• 제목/요약/키워드: Natural reproduction

검색결과 412건 처리시간 0.025초

The Development of Climax Index by Analysis of Eco-morphological Characters for Major Deciduous Tree Species

  • Kim, Ji Hong;Chung, Sang Hoon;Lee, Jeong Min;Kim, Se Mi
    • Journal of Forest and Environmental Science
    • /
    • 제28권4호
    • /
    • pp.199-204
    • /
    • 2012
  • This study was conducted to estimate climax index by eco-morphology for major 36 tree and sub-tree species in natural deciduous forests so as to interpret seral position of each species in the forest community. Fourteen eco-morphological characters which were considered to be associated with successional gradient in the forest were selected for the study. Four levels per character for each species were given on a standardized scale of increasing climax, and the index was computed by the proportion of the sum of total scores, expressed by percent values. With calculated mean value of 54.8 for all indices, Carpinus cordata had the highest index value of 90.5, and Populus davidiana recorded the lowest of 13.2. The most climax group, greater than 70 of the index, contained only 8 species, intermediate group, between 41 to 70 of the index, had 23 species, and the most pioneer group, less than 40 of the index comprised 5 species. The result has noticed that the large number of species would take advantage of most diverse resource and niche in the intermediate stage of the sere in the forest. By cluster analysis all 36 species were subjected to be classified into several species groups which had common similar eco-morphological characteristics. The indices were additionally plotted on the two dimensional graph to recognize the positions related to the light absorption factor and reproduction factor. The climax index of tree and sub-tree species developed by this study could be applied to understand the present status of successional stage on the basis of species composition by the method of summing up the indices. And comparison of forest successional stage among various forest communities could be done by summing up the climax indices of composed species in each community. However, this kind of applied methodology should be limited to the forest of similar species composition and site condition.

초등 교육과정에서 과학과의 생물 영역과 타 교과의 내용 연계성에 대한 분석 (An Analysis of the Relationship between Biology-related Contents Presented in Science and Other Subject Matter Areas in the Elementary School Curriculum)

  • 박재근;강호감;김용진
    • 한국초등과학교육학회지:초등과학교육
    • /
    • 제26권1호
    • /
    • pp.63-75
    • /
    • 2007
  • This study investigated how the contents of biology domains that were dealt with in the 7th national elementary-school science curriculum were in turn dealt with in the other subject matter areas. Through this, it was hoped that the place and identity of biology as a subject could be more clearly established and defined and additionally, more basic data for developing the new national science curriculum could be acquired at the same time. Subject matter areas that overlapped with biology in the 7th national elementary-school curriculum were practical arts, social studies and physical education. The structure and composition of specific components that were dealt with by these subject matter areas were very different from those of science, and the analysis showed that they failed to correspond across grades. Moreover, topics such as 'natural calamities and the environment' and 'human reproduction' that were dealt with by other subject matter areas, but not in science must be included for developing the new national science curriculum. Accordingly, when it comes to composing the contents of each subject matter area during creation of the new national curriculum, the relevant experts in related subject matter areas should be mobilized to conduct in-depth analysis of the following areas: viability, the most appropriate level of difficulty, and appropriateness of any hierarchy of relative importance between subjects. Additionally, efforts to reflect any improvements in the way the new national curriculum is developed which come about through this research are needed.

  • PDF

DnaJC18, a Novel Type III DnaJ Family Protein, is Expressed Specifically in Rat Male Germ Cells

  • Gomes, Cynthia;Soh, Jaemog
    • 한국발생생물학회지:발생과생식
    • /
    • 제21권3호
    • /
    • pp.237-247
    • /
    • 2017
  • Mammalian spermatogenesis occurs in a precise and coordinated manner in the seminiferous tubules. One of the attempts to understand the detailed biological process during mammalian spermatogenesis at the molecular level has been to identify the testis specific genes followed by study of the testicular expression pattern of the genes. From the subtracted cDNA library of rat testis prepared using representational difference analysis (RDA) method, a complimentary DNA clone encoding type III member of a DnaJ family protein, DnaJC18, was cloned (GenBank Accession No. DQ158861). The full-length DnaJC18 cDNA has the longest open reading frame of 357 amino acids. Tissue and developmental Northern blot analysis revealed that the DnaJC18 gene was expressed specifically in testis and began to express from postnatal week 4 testis, respectively. In situ hybridization studies showed that DnaJC18 mRNA was expressed only during the maturation stages of late pachytene, round and elongated spermatids of adult rat testis. Western blot analysis with DnaJC18 antibody revealed that 41.2 kDa DnaJC18 protein was detected only in adult testis. Immunohistochemistry study further confirmed that DnaJC18 protein, was expressed in developing germ cells and the result was in concert with the in situ hybridization result. Confocal microscopy with GFP tagged DnaJC18 protein revealed that it was localized in the cytoplasm of cells. Taken together, these results suggested that testis specific DnaJC18, a member of the type III DnaJ protein family, might play a role during germ cell maturation in adult rat testis.

