Seven residual heterozygous lines （RHLs） displaying different genotypic compositions in the genomic region covering probable locations of C （Chromogen for anthocyanin） gene on the short arm of rice chromosome 6 we...Seven residual heterozygous lines （RHLs） displaying different genotypic compositions in the genomic region covering probable locations of C （Chromogen for anthocyanin） gene on the short arm of rice chromosome 6 were selected from the progenies of the indica cross Zhenshan 97B/Milyang 46. Seeds were harvested from each of the seven plants, and the resultant F2：3 populations were used for fine mapping of C gene. It was shown in the populations that the apiculus coloration matched to basal leaf sheath coloration in each plant. By relating the coloration performances of the populations with the genotypic compositions of the RHLs, the C locus was located between rice SSR markers RM314 and RM253. By using a total of 1279 F2：3 individuals from two populations showing coloration segregation, the C locus was then located between RM111 and RM253, with genetic distances of 0.7 cM to RM111 and 0.4 cM to RM253. Twenty-two recombinants found in the two populations were assayed with seven more markers located between RM111 and RM253, including six SSR markers and one marker for the C gene candidate, OsCl. The C locus was delimited to a 59.3-kb region in which OsC1 was located.展开更多
This review addresses two puzzling findings related to mutations in galactocerebrosidase （GALC） that cause Krabbe disease （KD）, a severe lysosomal storage disorder characterized by extensive myelin damage in child...This review addresses two puzzling findings related to mutations in galactocerebrosidase （GALC） that cause Krabbe disease （KD）, a severe lysosomal storage disorder characterized by extensive myelin damage in children with mutations in both GALC alleles. First, heterozygous carriers of KD-causing mutations, which include the biological parents of children with KD, exhibit increased risk for developing other diseases. Second, variants in the GALC locus increase the risk of developing multiple sclerosis （MS）, another disease characterized by extensive myelin damage. What explains these correlations？ In studies on cuprizone-induced myelin damage in heterozygous （GALC＋/–） mice carrying one copy of a mutation that causes KD-like disease, the extent of damage was similar in GALC＋/– and wild-type （WT） mice. In contrast, GALC＋/- mice had striking defects in repair of cuprizone-induced damage. We further found unexpected microglial defects in myelin debris clearance and in the ability to up-regulate the Trem2 microglial protein critical for debris uptake. These defects were rescued by exposure to a lysosomal re-acidifying drug discovered in our studies on KD, and which provides multiple clinically relevant benefits in the twitcher （GALC＋/–） mouse model of KD. Thus, heterozygous GALC mutations cause effects on biological function that may help to understand the increased disease risk in heterozygous carriers of such mutations and to understand why GALC variations increase the risk of MS. Our findings indicate that while some genetic risk factors may contribute to complex diseases by increasing the risk of tissue damage, others may do so by compromising tissue repair.展开更多
A residual heterozygous line （RHL） carrying a heterozygous segment between two S SR loci RM 11 and RM134 on the rice chromo- some 7 was selected from a set of recombinant inbred lines from the cross D50 （javanica）...A residual heterozygous line （RHL） carrying a heterozygous segment between two S SR loci RM 11 and RM134 on the rice chromo- some 7 was selected from a set of recombinant inbred lines from the cross D50 （javanica）/HB277 （indica）. The former parent produces much longer grains than the latter. Selfed progenies of this selection were analyzed genotypically （SSRs） and phenotypically （grain length）. Grain length was discontinuously variable in the mapping populations, allowing for the placement of this QTL qGL7-2 within a -4.8 cM interval defined by RM351 and RM234. A set of new markers within this region were developed, which narrowed the QTL to a 278 kb region defined by the markers Indell and RM21945. This region contains 49 predicted genes. The results also suggest that the novel allele for grain length will be used for the application of marker assisted selection for the improvement of grain length.展开更多
