• Title/Summary/Keyword: molecular breeding

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Individual-breed Assignment Analysis in Swine Populations by Using Microsatellite Markers

  • Fan, B.;Chen, Y.Z.;Moran, C.;Zhao, S.H;Liu, B.;Yu, M.;Zhu, M.J.;Xiong, T.A.;Li, K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.11
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    • pp.1529-1534
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    • 2005
  • Individual-breed assignments were implemented in six swine populations using twenty six microsatellites recommended by the Food and Agriculture Organization and the International Society for Animal Genetics (FAO-ISAG). Most microsatellites exhibited high polymorphisms as shown by the number of alleles and the polymorphism information content. The assignment accuracy per locus obtained by using the Bayesian method ranged from 33.33% (CGA) to 68.47% (S0068), and the accumulated assignment accuracy of the top ten loci combination added up to 96.40%. The assignment power of microsatellites based on the Bayesian method had positive correlations with the number of alleles and the gene differential coefficient ($G_{st}$) per locus, while it has no relationship to genetic heterozygosity, polymorphism information content per locus and the exclusion probabilities under case II and case III. The percentage of corrected assignment was highest for the Bayesian method, followed by the gene frequency and distancebased methods. The assignment efficiency of microsatellites rose with increase in the number of loci used, and it can reach 98% when using a ten-locus combination. This indicated that such a set of ten microsatellites is sufficient for breed verification purposes.

Cloning and Initial Analysis of Porcine MPDU1 Gene

  • Yang, J.;Yu, M.;Liu, B.;Fan, B.;Zhu, M.;Xiong, T.;Li, Kui
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.9
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    • pp.1237-1241
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    • 2005
  • Mannose-P-dolichol utilization defect 1 (MPDU1) gene is required for utilization of the mannose donor MPD in synthesis of both lipid-linked oligosaccharides (LLOs) and glycosylphosphatidylinositols (GPI) which are important for functions such as protein folding and membrane anchoring. The full length cDNA of the porcine MPDU1 was determined by in silico cloning and rapid amplification of cDNA ends (RACE). The deduced amino acid showed 91% identity to the corresponding human sequence with five predicted transmembrane regions. RT-PCR was performed to detect its expression pattern in five tissues and results showed that it is expressed ubiquitously among the tissues checked. A single nucleotide substitution resulting in the amino acid change (137 Tyr-137 His) was detected within exon 5. Allele frequencies in six pig breeds showed distinctive differences between those Chinese indigenous pigs breeds and European pigs. Using the pig/rodent somatic cell hybrid panel (SCHP), we mapped the porcine MPDU1 gene to SSC12, which is consistent with the comparative mapping result as conservative syntenic groups presented between human chromosome 17 and pig chromosome 12.

RAPD Variation and Genetic Distances among Tibetan, Inner Mongolia and Liaoning Cashmere Goats

  • Chen, Shilin;Li, Menghua;Li, Yongjun;Zhao, Shuhong;Yu, Chuanzhou;Yu, Mei;Fan, Bin;Li, Kui
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.11
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    • pp.1520-1522
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    • 2001
  • Relationship among Tibetan cashmere goats, Inner Mongolia cashmere goats and Liaoning cashmere goats was studied using the technique of random amplified polymorphic DNA (RAPD). One primer and four primer combinations were screened. With the five primers and primer combinations, DNA fragments were amplified from the three breeds. Each breed has 28 samples. According to their RAPD fingerprint maps, the Nei's (1972) standard genetic distance was: 0.0876 between Tibetan cashmere goats and Inner Mongolia cashmere goats, 0.1601 between Tibetan cashmere goats and Liaoning cashmere goats, 0.0803 between the Inner Mongolia cashmere goats and Liaoning cashmere goats. It coincides with their geographic location. The genetic heterogeneity of Tibetan cashmere goats, Inner Mongolia cashmere goats and Liaoning cashmere goats is 0.3266, 0.2622 and 0.2475 respectively. It is also consistent with their development history.

Genetic Status of ESR Locus and Other Unidentified Genes As sociated with Litter Size in Chinese Indigenous Tongcheng Pig Breed after a Long Time Selection

