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Roser Gonzàlez-duarte - One of the best experts on this subject based on the ideXlab platform.
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Molecular characterisation of partial chromosome 21 aneuploidies by fluorescent PCR.
Journal of medical genetics, 1999Co-Authors: Rebeca Valero, Gemma Marfany, Rosario Gil-benso, Maria De Los Angeles Ibáñez, Isidora López-pajares, Félix Prieto, Gaspar Rullan, Enric Sarret, Roser Gonzàlez-duarteAbstract:Although trisomy of chromosome 21 is the most prevalent human genetic disorder, data from partial 21 aneuploidies are very scanty. Eight different partial aneuploidies for chromosome 21 were characterised by fluorescence quantitative PCR. Allelic dosage analysis was performed for each patient using 25 CHLC STRs covering the entire q arm. The length of the corresponding trisomies and monosomies was ascertained for five partial Trisomics and three partial monosomics. All trisomic patients carried unbalanced translocations involving chromosome 21, whereas one of the monosomic patients bore a ring chromosome 21 and another showed an interstitial deletion of chromosome 21. The chromosomal breakpoints of two partial trisomy patients could be clearly delimited. However, the other three trisomies involved most of the 21 q arm as three allelic doses were detected for each marker. Although these latter patients do not show all the features of Down syndrome, genotype/phenotype correlations agree with previously reported data. The chromosomal breakpoints observed in two partially monosomic patients helped further to define the region involved in different phenotypic features associated with chromosome 21 monosomy. Telomeric material loss was also detected in a patient bearing a ring 21 chromosome. The parental origin of the aneuploidy was assigned for each case, which allowed us to conclude that two of the monosomic cases originated from de novo chromosomal rearrangements. There was no correlation with parental sex in contrast to trisomic patients originating from meiotic non-disjunction.
Shu-xin Xuan - One of the best experts on this subject based on the ideXlab platform.
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Determination of n+1 gamete transmission rate of Trisomics and location of gene controlling 2n gamete formation in Chinese cabbage (Brassica rapa).
Journal of Integrative Plant Biology, 2008Co-Authors: Cheng-he Zhang, Shu-xing Shen, He Yuan, Shu-xin XuanAbstract:A set of Trisomics of Chinese cabbage was used for determining the n+1 gamete transmission rate and locating the gene controlling 2n gamete formation on the corresponding chromosome. The results showed that the transmission rates of extra chromosomes in different Trisomics varied from 0% to 15.38% by male gametes and from 0% to 17.39% by female gametes. Of the nine F(2) populations derived from the hybridizations between each trisomic and Bp058 (2n gamete material), only Tri-4xBp058 showed that the segregation ratio of plants without 2n gamete formation to plants with 2n gamete formation was 10.38:1, which fitted the expected segregation ratio of the Trisomics (AAa) based on the 7.37% of n+1 gamete transmission through female and 5.88% through male. In other populations the segregation ratios varied from 2.48:1 to 3.72:1, which fitted the expected 3:1 segregation ratio of the bisomics (Aa). These results suggested that the gene controlling 2n gamete formation in Chinese cabbage Bp058 was located on chromosome 4. Further trisomic analysis based on the chromosome segregation and the incomplete stochastic chromatid segregation indicated that the gene locus was tightly linked to the centromere.
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Obtaining and Cytological Identification of a Set of Primary Trisomics in Cabbage
Agricultural Sciences in China, 2006Co-Authors: Cheng-he Zhang, Shu-xing Shen, Hai-yan Zhu, Xueping Chen, Hong Man, Shu-xin XuanAbstract:Selection of primary Trisomics of the cabbage (Brassica oleracea var.capitata L) forms an important basis for gene chromosome mapping and for other genetic studies. The cabbage self-fertilization line - 9601 was used as material, using the root-tip cell chromosome number and pollen mother cell chromosome number identification and karyotype analysis to select the primary Trisomics from the progenies of 3x × 2x in the cabbage. Many aneuploid plants with one or two extra chromosomes were obtained and a set of primary Trisomics (Tri-1, Tri-2, Tri-3, Tri-4, Tri-5, Tri-6, Tri-7, Tri-8, and Tri-9, in which the Tri-1 and Tri-4 were from 2n + 2 plants and others from 2n + 1 plants) was acquired from these plants. Each trisomic exhibited some unique features, such as plant height, plant type, leaf type, size of flower bud, and inflorescence. The triploid crossing by the diploid is a convenient and effective way to select Trisomics in the cabbage.