This study was undertaken to dissect quantitative trait loci （QTLs） controlling yield traits on the short arm of rice chromosome 6. A residual heterozygous line that carries a heterozygous segment extending from RM5...This study was undertaken to dissect quantitative trait loci （QTLs） controlling yield traits on the short arm of rice chromosome 6. A residual heterozygous line that carries a heterozygous segment extending from RM587 to RM19784 on the short arm of rice chromosome 6 was selected from an F7 population of the indica rice cross Zhenshan 97B/Milyang 46. An F2：3 population consisting of 221 lines was derived and grown in two trial sites. Six yield traits including number of panicles per plant, number of filled grains per panicle, total number of spikelets per panicle, spikelet fertility, 1 000-grain weight, and grain yield per plant were measured. An SSR marker linkage map was constructed and employed to determine QTLs for yield traits with Windows QTL Cartographer 2.5. QTLs were detected in the target interval for all the traits analyzed except NP, with phenotypic variance explained by a single QTL ranging between 6.3% and 35.2%. Most of the QTLs for yield components acted as additive QTLs, while the three QTLs for grain yield had dominance degrees of 1.65, 0.84, and -0.42, respectively. It was indicated that three or more QTLs for yield traits were located in the target region. The genetic action mode, the direction of the QTL effect, and the magnitude of the QTL effect varied among different QTLs for a given trait, and among QTLs for different traits that were located in the same interval.展开更多
The results of a series of progeny tests showed that "dragon15"(Cunninghamia lanceolata) had the characters of rapid growth,excellent quality and high resistance.Though a series of exploring experiments by m...The results of a series of progeny tests showed that "dragon15"(Cunninghamia lanceolata) had the characters of rapid growth,excellent quality and high resistance.Though a series of exploring experiments by means of polyacrylamide gel electrophoresis technique,5 allozyme systems,amounting to 7 allozyme loci,were found out: GOT-1,GOT-2,GOT-3,FDH,MNR-2,ME,α-amylase.Genetic types of several Chinese fir parents in biclonal seed orchard of 11-year-old were confirmed by use of allozyme technique.The results indicated there was a obvious relationship between offspring’s performances of parent clones and its heterozygous locus numbers.The genetic foundation of biochemistry that the offspring of "dragon15" had rapid growth,excellent quality and high resistance is because it possessed more heterozygous numbers: 5 of 7 allozyme loci in total: GOT-1,GOT-2,GOT-3,FDH,MNR-2.The heterozygous locus numbers could be used to early identification and early selection.展开更多
Three residual heterozygous lines (RHLs) carrying heterozygous segments in the intervals RM587–RM225, RM204–RM6119 and RM6119–RM402 on the short arm of rice chromosome 6, respectively, were selected from a rice pop...Three residual heterozygous lines (RHLs) carrying heterozygous segments in the intervals RM587–RM225, RM204–RM6119 and RM6119–RM402 on the short arm of rice chromosome 6, respectively, were selected from a rice population derived from an RHL for the interval RM587–RM402. Ten maternal homozygotes, 10 paternal homozygotes and 20 heterozygotes were selected from each of the F2 populations derived from the three RHLs. The three sets of near isogenic lines (NILs) were grown to detect the grain yield per plant, number of panicles per plant, number of filled grains per panicle and 1000-grain weight. With analysis on the phenotypic differences among the three genotype groups in each NIL set and those among overlapping chromosome segment substitution lines, three QTLs for number of filled grains per panicle and two QTLs for grain yield per plant were resolved. They were located in the intervals ranging from 0.66 Mb to 2.49 Mb. The additive effect was higher than the dominance effect at each locus. The allele for increasing the trait value was derived from the paternal parent at qNFGP6-1, and from the maternal alleles at other QTLs. Based on the present study, an approach for constructing new genetic resource to facilitate fine mapping of QTLs in rice was proposed.展开更多
