• Title/Summary/Keyword: Reproductive structures

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Analysis of the misguided practice of recognizing Gymnosperms as flowering plants (나자식물이 꽃피는 식물로 인식되고 있는 잘못된 관행의 분석)

  • Lee, Kyu Bae
    • Korean Journal of Plant Taxonomy
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    • v.44 no.4
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    • pp.288-297
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    • 2014
  • The aim of this study is to analyse misinformation about gymnosperm taxon used for over 57 years, since 1957 when plant biology as a discipline was established in our country. That is, terminologies and descriptions of the reproductive structure (flower) of angiosperms (flowering seed plants) have been incorrectly applied to the reproductive structures (typically cones and pollen grain) of gymnosperms (non-flowering seed plants) by numerous and various media such as text books, dictionaries, and internet websites for plant biology. Thus, these resources have been misleading teachers, students, and other people interested in plant biology in general and taxonomy in particular by describing gymnosperm reproductive structures as if they are the same as angiosperms. Such a practice has an especially adverse effect on plant biology education at all levels of instruction, with teachers and students confused in their understanding of the concept and definition of a flower. In this paper, these incorrect expressions for the reproductive structures of gymnosperms from the various media are analysed and discussed in terms of cladogram, anatomy of reproductive structures, and historical context of classification systems.

Analysis of Some Korean Terminologies on the Reproductive Structures of Seed Plants in Plant Morphology (식물형태학에서 사용하는 종자식물의 생식구조에 관한 한글 용어의 분석)

  • Lee, Kyu Bae
    • Journal of Integrative Natural Science
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    • v.1 no.3
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    • pp.195-209
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    • 2008
  • Some Korean terminologies on reproductive structures of seed plants in plant morphology, written incorrectly in many books, were analysed to propose accurately expressed terminologies. 31 books in areas such as general biology, plant biology, plant morphology, and biological dictionaries and glossaries were selected to analyse the accuracy of the terminologies for reproductive structures in gymnosperms, e.g., cone or strobilus, seed (or ovulate) cone and pollen cone, and conifer(s) or coniferous plants, and for flower structures in angiosperms, e.g., corolla, anther, filament, pistillate (or female) flower and staminate (or male) flower, apocarpous, and syncarpous. The definition and etymology of the terminologies were traced in 4 textbooks of plant anatomy and 2 dictionaries of biology and botany written in English. On the basis of the definition, etymology, and principles for terminology formation according to the International Organization for Standardization (ISO 704:2000), reasonably expressed Korean terminologies were proposed. All of the 8 terminologies examined in this study were included in the glossary of biological terminologies, published by the Korean Association of Biological Sciences in 2005, and designated as an editorial source for science and biology textbooks for middle and high schools by Ministry of Education in 2007. However, the only 1 of the 8 terminologies described in the glossary were consistent with the proposed expression in the present study. These inconsistencies indicated the need for a reassessment of this glossary of biological terminologies. The newly proposed terminologies would facilitate mutual understanding between teachers and students of plant biology.

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Subretinal transplantation of putative retinal pigment epithelial cells derived from human embryonic stem cells in rat retinal degeneration model

  • Park, Un-Chul;Cho, Myung-Soo;Park, Jung-Hyun;Kim, Sang-Jin;Ku, Seung-Yup;Choi, Young-Min;Moon, Shin-Yong;Yu, Hyeong-Gon
    • Clinical and Experimental Reproductive Medicine
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    • v.38 no.4
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    • pp.216-221
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    • 2011
  • Objective: To differentiate the human embryonic stem cells (hESCs) into the retinal pigment epithelium (RPE) in the defined culture condition and determine its therapeutic potential for the treatment of retinal degenerative diseases. Methods: The embryoid bodies were formed from hESCs and attached on the matrigel coated culture dishes. The neural structures consisting neural precursors were selected and expanded to form rosette structures. The mechanically isolated neural rosettes were differentiated into pigmented cells in the media comprised of N2 and B27. Expression profiles of markers related to RPE development were analyzed by reverse transcription-polymerase chain reaction and immunostaining. Dissociated putative RPE cells ($10^5$ cells/5 ${\mu}L$) were transplanted into the subretinal space of rat retinal degeneration model induced by intravenous sodium iodate injection. Animals were sacrificed at 1, 2, and 4 weeks after transplantation, and immnohistochemistry study was performed to verify the survival of the transplanted cells. Results: The putative RPE cells derived from hESC showed characteristics of the human RPE cells morphologically and expressed molecular markers and associated with RPE fate. Grafted RPE cells were found to survive in the subretinal space up to 4 weeks after transplantation, and the expression of RPE markers was confirmed with immunohistochemistry. Conclusion: Transplanted RPE cells derived from hESC in the defined culture condition successfully survived and migrated within subretinal space of rat retinal degeneration model. These results support the feasibility of the hESC derived RPE cells for cell-based therapies for retinal degenerative disease.

Molecular analyses and reproductive structure to verify the generic relationships of Hypnea and Calliblepharis (Cystocloniaceae, Gigartinales), with proposal of C. saidana comb. nov.

