Mapping and characterization of FLC homologs and QTL analysis of flowering time in Brassica oleracea

The FLC gene product is an inhibitor of flowering in Arabidopsis. FLC homologs in Brassica species are thought to control vernalization. We cloned four FLC homologs (BoFLCs) from Brassica oleracea. Three of these, BoFLC1, BoFLC3 and BoFLC5, have been previously characterized. The fourth novel sequence displayed 98% sequence homology to the previously identified gene BoFLC4, but also showed 91% homology to BrFLC2 from Brassica rapa. Phylogenetic analysis showed that this clone belongs to the FLC2 clade. Therefore, we designated this gene BoFLC2. Based on the segregation of RFLP, SRAP, CAPS, SSR and AFLP loci, a detailed linkage map of B. oleracea was constructed in the F(2) progeny obtained from a cross of B. oleracea cv. Green Comet (broccoli; non-vernalization type) and B. oleracea cv. Reiho (cabbage; vernalization type), which covered 540 cM, 9 major linkage groups. Six quantitative trait loci (QTL) controlling flowering time were detected. BoFLC1, BoFLC3 and BoFLC5 were not linked to the QTLs controlling flowering time. However, the largest QTL effect was located in the region where BoFLC2 was mapped. Genotyping of F(2 )plants at the BoFLC2 locus showed that most of the early flowering plants were homozygotes of BoFLC-GC, whereas most of the late- and non-flowering plants were homozygotes of BoFLC-Rei. The BoFLC2 homologs present in plants of the non-vernalization type were non-functional, due to a frameshift in exon 4. Moreover, duplications and deletions of BoFLC2 were detected in broccoli and a rapid cycling line, respectively. These results suggest that BoFLC2 contributes to the control of flowering time in B. oleracea.

Fine mapping of the clubroot resistance gene, Crr3, in Brassica rapa

A linkage map of Chinese cabbage (Brassica rapa) was constructed to localize the clubroot resistance (CR) gene, Crr3. Quantitative trait loci analysis using an F(3) population revealed a sharp peak in the logarithm of odds score around the sequence-tagged site (STS) marker, OPC11-2S. Therefore, this region contained Crr3. Nucleotide sequences of OPC11-2S and its proximal markers showed homology to sequences in the top arm of Arabidopsis chromosome 3, suggesting a synteny between the two species. For fine mapping of Crr3, a number of STS markers were developed based on genomic information from Arabidopsis. We obtained polymorphisms in 23 Arabidopsis-derived STS markers, 11 of which were closely linked to Crr3. The precise position of Crr3 was determined using a population of 888 F(2) plants. Eighty plants showing recombination around Crr3 locus were selected and used for the mapping. A fine map of 4.74 cM was obtained, in which two markers (BrSTS-41 and BrSTS-44) and three markers (OPC11-2S, BrSTS-54 and BrSTS-61) were cosegregated. Marker genotypes of the 21 selected F(2) families and CR tests of their progenies strongly suggested that the Crr3 gene is located in a 0.35 cM segment between the two markers, BrSTS-33 and BrSTS-78.

Fine mapping of the clubroot resistance gene, Crr3, in Brassica rapa

A linkage map of Chinese cabbage (Brassica rapa) was constructed to localize the clubroot resistance (CR) gene, Crr3. Quantitative trait loci analysis using an F(3) population revealed a sharp peak in the logarithm of odds score around the sequence-tagged site (STS) marker, OPC11-2S. Therefore, this region contained Crr3. Nucleotide sequences of OPC11-2S and its proximal markers showed homology to sequences in the top arm of Arabidopsis chromosome 3, suggesting a synteny between the two species. For fine mapping of Crr3, a number of STS markers were developed based on genomic information from Arabidopsis. We obtained polymorphisms in 23 Arabidopsis-derived STS markers, 11 of which were closely linked to Crr3. The precise position of Crr3 was determined using a population of 888 F(2) plants. Eighty plants showing recombination around Crr3 locus were selected and used for the mapping. A fine map of 4.74 cM was obtained, in which two markers (BrSTS-41 and BrSTS-44) and three markers (OPC11-2S, BrSTS-54 and BrSTS-61) were cosegregated. Marker genotypes of the 21 selected F(2) families and CR tests of their progenies strongly suggested that the Crr3 gene is located in a 0.35 cM segment between the two markers, BrSTS-33 and BrSTS-78.

