• Title/Summary/Keyword: genetic variability

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Estimation of Effective Population Size in the Sapsaree: A Korean Native Dog (Canis familiaris)

  • Alam, M.;Han, K.I.;Lee, D.H.;Ha, J.H.;Kim, J.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.8
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    • pp.1063-1072
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    • 2012
  • Effective population size ($N_e$) is an important measure to understand population structure and genetic variability in animal species. The objective of this study was to estimate $N_e$ in Sapsaree dogs using the information of rate of inbreeding and genomic data that were obtained from pedigree and the Illumina CanineSNP20 (20K) and CanineHD (170K) beadchips, respectively. Three SNP panels, i.e. Sap134 (20K), Sap60 (170K), and Sap183 (the combined panel from the 20K and 170K), were used to genotype 134, 60, and 183 animal samples, respectively. The $N_e$ estimates based on inbreeding rate ranged from 16 to 51 about five to 13 generations ago. With the use of SNP genotypes, two methods were applied for $N_e$ estimation, i.e. pair-wise $r^2$ values using a simple expectation of distance and $r^2$ values under a non-linear regression with respective distances assuming a finite population size. The average pair-wise $N_e$ estimates across generations using the pairs of SNPs that were located within 5 Mb in the Sap134, Sap60, and Sap183 panels, were 1,486, 1,025 and 1,293, respectively. Under the non-linear regression method, the average $N_e$ estimates were 1,601, 528, and 1,129 for the respective panels. Also, the point estimates of past $N_e$ at 5, 20, and 50 generations ago ranged between 64 to 75, 245 to 286, and 573 to 646, respectively, indicating a significant $N_e$ reduction in the last several generations. These results suggest a strong necessity for minimizing inbreeding through the application of genomic selection or other breeding strategies to increase $N_e$, so as to maintain genetic variation and to avoid future bottlenecks in the Sapsaree population.

Genotype and Environment Effects on Gliadin Content and Polyphenol Oxidase Activity in Wheat

  • Seo, Yong-Weon;Park, Yong-Hack;Hong, Byung-Hee;Park, Moon-Woong;Nam, Jung-Hyun
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.45 no.1
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    • pp.38-43
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    • 2000
  • The environment in which a given genotype is grown may influence its grain quality characteristics. When varieties are $\times$ evaluated over numerous environments, a variety environment interaction usually is observed, but the relative magnitude of environmental(E), genetic(G), and G $\times$ E effects on quality is unclear. In order to determine relative contribution of genotype, environment, and G $\times$ E interaction to the variations observed in grain quality characteristics, 18 Korean wheat cultivars and experimental lines were evaluated in two environments in 1998 and 1999. Correlation coefficients between grain quality and agronomic characteristics were also estimated. The analysis of variance for the optical density obtained by reaction bet- ween gliadin and anti-gliadin polyclonal antibody (AGPab) indicated that gliadin content measured by Enzyme-Linked Immunosorbent Assay(ELISA) was significantly in- fluenced by environment and cultivar differences. The significant differences of year and year $\times$ location were also found. The ratio of the variances associated with environmental effects to the variances associated with genetic effect gave relatively greater influence of environmental factor on gliadin content. The different protein content from same genotype grown in different environment might be associated with degree of storage protein accumulations. Significant relationships between ELISA and protein content, yield, ten spike weight, and ten spike number were detected. Polyphenol oxidase (PPO) activity was significantly influenced by year, location, cultivar and year $\times$ location. The variance in grain PPO activities among growing years appeared larger than the variation produced by the cultivar examined. This suggested that the growing environment contributed more to variability in grain PPO concentration.

