• Title/Summary/Keyword: Zoology

Search Result 3,092, Processing Time 0.023 seconds

Study on the Sex Chromosome Dependent Segregation of the Third Chromosome in Drosophila melanogaster (초파리의 성 옆색체의 구성이 제 3옆색체의 분리에 미치는 영향에 대하여)

  • Kang, M.J.;Kang, S.J.;Chung, Y.J.
    • The Korean Journal of Zoology
    • /
    • v.13 no.1
    • /
    • pp.15-20
    • /
    • 1970
  • The present study was undertaken in an attempt to see if the segregation frequency of a third chromosome was changed by changing the sex chromosome which were free of SD in the second chromosome. The eight genotype males having different sex chromosome constitution each were constructed by appropriate matings and the two standard laboratory stocks of Drosophila melanogaster, e and se were used as the third chromosome recessive markers for the present experiment. The results of the present investigation are given below: 1. The k values which are the proportion of the se third chromosomes recovered among progeny flies from the mating of se/e males to e females were highly signiicantly different among the four genotypes and between the two sexes,and the interaction of genotype and sex was significantly different. Thus the setregation frequency of the se third chromosome in the male, when made heterozygous with the e third chromosome, was dependent upon the sex chromosome constitution. 2. Both of the k(Woman) and the k(man) remains roughly constant among genotypes. 3. The sex ratio o the se progeny class was highly significantly heterogeneous among the four genotypes but it was homogeneous for the e progeny class. 4. The values of the k(man) and the sex ratio of the se progeny class, on the average, were higher than that of the k(Woman) and of the e progeny class, respectively. 5. Those phenomena suggest that some sort of prezygotic selection could be operating such that the combination of the e third chromosome and the Y chromosome tends to be eliminated before fertilization. This tendency argues for a re-examination of the viability estimations of Drosophila melanogaster.

  • PDF

An Electron Microscopic Observation of Some Membrane Structures of Lens Fibers of Regenerating Lens in Triturus pyrrhogaster (Triturus pyrrhogaster 에서 再生되는 水晶體纖維 細胞中 膜構造에 관한 電子顯微鏡的 觀察)

  • Sung, Hwan-Soon;Sung, Hwan-Sang
    • The Korean Journal of Zoology
    • /
    • v.11 no.1
    • /
    • pp.5-12
    • /
    • 1968
  • The membrane structures were electron microscopically studied in the elongating lens fibers of the regenerating lens of adult Triturus pyrrhogaster. Observations were focused on the endoplasmic reticulum and mitochondria. The endoplasmic reticulum developed in the vicinity of the nucleus with active blebbing of the outer membrane. At the same time, the concentration of mitochondria around the rough-surfaced endoplasmic reticulum near by the nucleus was always observed. Both endoplasmic reticulum and mitochondrion undergo disintegration in the apical portion apart from the nucleus. Some considerations were discussed with reference to published data.

  • PDF

The Abstracting Services in Korea: The Present State, Problems and Some Suggestions for Action in the Future (우리나라의 초록시스템 - 현황, 문제 및 개선방안)

