• Title/Summary/Keyword: Morphological variability

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Molecular Biodesign of Plant Leaves and Flowers

  • Kim Gyung-Tae
    • Journal of Plant Biotechnology
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    • v.5 no.3
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    • pp.137-142
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    • 2003
  • The morphology of the leaves and the flowers of angiosperms exhibit remarkable diversity. One of the factors showing the greatest variability of leaf organs is the leaf index, namely, the ratio of leaf length to leaf width. In some cases, different varieties of a single species or closely related species can be distinguished by differences in leaf index. To some extent, the leaf index reflects the morphological adaptation of leaves to a particular environment. In addition, the growth of leaf organs is dependent on the extent of the expansion of leaf cells and on cell proliferation in the cellular level. The rates of the division and enlargement of leaf cells at each stage contribute to the final shape of the leaf, and play important roles throughout leaf development. Thus, the control of leaf shape is related to the control of the shape of cells and the size of cells within the leaf. The shape of flower also reflects the shape of leaf, since floral organs are thought to be a derivative of leaf organs. No good tools have been available for studies of the mechanisms that underlie such biodiversity. However, we have recently obtained some information about molecular mechanisms of leaf morphogenesis as a result of studies of leaves of the model plant, Arabidopsis thaliana. For example, the ANGUSTIFOLIA (AN) gene, a homolog of animal CtBP genes, controls leaf width. AN appears to regulate the polar elongation of leaf cells via control of the arrangement of cortical microtubules. By contrast, the ROTUNDIFOLIA3 (ROT3) gene controls leaf length via the biosynthesis of steroid(s). We provide here an overview of the biodiversity exhibited by the leaf index of angiosperms. Taken together, we can discuss on the possibility of the control of the shapes and size of plant organs by transgenic approaches with the results from basic researches. For example, transgenic plants that overexpressed a wildtype ROT3 gene had longer leaves than parent plants, without any changes in leaf width. Thus, The genes for leaf growth and development, such as ROT3 gene, should be useful tools for the biodesign of plant organs.

Assessment of Genetic Variability in Two North Indian Buffalo Breeds Using Random Amplified Polymorphic DNA (RAPD) Markers

  • Sodhi, M.;Mukesh, M.;Anand, A.;Bhatia, S.;Mishra, B.P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.9
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    • pp.1234-1239
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    • 2006
  • Murrah and NiliRavi are the important North Indian buffalo breeds occupying the prominent position of being the highest milk producers. These breeds are more or less similar at morphological as well as physiological levels. The technique of RAPD-PCR was applied in the present study to identify a battery of suitable random primers to detect genetic polymorphism, elucidation of the genetic structure and rapid assessment of the differences in the genetic composition of these two breeds. A total of 50 random primers were screened in 24 animals each of Murrah and NiliRavi buffaloes to generate RAPD patterns. Of these, 26 (52%) primers amplified the buffalo genome generating 263 reproducible bands. The number of polymorphic bands for the 26 chosen RAPD primers varied from 3 (OPG 06 and B4) to 26 (OPJ 04) with an average of 10.1 bands per primer and size range of 0.2 to 3.2 kb. DNA was also pooled and analyzed to search for population specific markers. Two breed specific RAPD alleles were observed in each of Murrah (OPA02 and OPG16) and NiliRavi (OPG09) DNA pools. RAPD profiles revealed that 11 (4.2%) bands were common to all the 48 individuals of Murrah and NiliRavi buffaloes. Pair-wise band sharing calculated among the individual animals indicated considerable homogeneity of individuals within the breeds. Within breed, band sharing values were relatively greater than those of interbreed values. The low genetic distance (Nei's) value (0.109) estimated in this study is in accordance with the origin and geographical distribution of these breeds. The RAPD analysis indicated high level of genetic similarity between these two important North Indian buffalo breeds.