2'-,5'-Oligoadenylate synthetase response ratio predicting virological response to PEG-interferon-α2b plus ribavirin therapy in patients with chronic hepatitis C

OBJECTIVE

Although all the mechanisms of elimination of hepatitis C virus (HCV) by Interferon (IFN) have not been fully elucidated, the 2'-5'-oligoadenylate (2-5A) system is one of the mechanisms of the antiviral effect of IFN. Consequently, the measurement of 2'-5'-oligoadenylate synthetase (2-5AS) activity could be useful for the evaluation of IFN treatment. This retrospective study was aimed at assessing whether 2-5AS activity functions as a clinical marker of virological response to PEG-interferon-alpha2b (PEG-IFN) plus ribavirin therapy of chronic hepatitis C.

METHODS

The 32 patients included in this study had high viral loads of serum HCV-RNA of genotype 1b with chronic hepatitis C. All the patients received a regimen of PEG-IFN plus ribavirin for 48 weeks, and were then divided into two groups: one group (effective group) with undetectable serum HCV-RNA levels at 24 weeks (n = 22) of therapy, the other group (ineffective group) with persistent presence of HCV-RNA in serum at 24 weeks (n = 10). The 2-5AS activity in serum was measured 2, 8 and 12 weeks before initial administration.

RESULTS

The 2-5AS response ratio (measured value/measured value of baseline 2-5AS) at 2, 8 and 12 weeks after the administration in the effective group was significantly higher than that in the ineffective group.

CONCLUSIONS

These results suggest that the ratio of 2-5AS is closely related to the antiviral effect, and that the measurement of 2-5AS response ratio may be a useful clinical parameter of virological response to PEG-IFN plus ribavirin therapy of chronic hepatitis C.

Production of lipopeptide antibiotic iturin A using soybean curd residue cultivated with Bacillus subtilis in solid-state fermentation

Bacillus subtilis RB14-CS, which suppresses the growth of various plant pathogens in vitro by producing the lipopeptide antibiotic iturin A, was cultured using soybean curd residue, okara, a by-product of tofu manufacture in solid-state fermentation. After 4 days incubation, iturin A production reached 3,300 mg/kg wet solid material (14 g/kg dry solid material), which is approximately tenfold higher than that in submerged fermentation. When the okara product cultured with RB14-CS was introduced into soil infested with Rhizoctonia solani, which is a causal agent of damping-off of tomato, the disease occurrence was significantly suppressed. After 14 days, the number of RB14-CS cells remained in soil at the initial level, whereas almost no iturin A was detected in soil. As the okara cultured with RB14-CS exhibited functions of both plant disease suppression and nutritional effect on tomato seedlings, this product is expected to contribute to the recycling of the soybean curd residue.

Effect of elastic compression stockings on oedema prevention in healthy controls evaluated by a three-dimensional measurement system

BACKGROUND/AIMS

The degree of oedema may differ at various sites on the leg. This study evaluated the degree of oedema at the calf, ankle and foot using a three-dimensional measurement system.

METHODS

By three-dimensional measurement system using the grid pattern projection method, the effects of four different types of elastic compression stockings on oedema prevention were compared in healthy subjects.

RESULTS

Without stockings, a significant increase in the circumference and volume was seen at the ankle and foot in the evening compared with morning values. The average increase in circumference was greater at the foot than that at the ankle. A significant increase in circumference and volume in the evening after a day without stockings disappeared when elastic compression stockings were worn during the day. The coefficient of variation was greater for measurements at the foot than for those at the calf and ankle.

