Life Sciences Commons^™

Leaf Anatomy And Ultrastructure Of Poa Ligularis After Defoliation And Water Stress, M G. Klich, R E. Brevedan, S C. Villamil

IGC Proceedings (1997-2023)

The objective of this study was to determine the effect of defoliation and water stress on leaf anatomy and the mesophyll cell ultrastructure of Poa ligularis. Anatomical differences were detected mainly at epidermal level. Under water stress, leaf roughness was enhanced since the epidermal-cell surface contours became conspicuous. Under defoliation the microscopic roughness decreased as a result of fewer epicuticular wax crystals being formed. Defoliation produced an enhancement of the interlamellar spaces in the irrigated plantís chloroplast. Under no defoliation conditions, chloroplast structure was not affected by water stress. When subjected to water stress, lightly defoliated plants presented chloroplasts …

Preantral Follicle Morphometry And Ultrastructure Of Antral Follicles In Anatolian Water Buffalo, Duygu Baki̇ Acar, Muhammed Kürşad Bi̇rdane, Çi̇ğdem Tokyol, Nermi̇n Nüket Göçmen Karabeki̇r, Hati̇ce Mürvet Hayran, Erhan Özenç, Fatma Aktepe, Ebubeki̇r Yazici, İlknur Pi̇r Yağci, Mehmet Uçar

Turkish Journal of Veterinary & Animal Sciences

This study aimed to evaluate quantitative and morphometric analyses of preantral follicles and the ultrastructural characteristics of antral follicles in different oestrous cycle stages in Anatolian water buffaloes. Twenty-four ovaries collected from twelve slaughtered Anatolian water buffaloes were classified macroscopically as luteal or follicular stages. The ovaries were prepared for histological examination (Hematoxylin-eosin staining), and primordial, primary, and secondary follicle numbers were calculated, and the diameters of oocytes, follicles, and nuclei were measured under a light microscope with a micrometre. The theca and granulosa cells of antral follicles were observed under a transmission electron microscope. The mean number of preantral …

Ultrastructural Correlates Of Axons And Synapses Belonging To Different Circuits In Ferret Primary Visual Cortex, Anjelique Sawh

Dissertations and Theses

The goal of this study was to determine differences in distinctive layers of mammalian primary visual cortex through analysis of their ultrastructural characteristics. Characterizing brain circuitry using 3-dimensional reconstruction of electron microscopy images, and subsequent ultrastructural analysis of axonal populations provides us with a better understanding of the connectivity of the neural circuits. By quantifying ultrastructural differences in axonal processes such as synaptic densities, types of synapses and their post-synaptic densities (PSDs), mitochondrial volumes, synaptic vesicle aggregates, dendritic targets, and bouton volumes, we aimed to understand whether differences in anatomical specializations among different cortical layers could underlie differences in function …

Olfactory Organ Morphology And Ultrastructure Of The Larval Koh Tao Island Caecilian (Ichthyophis Kohtaoensis), Jaclyn M. Patmore

Cal Poly Humboldt theses and projects

The olfactory system of living amphibians (Lissamphibia) undergoes major changes as it transitions from an aquatic to a terrestrial system during metamorphosis. Patterns of change in the cellular morphology of the nose have been examined for frogs (Anura) and salamanders (Caudata). However, it remains unknown if caecilians (Gymnophiona) have similar patterns of change in their nasal ultrastructure. In particular, no data on larval caecilian olfactory cell types are available. Here, using light microscopy and transmission electron microscopy, I examined the olfactory organ of larvae of the caecilian Ichthyophis kohtaoensis, to establish the ultrastructure of the epithelium and compare it …

Characterization Of Hemocytes In Amblyomma Americanum And Investigation Of Traf6’S Role In Proliferation Of Hemocytes In Response To Infection, Jacquelyn T. May

Electronic Theses and Dissertations

Amblyomma americanum is a medically important vector in the southeast United States. Cellular and molecular aspects of the immune system of this species were examined. To investigate cellular processes, hemocytes produced in response to gram-negative infection were characterized according to their ultrastructure. Four hemocyte types were identified: prohemocytes, plasmatocytes, type-I granulocytes, and type-II granulocytes. To elucidate molecular processes, we investigated AamTRAF as an immune-related gene by silencing the gene using RNAi then quantifying the hemocytes after inoculation with gram-negative and positive bacteria. It was found that silencing AamTRAF caused a decrease in hemocyte proliferation in response to gram-positive but not …

