Comparative ultrastructure and biochemistry of chytridiomycetous fungi and the future of the Harpochytriales

1980 ◽  
Vol 58 (19) ◽  
pp. 2098-2109 ◽  
Author(s):  
Larry P. Gauriloff ◽  
Rona J. Delay ◽  
Melvin S. Fuller
Keyword(s):  
Fine Structure ◽  
Ribosomal Rna ◽  
Posterior Region ◽  
Anterior Region ◽  
Serial Sections ◽  
Molecular Weights ◽  
Body Complex ◽  
Translucent Material ◽  
Relationship Of ◽  
Comparative Ultrastructure

The ultrastructure of the zoospores of Oedogoniomyces lymnaeae and Monoblepharella sp. are reexamined using serial sections. The relative molecular weights of the ribosomal RNA of various chytridiomycetous fungi are also determined and compared. The fine structure of each of these zoospores is very similar. The nucleus and "nuclear cap" are centrally located in the zoospores. The anterior region contains lipid globules, a few large, empty vacuoles and numerous, small vesicles. The posterior region is filled with an electron-translucent material throughout which are scattered spherical mitochondria and large vacuoles with electron-opaque inclusions. The basal body complex is located at the center of the posterior end, and the rumposomal complex is adjacent to the plasmalemma in the posterior region of these zoospores. A system of cisternae that are associated with microbodies appears to connect the lipid globules in the anterior region with the rumposomal complex in the posterior region of these zoospores. Small differences in the structure and distribution of certain organelles are considered minor compared with the overall similarities between these two zoospores. It is suggested that Oedogoniomyces be transferred to the Monoblepharidales. The fine structure of the Harpochytrium hedinii zoospore is not only similar to that of the zoospores studied herein, but also resembles the zoospores of chytrids. The possible relationship of Harpochytrium to the Chytridiales is supported by zoospore ultrastructure and the relative molecular weights of ribosomal RNA. The data available at the present time suggest that the order Harpochytriales be abandoned and that Harpochytrium be considered either a genus of nematosporangial, operculate, eucarpic chytrids or a monoblepharidalean genus with Oedogoniomyces. It is recommended that speculation concerning the taxonimic relationship between Harpochytrium and other Chytridiomycetes be delayed until more data concerning other species of Harpochytrium and monoblepharidalean fungi are available.

The fine structure of zoospores of Harpochytrium hedinii

1980 ◽  
Vol 58 (19) ◽  
pp. 2090-2097 ◽  
Author(s):  
Larry P. Gauriloff ◽  
Rona J. Delay ◽  
Melvin S. Fuller
Keyword(s):  
Fine Structure ◽  
Basal Body ◽  
Posterior Region ◽  
Anterior Region ◽  
Serial Sections ◽  
Wide System ◽  
Body Complex

The fine structure of the Harpochytrium hedinii Wille zoospore is reexamined using serial sections. All of the major organelles are located in the posterior two-thirds of the zoospore; the anterior region contains only a few vacuoles and a network of filaments. The basal body complex is located at the center of the posterior end of the zoospore. The nucleus and "nuclear cap" are located directly anterior to the basal body complex on one side of the zoospore. All of the microbodies, lipid globules, and mitochondria are arranged into a complex associated with the rumposome along the opposite side of the zoospore. A spore-wide system of cisternae, the vesicular system, is continuous throughout the posterior region of the zoospore. The overall arrangement of organelles in the H. hedinii zoospore most closely resembles the internal morphologies of certain chytridialean zoospores. This suggests that Harpochytrium may be more closely related to the chytrids than has been previously assumed.

GAMBARAN MALOKLUSI BERDASARKAN INDEKS HANDICAPPING MALOCCLUSION ASSESSMENT RECORD (HMAR) PADA SISWA SMA N 9 MANADO

e-GIGI ◽  
2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Monalisa Loblobly ◽  
P. S. Anindita ◽  
Michael A. Leman
Keyword(s):  
Total Sample ◽  
Posterior Region ◽  
Anterior Region ◽  
Cross Sectional ◽  
Consecutive Sampling ◽  
Need Of Care ◽  
Cross Sectional Design ◽  
Jaw Position ◽  
Relationship Of ◽  
The Relationship

