• Title/Summary/Keyword: Gametes

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Development of a Modified Real-valued Genetic Algorithm with an Improved Crossover (교배방법의 개선을 통한 변형 실수형 유전알고리즘 개발)

  • Lee, Deog-Kyoo;Lee, Sung-Hwan;Woo, Chun-Hee;Kim, Hag-Bae
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.12
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    • pp.667-674
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    • 2000
  • In this paper, a modified real-valued genetic algorithm is developed by using the meiosis for human's chromosome. Unlike common crossover methods adapted in the conventional genetic algorithms, our suggested modified real-valued genetic algorithm makes gametes by conducting the meiosis for individuals composed of chromosomes, and then generates a new individual through crossovers among those. Ultimately, when appling it for the gas data of Box-Jenkin, model and parameter identifications can be concurrently done to construct the optimal model of a neural network in terms of minimizing with the structure and the error.

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The Effects of Temperature on Biological Evaluation of Seawater with Seaurchins (성게를 이용한 해수의 생물학적평가에 있어 온도가 미치는 영향)

  • 유춘만;조기안
    • Journal of Environmental Science International
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    • v.8 no.2
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    • pp.161-164
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    • 1999
  • This study was done to research the effects of temperature on biological evaluation of seawater quality using gametes, embryos and early development system of seaurchin species, Hemicentrotus pulcherrimus, Anthocidaris crassispina and Scaphechinus brevis. As the result of performing effects of temperature on early embryo development, the conditions of appropriate temperature on formation of normal pluteus were appropriate at 5-16$^{\circ}C$ for H. pulcherrimus, 8-2$0^{\circ}C$ for A. crassispina, 12-2$0^{\circ}C$ for S. brevis. The conditions of optimum temperature on biological evaluation were 16$^{\circ}C$ for H. pulcherrimus and 2$0^{\circ}C$ for A. crassispina and S. brevis.

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PRIMORDIAL GERM CELLS IN AVES - Review -

  • Han, J.Y.;Seo, D.S.;Shoffner, R.N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.7 no.4
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    • pp.459-466
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    • 1994
  • Primordial germ cells (PGCs) in aves are the progenitor cells for the gametes. These cells first appear in the epiblast (Eyal-Giladi et al.. 1981). Then translocate and concentrate to endoderm of germinal crescent area in the junction of the area opaca and area pellucida lateral to the primitive streak in stage 4 through 7. They separate from the endoderm, temporarily circulate via the blood vascular system, leave the blood vessels, and finally settle down in the gonadal anlagen at stage 20-24 where they rapidly proliferate to form germ cells. Recently, several attempts have been made to introduce foreign gene into the avian genome to form a transgenic chicken. The stem cells most readily available as vehicles for genetic manipulation of germline in avian species are the PGCs. PGCs have recently been manipulated genetically and used successfully as a vector for gene transfer.

A Study on Cultivation of Petalonia fascia (Scytosiphonales, Phaeophyta) by Vegetative Regeneration

  • Lee,Kang-Hwa;Cho,Jae-Hyun;Shin,Jong-Ahm
    • ALGAE
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    • v.18 no.4
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    • pp.333-339
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    • 2003
  • To establish a cultivation method of Petalonia fascia, seeds and seedlings cultures and growth tests were performed at the Daeri aquafarm in Haeui, Shinan, Jeollanamdo, Korea. Gametes were easily released from the mature plurilocular sporangia. They developed to crustose discoidal stolons and grew to filamentous and discoidal stolons. The indoor seeding was performed by using the 100-150 ${\mu}m$long fragments of stolons on Porphyra nets and the erect thalli developed from the cuttings when the seawater temperatures were 10-15$^{\circ}C$. In the experimental cultivation in the sea, 1-2mm long plantlets were found after 15 days of cultivation; after two months thalli grew to their maximal size of 215-355 mm long blades; after three months the length of thalli began to decrease due to distal disintegration and the plant color changed to yellow and epiphytic diatoms were attached on the thalli, which deteriorated the quality of products. The cultivation of P. fascia by the regeneration of filamentous-discoidal complexes was carried out successfully for the first time in Korea.