Longevity and Stress Resistant Property of 6-Gingerol from Zingiber officinale Roscoe in Caenorhabditis elegans

  • Lee, Eun Byeol;Kim, Jun Hyeong;An, Chang Wan;Kim, Yeong Jee;Noh, Yun Jeong;Kim, Su Jin;Kim, Ju-Eun;Shrestha, Abinash Chandra;Ham, Ha-Neul;Leem, Jae-Yoon;Jo, Hyung-Kwon;Kim, Dae-Sung;Moon, Kwang Hyun;Lee, Jeong Ho;Jeong, Kyung Ok;Kim, Dae Keun
    • Biomolecules & Therapeutics
    • /
    • 제26권6호
    • /
    • pp.568-575
    • /
    • 2018
  • In order to discover lifespan-extending compounds made from natural resources, activity-guided fractionation of Zingiber officinale Roscoe (Zingiberaceae) ethanol extract was performed using the Caenorhabditis elegans (C. elegans) model system. The compound 6-gingerol was isolated from the most active ethyl acetate soluble fraction, and showed potent longevity-promoting activity. It also elevated the survival rate of worms against stressful environment including thermal, osmotic, and oxidative conditions. Additionally, 6-gingerol elevated the antioxidant enzyme activities of C. elegans, and showed a dose-depend reduction of intracellular reactive oxygen species (ROS) accumulation in worms. Further studies demonstrated that the increased stress tolerance of 6-gingerol-mediated worms could result from the promotion of stress resistance proteins such as heat shock protein (HSP-16.2) and superoxide dismutase (SOD-3). The lipofuscin levels in 6-gingerol treated intestinal worms were decreased in comparison to the control group. No significant 6-gingerol-related changes, including growth, food intake, reproduction, and movement were noted. These results suggest that 6-gingerol exerted longevity-promoting activities independently of these factors and could extend the human lifespan.

인진의 안정성에 대한 연구 - 주산$\cdot$수유기 생식 독성을 중심으로 - (Studies on the Safety of Artemisiae Capillaris Herba - With the Perinatal and Lactational Reproductive Toxicity -)

  • 왕오호;박재현
    • 대한한의학회지
    • /
    • 제26권2호
    • /
    • pp.32-51
    • /
    • 2005
  • Objectives: To study the effect of Artemisiae Capillaris Herba extracts, that have been used as oriental medicine to treat liver disease, on the perinatal and lactational n;)productive toxicity of SD rats when administered by oral lavage. Methods: Female SD rats were dosed from 6 days of gestation to 3 weeks postpartum. This was conducted in accordance with the recommendations of the KFDA Guidelines for Detection of Toxicity to Reproduction for Medicinal Products. Results: No Artemisiae Capillaris Herba extracts treatment-related changes in clinical signs, mortalities, implantation number, dead fetus number, loss rate of fetus, number of live young, survival rate of fetus, sex ratio of live young, external anomalies, pregnancy periods, viability index, lactational index, survival rate of litters at 4 days after birth or delivery index were demonstrated in any dosed levels in this study. However, the body weight and gains, food consumption and absolute organ weights of brain, adrenal glands, liver, spleen, kidney, ovaries and heart were significantly increased in 2000 or 1000mg/kg-dosing groups and the relative organ Weights of adrenal glands were significantly increased in 2,000mg/kg-dosing groups. Therefore, it was concluded that this increase was natural according to growth. Also, no changes of gross findings, clinical signs, mortalities, body weight and gains, physical development results, necropsy findings, organ weight, faculty test, open filed test and water-filled simple T-maze test, copulation, fertility, pregnancy indices, body weight and gains during gestation periods, necropsy findings, corpora lutea number, implantation number, implantation rate, dead fetus number, post-implantation loss rate, live young, post-implantation survival rate, sex ratio of live young, external anomalies and individual body weights of live young were demonstrated in any dosed levels in this study. Conclusions: It is considered that the NOAEL (No-Observed-Adverse-Effect Level) for perinatal and lactational reproductive toxicity of Artemisiae Capillaris Herba extracts was up to 2000mg/kg/day because no changes of other perinatal and lactational reproductive indices were demonstrated.