Rebeca Valero - One of the best experts on this subject based on the ideXlab platform.
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Molecular characterisation of partial chromosome 21 aneuploidies by fluorescent PCR.
Journal of medical genetics, 1999Co-Authors: Rebeca Valero, Gemma Marfany, Rosario Gil-benso, Maria De Los Angeles Ibáñez, Isidora López-pajares, Félix Prieto, Gaspar Rullan, Enric Sarret, Roser Gonzàlez-duarteAbstract:Although trisomy of chromosome 21 is the most prevalent human genetic disorder, data from partial 21 aneuploidies are very scanty. Eight different partial aneuploidies for chromosome 21 were characterised by fluorescence quantitative PCR. Allelic dosage analysis was performed for each patient using 25 CHLC STRs covering the entire q arm. The length of the corresponding trisomies and monosomies was ascertained for five partial Trisomics and three partial monosomics. All trisomic patients carried unbalanced translocations involving chromosome 21, whereas one of the monosomic patients bore a ring chromosome 21 and another showed an interstitial deletion of chromosome 21. The chromosomal breakpoints of two partial trisomy patients could be clearly delimited. However, the other three trisomies involved most of the 21 q arm as three allelic doses were detected for each marker. Although these latter patients do not show all the features of Down syndrome, genotype/phenotype correlations agree with previously reported data. The chromosomal breakpoints observed in two partially monosomic patients helped further to define the region involved in different phenotypic features associated with chromosome 21 monosomy. Telomeric material loss was also detected in a patient bearing a ring 21 chromosome. The parental origin of the aneuploidy was assigned for each case, which allowed us to conclude that two of the monosomic cases originated from de novo chromosomal rearrangements. There was no correlation with parental sex in contrast to trisomic patients originating from meiotic non-disjunction.
James A. Birchler - One of the best experts on this subject based on the ideXlab platform.
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2002 The American Genetic Association 93:42–47 Maize Tertiary Trisomic Stocks Derived From
2015Co-Authors: B-a Translocations, Donald L. Auger, James A. BirchlerAbstract:Reciprocal translocations between supernumerary B chromosomes and the basic complement of A chromosomes in maize have resulted in a powerful set of tools to manipulate the dosage of chromosomal segments. From 15 B-A reciprocal trans-location stocks that have the B-A chromosome genetically marked we have devel-oped tertiary trisomic stocks. Tertiary Trisomics are 2n 1 aneuploids where the extra chromosome is a translocation element, in this case a B-A chromosome. Whereas B-A translocations produce aneuploidy in the sperm, the tertiary trisomic plant efficiently transmits hyperploid gametes maternally. Because the B-A tertiary trisomic stocks and the B-A translocation stocks from which they were derived are introgressed into the W22 inbred line, the effects of maternally and paternally trans-mitted trisomic B-A chromosomes can be compared. Data are presented on both the male and female transmission rates of the B-A chromosomes in the tertiary trisomic stocks. B-A reciprocal translocations of maize have proven to be invaluable tools. Super
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Maize Tertiary Trisomic Stocks Derived From B-A Translocations
The Journal of heredity, 2002Co-Authors: Donald L. Auger, James A. BirchlerAbstract:Reciprocal translocations between supernumerary B chromosomes and the basic complement of A chromosomes in maize have resulted in a powerful set of tools to manipulate the dosage of chromosomal segments. From 15 B-A reciprocal translocation stocks that have the B-A chromosome genetically marked we have developed tertiary trisomic stocks. Tertiary Trisomics are 2n + 1 aneuploids where the extra chromosome is a translocation element, in this case a B-A chromosome. Whereas B-A translocations produce aneuploidy in the sperm, the tertiary trisomic plant efficiently transmits hyperploid gametes maternally. Because the B-A tertiary trisomic stocks and the B-A translocation stocks from which they were derived are introgressed into the W22 inbred line, the effects of maternally and paternally transmitted trisomic B-A chromosomes can be compared. Data are presented on both the male and female transmission rates of the B-A chromosomes in the tertiary trisomic stocks.