Automatic Liver Segmentation on Abdominal Contrast-enhanced CT Images for the Pre-surgery Planning of Living Donor Liver Transplantation

  • Jang, Yujin;Hong, Helen;Chung, Jin Wook
    • Journal of International Society for Simulation Surgery
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    • v.1 no.1
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    • pp.37-40
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    • 2014
  • Purpose For living donor liver transplantation, liver segmentation is difficult due to the variability of its shape across patients and similarity of the density of neighbor organs such as heart, stomach, kidney, and spleen. In this paper, we propose an automatic segmentation of the liver using multi-planar anatomy and deformable surface model in portal phase of abdominal contrast-enhanced CT images. Method Our method is composed of four main steps. First, the optimal liver volume is extracted by positional information of pelvis and rib and by separating lungs and heart from CT images. Second, anisotropic diffusing filtering and adaptive thresholding are used to segment the initial liver volume. Third, morphological opening and connected component labeling are applied to multiple planes for removing neighbor organs. Finally, deformable surface model and probability summation map are performed to refine a posterior liver surface and missing left robe in previous step. Results All experimental datasets were acquired on ten living donors using a SIEMENS CT system. Each image had a matrix size of $512{\times}512$ pixels with in-plane resolutions ranging from 0.54 to 0.70 mm. The slice spacing was 2.0 mm and the number of images per scan ranged from 136 to 229. For accuracy evaluation, the average symmetric surface distance (ASD) and the volume overlap error (VE) between automatic segmentation and manual segmentation by two radiologists are calculated. The ASD was $0.26{\pm}0.12mm$ for manual1 versus automatic and $0.24{\pm}0.09mm$ for manual2 versus automatic while that of inter-radiologists was $0.23{\pm}0.05mm$. The VE was $0.86{\pm}0.45%$ for manual1 versus automatic and $0.73{\pm}0.33%$ for manaual2 versus automatic while that of inter-radiologist was $0.76{\pm}0.21%$. Conclusion Our method can be used for the liver volumetry for the pre-surgery planning of living donor liver transplantation.

Redescription of Canthocamptus mirabilis Sterba (Copepoda, Harpacticoida), Based on the Topotypic Material from China (중국의 모식산지에서 채집한 갈고리노벌레류 Canthocamptus mirabilis Sterba의 재기재)

  • Chang, Cheon-Young
    • Animal Systematics, Evolution and Diversity
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    • v.17 no.1
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    • pp.1-11
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    • 2001
  • Conthocamptus mirabilis Sterba is redescribed on the basis of the material newly collected from the type locality near Bekijing, China, with an evaluation of the variability of several characters. C. mirabilis possesses the plesiomorphic characters of the round and narrow hyaline membrane and the unmodified outer terminal furcal setae, while it also bears the apomorphic ones of the male-type caudal rami in females and the modified outer terminal setae of male leg 4 exopod. the peculiar dorsal keel ornamented with spinule array on the female's caudal rami is the most significant feature differentiating this species from its relatives of the mirabilis group, which turned out to be a species group of closely related and largely allopatric or parapatric species. Affinities with the allies of the species group are discussed, and the morphological discrepancies differentiating the Japanese population are enumerated.

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Molecular Biodesign of Plant Leaves and Flowers

  • Kim, Gyung-Tae
    • Proceedings of the Korean Society of Plant Biotechnology Conference
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    • 2003.04a
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    • pp.49-55
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    • 2003
  • The morphology of the leaves and the flowers of angiosperms exhibit remarkable diversity. One of the factors showing the greatest variability of leaf organs is the leaf index, namely, the ratio of leaf length to leaf width. In some cases, different varieties of a single species or closely related species can be distinguished by differences in leaf index. To some extent, the leaf index reflects the morphological adaptation of leaves to a particular environment. In addition, the growth of leaf organs is dependent on the extent of the expansion of leaf cells and on cell proliferation in the cellular level. The rates of the division and enlargement of leaf cells at each stage contribute to the final shape of the leaf, and play important roles throughout leaf development. Thus, the control of leaf shape is related to the control of the shape of cells and the size of cells within the leaf. The shape of flower also reflects the shape of leaf, since floral organs are thought to be a derivative of leaf organs. No good tools have been available for studies of the mechanisms that underlie such biodiversity. However, we have recently obtained some information about molecular mechanisms of leaf morphogenesis as a result of studies of leaves of the model plant, Arabidopsis thaliana. For example, the ANGUSTIFOLIA (AN) gene, a homolog of animal CtBP genes, controls leaf width. AN appears to regulate the polar elongation of leaf cells via control of the arrangement of cortical microtubules. By contrast, the ROTUNDIFOLIA3 (ROT3) gene controls leaf length via the biosynthesis of steroid(s). We provide here an overview of the biodiversity exhibited by the leaf index of angiosperms. Taken together, we can discuss on the possibility of the control of the shapes and size of plant organs by transgenic approaches with the results from basic researches. For example, transgenic plants that overexpressed a wild-type ROT3 gene had longer leaves than parent plants, without any changes in leaf width. Thus, The genes for leaf growth and development, such as ROT3 gene, should be useful tools for the biodesign of plant organs.