CONCLUSION

Oedema develops easily in order of the foot, the ankle and the calf in healthy populations. Elastic stockings, even with a pressure as low as 8 mmHg, are effective on oedema prevention. In measurement at the foot, further developments are necessary to improve this system.

QTL analysis of powdery mildew resistance in cucumber (Cucumis sativus L.)

A population of F7 recombinant inbred lines (RILs) was made from a cross between susceptible ('Santou') and resistant (PI197088-1) lines of cucumber in order to study powdery mildew resistance loci. Susceptibility to powdery mildew in the F7 RIL individuals showed a continuous distribution from susceptible to resistant, suggesting that powdery mildew resistance is controlled by quantitative trait loci (QTLs). A QTL analysis identified two and three loci for powdery mildew resistance under 26 and 20 degrees C conditions, respectively. One QTL was found in the same position under both temperature conditions. Therefore, it is more likely that one major QTL acts under both temperature conditions and that other QTLs are specific to the two temperature conditions. The above results suggest that the four QTLs are controlled in a different temperature manner, and that their combination played an important role in expressing a high level of resistance to powdery mildew in this cucumber population. Sequence-tagged site (STS) markers associated with each QTL were developed and would be useful for breeding a cucumber line with a high level of powdery mildew resistance.

Isolation of a protease-deficient mutant of Bacillus brevis and efficient secretion of a fungal protein disulfide isomerase by the mutant

The efficient production of a thermostable protein disulfide isomerase (PDI) was successfully achieved using the newly isolated protease-deficient mutant, Bacillus brevis 31-OK. Extracellular protease (exoprotease) activity was about a quarter of that in the parent, and the mutant was deficient in at least one of the major exoproteases. The cDNA encoding the fungal PDI was inserted downstream of the signal peptide-encoding region in an expression-secretion vector for B. brevis. Efficient production of PDI was feasible using B. brevis 31-OK as a host and modified signal sequences composed of three leucine residues inserted in the hydrophobic region of the MWP (middle wall protein) signal sequence. The maximal secretion of PDI into the culture medium was 1.1 g/l, which is about twice that by the parent strain and fifty times greater than the amount of rat and murine PDIs produced by Escherichia coli. The enzymatic properties such as the specific activity and thermal stability of the recombinant PDI are similar to those of natural PDI derived from Humicola insolens mycelia. B. brevis 31-OK was able to maintain its exoprotease activity at a low level throughout the cultivation and is considered to be useful host for production of a protease-sensitive protein and for increase of protein productivity due to stable accumulation.

Comparison of the biological H2S removal characteristics among four inorganic packing materials

Four inorganic packing materials were evaluated in terms of their availability as packing materials of a packed tower deodorization apparatus (biofilter) from the viewpoints of biological H2S removal characteristics and some physical properties. Among porous ceramics (A), calcinated cristobalite (B), calcinated and formed obsidian (C), granulated and calcinated soil (D), the superiority of these packing materials determined based on the values of non-biological removal per unit weight or unit volume of packing material, complete removal capacity of H2S per unit weight of packing material per day or unit volume of packing material per day and pressure drop of the packed bed was in the order of A approximately equal to C > D approximately equal to B, which is correlated with the maximum water content, porosity, and mean pore diameter.