  • Zhu, M.J.;Yu, M.;Liu, B.;Zhu, Z.Z.;Xiong, T.A.;Fan, B.;Xu, S.P.;Du, Y.Q.;Peng, Z.Z.;Li, K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.5
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    • pp.598-602
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    • 2004
  • The Tongcheng pig breed is a famous Chinese indigenous breed. The Ministry of Agriculture of China has filed it as 1 of 19 national key conservation breeds selected from more than 100 Chinese indigenous pig breeds in 2000. In order to improve the reproductive performance, it has been intensively selected to increase the litter size for about 10 years. The population randomly sampled from conservation nucleus of eight families in the Tongcheng pigs was genotyped for identification of their estrogen receptor locus polymorphisms with the PCR-RFLPs method. Only AB heterozygotes and BB homozygotes were detected, and $X^2$ test demonstrated that the locus was in disequilibrium at a significant level (p<0.05). In the present paper, the litter sizes in different parities were regarded as different traits. Holistic status of other unspecific and unidentified genes was estimated by using the statistical methods. Coefficients of kurtosis and skewness showed that the litter size still presented segregating characteristic in the 2nd, 5th, 7th, 8th and 9th parities. Analysis of homogeneity of variance between families confirmed the results for the 5th, 7th and 8th parities. The heritability of litter size for the 1st to 10th parities was estimated with paternal half-sib model and individual estimated breeding values (EBVs) were evaluated by a single trait animal model as well. We found that the averages of EBVs for litter size in each parity did not differ significantly between genotypes, despite the significant difference for original phenotype records in the 3rd, 4th and 5th parities (p<0.05 or p<0.01). The results may be explained by the deduction that the polymorphisms of ESR locus are no longer the important genetic base of litter size variation when the frequency of allele B accumulated in the experience of selection procedure, and further conferring that there exist special genes associated with litter size in the recent Tongcheng pigs population can be made.

Investigation of PCR-RFLPs within Major Histocompatibility Complex B-G Genes Using Two Restriction Enzymes in Eight Breeds of Chinese Indigenous Chickens

  • Xu, R.F.;Li, K.;Chen, G.H.;Qiang, B.Y.Z.;Mo, D.L.;Fan, B.;Li, C.C.;Yu, M.;Zhu, M.J.;Xiong, T.A.;Liu, Bang
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.7
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    • pp.942-948
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    • 2005
  • New polymorphism of major histocompatibility complex B-G genes was investigated by amplification and digestion of a 401bp fragment including intron 1 and exon 2 using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique with two restriction enzymes of Msp I and Tas I in eight breeds of Chinese indigenous chickens and one exotic breed. In the fragment region of the gene, three novel single nucleotide polymorphisms (SNPs) were detected at the two restriction sites. We found the transition of two nucleotides of A294G and T295C occurred at Tas I restriction site, and consequently led to a non-synonymous substitution of asparagine into serine at position 54 within the deduced amino acid sequence of immunoglobulin variable-region-like domain encoded by the exon 2 of B-G gene. It was observed at rare frequency that a single mutation of A294G occurring at the site, also caused an identical substitution of amino acid, asparagine 54-to-serine, to that we described previously. And the transversion of G319C at Msp I site led to a non-synonymous substitution, glutamine 62-to-histidine. The new alleles and allele frequencies identified by the PCR-RFLP method with the two enzymes were characterized, of which the allele A and B frequencies at Msp I and Tas I loci were given disequilibrium distribution either in the eight Chinese local breeds or in the exotic breed. By comparison, allele A at Msp I locus tended to be dominant, while, the allele B at Tas I locus tended to be dominant in all of the breeds analyzed. In Tibetan chickens, the preliminary association analysis revealed that no significant difference was observed between the different genotypes identified at the Msp I and Tas I loci and the laying performance traits, respectively.

Genetic Improvement of Maize by Marker-Assisted Breeding (분자마커를 활용한 옥수수 육종)

  • Kim, Jae Yoon;Moon, Jun-Cheol;Baek, Seong-Bum;Kwon, Young-Up;Song, Kitae;Lee, Byung-Moo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.59 no.2
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    • pp.109-127
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    • 2014
  • Maize is one of the most important food and feed crops in the world including Southeast Asia. In spite of numberous efforts with conventional breeding, the maize productions remain low and the loss of yields by drought and downy mildew are still severe in Asia. Genetic improvement of maize has been performed with molecular marker and genetic engineering. Because maize is one of the most widely studied crop for its own genome and has tremendous diversity and variant, maize is considered as a forefront crop in development and estimation of molecular markers for agricultural useful trait in genetics and breeding. Using QTL (Quantitative Trait Loci) and MAS (Marker Assisted Breeding), molecular breeders are able to accelerate the development of drought tolerance or downy mildew resistance maize genotype. The present paper overviews QTL/MAS approaches towards improvement of maize production against drought and downy mildew. We also discuss here the trends and importance of molecular marker and mapping population in maize breeding.

Cleaved Amplified Polymorphic Sequence and Amplified Fragment Length Polymorphism Markers Linked to the Fertility Restorer Gene in Chili Pepper (Capsicum annuum L.)