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Development and evaluation of next-generation cardiotoxicity assay based on embryonic stem cell-derived cardiomyocytes

  • Ryu, Bokyeong;Choi, Seong Woo;Lee, Seul-Gi;Jeong, Young-Hoon;Kim, Ukjin;Kim, Jin;Jung, Cho-Rok;Chung, Hyung-Min;Park, Jae-Hak;Kim, C-Yoon
    • BMB Reports
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    • v.53 no.8
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    • pp.437-441
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    • 2020
  • In accordance with requirements of the ICH S7B safety pharmacology guidelines, numerous next-generation cardiotoxicity studies using human stem cell-derived cardiomyocytes (CMs) are being conducted globally. Although several stem cell-derived CMs are being developed for commercialization, there is insufficient research to verify if these CMs can replace animal experiments. In this study, in vitro high-efficiency CMs derived from human embryonic stem cells (hESC-CMs) were compared with Sprague-Dawley rats as in vivo experimental animals, and primary cultured in vitro rat-CMs for cardiotoxicity tests. In vivo rats were administrated with two consecutive injections of 100 mg/kg isoproterenol, 15 mg/kg doxorubicin, or 100 mg/kg nifedipine, while in vitro rat-CMs and hESC-CMs were treated with 5 μM isoproterenol, 5 μM doxorubicin, and 50 μM nifedipine. We have verified the equivalence of hESC-CMs assessments over various molecular biological markers, morphological analysis. Also, we have identified the advantages of hESC-CMs, which can distinguish between species variability, over electrophysiological analysis of ion channels against cardiac damage. Our findings demonstrate the possibility and advantage of high-efficiency hESC-CMs as next-generation cardiotoxicity assessment.

Evaluation of normal masseter muscles on ultrasonography (초음파영상을 이용한 정상 교근의 평가)

  • Hwang, Hyoung-Zoo;Kim, Gyu-Tae;Choi, Yong-Suk;Hwang, Eui-Hwan
    • Imaging Science in Dentistry
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    • v.38 no.2
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    • pp.73-79
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    • 2008
  • Purpose: To assess the internal echo intensity and morphological variability of masseter muscles on ultrasonography and to establish diagnostic criterion of estimation. Materials and Methods: Participants consisted of 50 young adults (male 25, female 25) without pathologic conditions and with full natural dentitions. Sonographic examinations were done with real time ultrasound equipment as Logiq 500 (GE Medical Systems, Seoul, Korea) at 3 parts according to lines paralleling with ala-tragus line as reference line. The thickness and area of masseter muscles according to reference line in cross-sectional images were measured at rest and at maximum contraction. The visibility and width of the internal echogenic intensity of the masseter muscles were also assessed and the muscle appearance was classified into 4 types. Data were statistically analyzed by paired t-test and $x^2$-test. Results: 1. When comparing the thickness and area of masseter muscles concerning with gender, there was few significant difference between right and left sides, however, there were significant differences between males and females except for the greatest thickness of left side. 2. The changes of the greatest thickness and the area between rest and maximum contraction showed that the part of the least thickness manifested more increase at maximum contraction. 3. Each part the manifestations of the internal echogenic intensity of the masseter muscles were different depending on the locations. But there was no statistically significance. Conclusion: Changes of muscles thickness with contraction and internal echogenic intensity with locations showed great disparity within the masseter muscles, which will be diagnostic criteria for pathophysiologic and anatomic changes of masseter muscles.

