• Korean Journal of Mathematics
• /
• v.31 no.1
• /
• pp.17-23
• /
• 2023

For a locus with two alleles (I^A and I^B), the frequencies of the alleles are represented by $$p=f(I^A)={\frac{2N_{AA}+N_{AB}}{2N}},\;q=f(I^B)={\frac{2N_{BB}+N_{AB}}{2N}}$$ where N_AA, N_AB and N_BB are the numbers of I^AI^A, I^AI^B and I^BI^B respectively and N is the total number of populations. The frequencies of the genotypes expected are calculated by using p², 2pq and q². Choi defined the density and operator for the value of the frequency of one gene and found the adapted partial differential equation as a follow-up for the frequency of alleles and applied this adapted partial differential equation to several diploid model [1]. In this paper, we find adapted equations for the model for selection against recessive homozygotes and in case that the alley frequency changes after one generation of selection when there is no dominance. Also we consider the triploid model with three alleles I^A, I^B and i and determine whether six genotypes observed are in Hardy-Weinburg for equilibrium.

• Korean Journal of Agricultural Science
• /
• v.39 no.4
• /
• pp.467-471
• /
• 2012

In this study, we investigated the antioxidative and antiaging activity of Perilla frutescens using LLC-$PK_1$ porcine renal epithelial cell and WI-38 human diploid fibroblast cell. The extract from Perilla frutescens showed strong protective effect against nitric oxide (NO) and superoxide ($O_2{^-}$)-induced oxidative stress generated by sodium nitroprusside (SNP) and pyrogallol, respectively. The result showed that P. frutescens increased the cell viability and showed scavenging activity of NO and $O_2{^-}$. In addition, the extract of P. frutescens exerted the protective effect against peroxynitrite ($ONOO^-$) induced by 3-morpholinosydnonimine. It suggests that P. frutescens would have the protective role against $ONOO^-$ itself and its precursors, NO and $O_2{^-}$. Furthermore, the aging model of hydrogen peroxide ($H_2O_2$)-treated WI-38 human diploid fibroblast was employed to investigate the anti-aging effect of P. frutescens. $H_2O_2$-treated WI-38 cells showed the loss of cell viability, however before-treatment with P. frutescens to WI-38 cells under premature senescence could delay the cellular aging process. The present study suggests the antioxidative and antiaging potential against free radical-induced oxidative damage of P. frutescens.

• Proceedings of the KIEE Conference
• /
• 1993.07b
• /
• pp.923-928
• /
• 1993

Genetic algorithms are powerful optimization methods based on the mechanism of natural genetics and natural selection. Genetic algorithms reduce chance of searching local optima unlike most conventional search algorithms and especially show good performances in complex nonlinear optimization problems because they do not require any information except objective function value. This paper presents a new model based on sexual reproduction in nature. In the proposed Sexual Reproduction model(SR model), individuals consist of the diploid of chromosomes, which are artificially coded as binary string in computer program. The meiosis is modeled to produce the sexual cell(gamete). In the artificial meiosis, crossover between homologous chromosomes plays an essential role for exchanging genetic informations. We apply proposed SR model to optimization of the design parameters of Single-sided Linear Induction Motor(SLIM). Sequential Unconstrained Minimization Technique(SUMT) is used to transform the nonlinear optimization problem with many constraints of SLIM to a simple unconstrained problem, We perform optimal design of SLIM available to FA conveyer systems and discuss its results.