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Genetic Variation of Scytalone Dehydratase Gene in Colletotrichum spp. (Colletotrichum spp. 유래 scytalone dehydratase 유전자의 유전적 다양성 비교)

  • Yun, Yeo-Hong;Hyeon, Min-U;Suh, Dong-Yeon;Kim, Yong-Min;Kim, Seong-Hwan;Choi, Chang-Won;Kim, Young-Shick
    • The Korean Journal of Mycology
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    • v.37 no.2
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    • pp.155-160
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    • 2009
  • The production of dihydroxynaphthalene (DHN) melanin is known to be essential factor for pathogenicity in Colletotrichum lagenarium. However, the genetic diversity of melanin genes was not much known among Colletotrichum spp. To investigate the variability of melanin gene in Colletotrichum spp. that cause anthracnose on diverse crops including tomato, we cloned and sequenced partial sd, one of DHN melanin genes encoding for scytalone dehydratase, from eight strains of C. coccodes, C. acutatum, C. truncatum C. caricae, and C. musae. The size of PCR-amplified sd ranged 437 bp to 545 bp. The nucleotide sequence identity of sd among the Colletotrichum strains tested varied from 49% to 99%. All of the PCR-amplified sd from eight strains contain an intron and have two exons coding for 122 amino acids. Overall, the size and nucleotide sequence of sd varied among the five Colletotrichum spp. Sequence identity of the predicted scytalone dehydratase protein of 122 amino acids ranged 50 to 99%. Phylogentic analysis based on the sd nucleotide sequences revealed that the five Colletotrichum spp. could be genetically divided.

Ten new microsatellite markers in cutlassfish Trichiurus lepturus derived from an enriched genomic library

  • An, Hye-Suck;Lee, Jeong-Ho;Noh, Jae-Koo;Kim, Hyun-Chul;Park, Chul-Ji;Min, Byung-Hwa;Myeong, Jeong-In
    • Animal cells and systems
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    • v.14 no.3
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    • pp.169-174
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    • 2010
  • Cutlassfish (Trichiurus lepturus Linnaeus 1758) is a commercially important fish in Korea. In recent years, the catch of cutlassfish in the coastal waters of Korea has significantly declined. Its genetic characterization has been little studied. To assist conservation and management efforts, we isolated and characterized 10 microsatellite loci using an enrichment method based on magnetic/biotin capture of microsatellite sequences from a size-selected genomic library. To characterize each locus, 30 individuals from a natural T. lepturus population in the coastal waters of Jeju Island, Korea, were genotyped. All loci except two, KTh9B and KTh22A, were polymorphic, with an average of 14.3 alleles per locus (range, 10 22). The mean observed and expected heterozygosities were 0.80 (range, 0.50 0.97) a 0.82 (range, 0.68 0.95), respectively. A significant deviation from Hardy-Weinberg equilibrium was observed at three loci (KTh6B, KTh10, and KTh16). This high variability indicates that these microsatellites may be useful for high-resolution studies of population genetics.

Protection provided by a commercial modified-live porcine reproductive and respiratory syndrome virus (PRRSV) 1 vaccine (PRRSV1-MLV) against a Japanese PRRSV2 field strain

  • Joel Miranda;Salvador Romero;Lidia de Lucas;Fumitoshi Saito;Mar Fenech;Ivan Diaz
    • Journal of Veterinary Science
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    • v.24 no.5
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    • pp.54.1-54.13
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    • 2023
  • Background: Porcine reproductive and respiratory syndrome virus (PRRSV) vaccines do not provide full cross-protection, mainly due to the virus genetic variability. Despite this, vaccines based on modified-live PRRSV (PRRSV-MLV) reduce the disease impact. Objectives: To assess the efficacy of two commercial vaccines-one based on PRRSV1 (PRRSV1-MLV) and another on PRRSV2 (PRRSV2-MLV)-against a Japanese PRRSV2 field strain. Methods: Two groups of three-week-old piglets were vaccinated (G1: PRRSV1-MLV; G2: PRRSV2-MLV) and two were kept as non-vaccinated (INF and CTRL). One month later, G1, G2, and INF were challenged with a PRRSV2 field strain. Results: After the challenge, clinical signs were only observed in INF. Moreover, the highest rectal temperatures and values for the area under the curve (AUC) were observed in INF. Regarding viral detection, both AUC and the proportion of positive samples in blood were higher in INF. In G1, viremic animals never reached 100%. At necropsy (21 d after the challenge), differences for titers among groups were only found in tonsils (G1 < G2 and INF). One animal (belonging to G1) was negative in all tissues. Regarding humoral responses, G1 and G2 seroconverted after vaccination, as detected in the corresponding enzyme-linked immunosorbent assay. Specific neutralizing antibodies (NA) against PRRSV1-MLV were already detected at 14 d after vaccination in G1, showing a significant booster after the challenge, while PRRSV2-MLV NA were detected in G2 at the end of the experiment. Conclusions: Despite genetic differences, PRRSV1-MLV has been demonstrated to confer partial protection against a Japanese PRRSV2 strain, at least as good as PRRSV2-MLV.