N. Iwata - One of the best experts on this subject based on the ideXlab platform.
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Aneuhaploids and tetrasomics in rice (Oryza sativa L.) derived from anther culture of Trisomics.
Genome, 1995Co-Authors: Z. X. Wang, N. IwataAbstract:Eight types of aneuhaploids (Aneuhaplo 4, 5, 6, 8, 9, 10, 11, and 12) and eight types of tetrasomics (Tetraplo 4, 5, 6, 7, 8, 9, 10, and 12) of rice have been obtained from anther culture of Trisomics. This paper reports the plant morphology of these aneuploids and their chromosome behavior at metaphase I. Aneuhaploids for different chromosomes are distinguishable from each other and are morphologically similar to the parental Trisomics, suggesting that the extra chromosome has similar genetic effects on plant morphology at the haploid level as at the diploid level. Similarly, tetrasomics with different extra chromosomes are distinguishable from each other and are similar morphologically to the parental trisomic. However, stronger changes in morphological characters were observed in tetrasomics compared with Trisomics having the same extra chromosome, as a result of a dosage effect of the extra chromosomes. Comparing plant size between aneuhaploid, tetrasomic, and trisomic with the same extra chromosome, ...
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production of n 1 plants and tetrasomics by means of anther culture of trisomic plants in rice oryza sativa l
Theoretical and Applied Genetics, 1991Co-Authors: Z. X. Wang, N. IwataAbstract:Eleven primary Trisomics of rice, variety Nipponbare, were subjected to anther culture. The 12th trisomic did not produce normal anthers. A total of 3,734 plants were obtained, which were examined morphologically at the seedling stage in the greenhouse. A number of plants appeared in the progenies of ten Trisomics which had unique morphological features. The frequency of these variant types differed among different progenies. Cytological observations revealed that 43 variant plants in the progenies of nine Trisomics had 13 chromosomes (n + 1), and 56 were tetrasomics (2n = 26). The tetrasomic plants in the progeny of a trisomic were morphologically identical. Similarly, n + 1 plants in the progeny of a trisomic were also identical. Plants with 23, 25, 36, 39, and 73 chromosomes were also obtained. Results show that valuable aneuploids such as n + 1 and 2n + 2 can be obtained in the anther-culture-derived progenies of Trisomics.
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Production of n + 1 plants and tetrasomics by means of anther culture of trisomic plants in rice (Oryza sativa L.)
TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik, 1991Co-Authors: Z. X. Wang, N. IwataAbstract:Eleven primary Trisomics of rice, variety Nipponbare, were subjected to anther culture. The 12th trisomic did not produce normal anthers. A total of 3,734 plants were obtained, which were examined morphologically at the seedling stage in the greenhouse. A number of plants appeared in the progenies of ten Trisomics which had unique morphological features. The frequency of these variant types differed among different progenies. Cytological observations revealed that 43 variant plants in the progenies of nine Trisomics had 13 chromosomes (n + 1), and 56 were tetrasomics (2n = 26). The tetrasomic plants in the progeny of a trisomic were morphologically identical. Similarly, n + 1 plants in the progeny of a trisomic were also identical. Plants with 23, 25, 36, 39, and 73 chromosomes were also obtained. Results show that valuable aneuploids such as n + 1 and 2n + 2 can be obtained in the anther-culture-derived progenies of Trisomics.