The QTL qHUS6 for hull silicon content in rice was previously located on the short arm of rice chromosome 6. By using an F2：3 population segregating in the RM587-RM19784 region harboring qHUS6 in an isogenic backgrou...The QTL qHUS6 for hull silicon content in rice was previously located on the short arm of rice chromosome 6. By using an F2：3 population segregating in the RM587-RM19784 region harboring qHUS6 in an isogenic background, two QTLs for hull silicon content were detected, of which qHUS6-1 was located in the distal region and qHUS6.2 in the region proximal to the centromere. Three rice plants carrying small heterozygous segments in the target region were selected, of which two covered the qHUS6-1 region and the other covered the qHUS6-2 region. Three F2：3 populations were derived from the selfed seeds of the three plants, respectively. QTL mapping was performed using the two populations segregating in the qHUS6-1 region, and qHUS6-1 was delimited to a 147.0-kb region flanked by the markers RM510 and RM19417. Five groups of F3 lines with different genotypic compositions in the qHUS6-2 region were selected from the other F2-3 population. Two QTLs were separated with two-way ANOVA, of which qHUS6-2a was located in the interval defined by RM19706-RM19795 and qHUS6-2b in the interval RM314-RM19665.展开更多
A rice residual heterozygous line （RHL） carrying a heterozygous segment extending from RM111 to RM19784 on the short arm of rice chromosome 6 was selected from a RHL-derived population used previously. The resultant...A rice residual heterozygous line （RHL） carrying a heterozygous segment extending from RM111 to RM19784 on the short arm of rice chromosome 6 was selected from a RHL-derived population used previously. The resultant F2：3 population was used to detect quantitative trait loci （QTLs） for three yield traits, the number of spikelets per panicle （NSP）, the number of grains per panicle （NGP） and grain yield per plant （GY）. Two QTLs for NSP, one QTL for NGP and one QTL for GY were detected, all of which were partially dominant and had the enhancing alleles from the maternal line Zhenshan 97B. Analysis based on the genotypic groups of the markers closely linked to the two QTLs for NSP indicated that they did not interact with each other. Two F2 populations and two near isogenic line （NIL） sets segregating in two sub-regions of interval RM111-RM19784 were developed. The two QTLs for NSP were validated, of which one had major effect and was co-segregated with heading date gene Hdl, and the other had smaller effect and was located in an upper region linked to Hdl. The two regions also showed significant effects on the number of filled grain and grain yield, although the effect on the number of filled grain was less consistent.展开更多
基金This work was supported by the Chinese 863 Program(Grant No.2006AA10Z1E8)the Super Rice Program of the Chinese Ministry of Agriculture(Grant No.200606)the Natural Science Foundation of Zhejiang Province(Grant No.Y304446).
文摘Seven residual heterozygous lines （RHLs） displaying different genotypic compositions in the genomic region covering probable locations of C （Chromogen for anthocyanin） gene on the short arm of rice chromosome 6 were selected from the progenies of the indica cross Zhenshan 97B/Milyang 46. Seeds were harvested from each of the seven plants, and the resultant F2：3 populations were used for fine mapping of C gene. It was shown in the populations that the apiculus coloration matched to basal leaf sheath coloration in each plant. By relating the coloration performances of the populations with the genotypic compositions of the RHLs, the C locus was located between rice SSR markers RM314 and RM253. By using a total of 1279 F2：3 individuals from two populations showing coloration segregation, the C locus was then located between RM111 and RM253, with genetic distances of 0.7 cM to RM111 and 0.4 cM to RM253. Twenty-two recombinants found in the two populations were assayed with seven more markers located between RM111 and RM253, including six SSR markers and one marker for the C gene candidate, OsCl. The C locus was delimited to a 59.3-kb region in which OsC1 was located.