  • PDF

Co-expression of IRES-mediated hG-CSF cDNA and hGH Gene under the Control of Goat beta-Casein Promoter

  • Oh, Keon-Bong;Lee, Chul-Sang
    • 한국발생생물학회지:발생과생식
    • /
    • 제14권1호
    • /
    • pp.13-19
    • /
    • 2010
  • We developed a novel dicistronic system for the expression of target cDNA sequences in the milk of transgenic animals using goat beta-casein/hGH fusion construct, pGbc5.5hGH (Lee, 2006) and internal ribosome entry site (IRES) sequences of encephalomyocarditis virus (EMCV). Granulocyte colony-stimulating factor (hG-CSF) cDNA was linked to 3' untranslated region of hGH gene in the pGbc5.5hGH via EMCV IRES sequences. Transgenic mice were generated by microinjection and transgene expression was examined in the milk and mammary gland of transgenic mice at 10 days of lactation. Northern blot analysis showed that hGH gene and hG-CSF cDNA were transcribed as a single dicistronic mRNA. The hG-CSF and hGH proteins were independently translated from the dicistronic mRNA and secreted into the milk of transgenic mice. The highest concentration of hG-CSF and hGH in the milk of transgenic mice were $237{\mu}g/m{\ell}$ and $8,990{\mu}g/m{\ell}$, respectively. In contrast, another hG-CSF expression cassette, in which hG-CSF genomic sequences were inserted into a commercial milk-specific expression vector (pBC1), generated a lower level ($91{\mu}g/m{\ell}$) of hG-CSF expression in the milk of transgenic mice. These results demonstrated that the novel pGbc5.5hGH-based dicistronic construct could be useful for an efficient cDNA expression in the milk of transgenic animals.

Influence of Osmolality and Acidity on Fertilized Eggs and Larvae of Olive Flounder (Paralichthys olivaceus)

  • Kim, Ki-Hyuk;Moon, Hye-Na;Noh, Yun-Hye;Yeo, In-Kyu
    • 한국발생생물학회지:발생과생식
    • /
    • 제24권1호
    • /
    • pp.19-30
    • /
    • 2020
  • The pH of water is one of the main environmental factors exerting selective pressure on marine and freshwater organisms. Here, we focus on the influence of pH on an organism's ability to maintain homeostasis and investigate the effects of acidification on immunity-related genes and osmotic pressure during early development of the olive flounder, Paralichthys olivaceus. The aim of our study was to determine the influence of various pH levels on the fertilized eggs and larvae of P. olivaceus. Gametes of P. olivaceus were artificially introduced and the resulting fertilized eggs were incubated at pH 4.0 (low), 6.0, and 8.0 (equivalent to natural sea water; control). We found that all eggs sank from the water column at pH 4.0. After 38 h, these eggs showed slow development. Hatching occurred more slowly at pH 4.0 and 6.0 and did not occur at all at pH 4.0. Result of gene expression, caspase and galectin-1 were expressed from the blastula to pre-hatch stages, with the exception of the two-cell stage. HSP 70 was also steadily expressed at all pH levels over the five days. The osmolality of fertilized eggs differed marginally at each stage and across pH levels. So, this results demonstrates that low pH level is detrimental to P. olivaceus fertilized eggs.