  • Choi, Sung-Jin
    • Journal of the Korean BIBLIA Society for library and Information Science
    • /
    • v.6 no.1
    • /
    • pp.133-160
    • /
    • 1984
  • The main purpose of the present study is to survey the major abstracting bulletins of national nature in Korea, to define such problem areas as lacunae, duplicates and limitation in coverage in the abstracting services currently available in Korea, and to make some suggestions for action for improving the abstracting services in the light of general principles and the tradition and situations unique to Korea. The major conclusions reached at this study are summarised as follows: (A) A new abstracting bulletin of general nature covering the whole field needs to be created in each of the following fields where no established abstracting service is available for the outcome of research and development activities in Korea. (1) Language (2) Religion (3) Art (4) Language (5) Literature (6) History (B) A new specialised abstracting bulletin needs to be created in each of the following fields of science where abstracting services limited in coverage are partially available. (a) Statistics (b) Sociology (c) political science (d) Public administration (e) Law (f) Folk lore (g) Military science (2) Pure sciences (a) Mathematics (b) Chemistry (c) Astronomy (d) Geology (e) Mineralogy (f) Life sciences (g) Botany (h) Zoology (3) Applied sciences (a) Agriculture (b) Architectural engineering (c) Mechanical engineering (d) Electrical engineering (e) Chemical engineering (f) Manufacturing industry (g) Domestic science (C) Publication of the abstracting bulletins suggested in (A) and (B) above may be ideally carried on by a qualified learned society established in the respective field. and should be financially supported by the public fund under the provisions of Art. 27 of the Research Promotion Act of 1979. (D) The current practice of adding the author's abstract and keywords to each of the records of the "Doctoral Theses in Humanities and Social Sciences" part of the" Catalogue of Doctoral and Master's Theses Submitted to the Universities in Korea" published by the National Assembly Library should be applied to all the other parts, i. e. to the parts of the "Master's Theses in Humanities and Social Sciences" and of the "Doctoral and Master's Theses in Natural Sciences': which will not only increase the Catalogue's use value but also discourage appearance of various theses abstracts of individual academic institutions such as the" Abstracts of the Doctoral and Master's Theses Submitted to Korea Advanced Institute of Science and Technology" which will in turn reduce inefficiency involved in the abstracting services at national level. (E) A general abstracting bulletin covering most part of the outcome of research and development activities in Korea other than that covered by the existing abstracts needs to be created to be temporarily. used till the abstracting journals suggested in this study will be fully available. A realistic way of having such a bulletin may be to expand the present coverage of "The Abstracts of the Reports of the Government-sponsored Projects" currently published by Korean Research Foundation.

  • PDF

Morphometric Analyses of the Three Subspecies of Striped Field Mouse, Apodemus agrarius Pallas (Mammalia: Rodentia) from Far Eastern Asia: Taxonomic Status of North Korean Striped Field Mice (극동아시아에 서식하고 있는 등줄쥐 Apodemus agrarius Pallas (포유강 :설치 목) 3아종의 형태 형질의 분석: 북한산 등줄쥐의 분류학적 위치)

  • Koh, Hung-Sun;G. Csorba;M.P. Tiunov;G. Tikhonova
    • Animal Systematics, Evolution and Diversity
    • /
    • v.14 no.4
    • /
    • pp.327-334
    • /
    • 1998
  • Four external and 27 cranial characters of three subspecies of striped field mice (Apodemus agrarius) from 15 regions in far eastern Asia(South Korea, North Korea, northeastern China, and far eastern Russia) were analyzed by multivariate methods in order to determine taxonomic status of striped field mice from North Korea. Three subgroups were recognized: a large-size form from two localities in South Korea(Cheju Island, Wando Island): a medium-size form from eight localities in South Korea and North Korea(Jindo Island, Kunsan, Mt. Chirisan, Cheongju, Mt. Weoleksan, Mt. taebaksan; Haeju, Sineuiju); a small-size form from five localities in North Korea, northeastern China, and far eastern Russia (Mt. Kumkangsan, Mt. Myohyangsan; Jirin, Yichun; Vladivostok). It is confirmed that the large-size form, the medium-size form, and the small-size form are subspecies chejuensis, coreae, and manchuricus, respectively, as noted by Koh et al.(1997). It is revealed that striped field mice(the medium-size form) from western region of North Korea (Haeju, Sineuiju) is classified into A. agrarius coreae, as noted by Thomas(1908), but striped field mice(the small-size form) from eastern region of North Korea(Mt. Kumkangsan, Mt. Myohyangsan) is A. agrarius manchuricus.

  • PDF

Taxonomy of Ascidians from Geojedo Island in Korea (한국 거제도 해초류의 분류)

  • Boon Jo Rho;Kyung-Sook Park
    • Animal Systematics, Evolution and Diversity
    • /
    • v.14 no.3
    • /
    • pp.173-192
    • /
    • 1998
  • This study was made as a part of the benethic fauna of Geojedo Island. The material was obtained from 17 localities (Fig. 1) along the coastal sea of Geojedo Island and it's adjacent waters during the years 1995-1998. This paper includes 38 species from a limited area of the southern part of Korea and includes 13 previously known species by Rho(1975-1991). Of these Didemnum (D.) pardum, Symplegma oceania, and Styela coriacea, are new to the Korean fauna, and 22 species are newly added to the fauna of Geojedo Island. We provided taxonomic notes and brief notes on the ascidian fauna, and the biogeographical distribution of Geojedo island. Its ascidian fauna are characterized by a high percentage of 18(47.4%) warm-water species and the extreme scarcity of eight(21.1%) boreal-water forms. This result may be attributable to the fact that Geojedo island and its adajacent waters are located under the influence of the warm Kuroshio Current.