基金supported by the following funding sources:National Institutes of Health,F31-NS078911,https://www.nih.gov(NSH)New York State Department of Health,NYS-DOH-C026877,http://www.stemcell.ny.gov(NSH)+4 种基金New York State Department of Health,NYS-DOH-C029557,http://www.stemcell.ny.gov(MN)New York State Department of Health,NYS-DOH-C026877,http://www.stemcell.ny.gov(CJF)Hunter’s Hope,http://www.huntershope.org/site/Page Server(MN)Children’s Neurobiological Solutions Foundation,http://pediatricbrainfoundation.org(MN)the Legacy of Angels,http://tloaf.org(MN)
文摘This review addresses two puzzling findings related to mutations in galactocerebrosidase （GALC） that cause Krabbe disease （KD）, a severe lysosomal storage disorder characterized by extensive myelin damage in children with mutations in both GALC alleles. First, heterozygous carriers of KD-causing mutations, which include the biological parents of children with KD, exhibit increased risk for developing other diseases. Second, variants in the GALC locus increase the risk of developing multiple sclerosis （MS）, another disease characterized by extensive myelin damage. What explains these correlations？ In studies on cuprizone-induced myelin damage in heterozygous （GALC＋/–） mice carrying one copy of a mutation that causes KD-like disease, the extent of damage was similar in GALC＋/– and wild-type （WT） mice. In contrast, GALC＋/- mice had striking defects in repair of cuprizone-induced damage. We further found unexpected microglial defects in myelin debris clearance and in the ability to up-regulate the Trem2 microglial protein critical for debris uptake. These defects were rescued by exposure to a lysosomal re-acidifying drug discovered in our studies on KD, and which provides multiple clinically relevant benefits in the twitcher （GALC＋/–） mouse model of KD. Thus, heterozygous GALC mutations cause effects on biological function that may help to understand the increased disease risk in heterozygous carriers of such mutations and to understand why GALC variations increase the risk of MS. Our findings indicate that while some genetic risk factors may contribute to complex diseases by increasing the risk of tissue damage, others may do so by compromising tissue repair.
基金supported by the National High-tech R&D Program (863 Program) (No. 2009AA101101)the National S&T Major Project (No. 2008ZX08001)the Central Level, Non-profit, Scientific Research Insti-tutes’ Basic R&D Operations Special Fund (No. 2009RG002-3)
文摘A residual heterozygous line （RHL） carrying a heterozygous segment between two S SR loci RM 11 and RM134 on the rice chromo- some 7 was selected from a set of recombinant inbred lines from the cross D50 （javanica）/HB277 （indica）. The former parent produces much longer grains than the latter. Selfed progenies of this selection were analyzed genotypically （SSRs） and phenotypically （grain length）. Grain length was discontinuously variable in the mapping populations, allowing for the placement of this QTL qGL7-2 within a -4.8 cM interval defined by RM351 and RM234. A set of new markers within this region were developed, which narrowed the QTL to a 278 kb region defined by the markers Indell and RM21945. This region contains 49 predicted genes. The results also suggest that the novel allele for grain length will be used for the application of marker assisted selection for the improvement of grain length.
基金supported by the Zhejiang Natural Science Foundation(Y304446)the National 863 Program of China(2006AA10Z1E8)the Chinese Super Rice Breeding Program(200606).
文摘This study was undertaken to dissect quantitative trait loci （QTLs） controlling yield traits on the short arm of rice chromosome 6. A residual heterozygous line that carries a heterozygous segment extending from RM587 to RM19784 on the short arm of rice chromosome 6 was selected from an F7 population of the indica rice cross Zhenshan 97B/Milyang 46. An F2：3 population consisting of 221 lines was derived and grown in two trial sites. Six yield traits including number of panicles per plant, number of filled grains per panicle, total number of spikelets per panicle, spikelet fertility, 1 000-grain weight, and grain yield per plant were measured. An SSR marker linkage map was constructed and employed to determine QTLs for yield traits with Windows QTL Cartographer 2.5. QTLs were detected in the target interval for all the traits analyzed except NP, with phenotypic variance explained by a single QTL ranging between 6.3% and 35.2%. Most of the QTLs for yield components acted as additive QTLs, while the three QTLs for grain yield had dominance degrees of 1.65, 0.84, and -0.42, respectively. It was indicated that three or more QTLs for yield traits were located in the target region. The genetic action mode, the direction of the QTL effect, and the magnitude of the QTL effect varied among different QTLs for a given trait, and among QTLs for different traits that were located in the same interval.
文摘The results of a series of progeny tests showed that "dragon15"(Cunninghamia lanceolata) had the characters of rapid growth,excellent quality and high resistance.Though a series of exploring experiments by means of polyacrylamide gel electrophoresis technique,5 allozyme systems,amounting to 7 allozyme loci,were found out: GOT-1,GOT-2,GOT-3,FDH,MNR-2,ME,α-amylase.Genetic types of several Chinese fir parents in biclonal seed orchard of 11-year-old were confirmed by use of allozyme technique.The results indicated there was a obvious relationship between offspring’s performances of parent clones and its heterozygous locus numbers.The genetic foundation of biochemistry that the offspring of "dragon15" had rapid growth,excellent quality and high resistance is because it possessed more heterozygous numbers: 5 of 7 allozyme loci in total: GOT-1,GOT-2,GOT-3,FDH,MNR-2.The heterozygous locus numbers could be used to early identification and early selection.