Abstract: Malocclusion is a condition of abnormal occlusion. If it is not treated it will result in several diseases for the patients. Studies about malocclusion have been done in several cities in Indonesia which showed that many people with malocclusion did not seek for treatment. One of the ways to identify and assess the severity of malocclusion is using the Handicapping Malocclusion Index Assessment Record (Hmar). This study aimed to describe malocclusions in students of SMA N 9 Manado.This was a descriptive cross sectional design. The study was conducted in August 2015 with a total sample of 30 students in grade eleven, obtained by using consecutive sampling. Malocclusion assessment obtained using HMAR consisted of comprising the teeth in one jaw, abnormal tooth relationships of both jaws in occlusion, and dentofacial abnormality examinations. The results showed that based on HMAR most of the malocclusions were in the severe category which were in need of care. Irregular teeth in one jaw in the anterior and posterior regions was the highest form of tooth rotation and tooth crowding. Abnormality in the relationship of both jaws in the occluded jaw position in the anterior region was the highest in the case of excessive nip distance and the lowest cross bites meanwhile in the posterior region was the mesial position of caninus. Concerning dentofacial abnormalities, there was only one palatal bite abnormality. Conclusion: Based on HMAR the highest percentage of malocclusion in this study was severe malocclusion.Keywords: malocclusion, malocclusion handicapping index assessment recordAbstrak: Maloklusi merupakan bentuk oklusi menyimpang dari normal yang jika tidak dirawat akan mengakibatkan hambatan bagi penderita. Penelitian mengenai maloklusi sudah dilakukan pada beberapa kota di Indonesia yang menunjukan bahwa banyak orang yang mengalami maloklusi tetapi tidak melakukan perawatan. Salah satu cara mengidentifikasi dan menilai keparahan maloklusi yaitu menggunakan Indeks Handicapping Malocclusion Assessment Record (HMAR). Penelitian ini bertujuan untuk mengetahui gambaran maloklusi berdasarkan Indeks HMAR pada siswa SMA N 9 Manado. Penelitian ini bersifat deskriptif dengan rancangan potong lintang. Penelitian ini dilaksanakan pada bulan Agustus tahun 2015 dengan jumlah sampel 30 siswa kelas sebelas, menggunakan consecutive sampling. Penilaian maloklusi diperoleh dengan pemeriksaan berdasarkan indeks HMAR pada model studi. Penilaian meliputi penyimpangan gigi dalam satu rahang, kelainan hubungan gigi kedua rahang dalam keadaan oklusi, dan kelainan dentofasial. Hasil penelitian penyimpangan gigi dalam satu rahang menunjukan persentase tertinggi yaitu gigi rotasi pada rahang atas. Kelainan hubungan gigi kedua rahang dalam keadaan oklusi menunjukkan di regio anterior presentase tertinggi yaitu berupa jarak gigit berlebih dan di regio posterior persentase tertinggi berupa kelainan anteroposterior yang menunjukkan gigi kaninus lebih ke mesial. Kelainan dentofasial hanya ditemukan satu kelainan berupa palatal bite. Simpulan: Gambaran maloklusi berdasarkan indeks HMAR dengan persentase tertinggi yaitu pada kategori maloklusi berat, sangat memerlukan perawatan.Kata kunci: maloklusi, indeks HMAR

scholarly journals DNA AND THE FINE STRUCTURE OF SYNAPTIC CHROMOSOMES IN THE DOMESTIC ROOSTER (GALLUS DOMESTICUS)

1964 ◽  
Vol 23 (1) ◽  
pp. 63-78 ◽  
Author(s):  
James R. Coleman ◽  
Montrose J. Moses
Keyword(s):  
Electron Microscopy ◽  
Heavy Metal ◽  
Fine Structure ◽  
Electron Microscope ◽  
Meiotic Prophase ◽  
Gallus Domesticus ◽  
Feulgen Staining ◽  
Synaptinemal Complex ◽  
Relationship Of ◽  
The Relationship

The indium trichloride method of Watson and Aldridge (38) for staining nucleic acids for electron microscopy was employed to study the relationship of DNA to the structure of the synaptinemal complex in meiotic prophase chromosomes of the domestic rooster. The selectivity of the method was demonstrated in untreated and DNase-digested testis material by comparing the distribution of indium staining in the electron microscope to Feulgen staining and ultraviolet absorption in thicker sections seen with the light microscope. Following staining by indium, DNA was found mainly in the microfibril component of the synaptinemal complex. When DNA was known to have been removed from aldehyde-fixed material by digestion with DNase, indium stainability was also lost. However, staining of the digested material with non-selective heavy metal techniques demonstrated the presence of material other than DNA in the microfibrils and showed that little alteration in appearance of the chromosome resulted from DNA removal. The two dense lateral axial elements of the synaptinemal complex, but not the central one to any extent, also contained DNA, together with non-DNA material.

