Authors:Renáta Fábián, András Kovács, Viktor Stéger, Krisztián Frank, István Egerszegi, János Oláh and Szilárd Bodó
A-qin , C. , Zi-rong , X. and Song-dong , Y. ( 2007 ): Sexing goat embryos by PCR amplification of Xand Y-chromosome specific sequence of the amelogenin gene . Asian-Aust. J. Anim. Sci. 20 , 1689 – 1693
Authors:I. Karsai, K. Mészáros, L. Láng and Z. Bedő
Tillering ability is a complex trait, the development of which is influenced by both environmental factors and complex genetic regulation. In the present experiments this complex regulation was dissected into its various components in an effort to separate the effect on tillering of major genes influencing ontogeny from that of other genomic factors. The tillering rate of a facultative × winter barley mapping population was examined in the field after autumn and spring sowing. The vernalisation sensitivity gene
exerted a considerable influence on tillering in spring-sown barley. In addition to the major genes, QTL analysis revealed two chromosome regions (1HS and 3HL) with a significant influence on the extent of tillering. Neither of these regions were involved in the regulation of heading date, and their effect on tillering was the most intense at the beginning of ontogeny, gradually declining as the influence of the
gene increased. The function of the
locus in the regulation of tillering is manifested partly through a direct effect on the transition from the vegetative to the generative phase and partly indirectly via epistatic regulation of other chromosome regions influencing tillering.
Authors:L. Keresztury, A. Lászik, A. Falus and et al
Genetic/genomic polymorphism, i.e. variations in DNA sequences are ideally assayed by direct nucleotide sequencing of a gene region or other homologous segment of the genome. An easier and cheaper approach, however, if the variants are analyzed by hybridization technology using restriction fragment length polymorphisms (RFLPs) or by detection of the number of tandem repeats (VNTR) of small DNA segments, the “minisatellites”. In this study we describe results of the DNA analysis of repetitive sequences of human 6th chromosome by the application of a chemiluminescent labeled probes. The allele frequency distribution of polymorphic DNA sequences has been determined in unrelated individuals. The isolated genomic DNA was cut with Pst I restriction enzyme, size fractionated on agarose gel and hybridized with a chemiluminescent labeled D6 S132 probe. At this locus the Pst I cleaved DNA fragments are ranging from 1841 to 6098 base pairs (bp). Specific genetic pattern was characterized by more frequent fragments (3313 and 3884 bp), and the rarely occurring ones (clustered between 1841-2595 and 5227-6098 bp). Our study provides a further possibility for characterization of individual genomic patterns.
Authors:A. Abderrahmane, L. Yi, G. Wen-Ying, S. Ping and Q. Song-Sheng
In this paper, a promoter-probe plasmid pKK232-8 was used as a vector, which functioned in Escherichia coli TG1 host. The plasmid DNA fragments from Pseudomonas maltophilia AT18 chromosome DNA active as promoter inEscherichia coli TG1, the promoter function was studied by means of microcalorimetry, the promoter is about 800 bp DNA, it can promote the chloramphenicol
(Cm) gene in plasmid pKK232-8, the Cm resistance level is about 80 μg mL–1, the promoter activity is high. It implicates that there are probably many promoters in Pseudomonas maltophilia AT18 chromosome. All these information is readily obtained by an LKB 2277-204 heat conduction microcalorimeter. Microcalorimetry
is a quantitative, inexpensive, and versatile method for microbiological genetic research.
Authors:J.W Guo, Q. Li, W.Q. Chen, X. Li, L.Q. Li, T.G. Liu, Z.L. Ren and P.G. Luo
Leaf senescence is a notably important trait that limits the yield and biomass accumulation of agronomic crops. Therefore, determining the chromosomal position of the expression sequence tags (ESTs) that are associated with leaf senescence is notably interesting in the manipulation of leaf senescence for crop improvement. A total of 32 ESTs that were previously identified during the delaying leaf senescence stage in the stay-green wheat cultivar CN17 were mapped to 42 chromosomes, a chloroplast, a mitochondrion, and a ribosome using in silico mapping. Then, we developed 19 pairs of primers based on these sequences and used them to determine the polymorphisms between the stay-green cultivars (CN12, CN17, and CN18) and the control cultivar MY11. Among the 19 pairs of primers, 5 pairs produced polymorphisms between the stay-green cultivar and the non-stay-green control. Further studies of Chinese Spring nullisomic-tetrasomics show that JK738991 is mapped to 3B, JK738983 is mapped to 5D, and JK738989 is mapped to 2A, 4A, and 3D. The other two ESTs, JK738994 and JK739003, were not assigned to a chromosome using the Chinese Spring nullisomic-tetrasomics, which indicates that these ESTs may be derived from rye DNA in the wide cross. In particular, the ESTs that produce polymorphisms are notably useful in identifying the stay-green cultivar using molecular marker-assisted selection. The results also suggest that the in silico mapping data, even from a comparison genomic analysis based on the homogeneous comparison, are useful at some points, but the data were not always reliable, which requires further investigation using experimental methods.