• The Plant Pathology Journal
• /
• v.17 no.2
• /
• pp.67-70
• /
• 2001

Medicago truncatula is a diploid legume plant related to the forage crop alfalfa. Recently, it has been chosen as a model species for genomic studies due to its small genome, self-fertility, short generation time, and high transformation efficiency. M. truncatula engages in symbiosis with nitrogen-fixing soil bacterium Rhizobium meliloti. M. truncatula mutants that are defective in nodulation and developmental processes have been generated. Some of these mutants exhibited altered phenotypes in symbiotic responses such as root hair deformation, expression of nodulin genes, and calcium spiking. Thus, the genes controlling these traits are likely to encode functions that are required for Nod-factor signal transduction pathways. To facilitate genome analysis and map-based cloning of symbiotic genes, a bacterial artificial chromosome library was constructed. An efficient polymerase chain reaction-based screening of the library was devised to fasten physical mapping of specific genomic regions. As a genomics approach, comparative mapping revealed high levels of macro- and microsynteny between M. truncatula and other legume genomes. Expressed sequence tags and microarray profiles reflecting the genetic and biochemical events associated with the development and environmental interactions of M. truncatula are assembled in the databases. Together, these genomics programs will help enrich our understanding of the legume biology.

• Korean Journal of Mathematics
• /
• v.28 no.1
• /
• pp.1-7
• /
• 2020

A partition X describes that there exists α_i kinds of alleles occurring i loci for each i. All genes have multiple alleles, i.e., they exist in more than two allelic forms, although any one diploid organism can carry no more than two alleles. The number of possible genotypes in a multiple allel series depends on the number of alleles. We will deal with an n locus model in which mutation and gene conversion are taken into consideration. In this paper, we firstly find the probability p_n(x) of genotype $$p_{n+1}(x)=p_n(x){\sum\limits_{k=1}^{r}}q_{kx}p_n(k)$$ with the rates of mutation and gene conversion. Also we find the probability of genotype without the rates of mutation and gene conversion and we apply this probability to two examples.

• Molecules and Cells
• /
• v.45 no.11
• /
• pp.846-854
• /
• 2022

Neurons make long-distance connections via their axons, and the accuracy and stability of these connections are crucial for brain function. Research using various animal models showed that the molecular and cellular mechanisms underlying the assembly and maintenance of neuronal circuitry are highly conserved in vertebrates. Therefore, to gain a deeper understanding of brain development and maintenance, an efficient vertebrate model is required, where the axons of a defined neuronal cell type can be genetically manipulated and selectively visualized in vivo. Placental mammals pose an experimental challenge, as time-consuming breeding of genetically modified animals is required due to their in utero development. Xenopus laevis, the most commonly used amphibian model, offers comparative advantages, since their embryos ex utero during which embryological manipulations can be performed. However, the tetraploidy of the X. laevis genome makes them not ideal for genetic studies. Here, we use Xenopus tropicalis, a diploid amphibian species, to visualize axonal pathfinding and degeneration of a single central nervous system neuronal cell type, the retinal ganglion cell (RGC). First, we show that RGC axons follow the developmental trajectory previously described in X. laevis with a slightly different timeline. Second, we demonstrate that co-electroporation of DNA and/or oligonucleotides enables the visualization of gene function-altered RGC axons in an intact brain. Finally, using this method, we show that the axon-autonomous, Sarm1-dependent axon destruction program operates in X. tropicalis. Taken together, the present study demonstrates that the visual system of X. tropicalis is a highly efficient model to identify new molecular mechanisms underlying axon guidance and survival.

• Molecules and Cells
• /
• v.24 no.3
• /
• pp.358-363
• /
• 2007

Swine endothelial cells are commonly used as an in vitro model for studying features of the blood-brain barrier and some hemorrhagic diseases. However, primary cultures of swine cells have finite lifespans. To establish immortalized swine umbilical vein endothelial cells (SUVECs) using human telomerase reverse transcriptase (hTERT), the plasmid pCI-neo-hTERT was transfected into SUVECs by lipofection. Clones were selected for G418 resistance, and positive clones were amplified. One of the clones was cultured for up to 50 passages. Factor VIII-related antigen and CD34 were detected. The immortalized cells shared the properties of normal cells, such as contact inhibition, serum requirement and anchorage dependence. Karyotype analysis revealed that the immortalized cells were in the diploid range. In addition, both in vivo and in vitro assays of tumorigenicity showed no neoplastic transformation. Furthermore, NO, $PGI_2$, and ET-1 concentrations in the transfected cells were normal. These results suggest that the SUVECs immortalized by hTERT retain their original characteristics.