Enhancement of styrene removal by Pseudomonas sp. SR-5 in mixed culture with a benzoic acid-degrading bacterium in biofilter

The growth of a styrene-degrading bacterium, Pseudomonas sp. SR-5, was inhibited by benzoic acid (BA), one of the styrene degradation intermediates, in liquid culture. A benzoic acid-degrading microorganism, Raoultella sp. strain A, was isolated from a peat biofilter inoculated with a wastewater. The styrene removal efficiencies of the two laboratory-scale biofilters inoculated with only strain SR-5 and a mixed culture of strains SR-5 and A were compared using a mixed packing material of peat and ceramic (1:1) for 45 days. The biofilter with the mixed culture showed a higher removal efficiency than that with a single culture of SR-5. The maximum elimination capacities of the biofilters with the mixed culture and the single culture were 141 g m(-3)h(-1) and 106 g m(-3)h(-1), respectively. In the biofilter with the single culture, 136 g of benzoic acid (m3 of dry packing material)(-1) was accumulated at the end of the experiment. However, no accumulation of benzoic acid was observed in the biofilter with the mixed culture.

Dose calculation system for remotely supporting radiotherapy

The dose calculation system IMAGINE is being developed keeping in mind remotely supporting external radiation therapy using photon beams. The system is expected to provide an accurate picture of the dose distribution in a patient body, using a Monte Carlo calculation that employs precise models of the patient body and irradiation head. The dose calculation will be performed utilising super-parallel computing at the dose calculation centre, which is equipped with the ITBL computer, and the calculated results will be transferred through a network. The system is intended to support the quality assurance of current, widely carried out radiotherapy and, further, to promote the prevalence of advanced radiotherapy. Prototypes of the modules constituting the system have already been constructed and used to obtain basic data that are necessary in order to decide on the concrete design of the system. The final system will be completed in 2007.

Promoter polymorphism of SLC11A1 (formerly NRAMP1) confers susceptibility to autoimmune type 1 diabetes mellitus in Japanese

Defective function of antigen-presenting cells has been postulated to be one of the non-HLA-linked susceptibility factors for type 1 diabetes mellitus, though the underlying genetic factors remain unclear. SLC11A1 (formerly NRAMP1), a divalent cation transporter, plays a crucial role in macrophage activation. We performed a case-control study in 224 healthy and 95 type 1 diabetic Japanese subjects, examining the length polymorphisms in the promoter region (-377 to -222) of SLC11A1, which may influence transcriptional activity. Alleles designated 2, 3, and 7 have been identified in Japanese subjects. The frequency of allele 7 was significantly higher in subjects with type 1 diabetes (9.47%) than in the healthy controls (4.46%). The difference is more marked in the subpopulation of Japanese subjects with type 1 diabetes; diabetic subjects with at least one protective HLA class II allele and those without any susceptibility HLA class II haplotypes, DR4-DQ4 or DR9-DQ9, had a much higher allele 7 frequency than controls. These findings suggest that the novel promoter polymorphism of SLC11A1 influences the susceptibility to type 1 diabetes in Japanese subjects.

Baculovirus and dsRNA induce Hemolin, but no antibacterial activity, in Antheraea pernyi

Hemolin is one of the haemolymph proteins most strongly induced upon bacterial infection in Lepidoptera. When we applied RNA interference (RNAi) to suppress Hemolin expression in the Chinese oak silk moth Antheraea pernyi, we discovered that Hemolin is induced by double-stranded RNA (dsRNA) per se. As dsRNA is recognized as a virus pattern molecule, we then investigated the effect of a baculovirus (ApNPV) infection. We found that Hemolin is induced and expressed with similar kinetics as upon dsRNA injection. Notably, no Attacin gene expression or antibacterial activity was recorded. When baculovirus and high amounts of dsRNA were coinjected, the viral symptoms appeared earlier with Hemolin dsRNA than with GFP dsRNA. This indicates that silencing of hemolin affected the progress of the viral infection.