  • PDF

Effects of Organic Acids on the Storability of Chilled Beef (유기산에 의한 냉장우육의 저장효과)

  • Jung, Hae-Man;Lee, Kyu-Han
    • Korean Journal of Food Science and Technology
    • /
    • v.23 no.3
    • /
    • pp.379-387
    • /
    • 1991
  • The effects of organic acids (acetic, citric and lactic acids) treatment on microbial spoilage of chilled beef were studied during aerobic storage at $4^{\circ}C$ for 11 days. The organic acids had definite effects on the delay of the development of off-odor and slime of chilled beef. When chilled beef slices were treated with 1, 2, 3 and 4% of organic acids, off-odor was developed 1, 2, 3 and 5 days later than control, respectively, regardless of the kinds of organic acid. The slime was produced two days after the day of off-odor development in $1{\sim}3%$ organic acid-treated chilled beef, but no slime was produced on chilled beef treated with 4% organic acid. The off-odor was detected organoleptically when pH and number of microorganisms of chilled beef were, $5.6{\sim}5.8\;and\;0.8{\times}10^7{\sim}1.8{\times}10^7\;cell/cm^2$, respectively, and slime was observed when pH and number of microorganisms of chilled beef were $5.9{\sim}6.2\;and\;2.0{\times}10^7{\sim}6.0{\times}10^7\;cell/cm^2$, respectively, in control and treated groups.

  • PDF

UV Effect on the Number of Primordial Germ Cells in the Embryo of Rana dybowskii (자외선이 산개구리 (Rana dybowskii) embryo의 시원생식세포 수에 미치는 영향)

  • 정해문;김원숙
    • The Korean Journal of Zoology
    • /
    • v.27 no.1
    • /
    • pp.13-24
    • /
    • 1984
  • The fertilized eggs of Rana dybowskii were irradiated with UV (254 nm wave length) on the vegetal hemisphere to investigate the effects on the primordial germ cells (PGCs) and axis formation. The investigations were carried out in two ways; namely time course and UV dose. Up to 1,600 $ergs/mm^2$ of UV dose, irradiated at 60 min. after fertilization, there was no effect on the PGC number. However, the number of PGC comparing with that of unirradiated control was decreased more than 40%. As the amount of irradiation was increased, the number of PGC was inversely declined. The maximal dose of irradiation which eliminates PGC completely without inducing any axis abnormality was 4,800 $ergs/mm^2$. If the eggs were irradiated earlier with this amount the severer effect could be obtained. Thus the UV effect on the PGC number was most effective when irradiated by 60 min. post fertilization. Thereasfter stage. At UV doses over 9,600 $erge/mm^2$ other effects start to appear; namely abnormalities of nerual tube and axis formation. Therefore, comparative study on the UV sensitivity of PGC and axis formation was carried out. It was revealed that UV effect on the axis was drastically decreased at the time of $0.7\\sim0.8$ between fertilization and 1st cleavage, while the germ plasm was sensitive to UV until 4 cell stage.

  • PDF

Comparisons Among the Fishes of Genus Liobagrus in Korea by Their Morphology and Electrophoretic Patterns of Proteins (形態 및 蛋白質 電氣泳動像에 依한 韓國産 퉁가리屬 魚類의 比較)

  • 손영목;최의열;안태인
    • The Korean Journal of Zoology
    • /
    • v.27 no.1
    • /
    • pp.25-34
    • /
    • 1984
  • Two species of fishes of Genus Liobagrus that had been collected from three separate river systems in Korea were compared by their morphology and gel electrophoretic patterns of water soluble proteins. In morphology L. andersoni from Han River was distinctly different from L. mediadiposalis collected from both Gum River and Nagdong River. But L. andersoni collected from Gum River not only showed partial similarity for both groups of fishes above in their classifying characteristics but also had a unique ratio of body width/standard length. Comparable similarity and difference among the three groups were also noted in their protein patterns of SDS polyacrylamide gel electrophoresis of various tissues. The difference was clearer and more distinct in the gel run with muscle proteins. A couple of more distinctly different low molecular polypeptides were detected by two dimensional gel electrophoresis. Since the protein patterns shown in this study are not only agreeable with the morphological results but also provide detailed comparisons, fishes of Liobagrus from various water sources can be classified reliably by gel electrophoresis. On the bases of tghe findings above, L. andersoni like fishes collected from Gum River should no longer be classified as L. andersoni. Before naming them as an independent species, the possibility of natural hybrid between the two defined species, or of a varient of L. andersoni by geograpic isolation should be tested.