  • Yang, Mi Yeon;Kim, Myung Sook
    • ALGAE
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    • v.32 no.2
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    • pp.87-100
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    • 2017
  • The genera Hypnea and Calliblepharis of the family Cystocloniaceae are discriminated by their female reproductive structure, especially in the formation of carposporangia and gonimoblasts. Hypnea saidana, once classified based on obsolete evidence, has not been studied phylogenetically using molecular analysis and detailed reproductive structure though it shares many morphologic features with the genus Calliblepharis. To provide better understanding of generic relationship of H. saidana with Hypnea and Calliblepharis, we carried out molecular analyses using the nuclear-encoded small subunit ribosomal DNA (SSU) and chloroplast-encoded large subunit of the RuBisCO (rbcL), and exact morphological observations focusing on the reproductive structures of wild specimens. Our molecular phylogeny showed that H. saidana is closely related to Calliblepharis, but distinct from the clade of Hypnea. Female reproductive structure of H. saidana characterized by upwardly developing chains of carposporangia, central reticulum of cell, and gonimoblast filaments not connected to the pericarp provides definite evidence to assign the taxonomic position of this species to Calliblepharis. Based on our combined molecular and morphological analyses, we have proposed Calliblepharis saidana comb. nov., expanding the distribution of Calliblepharis habitat from the eastern Atlantic South Africa, the northern Indian Ocean, Australasia, and Brazil to the western Pacific Ocean.

Evaluation of the Spermatozoal Defect with Immunochemical Method (면역화학적 방법에 의한 정자결함 검색)

  • Kim, Se-Joong;Lee, Moo-Sang
    • Clinical and Experimental Reproductive Medicine
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    • v.18 no.1
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    • pp.101-105
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    • 1991
  • Although many therapies have been advocated in the treatment of idiopathic male infertility, the results of treatment are poor. This probably seems to be due to a lack of one or more proteins constituting the key structures of the spermatozoa. We evaluated the functional structures of the spermatozoa in 11 infertile patients whose semen showed severe oligoasthenozoospermia with immunochemical method and found a case with spermatozoa lacking acrosin. Evaluation of the spermatozoal defect with immunochemical method is desirable in patients with severe oligoasthenozoospermia, especially in cases unresponsive to medical therapy.

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Confirmation on Taxonomic Status of Spatoglossum pacificum Yendo (Dictyotaceae, Phaeophyceae) Based on Morphology and Plastid Protein Coding rbcL, rbcS, psaA, and psbA Gene Sequences

  • Hwang, Il-Ki;Kim, Hyung-Seop;Lee, Wook-Jae
    • ALGAE
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    • v.19 no.3
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    • pp.161-174
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    • 2004
  • Phonological, morphological and molecular characteristics of Spatoglossum pacificum Yendo are examined. S. pacificum has an annual life cycle composed of saprophytes with apparent absence of male and female gametophytes in Korea. The seasonal growth of this species explains that the annual growth is closely related to the monthly variation of water temperature. S. pacificum has protruding reproductive structures above the outmost cortical layer. Although this observation is restricted to several species, reproductive structures on the thallus can make S. pacificurn distinguishable from S. crassum and S. lacturn. The morphogenesis of a midrib at the base of S. pacificum in this study is the same as those of Dictyopteris but different from those of S. crassum and S. lacturn, suggesting that S. pacificum is closely related to Dictyopteris. In the comparison of plastid gene sequences among species of Spatoglossum and Dictyopteris, S. pacificum is more similar to D. divaricata and D. undulate than those of S. crassum in rbcL, rbcS, psbA and psaA. This result is congruent with the anatomical characteristic of a midrib at the base of the thallus and the protrusion of reproductive organs on the thallus. The phylogenetic relationship based on these plastid genes also shows that S. pacifism is included in Dictyotpteris Glade and separated from S. crassum. We propose the new combination of Dictyopteris pacifica (Yendo) I.K. Hwang, H.S. Kim et W.J. Lee, comb. nov. based on the differences of anatomical characteristics of the midrib, the existence of reproductive organs on thallus and the molecular analyses.

Evaluation of polyglycolic acid as an animal-free biomaterial for three-dimensional culture of human endometrial cells

  • Sadegh Amiri;Zohreh Bagher;Azadeh Akbari Sene;Reza Aflatoonian;Mehdi Mehdizadeh;Peiman Broki Milan;Leila Ghazizadeh;Mahnaz Ashrafi;FatemehSadat Amjadi
    • Clinical and Experimental Reproductive Medicine
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    • v.49 no.4
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    • pp.259-269
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    • 2022
  • Objective: Animal-free scaffolds have emerged as a potential foundation for consistent, chemically defined, and low-cost materials. Because of its good potential for high biocompatibility with reproductive tissues and well-characterized scaffold design, we investigated whether polyglycolic acid (PGA) could be used as an animal-free scaffold instead of natural fibrin-agarose, which has been used successfully for three-dimensional human endometrial cell culture. Methods: Isolated primary endometrial cells was cultured on fibrin-agarose and PGA polymers and evaluated various design parameters, such as scaffold porosity and mean fiber diameter. Cytotoxicity, scanning electron microscopy (SEM), and immunostaining experiments were conducted to examine cell activity on fabricated scaffolds. Results: The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay and SEM results showed that endometrial cells grew and proliferated on both scaffolds. Immunostaining showed cytokeratin and vimentin expression in seeded cells after 7 days of culture. On both scaffolds, an epithelial arrangement of cultured cells was found on the top layer and stromal arrangement matrix on the bottom layer of the scaffolds. Therefore, fibrin-agarose and PGA scaffolds successfully mimicked the human endometrium in a way suitable for in vitro analysis. Conclusion: Both fibrin-agarose and PGA scaffolds could be used to simulate endometrial structures. However, because of environmental and ethical concerns and the low cost of synthetic polymers, we recommend using PGA as a synthetic polymer for scaffolding in research instead of natural biomaterials.