  • Kim, Dong Sun;Kim, Dong Hwan;Yoo, Jae Hyoung;Kim, Byung-Dong
    • Molecules and Cells
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    • v.21 no.1
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    • pp.135-140
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    • 2006
  • Cytoplasmic male sterility (CMS) in plants, which is due to failure to produce functional pollen, is a maternally inherited trait. Specific nuclear genes that suppress CMS, termed fertility restorer (Rf) genes, have been identified in several plants. In this study, Rfl-inked molecular markers in pepper (Capsicum annuum L.) were detected by bulked segregant analysis of eight amplified fragment length polymorphisms (AFLPs). Only AFRF8 was successfully converted to a cleaved amplified polymorphic sequence (CAPS) marker. This was named AFRF8CAPS and genotype determination using it agreed with that obtained with the original AFRF8. A linkage map with a total size of 54.1 cM was constructed with AFRF8CAPS and the seven AFLP markers using the Kosambi function. The AFRF8CAPS marker was shown to be closest to Rf with a genetic distance of 1.8 cM. These markers will be useful for fast and reliable detection of restorer lines during $F_1$ hybrid seed production and breeding programs in pepper.

MiR-126-3p inhibits apoptosis and promotes proliferation by targeting phosphatidylinositol 3-kinase regulatory subunit 2 in porcine ovarian granulosa cells

  • Zhou, Xiaofeng;He, Yingting;Jiang, Yao;He, Bo;Deng, Xi;Zhang, Zhe;Yuan, Xiaolong;Li, Jiaqi
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.6
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    • pp.879-887
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    • 2020
  • Objective: Numerous studies have indicated that the apoptosis and proliferation of granulosa cells (GCs) are closely related to the normal growth and development of follicles and ovaries. Previous evidence has suggested that miR-126-3p might get involved in the apoptosis and proliferation of GCs, and phosphatidylinositol 3-kinase regulatory subunit 2 (PIK3R2) gene has been predicted as one target of miR-126-3p. However, the molecular regulation of miR-126-3p on PIK3R2 and the effects of PIK3R2 on porcine GCs apoptosis and proliferation remain virtually unexplored. Methods: In this study, using porcine GCs as a cellular model, luciferase report assay, mutation and deletion were applied to verify the targeting relationship between miR-126-3p and PIK3R2. Annexin-V/PI staining and 5-ethynyl-2'-deoxyuridine assay were applied to explore the effect of PIK3R2 on GCs apoptosis and proliferation, respectively. Real-time quantitative polymerase chain reaction and Western Blot were applied to explore the regulation of miR-126-3p on PIK3R2 expression. Results: We found that miR-126-3p targeted at PIK3R2 and inhibited its mRNA and protein expression. Knockdown of PIK3R2 significantly inhibited the apoptosis and promoted the proliferation of porcine GCs, and significantly down-regulated the mRNA expression of several key genes of PI3K pathway such as insulin-like growth factor 1 receptor (IGF1R), insulin receptor (INSR), pyruvate dehydrogenase kinase 1 (PDK1), and serine/threonine kinase 1 (AKT1). Conclusion: MiR-126-3p might target and inhibit the mRNA and protein expressions of PIK3R2, thereby inhibiting GC apoptosis and promoting GC proliferation by down-regulating several key genes of the PI3K pathway, IGF1R, INSR, PDK1, and AKT1. These findings would provide great insight into further exploring the molecular regulation of miR-126-3p and PIK3R2 on the functions of GCs during the folliculogenesis in female mammals.

Development and Validation of Single Nucleotide Polymorphism (SNP) Markers from an Expressed Sequence Tag (EST) Database in Olive Flounder (Paralichthys olivaceus)

  • Kim, Jung Eun;Lee, Young Mee;Lee, Jeong-Ho;Noh, Jae Koo;Kim, Hyun Chul;Park, Choul-Ji;Park, Jong-Won;Kim, Kyung-Kil
    • Development and Reproduction
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    • v.18 no.4
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    • pp.275-286
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    • 2014
  • To successful molecular breeding, identification and functional characterization of breeding related genes and development of molecular breeding techniques using DNA markers are essential. Although the development of a useful marker is difficult in the aspect of time, cost and effort, many markers are being developed to be used in molecular breeding and developed markers have been used in many fields. Single nucleotide polymorphisms (SNPs) markers were widely used for genomic research and breeding, but has hardly been validated for screening functional genes in olive flounder. We identified single nucleotide polymorphisms (SNPs) from expressed sequence tag (EST) database in olive flounder; out of a total 4,327 ESTs, 693 contigs and 514 SNPs were detected in total EST, and these substitutions include 297 transitions and 217 transversions. As a result, 144 SNP markers were developed on the basis of 514 SNP to selection of useful gene region, and then applied to each of eight wild and culture olive flounder (total 16 samples). In our experimental result, only 32 markers had detected polymorphism in sample, also identified 21 transitions and 11 transversions, whereas indel was not detected in polymorphic SNPs. Heterozygosity of wild and cultured olive flounder using the 32 SNP markers is 0.34 and 0.29, respectively. In conclusion, we identified SNP and polymorphism in olive flounder using newly designed marker, it supports that developed markers are suitable for SNP detection and diversity analysis in olive flounder. The outcome of this study can be basic data for researches for immunity gene and characteristic with SNP.