Variation in morphological traits over a wave-exposure gradient in one but not in another species of the brown alga Carpophyllum (Fucales)

  • Hodge, Fiona;Buchanan, Joseph;Zuccarello, Giuseppe C.
    • ALGAE
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    • v.26 no.3
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    • pp.243-251
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    • 2011
  • Environmental conditions can influence the morphology of local biota through phenotypic plasticity or local adaptation. Macroalgal morphologies are often associated with wave-exposure conditions. We investigated the relationship between morphology and wave exposure in two common endemic subtidal macroalgae, Carpophyllum angustifolium and C. maschalocarpum, from the East Cape of New Zealand. Morphological comparisons were made between individuals from two sites and four different wave-exposure zones, as defined by fetch and barnacle composition. Of the seven morphological traits measured in C. angustifolium, only total length varied, and individuals were longer in more wave-exposed environments between the two exposure zones where the species were found. In contrast, total length, stipe thickness and vesicle presence all varied significantly between exposure zones in C. maschalocarpum. C. maschalocarpum specimens were shorter with thinner stipes, and fewer individuals had vesicles in the more wave-exposed zones. Morphological traits of both species also varied between sites, suggesting that other influences are important for determining species morphology. Further study is needed to investigate the role of phenotypic plasticity and genetic variability for driving morphological variation in C. angustifolium and C. maschalocarpum.

Molecular Characterisation of the Mafriwal Dairy Cattle of Malaysia Using Microsatellite Markers

  • Selvi, P.K.;Panandam, J.M.;Yusoff , K.;Tan, S.G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.10
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    • pp.1366-1368
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    • 2004
  • The Mafriwal dairy cattle was developed to meet the demands of the Malaysian dairy Industry. Although there are reports on its production and reproductive performance, there has been no work on its molecular characterization. This study was conducted to characterize the Mafriwal dairy cattle using microsatellite markers. Fifty two microsatellite loci were analysed for forty Mafriwal dairy cows kept at Institut Haiwan Kluang, Malaysia. The study showed two microsatellite loci to be monomorphic. Allele frequencies for the polymorphic loci ranged from 0.01 to 0.31. Genotype frequencies ranged from 0.03 to 0.33. The mean overall heterozygosity was 0.79. All polymorphic microsatellite loci deviated significantly (p<0.01) from Hardy-Weinberg equilibrium. The Mafriwal dairy cattle showed high genetic variability despite being a nucleus herd and artificial insemination being practiced.

Sequence and phylogenetic analysis of Intergenic spacer (IGS) region of ten microsporian isolates infecting Indian vanya silkworms (Samia cynthia ricini and Antheraea assamensis).