Comparative Study Of The Effects Of Light On Photophore Ultrastructure From Two Families Of Deep-Sea Decapod Crustaceans: Oplophoridae And Sergestidae, Jamie E. Sickles

HCNSO Student Theses and Dissertations

Counterillumination, the mechanism by which pelagic species produce bioluminescence to replace the light blocked by their bodies to hide their silhouettes, has been known for over 100 years. However, little is known about how these animals are able to so precisely replicate the intensity of downwelling light. The recent discovery of opsins in photophores (Bracken-Grissom et al. 2020) suggests that these autogenic organs (i.e. non-bacterial) may be sensitive to light, in addition to their function of emitting visible light. The study presented here is 1) the first ultrastructural assessment of photophores in species Systellaspis debilis, Janicella spinicauda, Parasergestes armatus, …

Lorelei Localization And Ovule Ultrastructure In Arabidopsis Thaliana, Juleen May Dickson

Theses and Dissertations

Communication between the male and female gametophyte is vital to successful fertilization during sexual reproduction in plants. One of the proteins known to be important for communication between the male and female gametophyte is LORELEI (LRE). Several studies have shown that there are defects in pollen tube guidance and synergid degeneration, however this is the first study that shows that cell wall thickness in the female gametophyte may also be affected. Previous confocal studies have documented that LRE is present both in the filiform apparatus and found in puncta throughout the cytoplasm. This study confirmed this, but our studies suggest …

Ultrastructural Studies Of Acrosomal Formation In The Testis Of Male Greater Cane Rat (Thryonomys Swinderianus), A. O. Adebayo, A. K. Akinloye, Amadi O. Ihunwo, V. O. Taiwo, B. O. Oke

Brain and Mind Institute

Purpose:

In furthering the understanding of the process of spermatogenesis in the greater cane rat, this study describes the ultrastructural spermiogenic transformation and acrosomal formation in the testes of this hystricomorphic rodent that is currently undergoing domestication in parts of West Africa.

Materials and Methods:

Testicular samples were obtained from ten sexually mature cane rats that were perfused-fixed using Karnovsky's fixative (phosphate buffered 2% paraformaldehyde – 2.5% glutaraldehyde fixative at pH 7.4). The samples were processed for ultrastructural analysis and examined under the transmission electron microscope.

Results:

The testes of the cane rat showed uniqueness in its cellular associations and …

Primary Utricle Structure Of Six Halimeda Species And Potential Relevance For Ocean Acidification Tolerance, Katherine E. Peach, Marguerite S. Koch, Patricia Blackwelder, Debbie Guerrero-Given, Naomi Kamasawa

Marine & Environmental Sciences Faculty Articles

Variations in utricle morphology may be responsible for different tolerances to ocean acidification (OA) within the macroalgal genus Halimeda, an important sediment producer on reefs. However, differences in species’ utricle morphology and their relationship to calcification and crystal formation have not been well articulated. In the present study, we characterized the utricle morphologies of six Halimeda species. Primary utricle ultrastructure was quantitatively and qualitatively compared to tissue inorganic content and crystal microstructure. Morphologies differed across species and several morphometric relationships were revealed. Primary utricle size (r²=0.70) and diffusion pathway length (r²=0.87) had inverse relationships with …

Ultrastructure Of Rat Umbilical Cord Stroma-Derived Mesenchymal Stem Cells, Ahmet Ceylan, Özge Özgenç, Korhan Altunbaş, Petek Korkusuz, Asuman Özen

Turkish Journal of Veterinary & Animal Sciences

Being multipotent progenitor cells, mesenchymal stem cells continue to attract attention as a promising tool for cell-based therapy and tissue engineering. However, research on the ultrastructure of these cells is rather scarce. This study was aimed at the investigation of the transmission electron microscopic ultrastructure and morphology of mesenchymal stem cells isolated from the stroma of rat umbilical cord using the explant culture method. At the end of the third passage, some of the cells isolated from the stroma of the umbilical cord were harvested for electron microscopic examination. The remaining cells were induced for osteogenic, chondrogenic, and adipogenic differentiation. …