scholarly journals A highly polarized excitable cell separates sodium channels from sodium-activated potassium channels by more than a millimeter

2015 ◽  
Vol 114 (1) ◽  
pp. 520-530 ◽  
Author(s):  
Yue Ban ◽  
Benjamin E. Smith ◽  
Michael R. Markham
Keyword(s):  
Ion Channels ◽  
Three Dimensional ◽  
Electric Organ ◽  
Metabolic Cost ◽  
Great Distance ◽  
Posterior Region ◽  
Anterior Region ◽  
Cell Periphery ◽  
Spatial Coupling ◽  
Eigenmannia Virescens

The bioelectrical properties and resulting metabolic demands of electrogenic cells are determined by their morphology and the subcellular localization of ion channels. The electric organ cells (electrocytes) of the electric fish Eigenmannia virescens generate action potentials (APs) with Na+ currents >10 μA and repolarize the AP with Na+-activated K+ (KNa) channels. To better understand the role of morphology and ion channel localization in determining the metabolic cost of electrocyte APs, we used two-photon three-dimensional imaging to determine the fine cellular morphology and immunohistochemistry to localize the electrocytes' ion channels, ionotropic receptors, and Na+-K+-ATPases. We found that electrocytes are highly polarized cells ∼1.5 mm in anterior-posterior length and ∼0.6 mm in diameter, containing ∼30,000 nuclei along the cell periphery. The cell's innervated posterior region is deeply invaginated and vascularized with complex ultrastructural features, whereas the anterior region is relatively smooth. Cholinergic receptors and Na+ channels are restricted to the innervated posterior region, whereas inward rectifier K+ channels and the KNa channels that terminate the electrocyte AP are localized to the anterior region, separated by >1 mm from the only sources of Na+ influx. In other systems, submicrometer spatial coupling of Na+ and KNa channels is necessary for KNa channel activation. However, our computational simulations showed that KNa channels at a great distance from Na+ influx can still terminate the AP, suggesting that KNa channels can be activated by distant sources of Na+ influx and overturning a long-standing assumption that AP-generating ion channels are restricted to the electrocyte's posterior face.

scholarly journals Nasal Wall Oriented Implants for All-on-4 Fix-Detachable Maxillary Reconstruction

2020 ◽  
pp. 151-160
Author(s):  
Jean Uhlendorf ◽  
Carolina A. Cartelli ◽  
Larissa C. Trojan ◽  
Geninho Thomé ◽  
Marcos B. Moura
Keyword(s):  
Case Report ◽  
Dental Implants ◽  
Dental Care ◽  
Clinical Case ◽  
Posterior Region ◽  
Anterior Region ◽  
Second Step ◽  
Immediate Loading ◽  
Viable Option ◽  
Tapered Connection

Immediate loading of full-arch prostheses on dental implants in the upper arch is challenging, as the bone is of low quality and obtaining sufficient torque may be difficult. The purpose of this case report is to describe the rehabilitation of a full-arch by means of placement of four internal tapered connection tilted implants and immediate loading. A 65-year-old man sought dental care with a partially edentulous upper arch. The teeth presented mobility and were extracted. In a second step, two conventional-length implants were placed in the anterior region and two tilted and nasal wall–directed extra-long implants in the posterior region. The insertion torques of 60 N.cm allowed the installation of an immediate prosthesis (hybrid). The clinical case report suggests that the placement of tilted and extra-long implants in the paranasal bone and immediate loading may be a viable option for rehabilitation of the edentulous upper arch.

scholarly journals A comparative study of the brains in pleuronectidae

1937 ◽  
Vol 122 (828) ◽  
pp. 308-343 ◽  
Keyword(s):  
Comparative Study ◽  
Medulla Oblongata ◽  
Royal Society ◽  
Feeding Habits ◽  
Serial Sections ◽  
Naked Eye ◽  
The Family ◽  
Relationship Of ◽  
The Relationship ◽  
The Brain

Part I. The Medulla Oblongata, And Its Variations Acoording To Diet And Feeding Habits In previous communications to this Society the relationship of the habits of feeding and diet to the form and pattern of the medulla oblongata has been described in the cyprinoids, clupeids, and gadoids (Evans, 1931, 1932, 1935). This research takes up a similar study of the brain of the Pleuronectidae. The expense has been borne by a grant from the Royal Society for which the author tenders his grateful thanks. It has seemed to be desirable to extend the observations to the fore- and mid-brain, as in some members of the family these present a very marked development. In order to elucidate some of the problems that arise I have also studied the brain of the eel, and some interesting conclusions have resulted. We find, as a result of examination by the naked eye and of serial sections, that we can divide the following species into four groups as follows: I. The sole, Solea vulgaris .

