽  
Conserved Residue

Here we report for the first time the three-dimensional structure of a mannose 6-phosphate receptor homology (MRH) domain present in a protein with enzymatic activity, glucosidase II (GII). GII is involved in glycoprotein folding in the endoplasmic reticulum. GII removes the two innermost glucose residues from the Glc3Man9GlcNAc2 transferred to nascent proteins and the glucose added by UDP-Glc:glycoprotein glucosyltransferase. GII is composed of a catalytic GIIα subunit and a regulatory GIIβ subunit. GIIβ participates in the endoplasmic reticulum localization of GIIα and mediates in vivo enhancement of N-glycan trimming by GII through its C-terminal MRH domain. We determined the structure of a functional GIIβ MRH domain by NMR spectroscopy. It adopts a β-barrel fold similar to that of other MRH domains, but its binding pocket is the most shallow known to date as it accommodates a single mannose residue. In addition, we identified a conserved residue outside the binding pocket (Trp-409) present in GIIβ but not in other MRHs that influences GII glucose trimming activity.

On the Baeocera Erichson (Coleoptera: Staphylinidae: Scaphidiinae) of Sabah, Malaysia, and a tale on mystified biodiversity

2021 ◽  
Vol 23 (2) ◽  
pp. 23-42
Author(s):  
IVAN LÖBL ◽  
ALEŠ SMETANA
Keyword(s):  
New Species ◽  
Species Diversity ◽  
Key Words ◽  
Sampling Methods ◽  
Biodiversity Study ◽  
First Time

Quantitative attemps to assess species diversity in the absence of a robust taxonomy are questioned. In addition, the sampling methods may be a major source of uncertainty, as illustrated in a commented biodiversity study of the Coleoptera of Sabah. The Sabah members of the staphylinid genus Baeocera Erichson are reviewed and keyed, the following new species are described: B. omnigena Löbl sp. nov., B. rudis Löbl sp. nov., B. secreta Löbl sp. nov., B. sedata Löbl sp. nov., B. segregata Löbl sp. nov., B. seiugata Löbl sp. nov., B. semirufa Löbl sp. nov. Baeocera barbara Löbl, B. obliqua (Löbl), B. rufula (Löbl) and B. serendibensis (Löbl) are reported for the first time from Malaysia, B. doriae (Pic) and B. sarawakensis Löbl are new to Sabah and B. kinabalua Löbl is new to Sarawak. Key words: biodiversity, trends, taxonomy, insects, shining fungus beetles, Borneo

An updated checklist of Turkish crabronid wasps (Hymenoptera: Crabronidae) with new and additional records

2021 ◽  
Vol 21 (2) ◽  
pp. 18-109
Author(s):  
EMIN KAPLAN ◽  
EROL YILDIRIM
Keyword(s):  
Key Words ◽  
New Records ◽  
First Time

An updated checklist of the wasp family Crabronidae in Turkey is provided. It is based on records present in the literature and on newly identified specimens collected in Turkey. In this study, 537 species and 16 subspecies in 65 genera are listed. Among them, five species, namely Dryudella esterinae Pagliano, 2001, Nysson mimulus Valkeila, 1964, Crossocerus pullulus A. Morawitz, 1866, Oxybelus spectabilis Gerstaecker, 1867 and Diodontus insidiosus Spooner, 1938 are recorded for the first time from Turkey. New and additional records for 114 species are given. Collection localities and photographs of newly identified species are provided. Key words: Hymenoptera, Crabronidae, checklist, new records, additional records, Turkey

Sign in / Sign up

Export Citation Format

Share Document