Water Ph Effects On Survival, Reproductive Performances, And Ultrastructure Of Gonads, Gills, And Skins Of The Javanese Medaka (Oryzias Javanicus), Ahmad Fadhil Mohd Salleh, Mohammad Noor Amal Azmai, Nurrul Shaqinah Nasruddin, Syaizwan Zahmir Zulkifli, Ferdaus Mohamat Yusuff, Wan Norhamidah Wan Ibrahim, Ahmad Ismail

Turkish Journal of Veterinary & Animal Sciences

The Javanese medaka (Oryzias javanicus) has the potential to be developed as a test organism. It also exhibited many characteristics that are similar to those of well-known laboratory fishes. This study determined the effects of water pH on the survival, reproductive performances, and ultrastructure of the gonads, gills, and skins of the Javanese medaka. This study confirmed that Javanese medakas treated with pH 6-7 displayed the lowest mortality, but increased in egg production and hatchability. This supposition is supported by strong evidence from the oocytes and testes stage analyses, including histological examinations. The ultrastructure of gills and skins of fish …

Ultrastructure Of Apoptotic T Lymphocytes And Thymicepithelial Cells In Early Postnatal Pig Thymus, Ahmet Ceylan, Belma Alabay

Turkish Journal of Veterinary & Animal Sciences

The thymus is a primary lymphoid organ that provides the microenvironment required for the development of T lymphocytes. Thymic epithelial cells (TECs) are among the most critical components in the thymic microenvironment supporting thymocyte selection and maturation. Apoptosis is primarily a physiologic process that plays a major role during the development of T lymphocytes. The first purpose of this study was to examine morphological changes in apoptotic thymocytes by transmission electron microscope in piglets. The second purpose was to reveal the morphological typology of TECs in piglets. Tissue samples of the thymus were taken from healthy Yorkshire race pigs of …

Fine Structure Of The Malpighian Tubules In Gryllus Campestris(Linnaeus, 1758) (Orthoptera, Gryllidae), Irmak Polat, Nurcan Özyurt, Damla Amutkan, Zeki̇ye Suludere, Selami̇ Candan

Turkish Journal of Zoology

The Malpighian tubules are responsible for excretion and osmoregulation in insects. The Malpighian system consists of tubules that are closed at the distal end and extend from the point of junction of the midgut and hindgut. This organ helps the water and electrolyte balance of the internal metabolism by filtration with absorption of water and soluble materials as mineral salts from the hemolymph. In this study, the histology of Malpighian tubules in Gryllus campestris (Orthoptera, Gryllidae) has been examined in detail by light microscopy, scanning electron microscopy, and transmission electron microscopy. The distal ends of the Malpighian tubules in G. …

Histology And Ultrastructure Of Montastraea Cavernosa And Porites Astreiodes During Regeneration And Recruitment: Anthropogenic Stressors And Transplant Success, Dorothy-Ellen A. Renegar

D. Abigail Renegar

Corals combine photosynthesis and calcification in an intricate and delicately balanced relationship to form large biomineralized structures that are dominant features of tropical coastlines worldwide. Coral reefs have great scientific and economic importance but have recently experienced widespread decline attributed to increasing anthropogenic pressure on reef systems. Physical damage events, such as ship groundings, when coupled with existing nutrient stress and changing global climate present a poor outlook for successful natural recovery of reef communities. The main goal of the proposed research is to better understand how environmental factors, both local and global, affect the coral holobiont and influence overall …

Ultrastructural And Histological Analysis Of Dark Spot Syndrome In Siderastrea Siderea And Agaricia Agaricites, Dorothy-Ellen A. Renegar, Patricia Blackwelder, J. D. Miller, D. J. Gochfeld, Alison L. Moulding

D. Abigail Renegar

Dark Spot Syndrome (DSS) typically manifests in scleractinian corals as lesions of varying color, size, shape and location that can result in skeletal changes and tissue death. A causative agent for DSS has not yet been identified. The objective of this study was histological and ultrastructural comparison of the cellular and skeletal characteristics of DSS-affected and healthy Siderastrea siderea and Agaricia agaricites. The greater resolution possible with transmission electron microscopy (TEM) revealed microbial activity and tissue changes not resolvable utilizing histology. DSS-affected tissue had less integrity, with increasing cellular degradation and vacuolization. A high concentration of electron dense inclusions, …