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Genetic Diversity Measured by RAPDs in Korean Barley Germplasm Pools

  • Kim Hong-Sik;Park Kwang-Geun;Baek Seong-Bum;Kim Jung-Gon;Nam Jung-Hyun
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.2
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    • pp.131-141
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    • 2005
  • Molecular-based genetic diversity for a set of 141 accessions of Korean barley cultivars and 24 accessions of foreign exotic cultivars were analyzed using random amplified polymorphic DNAs (RAPDs). Different level of genetic variability was observed with 30 random decamer primers in the Korean barley varieties and breeding lines which were preliminarily classified by morphological (hulled & hulless barley) and end-use (malting barley) and/or by the released periods. A total of 74 RAPD bands were scored, and the number of bands per primer varied from 1 to 7 with an average of 2.74. The hulled barley pool had one more marker genotype per primer than the hulless barley pool. The polymorphic information content (PIC) values based on the band pattern frequencies among genotypes varied depending on genetic pools where mean PICs of hulled, hulless and malting barleys were 0.62, 0.57, and 0.43, respectively. Certain genomic loci amplified by opR04, opF01, opB05, and opC13 were highly polymorphic with PIC>0.8. Patterns and temporal trends of genetic diversity assessed over the period from 1970s to 1990s had a tendency to increase, and in particular, this upward slant was quite clear and significant for the hulless barley pool. In the cluster analysis using genetic similarity matrix calculated from RAPD profiles, two major groups and several small subgroups were classified. Major grouping of materials was not affected by the presence of the husk but by their genetic background and the spike-row type. The validity of information on the genetic diversity and relationships between genotypes will have been reviewed to predict their yield potential.

Damage of Ibuprofen Suppository on Rectal Mucosa of Rats (이부프로펜 좌제의 흰쥐 직장점막 자극성 시험)

  • Lee, Sung-Hack;Kim, Moon-Kyoung;Han, Yong-Hae;Shim, Chang-Koo
    • Journal of Pharmaceutical Investigation
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    • v.24 no.3
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    • pp.115-129
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    • 1994
  • In the present study, quantitative and qualitative histology was used to assess the effects of ibuprofen suppositories with various treatments on the rectal mucosa of rats. Two suppositories were prepared with Witepsol W35 and compared with two commercial ibuprofen suppositories Reference I (Showa Pharm.ind., Tokyo, Japan), Reference II (P.Pharm., Seoul, Korea). Single and multiple dose(dosing interval 4 hr, n=4) studies were conducted. All suppositories significantly increased epithelial cell loss, but the extent of rectal irritation was variable. These studies showed that the incorporation of ibuprofen into the suppository bases increases the morphological change in rectal tissue both for the single and multiple administrations of suppositories, but which was significantly recovered within 24 hr although the interanimal variability in scores was very substantial. Multiple administration of ibuprofen suppositories caused significant damage to rectal mucosa, but it must be considered that these were under the severe condition, that is, interval of administration (4 hr) was three times shorter than normal interval of administration and dose was fifteen times larger than usual human dose. Aluminum oxide $(Al_2O_3)$, a dispersing agent, slightly increased the irritation of rectal mucosa in rats at 5 hr and 24 hr after multiple administration, but it was possible to ignore the difference of irritation in the data at 5hr and 24hr after single administration. Finally, it was concluded that Witepsol W35 and ibuprofen had a slight rectal mucosa-irritating effect on the usual human dose, and ibuprofen suppositories prepared with Witepsol W35 or Witepsol W35, $Al_2O_3$ showed almost similar extent of rectal irritation with commercial ibuprofen products.

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Relationship between Virulence and Cultural Characteristics in Calonectria ilicicola (Calonectria ilicicola의 병원성과 배양적 특성간의 상호관계)

  • Kim, K.D.;Russin, J.S.;Snow, J.P.;Valverde, R.A.
    • The Korean Journal of Mycology
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    • v.26 no.3 s.86
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    • pp.387-395
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    • 1998
  • Mycelial growth, production of microsclerotia and perithecia, and presence of double-stranded RNA were examined in Calonectria ilicicola isolates from several hosts to detect morphological and/or genetic markers for comparison with levels of virulence. Variability in disease severity, production of microsclerotia and perithecia, and mycelial growth was observed across all isolates. None of 35 isolates of C. ilicicola examined contained detectable levels of double-stranded RNA. Disease severity on soybean cultivars correlated positively with production of both microsclerotia and perithecia. Mycelial growth correlated negatively with production of perithecia. Virulence on the cultivars and production of microsclerotia and perithecia were greater in isolates of C. ilicicola from soybean than those from peanut. These results suggest that the ability of isolates to produce microsclerotia and perithecia is a component of inoculum potential. Perithecia production may serve as a useful marker for characterizing virulence or host specialization in this homothallic fungus.

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