Styrene degradation by Pseudomonas sp. SR-5 in biofilters with organic and inorganic packing materials

Pseudomonas sp. SR-5 was isolated as a styrene-degrading bacterium. In liquid culture containing 1% (v/v) styrene, more than 90% styrene was degraded in 53 h and the doubling time of SR-5 was 2 h. The removal of styrene gas was investigated in biofilters for 31 days using an organic packing material of peat and an inorganic packing material of ceramic inoculated with SR-5. The maximum-styrene-elimination capacities for peat and ceramic packing materials were 236 and 81 g m(-3) h(-1), respectively. The percentage of styrene converted to low molecular weight compounds including CO(2) in the peat and ceramic biofilters during a 10-day operation were estimated to be 90.4 and 36.7%, respectively. As the pressure drop in the peat bioflter at the end of experiment was significantly higher than that in ceramic biofilter, a biofilter using a mixture of peat and ceramic was tested. We determined that the maximum elimination capacity was 170 g m(-3) h(-1) and the production of low molecular weight compounds was 95% at a low pressure drop for this mixed packing material filter.

A novel locus for clubroot resistance in Brassica rapa and its linkage markers

An inbred turnip ( Brassica rapa syn. campestris) line, N-WMR-3, which carries the trait of clubroot resistance (CR) from a European turnip, Milan White, was crossed with a clubroot-susceptible doubled haploid line, A9709. A segregating F(3) population was obtained by single-seed descent of F(2) plants and used for a genetic analysis. Segregation of CR in the F(3) population suggested that CR is controlled by a major gene. Two RAPD markers, OPC11-1 and OPC11-2, were obtained as candidates of linkage markers by bulked segregant analysis. These were converted to sequence-tagged site markers, by cloning and sequencing of the polymorphic bands, and named OPC11-1S and OPC11-2S, respectively. The specific primer pairs for OPC11-1S amplified a clear dominant band, while the primer pairs for OPC11-2S resulted in co-dominant bands. Frequency distributions and statistical analyses indicate the presence of a major dominant CR gene linked to these two markers. The present marker for CR was independent of the previously found CR loci, Crr1 and Crr2. Genotypic distribution and statistical analyses did not show any evidence of CR alleles on Crr1 and Crr2 loci in N-WMR-3. The present study clearly demonstrates that B. rapa has at least three CR loci. Therefore, the new CR locus was named Crr3. The present locus may be useful in breeding CR Chinese cabbage cultivars to overcome the decay of present CR cultivars.

cDNA cloning of human DNase gamma: chromosomal localization of its gene and enzymatic properties of recombinant protein

We report here on the nucleotide sequence of the cDNA encoding human DNase gamma, which is a candidate for an apoptotic endonuclease. The cDNA clone isolated from a human spleen cDNA library is composed of a 918 bp open reading frame encoding a 305 amino acid precursor protein for DNase gamma. Northern blot analysis reveals that the expression of a single transcript of 1.5 kb DNase gamma mRNA is detected in the spleen and liver. The chromosomal localization of DNase gamma gene is mapped to chromosome 3 at region p21.1-p14.2 by fluorescence in situ hybridization (FISH). Characterization of thioredoxin-DNase gamma fusion protein (Trx-hDNase gamma) shows that the recombinant protein has a Ca(2+)/Mg(2+)- or Mn(2+)-dependent endonuclease activity that cleaves chromatin DNA to nucleosomal units. The optimum pH is around 7.2. Zn(2+) and aurintricarboxylic acid (ATA) inhibits the activity in dose-dependent manners. These properties are identical to those of purified DNase gamma.

Gene arrangement at the Rhesus blood group locus of chimpanzees detected by fiber-FISH