• Korean Journal of Animal Reproduction
• /
• v.19 no.3
• /
• pp.171-179
• /
• 1995

This study was carried out to investigate the fertilizing ability of round spematids isolated from seminiferous tubules. A round spermatid was introduced into the perivitelline space of a mature oocyte using Leitz micromanipulators and then subjected to electrofusion. Electrofusion was induced by applying a single DC pulse of 90V with a duration of 60$\mu$sec using Model 611 Square Wave Stimulator(Phipps and Bird, U.S.A) in 0.3 M sucrose fusion medium containing 0.05mM CaCl2 and 0.1mM MgSO4, Oocyte pre-activation was conducted by exposure to a single DC(80V, 80$\mu$sec) pulse in electrofusion medium at 1 hour before electrofusion. The incidence of fusion with pre-activated oocytes(23.8%, 57/239) was higher than that with nonactivated oocytes(6.7%, 3/45). The most of electro-stimulated mouse oocytes cleaved regardless of the success or failure of fusion. Karyotyping of embryos that developed into blastocysts after exposure to the fusion pulse were performe. We found that blastocysts from the fused oocytes were diploid whereas blastocysts from the unfused oocytes were haploid. About 11.7 and 11.5% of fused and unfused oocytes were developmental potentials of fused and unfused oocytes. Therefore, these results suggest that the mouse mture oocyte can be fertilized by fusion with a round spermtid and subsequently developed normally.

• Proceedings of the Korean Society for Bioinformatics Conference
• /
• 2003.10a
• /
• pp.221-228
• /
• 2003

This paper presents a novel method that can identify the individual's haplotype from the given genotypes. Because of the limitation of the conventional single-locus analysis, haplotypes have gained increasing attention in the mapping of complex-disease genes. Conventionally there are two approaches which resolve the individual's haplotypes. One is the molecular haplotypings which have many potential limitations in cost and convenience. The other is the in-silico haplotypings which phase the haplotypes from the diploid genotyped populations, and are cost effective and high-throughput method. In-silico haplotyping is divided into two sub-categories - statistical and computational method. The former computes the frequencies of the common haplotypes, and then resolves the individual's haplotypes. The latter directly resolves the individual's haplotypes using the perfect phylogeny model first proposed by Dan Gusfield [7]. Our method combines two approaches in order to increase the accuracy and the running time. The individuals' haplotypes are resolved by considering the MLE (Maximum Likelihood Estimation) in the process of computing the frequencies of the common haplotypes.

• Parasites, Hosts and Diseases
• /
• v.51 no.6
• /
• pp.711-717
• /
• 2013

Opisthorchis viverrini (O. viverrini) is a well-known causative agent of cholangiocarcinoma (CCA) in humans. CCA is very resistant to chemotherapy and is frequently fatal. To understand the pathogenesis of CCA in humans, a rodent model was developed. However, the development of CCA in rodents is time-consuming and the xenograft-transplantation model of human CCA in immunodeficient mice is costly. Therefore, the establishment of an in vivo screening model for O. viverrini-associated CCA treatment was of interest. We developed a hamster CCA cell line, Ham-1, derived from the CCA tissue of O. viverrini-infected and N-nitrosodimethylamine-treated Syrian golden hamsters. Ham-1 has been maintained in Dulbecco's Modified Essential Medium supplemented with 10% fetal bovine serum for more than 30 subcultures. These cells are mostly diploid (2n=44) with some being polyploid. Tumorigenic properties of Ham-1 were demonstrated by allograft transplantation in hamsters. The transplanted tissues were highly proliferative and exhibited a glandular-like structure retaining a bile duct marker, cytokeratin 19. The usefulness of this for in vivo model was demonstrated by berberine treatment, a traditional medicine that is active against various cancers. Growth inhibitory effects of berberine, mainly by an induction of G1 cell cycle arrest, were observed in vitro and in vivo. In summary, we developed the allo-transplantable hamster CCA cell line, which can be used for chemotherapeutic drug testing in vitro and in vivo.