The mRNA Expression and Methylation Pattern of Apoptosis-related and Imprinted Genes in Day 35 of Cloned Pig Fetuses

  • Jung, Hyun-Ju;Ko, Yeoung-Gyu;Hwang, Seong-Soo;Im, Gi-Sun;Park, Mi-Rung;Woo, Jae-Seok;Park, Choon-Keun;Seong, Hwan-Hoo
    • Reproductive and Developmental Biology
    • /
    • 제31권4호
    • /
    • pp.227-233
    • /
    • 2007
  • This study was conducted to examine the mRNA expression of apoptosis-related and imprinted genes and methylation pattern of the differentially methylated region (DMR) of H19 gene in day 35 of SCNT pig fetuses. The day 35 of natural mating (control) or cloned (clone) pig fetuses were recovered from uterus. Endometrium from dam and liver from fetus were obtained, respectively. mRNA expression was evaluated by real-time PCR and methylation pattern was analyzed by bisulfite sequencing method. The Bcl-2 mRNA expression in clone was significantly lower than that of control (p<0.05). The mRNA expression of H19 gene in both endometrium and liver was significantly higher in clone than that of control, respectively (p<0.05). The level of IGF-2 mRNA in liver of clone was significantly lower than that of control (p<0.05), whereas the mRNA expression of IGF2-R gene in liver of clone was significantly higher than that of control (p<0.05). The DMR of H19 was lower methylation pattern in clone than that of control. These results suggest that the aberrant mRNA expression of apoptosis-related and imprinted genes and the lower DMR methylation pattern of imprinted gene may be closely related to the inadequate fetal development of cloned fetus.

현대 패션에 나타난 주술적 원시미술의 조형적 특성 연구 (A Study on the Formative Characteristics of Enchanting Primitive Art in Modern Fashion)

  • 이은경;김양원
    • 한국생활과학회지
    • /
    • 제8권2호
    • /
    • pp.327-337
    • /
    • 1999
  • Primitive men's primordial formative activity derives from incarnation contained in intensive vitality and strong creativity mind. The trend of modern fashion requiring the boundless imagination can be called that it, just, itself, has something in common with basic spiritual activity that primitive men had. What is concerning how modern fashion designers have developed formative language through enchanting primitive art is as follows. 1. The nature's mysterious power appears to be transformed into personified image. The incarnation for acquiring beauty, power, prestige of genius appears in the form of personification, making use of mask in modern fashion. 2. As for primitive men, the whole universe has a potentiality as a symbol. The symbolism of primitive art based on religion and myth appears in modern art as the form of presenting oppositional objects together in one space. 3. Primitive art is the purest form and the most unpolluted. This shows the natural quality being assimilated into nature, which is expressed in modern fashion as intensity, free-spirit, simplicity, etc. 4. The primitive men's anxiety to the outside world appears as impulse. The geometrical form of primitive art occurred in the shape of impulse appears in expressional form of modern fashion. 5. The real existence in primitive art inducing real materials and objects, in themselves, into formative world appears in modern art in the way of expression such as repetition, enlargement, exact reproduction.

  • PDF

Semi-domesticated and Irreplaceable Genetic Resource Gayal (Bos frontalis) Needs Effective Genetic Conservation in Bangladesh: A Review

  • Uzzaman, Md. Rasel;Bhuiyan, Md. Shamsul Alam;Edea, Zewdu;Kim, Kwan-Suk
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제27권9호
    • /
    • pp.1368-1372
    • /
    • 2014
  • Several studies arduously reported that gayal (Bos frontalis) is an independent bovine species. The population size is shrinking across its distribution. In Bangladesh, it is the only wild relative of domestic cattle and also a less cared animal. Their body size is much bigger than Bangladeshi native cattle and has prominent beef type characters along with the ability to adjust in any adverse environmental conditions. Human interactions and manipulation of biodiversity is affecting the habitats of gayals in recent decades. Besides, the only artificial reproduction center for gayals, Bangladesh Livestock Research Institute (BLRI), has few animals and could not carry out its long term conservation scheme due to a lack of an objective based scientific mission as well as financial support. This indicates that the current population is much more susceptible to stochastic events which might be natural catastrophes, environmental changes or mutations. Further reduction of the population size will sharply reduce genetic diversity. In our recent investigation with 80K indicine single nucleotide polymorphism chip, the $F_{IS}$ (within-population inbreeding) value was reported as $0.061{\pm}0.229$ and the observed ($0.153{\pm}0.139$) and expected ($0.148{\pm}0.143$) heterozygosities indicated a highly inbred and less diverse gayal population in Bangladesh. Prompt action is needed to tape the genetic information of this semi-domesticated bovine species with considerable sample size and try to investigate its potentials together with native zebu cattle for understanding the large phenotypic variations, improvement and conservation of this valuable creature.