• Title/Summary/Keyword: Population genetics

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Correlations of Genic Heterozygosity and Variances with Heterosis in a Pig Population Revealed by Microsatellite DNA Marker

  • Zhang, J.H.;Xiong, Y.Z.;Deng, C.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.5
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    • pp.620-625
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    • 2005
  • Correlation of microsatellite heterozygosity with performance or heterosis was reported in wild animal populations and domestic animal populations, but the correlation with heterosis in a crossbreeding F$_1$ pig population remained uncertain. To explore this, we had random selected and mated Yorkshire${\times}$Meishan (F, n = 82) and their reciprocal (G, n = 47) to F$_1$, and used the two straightbreds as control groups (Yorkshire = 34, Meishan = 55), and observed the heterosis of birth weight (BWT), average daily gain (ADG) and feed and meat ratio (FMR). Two Kinds of measurement-individual heterozygosity (IH) and individual mean d$^2$ (lg value, ID) were used as index of heterozygosity and variance from 39 microsatellite marker loci to perform univariate regression analysis against heterosis. We detected significant correlation of IH with BWT in all of F$_1$ (F+G) and in F. We observed significant correlation of ID with ADG in all of F$_1$ (F+G), and with FMR in all of F$_1$ (F+G) and in F. There was significant maternal effect on heterosis, which was indicated by significant difference of means and distribution of heterosis between F and G. This difference was consistent with distributions of IH and ID, and with difference of means in F and G. From this study, it would be suggested that the two kinds of genetic index could be used to explore the genetic basis of heterosis in crossbreeding populations but could not determine which is better.

Glioma Epidemiology in the Central Tunisian Population: 1993-2012

  • Trabelsi, Saoussen;Brahim, Dorra H'mida-Ben;Ladib, Mohamed;Mama, Nadia;Harrabi, Imed;Tlili, Kalthoum;Yacoubi, Mohamed Tahar;Krifa, Hedi;Hmissa, Sihem;Saad, Ali;Mokni, Moncef
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8753-8757
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    • 2014
  • Background: Glioma is a heterogeneous central nervous system (CNS) tumor group that encompasses different histological subtypes with high variability in prognosis. The lesions account for almost 80% of primary malignant brain tumors. The aim of this study is to extend our understanding of the glioma epidemiology in the central Tunisian region. Materials and Methods: We analyzed 393 gliomas recorded in cancer registry of central Tunisia from 1993 to 2012. Crude incidence rates (CR) and world age-standardized rates (ASR) were estimated using annual population data size and age structure. Statistic correlations were established using Chi-square and Kaplan-Meier test. Results: Tunisian glioma patients were identified with a mean age at diagnosis of 48 years and 1.5 sex ratio (male/female). During the 19 years period of study the highest incidence value was observed in male group between 1998 and 2002 (CR: 0.28, ASR: 0.3). Incidence results underline increasing high grade glioma occurring in the adulthood in the last period (2007-2012). Median survival was 27 months, with 1-, 2- and 5-year survival rates of 42%, 30% and 26%, respectively. Survival was greater in patients with younger age, lower tumor grade, infratentrial tumor location and undergoing a palliative treatment. Conclusions: This central Tunisia gliomas registry study provides important information that could improve glioma management and healthcare practice.

Mitochondrial DNA variation and phylogeography of native Mongolian goats

  • Ganbold, Onolragchaa;Lee, Seung-Hwan;Paek, Woon Kee;Munkhbayar, Munkhbaatar;Seo, Dongwon;Manjula, Prabuddha;Khujuu, Tamir;Purevee, Erdenetushig;Lee, Jun Heon
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.6
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    • pp.902-912
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    • 2020
  • Objective: Mongolia is one of a few countries that supports over 25 million goats, but genetic diversity, demographic history, and the origin of goat populations in Mongolia have not been well studied. This study was conducted to assess the genetic diversity, phylogenetic status and population structure of Mongolian native goats, as well as to discuss their origin together with other foreign breeds from different countries using hypervariable region 1 (HV1) in mtDNA. Methods: In this study, we examined the genetic diversity and phylogenetic status of Mongolian native goat populations using a 452 base-pair long fragment of HVI of mitochondrial DNA from 174 individuals representing 12 populations. In addition, 329 previously published reference sequences from different regions were included in our phylogenetic analyses. Results: Investigated native Mongolian goats displayed relatively high genetic diversities. After sequencing, we found a total of 109 polymorphic sites that defined 137 haplotypes among investigated populations. Of these, haplotype and nucleotide diversities of Mongolian goats were calculated as 0.997±0.001 and 0.0283±0.002, respectively. These haplotypes clearly clustered into four haplogroups (A, B, C, and D), with the predominance of haplogroup A (90.8%). Estimates of pairwise differences (Fst) and the analysis of molecular variance values among goat populations in Mongolia showed low genetic differentiation and weak geographical structure. In addition, Kazakh, Chinese (from Huanghuai and Leizhou), and Arabian (Turkish and Baladi breeds) goats had smaller genetic differentiation compared to Mongolian goats. Conclusion: In summary, we report novel information regarding genetic diversity, population structure, and origin of Mongolian goats. The findings obtained from this study reveal that abundant haplogroups (A to D) occur in goat populations in Mongolia, with high levels of haplotype and nucleotide diversity.