Memoirs: The Morphology and Development of the Genitalia and Genital Ducts of Homoptera and Zygoptera as Shown in the Life Histories of Philaenus and Agrion

1928 ◽  
Vol s2-72 (287) ◽  
pp. 447-483
Author(s):  
C. J. GEORGE
Keyword(s):  
Anterior Part ◽  
Ejaculatory Duct ◽  
Accessory Gland ◽  
Posterior Region ◽  
Anterior Region ◽  
Vaginal Opening ◽  
Forward Region ◽  
Efferent System ◽  
Accessory Glands ◽  
The Common

1. In the male Philaenus and Agrion the vasa deferentia terminate on the ninth segment in the early stages. An ectodermal invagination from that segment joins them subsequently and thus the male gonopore is established. 2. The accessory glands develop in Philaenus male from the anterior end of the swollen extremities of the vasa deferentia and the vesiculae seminales from a still more forward region. 3. The accessory glands of the male are mesodermal in origin and not ectodermal as some authors state. 4. There is no evidence as to the existence of a ‘pair of ectodermal ejaculatory’ ducts either in Philaenus orin Agrion, and reasons are adduced to show that they do not exist at all in the higher Insecta. 5. In the female nymph of Philaenus the oviducts terminate on the seventh segment. They are subsequently joined by an ectodermal invagination from the seventh segment. The common oviduct is formed in two parts: the anterior part is derived from the posterior region of the invagination on the seventh and the posterior region is formed as a groove from the ectodermis of the eighth segment and subsequently this groove is converted into a tube. When the second part is completed it is in connexion with the invagination from the seventh and opens to the outside on the eighth segment. The ectodermal invagination from the seventh also gives rise to the spermatheca. A median accessory gland develops as an invagination from the ninth segment between the bases of the inner ovipositor lobes. A pair of accessory glands develop as paired imaginations from the anterior region of the ninth segment. 6. In the female nymph of Agrion the oviducts fuse to form a single duct and terminate in the middle of the eighth segment. Posteriorly an ectodermal invagination from the eighth segment meets this duct and lies in a position dorsal to it. Later on the ectodermal invagination develops a spermatheca dorsally and the mesodermal and the ectodermal ducts unite into one. The accessory glands develop as paired ectodermal invaginations from the anterior region of the ninth segment. 7. The female gonopore is not homologous in the different groups of insects. The vaginal opening in Orthoptera, Hymenoptera, Homoptera, Diptera, and Lepidoptera is homologous. The vaginal opening in Coleoptera is homologous with the oviducal opening of Lepidoptera, with the opening of the accessory gland of Homoptera, Hymenoptera, Diptera, Isoptera, and the opening of the spermatheca in some Orthoptera. 8. The common oviduct, being formed differently in the different groups is not homologous. The accessory organs, e. g. spermatheca, are not homologous in the different groups. 9. There is no evidence to show that the common oviduct is of paired origin. 10. The occurrence of a median accessory structure on the ninth segment which develops in the young as an invagination between the bases of the inner ovipositor lobes is very general in the higher Insecta. In some it functions as a gland, in others as a storehouse for spermatozoa. 11. The homology of the paired accessory glands is indicated. 12. The male genital ducts are not strictly homologous with those of the female. The homologue of the ejaculatory duct is the invagination from the ninth segment in the female. 13. The Odonata stand isolated in having a mesodermal region for the common oviduct and in the peculiar development of the two processes between the anterior ovipositor lobes. 14. The probable lines of evolution of the female efferent system in Insecta are indicated. The study of the development of the female efferent system indicates that the groups Orthoptera, Homoptera, Lepidoptera, and Diptera are very closely allied. Coleoptera seem to have had quite a different line of evolution from the above groups in this respect. 15. The adult Odonatan anatomy of the genital organs in the female as observed by me is in some respects different from that described by Tillyard. In conclusion I wish to express my deep sense of gratitude towards Professor Balfour-Browne and Dr. J. W. Munroe, both of whom have always been ready to help me. My colleague Mr. R. I. Nel, who is working on similar lines in this department,, has rendered me valuable help, not only in matters connected with the subject proper but also in translating difficult German references. I am also indebted to Mr. Peter Gray who helped me a good deal in translating references in Italian.