Population Structure of Codium amplivesiculatum (Chlorophyta) Associated with Rhodolith Beds from the Southwestern Gulf of California

  • Riosmena-Rodriguez, Rafael;Holguin-Acosta, Elena
    • ALGAE
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    • v.23 no.2
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    • pp.141-150
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    • 2008
  • Populations of Codium amplivesiculatum were found in association with rhodolith beds. We present population trends of C. amplivesiculatum from surveys conducted in the southwestern Gulf of California based on monthly sampling from June 1999 to August 2000. Surveys were conducted at 2 sites in the San Lorenzo Channel at depths of 8 - 12 m. The parameters measured were percent cover, biomass and structure in relation to size of the thalli. From each thallus the following measurements were taken: length and diameter, proportion of each thallus with reproductive structures and the degree of fragmentation (measured as number of small thalli). Mean biomass and cover varied seasonally with the maximum (1036.6 gm$^{-2}$ and 100% cover) present in June 2000 and the minimum in winter (0 gm$^{-2}$ and 0% cover). The longest fronds (3 m) occurred during July 1999 and August 2000, while the maximum diameters of 1.0 cm were present during October and November 1999. There were no significant linear relationships between length and diameter of the fronds, suggesting independent growth. Reproductive structures were common in June and July 1999 with monoic and dioic thalli present. Most fronds were monoic, and this is the first record of this feature for this species. Fragmentation occurred in September, and may be associated with stress from early gametangial reproduction and the combination of high temperatures and low nutrients. A hypothetical life cycle for the species is presented.

Phenology and Reproductive Effort of Two Zostera marina L. Populations on the Southern Coast of Korea (남해 연안에 생육하는 거머리말(Zostera marina L.) 개체군의 생물계절학과 생식 능력)

  • Lee, Sang-Yong;Lee, Sung-Mi;Choi, Chung-Il
    • Ocean and Polar Research
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    • v.27 no.1
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    • pp.67-74
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    • 2005
  • The phonology and reproductive effort of Zostera marina L. (Dongdae Bay and Aenggang Bay) on the southern coast of Korea were investigated from September 2002 to August 2003. The Dongdae Bay(DB) exhibited a finer sediment grain size with richer organic content than the Aenggang Bay(AB). Water temperature at DB site ranged from $7.5^{\circ}C$ in February to $25.5^{\circ}C$ in August, while water temperature at AB site ranged rrom $6.7^{\circ}C$ in February to $25.2^{\circ}C$ in september. Both populations exhibited a perennial lifB span, but the sexual reproductive effort was significantly higher at DB than AB. The reproductive shoots of DB site were developed from February to June 2003, while those of AB site from March to June 2003. At DB site, the frequency of reproductive shoot ranged from 11 to 33%, whereas reproductive shoot of AB did below 5%. Reproductive structures were larger and more abundant at DB, with the exception of number of fruits and seeds per spadix. Water temperature seems most important to regulate the timing of reproductive phase of Z. marina populations for two study sites.

Effects of Short-Term Exposure with Tri-n-Butyltin Chloride (TBTCl) and Bisphenol A on the Reproduction of the Striped Field Mouse (TBTCl (tri-n-butyltin chloride)과 bisphenol A에 의한 단기노출이 등줄쥐의 번식에 미치는 영향)

  • Kim, Ji-Hye;Min, Byung-Yoon;Yoon, Myung-Hee
    • Journal of Life Science
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    • v.21 no.3
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    • pp.406-411
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    • 2011
  • To investigate the effects of short-term treatment with tri-n-butyltin chloride (TBTCl) and bisphenol A (BPA) on the reproduction of striped field mice, the mice were intramuscularly injected with TBTCl or BPA immediately before the reproductive season and examined in the reproductive season after keeping them for 4 months. As a result, there were no differences between the control and the compound-treated groups regarding body weight in both sexes, the residual levels of the compounds in the adult males, and the gonadosomatic index (GSI) and the histological structures with LM and EM of the testes and epididymides in both the adult and young males. The infant mortality and abortion rate, however, were high in the TBTCl-treated groups and BPA-treated groups respectively, compared to the control group. Conclusively, it was suggested that short-term treatment with TBTCl or BPA in mice in the non-reproductive season might have inhibited the development of the uterine embryos or fetuses, although it did not induce accumulations of these compounds or affect the reproductive organs of adult and young (F1) males.