Genetic Polymorphisms of the Human Thyroid Peroxidase Gene Using Amplified Fragment Length Polymorphism: Application to the Determination of Paternity in a Korean Population. (한국인에서 중합효소연쇄반응을 이용한 Human Thyroid Peroxidase 유전자의 유전적 다형성에 관한 연구)

  • Kyung Ok Lee;Taek-Kyu Park;Moon-Ju Oh;Eun-Ha Kim;Young-Suk Park;Yoon Jung Kim;Kyu Pum Lee
    • Biomedical Science Letters
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    • v.1 no.1
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    • pp.9-18
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    • 1995
  • Genetic polymorphisms due to variation in the number of tandem repeats of DNA sequences(VNTRs) provides a useful means for discrimination between individuals. Allele and genotype frequencies of the highly polymorphic Human Thyroid Peroxidase(TPO) gene were determined in Korean population samples by using PCR followed by polyacrylamide gel electrophoresis, a procedure called the amplified fragment length polymorphism(Amp-FLP) technique. In 123 unrelated Korean individuals 10 different alleles and 29 genotypes were observed. The TPO gene demonstrated a heterozygosity of 0.707 and the power of exclusion(POE) was 0.945. The probability of having the same DNA band within two unrelated individuals was 14.6$\times10^{-2}$. The distribution of observed genotypes conformed to Hardy-Weinberg equilibrium($x^2$=4.48, 0.05

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Characterization of Primary Epithelial Cells Derived from Human Salivary Gland Contributing to in vivo Formation of Acini-like Structures

  • Nam, Hyun;Kim, Ji-Hye;Hwang, Ji-Yoon;Kim, Gee-Hye;Kim, Jae-Won;Jang, Mi;Lee, Jong-Ho;Park, Kyungpyo;Lee, Gene
    • Molecules and Cells
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    • v.41 no.6
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    • pp.515-522
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    • 2018
  • Patients with head and neck cancer are treated with therapeutic irradiation, which can result in irreversible salivary gland dysfunction. Because there is no complete cure for such patients, stem cell therapy is an emerging alternative for functional restoration of salivary glands. In this study, we investigated in vitro characteristics of primarily isolated epithelial cells from human salivary gland (Epi-SGs) and in vivo formation of acini-like structures by Epi-SGs. Primarily isolated Epi-SGs showed typical epithelial cell-like morphology and expressed E-cadherin but not N-cadherin. Epi-SGs expressed epithelial stem cell (EpiSC) and embryonic stem cell (ESC) markers. During long-term culture, the expression of EpiSC and ESC markers was highly detected and maintained within the core population with small size and low cytoplasmic complexity. The core population expressed cytokeratin 7 and cytokeratin 14, known as duct markers indicating that Epi-SGs might be originated from the duct. When Epi-SGs were transplanted in vivo with Matrigel, acini-like structures were readily formed at 4 days after transplantation and they were maintained at 7 days after transplantation. Taken together, our data suggested that Epi-SGs might contain stem cells which were positive for EpiSC and ESC markers, and Epi-SGs might contribute to the regeneration of acini-like structures in vivo. We expect that Epi-SGs will be useful source for the functional restoration of damaged salivary gland.