Palate Morphogenesis

Development ◽  
1979 ◽  
Vol 53 (1) ◽  
pp. 75-90
Author(s):  
Elizabeth L. Wee ◽  
Bruce S. Babiarz ◽  
Stephen Zimmerman ◽  
Ernest F. Zimmerman
Keyword(s):  
Embryo Culture ◽  
Posterior Region ◽  
Anterior Region ◽  
Serotonin Antagonists ◽  
A Cell ◽  
Pharmacologic Agents ◽  
Muscle Contractile ◽  
Contractile Cells

Previous studies have localized non-muscle contractile systems in the posterior (region 2) and the anterior (region 3) ends of mouse palates at the time of shelf movement. In order to determine whether these contractile systems function in shelf rotation, effects of pharmacologic agents have been analyzed in embryo culture. First, it was shown that the posterior end of the palate rotates before the anterior end, and its rotation in culture was proportionally greater as development of the embryo progressed. Generally, the posterior end of the palate was more easily inhibited in embryo culture than the anterior end. Serotonin at 10–−8 M to 10–−5 M was shown to significantly stimulate rotation atthe anterior end of the palate after 2 h in embryo culture. The effect on the posterior palate was less pronounced. To investigate further the role of this neurotransmitter on palate shelf rotation, serotonin antagonists were employed. Methysergide (10–−4 M) inhibited anterior shelf rotation to 12% of control values (P < 0·005), while not significantly affecting the posterior end. Ergotamine (10–−6 M) significantly inhibited the stimulation induced by 10–−5 M serotonin (P < 0·025). Cyproheptadine (10–−9 M) partially inhibited anterior and posterior shelf rotation in embryo culture. When injected into the pregnant dam, cyproheptadine partially inhibited shelf rotation and fusion. The palate was examined histologically after embryo culture. In the presence of 10–−4 M methysergide, the elongated contractile cells in region 3 at the anterior and midpalatal mesenchyme were prevented from rounding. Thus, serotonin may be regulating rotation of the anterior end of the palate by an effect on a cell-mediated process.

Characterization of SSU and LSU rRNA genes of threeTrypanosoma (Herpetosoma) grosiisolates maintained in Mongolian jirds

Parasitology ◽  
2004 ◽  
Vol 130 (2) ◽  
pp. 157-167 ◽  
Author(s):  
H. SATO ◽  
A. OSANAI ◽  
H. KAMIYA ◽  
Y. OBARA ◽  
W. JIANG ◽  
...  
Keyword(s):  
Ribosomal Rna ◽  
Geographical Origin ◽  
Large Subunit ◽  
Meriones Unguiculatus ◽  
Rrna Genes ◽  
Systematic Revision ◽  
Rdna Sequences ◽  
Relationship Of ◽  
Rna Genes

Trypanosoma (Herpetosoma) grosi, which naturally parasitizesApodemusspp., can experimentally infect Mongolian jirds (Meriones unguiculatus). Three isolates fromA. agrarius,A. peninsulae, andA. speciosus(named SESUJI, HANTO, and AKHA isolates, respectively) of different geographical origin (AKHA from Japan, and the others from Vladivostok), exhibited different durations of parasitaemia in laboratory jirds (2 weeks for HANTO, and 3 weeks for the others). To assess the genetic background of theseT. grosiisolates, their small (SSU) and large subunit (LSU) ribosomal RNA genes (rDNA) were sequenced along with those of 2 otherHerpetosomaspecies from squirrels. The SSU rDNA sequences of these 3 species along with available sequences of 3 otherHerpetosomatrypanosomes (T. lewisi,T. musculiandT. microti)seemed to reflect well the phylogenetic relationship of their hosts. Three isolates ofT. grosiexhibited base changes at 2–6 positions of 2019-base 18S rDNA, at 5–29 positions of 1817/1818-base 28Sα rDNA, or 1–5 positions of 1557–1559-base 28Sβ rDNA, and none was separated from the other 2 isolates by rDNA nucleotide sequences. Since base changes ofHerpetosomatrypanosomes at the level of inter- and intra-species might occur frequently in specified rDNA regions, the molecular analysis on these regions of rodent trypanosomes could help species/strain differentiation and systematic revision ofHerpetosomatrypanosome species, which must be more abundant than presently known.

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