  • PDF

Redescription of Two Terrestrial Hypotrichous Ciliates from Jindo Island, Korea (진도의 육상 하모섬모충류 2미기록 종의 재기재)

  • Kwon, Choon-Bong;Shin, Mann-Kyoon
    • Animal Systematics, Evolution and Diversity
    • /
    • no.nspc5
    • /
    • pp.71-79
    • /
    • 2005
  • Two hypotrichous ciliates inhabiting the representative terrestrial habitats of Jindo Island, Holostichides chardezi Foissner, 1987 and Rigidocortex octonucleatus (Foissner, 1988) are found from Jindo Island. These two species are newly recorded from Korea. The description was based on the observation of living specimens, protargol impregnated specimens and biometric analysis. The morphological variations among the populations of these species were investigated with morphometry. The diagnostic characteristics of these species are as follows: Holostichides chardezi : elongate body flexible and twisted, yellowish subpellicular granules scattered entire cortex, adoral zone of membranelles covering about $28\%$ of body length, left and right rows of mid-ventral cirri paired, left row ended at buccal vertex and right row extending to center of body, no transverse cirri, both marginal rows of cirri not confluent at posterior end, 28-42 macronuclei and 1-5 micronuclei scattered entire body. 3 caudal cirri and 4 dorsal kineties. Rigidocortex octonucleatues: elongate-oval body rigid and not contractile, yellowish cytoplasmic crystals and fat globules densely packed, adoral zone of membranelles covering about $40\%$ of body length, 5 transverse cirri, both marginal rows of cirri not confluent at posterior end, 8 macronuclei longitudinally arranged in median of cell, 3 caudal cirri and 7-10 fragmented dorsal kineties.

Soybean meal substitution by dehulled lupine (Lupinus angustifolius) with enzymes in broiler diets

  • Mera-Zuniga, Fredy;Pro-Martinez, Arturo;Zamora-Natera, Juan F;Sosa-Montes, Eliseo;Guerrero-Rodriguez, Juan D;Mendoza-Pedroza, Sergio I;Cuca-Garcia, Juan M;Lopez-Romero, Rosa M;Chan-Diaz, David;Becerril-Perez, Carlos M;Vargas-Galicia, Artemio J;Bautista-Ortega, Jaime
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.32 no.4
    • /
    • pp.564-573
    • /
    • 2019
  • Objective: Evaluate the effects of i) dehulling of lupine seed on chemical composition and apparent metabolizable energy (AME) and ii) soybean meal substitution by dehulled lupine seed in broiler diets with enzymes on productive performance, size of digestive organs and welfare-related variables. Methods: Experiment 1, chemical composition and AME were determined in whole and dehulled lupine seed. Experiment 2, two hundred eighty-eight one-day-old male Ross 308 broilers were used. The experimental diets were maize-soybean meal (MS), MS with enzymes (MSE) and maize-dehulled lupine seed with enzymes (MLE). Diets were assigned to the experimental units under a completely randomized design (eight replicates per diet). The body weight (BW) gain, feed intake, feed conversion, digestive organ weights, gait score, latency to lie down and valgus/varus angulation were evaluated. Results: The dehulling process increased protein (25.0% to 31.1%), AME (5.9 to 8.8 MJ/kg) and amino acid contents. The BW gain of broilers fed the MLE diet was similar (p>0.05) to that of those fed the MS diet, but lower than that of those fed the MSE diet. Feed intake of broilers fed the MLE diet was higher (p<0.05) than that of those fed the MS diet and similar (p>0.05) to those fed the MSE diet. Feed conversion of broilers fed the MLE diet was 8.0% and 8.7% higher (p<0.05) than that of those fed the MS and MSE diets, respectively. Broilers fed the MLE diet had the highest (p<0.05) relative proventriculus and gizzard weights, but had poor welfare-related variables. Conclusion: It is possible to substitute soybean meal by dehulled lupine seed with enzymes in broiler diets, obtaining similar BW gains in broilers fed the MLE and MS diets; however, a higher feed intake is required. Additionally, the MLE diet reduced welfare-related variables.