Sequencing, Genomic Structure, Chromosomal Mapping and Association Study of the Porcine ADAMTS1 Gene with Litter Size

  • Yue, K.;Peng, J.;Zheng, R.;Li, J.L.;Chen, J.F.;Li, F.E.;Dai, L.H.;Ding, SH.H.;Guo, W.H.;Xu, N.Y.;Xiong, Y.ZH.;Jiang, S.W.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.7
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    • pp.917-922
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    • 2008
  • A disintegrin-like and metalloprotease (reprolysin type) with thrombospondin type 1 motif (ADAMTS1) plays a critical role in follicular rupture and represents a major advance in the proteolytic events that control ovulation. In this study, a 9,026-bp DNA sequence containing the full coding region, all 8 introns and part of the 5'and 3' untranslated region of the porcine ADAMTS1 gene was obtained. Analysis of the ADAMTS1 gene using the porcine radiation hybrid panel indicated that pig ADAMTS1 is closely linkage with microsatellite marker S0215, located on SSC13q49. The open reading frame of its cDNA covered 2,844 bp and encoded 947 amino acids. The coding region of porcine ADAMTS1 as determined by sequence alignments shared 85% and 81% identity with human and mouse cDNAs, respectively. The deduced protein contained 947 amino acids showing 85% sequence similarity both to the human and mouse proteins, respectively. Comparative sequencing of three pig breeds revealed one single nucleotide polymorphism (SNP) within exon 7 of which a G-C substitution at position 6006 changes a codon for arginine into a codon for proline. The substitution was situated within a PvuII recognition site and developed as a PCR-RFLP marker for further use in population variation investigations and association analysis with litter size. Allele frequencies of this SNP were investigated in seven pig breeds/lines. An association analysis in a new Qingping female line suggested that different ADAMTS1 genotypes have significant differences in litter size (p<0.01).

Evaluation of Chromosomal Alteration in Electrical Workers Occupationally Exposed to Low Frequency of Electro Magnetic Field (EMFs) in Coimbatore Population, India

  • Balamuralikrishnan, Balasubramanian;Balachandar, Vellingiri;Kumar, Shanmugam Suresh;Stalin, Nattan;Varsha, Prakash;Devi, Subramaniam Mohana;Arun, Meyyazhagan;Manikantan, Pappuswamy;Venkatesan, Chinnakulandhai;Sasikala, Keshavarao;Dharwadkar, Shahnaz N.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.6
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    • pp.2961-2966
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    • 2012
  • Extremely low frequency electro magnetic fields (EMFs) have been classified as possibly carcinogenic to humans by the International Agency for Research on Cancer. An increased number of chromosomal alterations in peripheral lymphocytes are correlated with elevated incidence of cancer. The aim of the present study was to assess occupationally induced chromosomal damage in EMF workers exposed to low levels of radiation. We used conventional metaphase chromosome aberration (CA) analysis and the micronucleus (MN) assay as biological indicators of non ionizing radiation exposure. In the present study totally 70 subjects were selected including 50 exposed and 20 controls. Informed written consent was obtained from all participants and the study was performed in accordance with the Declaration of Helsinki and the approval of the local ethical committee. A higher degree of CA and MN was observed in exposed subjects compared to controls, the frequency of CA being significantly enhanced with long years of exposure (P<0.05). Moreover increase in CA and MN with age was noted in both exposed subjects and controls, but was significantly greater in the former. The results of this study demonstrated that a significant induction of cytogenetic damage in peripheral lymphocytes of workers occupationally exposed to EMFs in electric transformer and distribution stations. In conclusion, our findings suggest that EMFs possess genotoxic capability, as measured by CA and MN assays; CA analysis appeared more sensitive than other cytogenetic end-points. It can be concluded that chronic occupational exposure to EMFs may lead to an increased risk of genetic damage among electrical workers.