  • Hassan, Wazid;Surendra Nath, B.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.33 no.2
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    • pp.121-131
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    • 2016
  • Ten microsporidian isolates from Samia cynthia ricini, and Antheraea assamensis in India along with a Nosema reference strain (NIK-1s_mys) from B. mori India were characterised morphologically and molecular based tools. The test isolates observed elongated oval in shape while reference strain was oval and ranging from 3.80 to 4.90 m in length and 2.60 to 3.05 m in width. The ribosomal DNA region 'IGS' of test isolates assessed by PCR amplification, followed by cloning and sequencing. IGS sequence and phylogenetic analysis of test microsporidian isolates showed very close relationship with three Nosema references species: N. philosamia, N. antheraea isolated from Philosamia cynthia ricini and Antheraea perny in China respectively and N. disstriae from Malacosma disstriae in Canada. The clustering pattern of dendogram reveals all test isolates appear distinct from Nosema std. (NIK-1s_mys) India used as reference strain in the study. The result suggests IGS indeed a suitable and highly applicable molecular tool for identifying and characterise the microsporidian isolates in similar population.

Semantic Modeling for SNPs Associated with Ethnic Disparities in HapMap Samples

  • Kim, HyoYoung;Yoo, Won Gi;Park, Junhyung;Kim, Heebal;Kang, Byeong-Chul
    • Genomics & Informatics
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    • v.12 no.1
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    • pp.35-41
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    • 2014
  • Single-nucleotide polymorphisms (SNPs) have been emerging out of the efforts to research human diseases and ethnic disparities. A semantic network is needed for in-depth understanding of the impacts of SNPs, because phenotypes are modulated by complex networks, including biochemical and physiological pathways. We identified ethnicity-specific SNPs by eliminating overlapped SNPs from HapMap samples, and the ethnicity-specific SNPs were mapped to the UCSC RefGene lists. Ethnicity-specific genes were identified as follows: 22 genes in the USA (CEU) individuals, 25 genes in the Japanese (JPT) individuals, and 332 genes in the African (YRI) individuals. To analyze the biologically functional implications for ethnicity-specific SNPs, we focused on constructing a semantic network model. Entities for the network represented by "Gene," "Pathway," "Disease," "Chemical," "Drug," "ClinicalTrials," "SNP," and relationships between entity-entity were obtained through curation. Our semantic modeling for ethnicity-specific SNPs showed interesting results in the three categories, including three diseases ("AIDS-associated nephropathy," "Hypertension," and "Pelvic infection"), one drug ("Methylphenidate"), and five pathways ("Hemostasis," "Systemic lupus erythematosus," "Prostate cancer," "Hepatitis C virus," and "Rheumatoid arthritis"). We found ethnicity-specific genes using the semantic modeling, and the majority of our findings was consistent with the previous studies - that an understanding of genetic variability explained ethnicity-specific disparities.

Genetic Variation of a Single Pollen-derived Doubled Haploid Population in Rice

  • Moon, Huhn-Pal;Kang, Kyung-Ho;Ahn, Sang-Nag;Choi, Seon-Hee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.43 no.4
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    • pp.250-253
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    • 1998
  • Somaclonal variation was observed in the field on doubled haploid plants derived from single pollen of a rice cultivar "Hwaseongbyeo". The variations of seven quantitative traits including plant height and one qualitative trait (pubescence) in 436 lines ($R_2$ generation) were analyzed. The number of lines which fell beyond the boundaries of the 95% confidence intervals of the check variety, Hwaseongbyeo was checked for each quantitative trait, and of those fertility showed the highest variation frequency (85.6%), followed by plant height (77.5%), flag leaf length (66.5%), grains per panicle (42.2%), days to heading (34.5%), panicle length (30.7%) and panicles per hill (22.7%). And the variations of quantitative traits except days to flowering appeared to move in the negative direction compared to "Hwaseongbyeo". Variability within lines was also observed for quantitative and qualitative traits. Twenty-nine $R_2$ lines (7%) segregated for pubescence and 130 $R_2$ lines (30%) showed variation with regard to fertility. This suggests that mutations usually occur before diploidization. Twenty-nine $R_2$ lines representing a wide spectrum of variation were chosen for RAPD analysis. The number of lines showing DNA polymorphism compared to Hwaseongbyeo ranged 0 from to 10 according to the primer used and this seems to indicate that specific loci have highly mutable genomic site.utable genomic site.

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