Genetic Variation in Early Survival of Chum Salmon Families with Respect to Seawater Temperature

  • Choe Mi-Kyung;Yeo In-Kyu
    • Fisheries and Aquatic Sciences
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    • v.3 no.2
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    • pp.88-96
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    • 2000
  • The present study estimated the variation of early survival of chum salmon families with respect to temperature and size after transfer to seawater. Heritability for seawater tolerance of half-sib families was also estimated at 45 days after hatching. Gametes were collected from 6 male and 18 female chum salmon to make 18 paternal half-sib families. Seawater tests were carried out at 3, 7 and $12^{\circ}C$ of $32\%$ seawater and compared with freshwater. Survival was significantly affected by seawater temperature. The highest seawater tolerance was obtained in 45-day old chum salmon at $7^{\circ}C$ seawater and the lowest seawater tolerance was obtained at $3^{\circ}C$. Overall survivals in seawater tolerance at $32\%$ varied among families. There were significant variance in fry survival among females (P=0.0001), and among males (P=0.0001). The heritabilities of survival in seawater in chum salmon were estimated to be 0.32-0.34 for the sire components at 45 days after hatching in 1998.

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The Effects of pH on Early Embryo Development of Sea Urchins (수소이온농도(pH)가 성게의 초기 배 발생에 미치는 영양)

  • 유춘만
    • Journal of Environmental Health Sciences
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    • v.30 no.2
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    • pp.104-107
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    • 2004
  • This study was conducted to evaluate the effects of pH, using gametes, embryos and early development system of three sea urchins species, Hemicentrotus pulcherrimus, Anthocidaris crassispina and Scaphechinus brevis. As the result of performing effects of pH on early embryo development, the conditions of appropriate pH on formation of normal pluteus were pH 7.0-8.0 for H. pulcherrimus, A. crassispina and S. brevis. Otherwise, the conditions of pH 5.0, pH 6.0, pH 9.0 and pH 10.0 damaged the development of early embryos of each testing animal moderately or strongly.

Sexual Reproduction Genetic Algorithms: The Effects of Multi-Selection & Diploidy on Search Performances (유성생식 유전알고리즘 : 다중선택과 이배성이 탐색성능에 미치는 영향)

  • Ryu, K.B.;Choi, Y.J.;Kim, C.E.;Lee, H.S.;Jung, C.K.
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.1006-1010
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    • 1995
  • This paper describes Sexual Reproduction Genetic Algorithm(SRGA) for function optimization. In SRGA, each individual utilize a diploid chromosome structure. Sex cells(gametes) are produced through artificial meiosis in which crossover and mutation occur. The proposed method has two selection operators, one, individual selection which selects the individual to fertilize, and the other, gamete selection which makes zygote for offspring production. We consider the effects of multi-selection and diploidy on search performance. SRGA improves local and global search(exploitation and exploration) and show optimum tracking performance in nonstationary environments. Gray coding is incorporated to transforming the search space and Genic uniform distribution method is proposed to alleviate the problem of premature convergence.

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Stem cells and reproduction

  • Lee, Yeonmi;Kang, Eunju
    • BMB Reports
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    • v.52 no.8
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    • pp.482-489
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    • 2019
  • Reproductive biotechnology has developed rapidly and is now able to overcome many birth difficulties due to infertility or the transmission of genetic diseases. Here we introduce the next generation of assisted reproductive technologies (ART), such as mitochondrial replacement technique (MRT) or genetic correction in eggs with micromanipulation. Further, we suggest that the transmission of genetic information from somatic cells to subsequent generations without gametes should be useful for people who suffer from infertility or genetic diseases. Pluripotent stem cells (PSCs) can be converted into germ cells such as sperm or oocytes in the laboratory. Notably, germ cells derived from nuclear transfer embryonic stem cells (NT-ESCs) or induced pluripotent stem cells (iPSCs) inherit the full parental genome. The most important issue in this technique is the generation of a haploid chromosome from diploid somatic cells. We hereby examine current science and limitations underpinning these important developments and provide recommendations for moving forward.