Association of the Porcine Cluster of Differentiation 4 Gene with T Lymphocyte Subpopulations and Its Expression in Immune Tissues

  • Xu, Jingen;Liu, Yang;Fu, Weixuan;Wang, Jiying;Wang, Wenwen;Wang, Haifei;Liu, Jianfeng;Ding, Xiangdong;Zhang, Qin
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.4
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    • pp.463-469
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    • 2013
  • Cluster of differentiation 4 (CD4) is mainly expressed on $CD4^+$ T cells, which plays an important role in immune response. The aim of this study was to detect the association between polymorphisms of the CD4 gene and T lymphocyte subpopulations in pigs, and to investigate the effects of genetic variation on the CD4 gene expression level in immune tissues. Five missense mutations in the CD4 gene were identified using DNA pooling sequencing assays, and two main haplotypes (CCTCC and AGCTG) in strong linkage disequilibrium (with frequencies of 50.26% and 46.34%, respectively) were detected in the population of Large White pigs. Our results indicated that the five SNPs and the two haplotypes were significantly associated with the proportions of $CD4^-CD8^-$, $CD4^+CD8^+$, $CD4^+CD8^-$, $CD4^+$ and $CD4^+/CD8^+$ in peripheral blood (p<0.05). Gene expression analysis showed the mRNA level of the CD4 gene in thymus was significantly higher than that in lymph node and spleen (p<0.05). However, no significant difference was observed between animals with CCTCC/CCTCC genotype and animals with AGCTG/AGCTG genotype in the three immune tissues (p>0.05). These results indicate that the CD4 gene may influence T lymphocyte subpopulations and can be considered as a candidate gene affecting immunity in pigs.

Role of microRNAs in myogenesis and their effects on meat quality in pig - A review

  • Iqbal, Ambreen;Jiang, Ping;Ali, Shaokat;Gao, Zhen;Liu, Juan;Jin, Zi Kang;Pan, Ziyi;Lu, Huixian;Zhao, Zhihui
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.12
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    • pp.1873-1884
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    • 2020
  • The demand for food is increasing day by day because of the increasing global population. Therefore, meat, the easiest and largely available source of protein, needs to be produced in large amounts with good quality. The pork industry is a significant shareholder in fulfilling the global meat demands. Notably, myogenesis- development of muscles during embryogenesis- is a complex mechanism which culminates in meat production. But the molecular mechanisms which govern the myogenesis are less known. The involvement of miRNAs in myogenesis and meat quality, which depends on factors such as myofiber composition and intramuscular fat contents which determine the meat color, flavor, juiciness, and water holding capacity, are being extrapolated to increase both the quantity and quality of pork. Various kinds of microRNAs (miRNAs), miR-1, miR-21, miR22, miR-27, miR-34, miR-127, miR-133, miR-143, miR-155, miR-199, miR-206, miR-208, miR-378, and miR-432 play important roles in pig skeletal muscle development. Further, the quality of meat also depends upon myofiber which is developed through the expression of different kinds of miRNAs at different stages. This review will focus on the mechanism of myogenesis, the role of miRNAs in myogenesis, and meat quality with a focus on the pig.

Mapping QTLs for Tissue Culture Response of Mature Wheat Embryos

  • Jia, Haiyan;Yi, Dalong;Yu, Jie;Xue, Shulin;Xiang, Yang;Zhang, Caiqin;Zhang, Zhengzhi;Zhang, Lixia;Ma, Zhengqiang
    • Molecules and Cells
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    • v.23 no.3
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    • pp.323-330
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    • 2007
  • The mature wheat embryo is arguably one of the best explants for genetic transformation because of its unlimited availability and lack of growth season restriction. However, an efficient regeneration system using mature wheat embryos (Triticum aestivum L.) is still not available. To identify genes related to the tissue culture response (TCR) of wheat, QTLs for callus induction from mature embryos and callus regeneration were mapped using an RIL population derived from the cross of 'Wangshuibai' with 'Nanda2419', which has a good TCR. By whole genome scanning we identified five, four and four chromosome regions conditioning, respectively, percent embryos forming a callus (PEFC), percent calli regenerating plantlets (PCRP), and number of plantlets per regenerating callus (NPRC). The major QTLs QPefc.nau-2A and QPcrp.nau-2A were mapped to the long arm of chromosome 2A, explaining up to 22.8% and 17.6% of the respective phenotypic variance. Moreover, two major QTLs for NPRC were detected on chromosomes 2D and 5D; these together explained 51.6% of the phenotypic variance. We found that chromosomes 2A, 2D, 5A, 5B and 5D were associated via different intervals with at least two of the three TCR indexes used. Based on this study and other reports, the TCRs of different explant types of wheat may be under the control of shared or tightly linked genes, while different genes or gene combinations may govern the stages from callus induction to plantlet regeneration. The importance of group 2 and 5 chromosomes in controlling the TCRs of Triticeae crops and the likely conservation of the corresponding genes in cereals are discussed.