Species Specific Microcalcification In Reef Building Caribbean Corals In Ocean Acidification Conditions, Ashley M. Dungan

HCNSO Student Theses and Dissertations

Coral reefs are one of the most economically important ecosystems on the planet. Despite their great contribution to the world economy, anthropogenic influence via carbon dioxide emissions is leading to unprecedented changes with concerns about subsequent negative impacts on reefs. Surface ocean pH has dropped 0.1 units in the past century; in spite of this rapid shift in oceanic chemistry, it is unclear if individual species or life stages of Caribbean stony corals will be more sensitive to ocean acidification (OA). Examined is the relationship between CO₂-induced seawater acidification, net calcification, photosynthesis, and respiration in three model Caribbean …

Histology And Ultrastructure Of Montastraea Cavernosa And Porites Astreiodes During Regeneration And Recruitment: Anthropogenic Stressors And Transplant Success, Dorothy-Ellen A. Renegar

HCNSO Student Theses and Dissertations

Corals combine photosynthesis and calcification in an intricate and delicately balanced relationship to form large biomineralized structures that are dominant features of tropical coastlines worldwide. Coral reefs have great scientific and economic importance but have recently experienced widespread decline attributed to increasing anthropogenic pressure on reef systems. Physical damage events, such as ship groundings, when coupled with existing nutrient stress and changing global climate present a poor outlook for successful natural recovery of reef communities. The main goal of the proposed research is to better understand how environmental factors, both local and global, affect the coral holobiont and influence overall …

Ultrastructure Of The Reproductive System Of The Black Swamp Snake (Seminatrix Pygaea): Part Ii. Annual Oviducal Cycle, David Sever, Travis Ryan, Deborah Patton, Shannon Swafford

Travis J. Ryan

This article is the first ultrastructural study on the annual oviducal cycle in a snake. The ultrastructure of the oviduct was studied in 21 females of the viviparous natricine snake Seminatrix pygaea. Specimens were collected and sacrificed in March, May, June, July, and October from one locale in South Carolina during 1998–1999. The sample included individuals: 1) in an inactive reproductive condition, 2) mated but prior to ovulation, and 3) from early and late periods of gravidity. The oviduct possesses four distinct regions from cranial to caudal: the anterior infundibulum, the posterior infundibulum containing sperm storage tubules (SSTs), the uterus, …

Ultrastructure Of The Reproductive System Of The Black Swamp Snake (Seminatrix Pygaea). I. Evidence For Oviducal Sperm Storage, David Sever, Travis Ryan

Travis J. Ryan

Oviducal sperm storage in the viviparous (lecithotrophic) colubrid snake Seminatrix pygaea was studied by light and electron microscopy. Out of 17 adult snakes examined from May–October, sperm were found in the oviducts of only two specimens. In a preovulatory female sacrificed 14 May, sperm were found in the oviducal lumen and sperm storage tubules (SSTs) of the posterior infundibulum. In a nonvitellogenic female sacrificed 9 June, sperm were found in the lumen and glands of the posterior uterus and anterior vagina, indicating a recent mating. The glands in the posterior infundibulum and vagina were simple or compound tubular, whereas glands …

Ultrastructural Effects Of Lead Acetate On The Spleen Of Rats, Mesure Türkay, Hüseyi̇n Türker, Turan Güven

Turkish Journal of Biology

In this experiment, the ultrastructural effects of orally administered lead acetate on rat (Rattus rattus) spleen were studied. Rats weighing approximately 200-250 g were used in this experiment. They were divided into five groups, each one including five rats. Group I served as the normal control group while the others served as the experimental groups. The rats were exposed to oral administrations of lead acetate of 2.5 mg dissolved in 1 mL of drinking water per day. The administration lasted 96, 144, 336, and 432 h. The animals were anesthetized using chloroform inhalation and the peritoneum was stripped open and …