Authors:L.V. Shchukina, T.A. Pshenichnikova, E.K. Khlestkina, S. Misheva, T. Kartseva, A. Abugalieva and A. Börner
Bread wheat is the primary bread crop in the majority of countries in the world. The most important product that is manufactured from its grain and flour is yeast bread. In order to obtain an excellent bread, grain with high physical properties is needed for flour and dough. The Russian spring wheat cultivar Saratovskaya 29 is characterized by its exclusively high physical properties of flour and dough. The purpose of this work was to identify the chromosomes carrying the main loci for these traits in Saratovskaya 29 and to map them using recombinant substitution lines genotyped with molecular markers. A set of inter-varietal substitution lines Saratovskaya 29 (Yanetzkis Probat) was used to identify the “critical” chromosomes. The donor of individual chromosomes is a spring cultivar with average dough strength and tenacity. Substitution of 1D and 4D*7A chromosomes in the genetic background of Saratovskaya 29 resulted in a significant decrease in the physical properties of the dough. Such a deterioration in the case of 1D chromosome might be related to the variability of gluten protein composition. With the help of recombinant substitution double haploid lines obtained from a Saratovskaya 29 (Yanetzkis Probat 4D*7A) substitution line the region on the 4D chromosome was revealed in the strong-flour cultivar Saratovskaya 29, with the microsatellite locus Xgwm0165 to be associated with the unique physical properties of flour and dough. The detected locus is not related to the composition gluten proteins. These locus may be recommended to breeders for the selection of strong-flour cultivars. Additionally, a QTL associated with vitreousness of grain was mapped in the short arm of chromosome 7A.
Authors:R. Pathak, A. Khuda Bukhsh, S. Dey, U. Ghosh, B. Sen Gupta, M. Semwal and N. Bhattacharyya
The paper aims to investigate cytogenetic and apoptotic responses of γ-irradiation in a radio-resistant cell strain designated
as M5. Induced micronuclei, chromosomal aberrations, nuclear fragmentation and nucleosomal ladders by γ-irradiation were less
at equal doses in M5 cells in comparison with that obtained in the parental Chinese hamster V79 cells. However, at equal survival,
there were no differences in the end points studied. Results indicate that the residual damages that lead to reproductive
cell death also resulted in the cytogenetic and apoptotic responses. We speculate that the repair efficiency in M5 cells was
more efficient and increased DNA repair could be the cause of radiation resistance observed in M5 cells.
Authors:F.M. Zhao, Y. Tan, L.Y. Zheng, K. Zhou, G.H. He, Y.H. Ling, L.H. Zhang and S.Z. Xu
Chromosome segment substitution lines (CSSLs) are powerful tools to combine naturally occurring genetic variants with favorable alleles in the same genetic backgrounds of elite cultivars. An elite CSSL Z322-1-10 was identified from advanced backcrosses between a japonica cultivar Nipponbare and an elite indica restorer Xihui 18 by SSR marker-assisted selection (MAS). The Z322-1-10 line carries five substitution segments distributed on chromosomes 1, 2, 5, 6 and 10 with an average length of 4.80 Mb. Spikilets per panicle, 1000-grain weight, grain length in the Z322-1-10 line are significantly higher than those in Nipponbare. Quantitative trait loci (QTLs) were identified and mapped for nine agronomic traits in an F3 population derived from the cross between Nipponbare and Z322-1-10 using the restricted maximum likelihood (REML) method in the HPMIXED procedure of SAS. We detected 13 QTLs whose effect ranging from 2.45% to 44.17% in terms of phenotypic variance explained. Of the 13 loci detected, three are major QTL (qGL1, qGW5-1 and qRLW5-1) and they explain 34.68%, 44.17% and 33.05% of the phenotypic variance. The qGL1 locus controls grain length with a typical Mendelian dominance inheritance of 3:1 ratio for long grain to short grain. The already cloned QTL qGW5-1 is linked with a minor QTL for grain width qGW5-2 (13.01%) in the same substitution segment. Similarly, the previously reported qRLW5-1 is also linked with a minor QTL qRLW5-2. Not only the study is important for fine mapping and cloning of the gene qGL1, but also has a great potential for molecular breeding.