The Rhesus (Rh) blood group system in humans is encoded by two genes with high sequence homology. These two genes, namely, RHCE and RHD, have been implied to be duplicated during evolution. However, the genomic organization of Rh genes in chimpanzees and other nonhuman primates has not been precisely studied. We analyzed the arrangement of the Rh genes of chimpanzees (Pan troglodytes) by two-color fluorescence in situ hybridization on chromatin DNA fibers (fiber-FISH) using two genomic DNA probes that respectively contain introns 3 and 7 of human RH genes. Among the five chimpanzees studied, three were found to be homozygous for the two-Rh-gene type, in an arrangement of Rh (5'-->3') - Rh (3'<--5'). Although a similar gene arrangement can be detected in the RH gene locus of typical Rh-positive humans, the distance between the two genes in chimpanzees was about 50 kb longer than that in humans. The remaining two chimpanzees were homozygous for a four-Rh-gene type, in an arrangement of Rh (5'-->3') - Rh (3'<--5') - Rh (3'<--5') - Rh (3'<--5') within a region spanning about 300 kb. This four-Rh-gene type has not been detected in humans. Further analysis of other great apes showed different gene arrangements: a bonobo was homozygous for the three-Rh-gene type; a gorilla was heterozygous for the one-Rh- and two-Rh-gene types; an orangutan was homozygous for the one-Rh-gene type. Our findings on the intra- and interspecific genomic variations in the Rh gene locus in Hominoids would shed further light on reconstructing the genomic pathways of Rh gene duplication during evolution.

Identification of two loci for resistance to clubroot (Plasmodiophora brassicae Woronin) in Brassica rapa L

In an analysis of 114 F(2) individuals from a cross between clubroot-resistant and susceptible lines of Brassica rapa L., 'G004' and 'Hakusai Chukanbohon Nou 7' (A9709), respectively, we identified two loci, Crr1 and Crr2, for clubroot (caused by Plasmodiophora brassicae Woronin) resistance. Each locus segregated independently among the F(2) population, indicating that the loci reside on a different region of chromosomes or on different chromosomes. Genetic analysis showed that each locus had little effect on clubroot resistance by itself, indicating that these two loci are complementary for clubroot resistance. The resistance to clubroot was much stronger when both loci were homozygous for resistant alleles than when they were heterozygous. These results indicate that clubroot resistance in B. rapa is under oligogenic control and at least two loci are necessary for resistance.

Identification of two loci for resistance to clubroot (Plasmodiophora brassicae Woronin) in Brassica rapa L

In an analysis of 114 F(2) individuals from a cross between clubroot-resistant and susceptible lines of Brassica rapa L., 'G004' and 'Hakusai Chukanbohon Nou 7' (A9709), respectively, we identified two loci, Crr1 and Crr2, for clubroot (caused by Plasmodiophora brassicae Woronin) resistance. Each locus segregated independently among the F(2) population, indicating that the loci reside on a different region of chromosomes or on different chromosomes. Genetic analysis showed that each locus had little effect on clubroot resistance by itself, indicating that these two loci are complementary for clubroot resistance. The resistance to clubroot was much stronger when both loci were homozygous for resistant alleles than when they were heterozygous. These results indicate that clubroot resistance in B. rapa is under oligogenic control and at least two loci are necessary for resistance.

Combined study with FDG PET and Tl SPECT in patients with idiopathic dilated cardiomyopathy

This study aimed to determine whether combined examinations of myocardial 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) and stress-redistribution 201Tl single-photon emission computed tomography (Tl SPECT) were useful in clarifying myocardial ischaemia and evaluating the prognosis in patients with idiopathic dilated cardiomyopathy (IDCM). Twenty-two patients with IDCM underwent echocardiography, cardiac catheterization, FDG PET, and Tl SPECT. In scintigraphic analysis, the total defect score (TDS) was semiquantitatively determined as the sum of scores of the 17 left ventricular (LV) segments with a 5-point scale (0 as normal to 4 as absent). Patients were classified according to the scintigraphic findings as follows: eight patients with small defects on Tl and FDG (TDS < or = 20) (group I), eight patients with small defects on FDG (TDS < or = 20) with FDG uptake increased relative to Tl or 'mismatch' (group II), and six patients with large defects on FDG and Tl (TDS >20) (group III). Eleven patients (50%) showed reversible defects on Tl and all showed preserved FDG uptake. The patients in group III had significantly lower LV ejection fraction (LVEF) (P<0.05, respectively) and a poorer prognosis as shown by the Kaplan-Meier event-free curve compared with those in groups I and II (P<0.01, respectively). Although patients in group II had significantly greater TDS on Tl compared with those in group I (P<0.01), no significant differences in LVEF and prognosis were found between patients in groups I and II. In multivariate analysis, a TDS on FDG revealed an independent predictor of subsequent cardiac events. In conclusion, such mismatched areas can be assumed to consist of impaired but viable myocardium, and may be associated with ischaemia of the microvasculature. Impaired myocardial glucose metabolism is a more powerful predictor of future cardiac events than perfusion abnormality in patients with IDCM.