Morphology, Histochemistry, And Ultrastructure Of Foliar Mucilage-Producing Trichomes Of Harpagophytum Procumbens (Pedaliaceae), Yougasphree Naidoo, Samia Heneidak, Arvind Bhatt, Nazeera Kasim, Gonasageran Naidoo

Turkish Journal of Botany

The morphology, histochemistry, and ultrastructure of foliar mucilage-producing trichomes of Harpagophytum procumbens are investigated using a combination of light and electron microscopy. The leaves of H. procumbens bear short and long glandular trichomes comprising 1 or 2 basal epidermal cells, a stalk of 1-3 cells, a short neck cell, and a head of 2-5 cells. These trichomes are distributed on both leaf sides with a greater abundance on the abaxial side. Both types of trichomes secrete copious amounts of secretion as droplets onto the leaf surface, and the release occurs through micropores in the head cuticles. The secreted material is …

Aspects Of The Innate Immune System In The Caribbean Octocoral Swiftia Exserta, Lorenzo P. Menzel

FIU Electronic Theses and Dissertations

The immune systems of cnidaria are important to study for two reasons: to gain a better understanding of the evolution of immune responses, and to provide a basis to partially redress the precipitous world-wide die-offs of reef corals, some of which have been attributed to diseases and stress. Many immune responses share ancient evolutionary origins and are common across many taxa.

Using Swiftia exserta, an azooxanthellate ahermatypic local octocoral, as a proxy model organism to study aspects of innate immunity in corals and cnidaria allows us to address both of the reasons listed above while not using endangered species. …

An Expanded View Of The Eukaryotic Cytoskeleton, James B. Moseley

Dartmouth Scholarship

A rich and ongoing history of cell biology research has defined the major polymer systems of the eukaryotic cytoskeleton. Recent studies have identified additional proteins that form filamentous structures in cells and can self-assemble into linear polymers when purified. This suggests that the eukaryotic cytoskeleton is an even more complex system than previously considered. In this essay, I examine the case for an expanded definition of the eukaryotic cytoskeleton and present a series of challenges for future work in this area.

Tricellulin Deficiency Affects Tight Junction Architecture And Cochlear Hair Cells, Gowri Nayak, Sue I. Lee, Rizwan Yousaf, Stephanie E. Edelmann, Claire Trincot, Christina M. Van Itallie, Ghanshyam P. Sinha, Maria Rafeeq, Sherri M. Jones, Inna A. Belyantseva, James M. Anderson, Andrew Forge, Gregory I. Frolenkov, Saima Riazuddin

Physiology Faculty Publications

The two compositionally distinct extracellular cochlear fluids, endolymph and perilymph, are separated by tight junctions that outline the scala media and reticular lamina. Mutations in TRIC (also known as MARVELD2), which encodes a tricellular tight junction protein known as tricellulin, lead to nonsyndromic hearing loss (DFNB49). We generated a knockin mouse that carries a mutation orthologous to the TRIC coding mutation linked to DFNB49 hearing loss in humans. Tricellulin was absent from the tricellular junctions in the inner ear epithelia of the mutant animals, which developed rapidly progressing hearing loss accompanied by loss of mechanosensory cochlear hair cells, while …

Inhibition Of The Host Translation Shutoff Response By Herpes Simplex Virus 1 Triggers Nuclear Envelope-Derived Autophagy, Kerstin Radtke, Luc English, Christiane Rondeau, David Leib

Dartmouth Scholarship

Macroautophagy is a cellular pathway that degrades intracellular pathogens and contributes to antigen presentation. Herpes simplex virus 1 (HSV-1) infection triggers both macroautophagy and an additional form of autophagy that uses the nuclear envelope as a source of membrane. The present study constitutes the first in-depth analysis of nuclear envelope-derived autophagy (NEDA). We established LC3a as a marker that allowed us to distinguish between NEDA and macroautophagy in both immunofluorescence and flow cytometry. NEDA was observed in many different cell types, indicating that it is a general response to HSV-1 infection. This autophagic pathway is known to depend on the …

An Ultrastructural Study On The Merogonic Stages Of Goussia Senegalensis (Faye, 1988) Diouf And Toguebaye, 1993 (Apicomplexa, Coccidia) From The Liver Of Pagellus Bellottii (Pisces, Teleostei), Jacques Ngor Diouf, Bhen Sikina Toguebaye