基金supported by the National High Technology Research and Development Program of China (Grant No. 2006AA10Z1E8)the Super Rice Program of Ministry of Agriculture, China (Grant No. 200606)the Natural Science Foundation of Zhejiang Province, China (Grant No. Y304446).
文摘Three residual heterozygous lines (RHLs) carrying heterozygous segments in the intervals RM587–RM225, RM204–RM6119 and RM6119–RM402 on the short arm of rice chromosome 6, respectively, were selected from a rice population derived from an RHL for the interval RM587–RM402. Ten maternal homozygotes, 10 paternal homozygotes and 20 heterozygotes were selected from each of the F2 populations derived from the three RHLs. The three sets of near isogenic lines (NILs) were grown to detect the grain yield per plant, number of panicles per plant, number of filled grains per panicle and 1000-grain weight. With analysis on the phenotypic differences among the three genotype groups in each NIL set and those among overlapping chromosome segment substitution lines, three QTLs for number of filled grains per panicle and two QTLs for grain yield per plant were resolved. They were located in the intervals ranging from 0.66 Mb to 2.49 Mb. The additive effect was higher than the dominance effect at each locus. The allele for increasing the trait value was derived from the paternal parent at qNFGP6-1, and from the maternal alleles at other QTLs. Based on the present study, an approach for constructing new genetic resource to facilitate fine mapping of QTLs in rice was proposed.
基金supported by the National Natural Science Foundation of China(GrantNo.30571062)National Hi-Tech Research and Development Program of China(Grant No.2006AA10Z1E8)the Program of Super Rice from Chinese Agricultural Ministry(Grant No.200906)
文摘The QTL qHUS6 for hull silicon content in rice was previously located on the short arm of rice chromosome 6. By using an F2：3 population segregating in the RM587-RM19784 region harboring qHUS6 in an isogenic background, two QTLs for hull silicon content were detected, of which qHUS6-1 was located in the distal region and qHUS6.2 in the region proximal to the centromere. Three rice plants carrying small heterozygous segments in the target region were selected, of which two covered the qHUS6-1 region and the other covered the qHUS6-2 region. Three F2：3 populations were derived from the selfed seeds of the three plants, respectively. QTL mapping was performed using the two populations segregating in the qHUS6-1 region, and qHUS6-1 was delimited to a 147.0-kb region flanked by the markers RM510 and RM19417. Five groups of F3 lines with different genotypic compositions in the qHUS6-2 region were selected from the other F2-3 population. Two QTLs were separated with two-way ANOVA, of which qHUS6-2a was located in the interval defined by RM19706-RM19795 and qHUS6-2b in the interval RM314-RM19665.
基金supported by the Chinese Super Rice Research Program(200906)the High-Yielding Transgenic Program,China(2008ZX08001-004)the National Natural Science Foundation of China(30571062)
文摘A rice residual heterozygous line （RHL） carrying a heterozygous segment extending from RM111 to RM19784 on the short arm of rice chromosome 6 was selected from a RHL-derived population used previously. The resultant F2：3 population was used to detect quantitative trait loci （QTLs） for three yield traits, the number of spikelets per panicle （NSP）, the number of grains per panicle （NGP） and grain yield per plant （GY）. Two QTLs for NSP, one QTL for NGP and one QTL for GY were detected, all of which were partially dominant and had the enhancing alleles from the maternal line Zhenshan 97B. Analysis based on the genotypic groups of the markers closely linked to the two QTLs for NSP indicated that they did not interact with each other. Two F2 populations and two near isogenic line （NIL） sets segregating in two sub-regions of interval RM111-RM19784 were developed. The two QTLs for NSP were validated, of which one had major effect and was co-segregated with heading date gene Hdl, and the other had smaller effect and was located in an upper region linked to Hdl. The two regions also showed significant effects on the number of filled grain and grain yield, although the effect on the number of filled grain was less consistent.