Speciation Mode Reconstruction for Lepilemur six species (L. mustelinus, L. edwardsi, L. dorsalis, L. leucopus, L. ruficaudatus, L. septentrionalis) Based on the Lepilemur Karyotype Analysis (여우원숭이속(Lepilemuridae)의 핵형 분석을 통해 나타난 Lepilemur 6종(L. mustelinus, L. edwardsi, L. dorsalis, L. leucopus, L. ruficaudatus, L. septentrionalis)의 종 분화 양상)

  • 정기윤
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.5 no.2
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    • pp.141-149
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    • 2004
  • The aim of this study was to test the validity of the hypothesis that the karyotypes of four species of Lepilemuridae were formed spontaneously from their ancestral hybrid karyotype. Hypothetical ancestral haploid Karyotype of Lepilemuridae is composed of 18 autosomes and X chromosomes. Lepilemur mustelinus karyotype has four tandem fused chromosomes and one Robertsonian translocated chromosome pairs. Lepilemur septentrionalis septentrionalis karyotype has only two pairs of translocated chromosomes. We reconstruct and suggest ancestral karyotype of LMU(ancLMU) and LSS(ancLSS), from which all four studied species were derived. Hybrids of ancLMU and ancLSS were formed and produce differently fused equilibrated gametes via circular form arrangement during gametogenesis. Five unit of trivalent homologous chromosome pairs were engaged in a circular form to give new gamete corresponding to the karyotype of L. dorsalis, orientation of one unit of trivalent was inversed in the circle to gave new gamete corresponding to the karyotype of L. leucopus. Seven homologous chromosome pairs were engaged in circular form to give haploid karyotype of Lepilemur ruficaudatus. Only one homologous chromosome pair is dissociated and the other chromosome pairs rearranged in the circle to form haploid karyotype of Lepilemur edwardsi. The new gametes could be produced from these circular forms. When the new gamete fertilized with the same type of gamete, The new homozygote is produced as existing L. dorsalis, L. leucopus, L. edwardsi and L. ruficaudatus. These results support the theory that new species could be formed in hybrid population through activated chromosome fusion, chromosome rearrangement in circular from at zygotene stage and production of equilibrated gametes to form homozygote new species.

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Fertility Restoration of F1 OA Interspecific Hybrid by Spontaneous Meiotic Polyploidization and Analysis of Their Progenies (자발적 생식세포 염색체 배수화 기작에 의한 Oriental-Asiatic hybrid(OA) F1 종간잡종의 임성회복과 후대검정)

  • Chung, Mi-Young;Chung, Jae-Dong;Van Tuyl, Jaap M.;Lim, Ki-Byung
    • Korean Journal of Breeding Science
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    • v.41 no.3
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    • pp.213-219
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    • 2009
  • This study was carried out to establish breeding system for interspecific hybridization of Lilium using spontaneous meiotic polyploidization of $F_1$ OA hybrid and its progenies. Pollen viability and germination of $F_1$ OA interspecific hybrid showed variation by collection time, indicating that pollen grain in June, which was natural blooming season, had better viability and germination ability than in October. 2n-gametes from spontaneous meiotic polyploidization of OA hybrid were crossed with either diploid Asiatic or Oriental hybrid, and subsequent progenies crossed with Asiatic hybrid as female and OA hybrid as male showed the highest efficiency, where 2x-2x A$\times$OA produced 0.64 plants per cross combination, while 2x-2x, O$\times$OA and 2x-2x, OA$\times$A crosses produced 0.42 and 0.4 plant per ovary, and especially no progeny was obtained in 2x-2x, OA$\times$O cross combination. For the subsequent progeny production, a cross between diploid Asiatic hybrid as female and diploid OA hybrid as male was the best ploidy combination. Ploidy level of subsequent progeny derived from backcross with 2n-gametes of OA hybrid revealed that triploids from 2x-2x OA$\times$A, tetraploids from both 4x-2x, AA$\times$OA and OO$\times$OA, diploid from 2x-2x, O$\times$OA, and diploids or triploids from 2x-2x, A$\times$OA crosses were produced respectively.