Turkish Journal of Zoology

Little is known about the merogony of coccidians from fishes in Africa. To our knowledge, including both freshwater and marine fishes, developmental stages have been recorded for only Goussia cichlidarum, Cryptosporidium sp. parasitizing the stomachs of juvenile cichlid fish, and Eimeria (s. l.) vanasi. A survey of coccidians parasitizing marine fishes from the coast of Senegal (West Africa) was done between 1988 and 1992 and samples of infected organs were collected for further transmission electron microscopy observations. Merogonic stages were observed. Goussia senegalensis undergoes merogony in the hepatic cells of Pagellus bellottii as follows: meronts develop inside the cytoplasm of …

L-Arginine Protects Against Ethylene Glycol-Induced Gastric Mucosal Damage In Rats: Immunohistochemical And Electron Microscopic Study, Samah Kandeel, Thoryaa El_Deeb, Ehsan Salah, Nafisa El-Bakary, Naglaa Sarhan, Mohamed Balaha, Hiroki Sakai, Tokuma Yanai

Turkish Journal of Biology

Ethylene glycol is an alcohol widely used in industry as an antifreeze. It affects the normal gastric mucosal defense mechanisms, inducing surface ulcerations. L-arginine is a precursor of nitric oxide that exhibits multiple biological properties; among them is the acceleration of wound healing, especially in the stomach. Caspase-3 immunohistochemistry, and semithin and ultrathin section examinations were used to investigate the possible protective effect of L-arginine on ethylene glycol-induced gastric mucosal damage in rats. Three animal groups were used: group A (control group), group B (received 3.3 mL/kg ethylene glycol for 2 weeks), and group C (received 200 mg/kg of L-arginine …

Seed Coat Ultrastructure Of Hard-Seeded And Soft-Seeded Varieties Of Vicia Sativa, Hati̇ce Nurhan Büyükkartal, Hati̇ce Çölgeçen, Nur Münevver Pinar, Nesli̇han Erdoğan

Turkish Journal of Botany

The mature seed coat structure in hard-seeded and soft-seeded varieties of Vicia sativa L. was examined by scanning and transmission electron microscopy to investigate differentiation in cytological and morphological features between these varieties. The outer layer of the seed coats was composed of macrosclereid (Malpighian) cells in the hard-seeded and soft-seeded varieties of Vicia sativa. The walls of the macrosclereid cells were thickened, and the cell vacuoles were filled with tannin. The cytoplasm of the macrosclereids contained small- and large-sized vacuoles and ribosomes, mitochondria, and endoplasmic reticulum. Under this layer there was a hypodermal layer composed of osteosclereids separated by …

Septin Phosphorylation And Coiled-Coil Domains Function In Cell And Septin Ring Morphology In The Filamentous Fungus Ashbya Gossypii, Rebecca A. Meseroll, Patricia Occhipinti, Amy S. Gladfelter

Dartmouth Scholarship

Septins are a class of GTP-binding proteins conserved throughout many eukaryotes. Individual septin subunits associate with one another and assemble into heteromeric complexes that form filaments and higher-order structures in vivo. The mechanisms underlying the assembly and maintenance of higher-order structures in cells remain poorly understood. Septins in several organisms have been shown to be phosphorylated, although precisely how septin phosphorylation may be contributing to the formation of high-order septin structures is unknown. Four of the five septins expressed in the filamentous fungus, Ashbya gossypii, are phosphorylated, and we demonstrate here the diverse roles of these phosphorylation sites …

Heterogeneity In Mitochondrial Morphology And Membrane Potential Is Independent Of The Nuclear Division Cycle In Multinucleate Fungal Cells, John P. Gerstenberger, Patricia Occhipinti, Amy S. Gladfelter

Dartmouth Scholarship

In the multinucleate filamentous fungus Ashbya gossypii, nuclei divide asynchronously in a common cytoplasm. We hypothesize that the division cycle machinery has a limited zone of influence in the cytoplasm to promote nuclear autonomy. Mitochondria in cultured mammalian cells undergo cell cycle-specific changes in morphology and membrane potential and therefore can serve as a reporter of the cell cycle state of the cytoplasm. To evaluate if the cell cycle state of nuclei in A. gossypii can influ