Esophageal actinomycosis after allogeneic peripheral blood stem cell transplantation for extranodal natural killer/T cell lymphoma, nasal type

We report a 19-year-old man with extranodal natural killer (NK)/T cell lymphoma, nasal type treated by allogeneic peripheral blood stem cell transplantation (allo-PBSCT). His lymphoma was chemoresistant, and disseminated during local radiotherapy. The patient received allo-PBSCT from his HLA-1 locus mismatched sister using busulfan (BU), cyclophosphamide (CY) and VP-16 as the conditioning regimen. His course was complicated by esophageal actinomycosis 9 months after transplantation, which resulted in the rupture of the right common carotid artery. These observations suggest that actinomycosis should be monitored carefully after transplantation in patients who have received local radiation therapy before the procedure.

Role of urotensin II gene in genetic susceptibility to Type 2 diabetes mellitus in Japanese subjects

AIM/HYPOTHESIS

Urotensin II is a potent vasoactive hormone and the urotensin II gene (UTS2) is localized to 1p36-p32, one of the regions reported to show possible linkage with Type 2 diabetes in Japanese subjects. The aim of this study is to investigate a possible contribution of SNPs in the UTS2 gene to the development of Type 2 diabetes.

METHODS

We surveyed SNPs in the UTS2 gene in 152 Japanese subjects with Type 2 diabetes mellitus and two control Japanese cohorts: one consisting of 122 elderly subjects who met stringent criteria for being non-diabetic, including being older than 60 years of age with no evidence of diabetes (HbA(1c)<5.6%), and another 268 subjects with normal glucose tolerance.

RESULTS

We identified two SNPs with amino acid substitutions, designated T21M and S89N. The allele frequency of 89N was higher in Type 2 diabetic patients than in both elderly normal subjects (p=0.0018) and subjects with normal glucose tolerance (p=0.0011), whereas the allele frequency of T21M was essentially identical in these three groups. Furthermore, in the subjects with normal glucose tolerance, 89N was associated with higher insulin concentrations on oral glucose tolerance test, suggesting reduced insulin sensitivity in subjects with 89N.

CONCLUSION/INTERPRETATION

These results strongly suggest that the S89N polymorphism in the UTS2 gene is associated with the development of Type 2 diabetes, via insulin sensitivity, in Japanese subjects.

Construction of a linkage map and QTL analysis of horticultural traits for watermelon [Citrullus lanatus (THUNB.) MATSUM & NAKAI] using RAPD, RFLP and ISSR markers

We have been constructing linkage maps for watermelon ( Citrullus lanatus) on the basis of random amplified polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP), inter-simple sequence repeats (ISSRs) and isozymes using an F(2) population derived from a crossing between a cultivated inbred line (H-7; C. lanatus) and an African wild form (SA-1; C. lanatus). A total of 120 F(2) plants was used for construction of a linkage map using 477 RAPDs, 53 RFLPs, 23 ISSRs and one isozyme markers. Linkage analysis revealed that 554 loci could be mapped to 11 linkage groups that extended for 2,384 centimorgans (cM). While a BC(1) population [(H-7 x SA-1) x H-7] consisting of 60 individuals was grown and scored for quantitative traits. Another linkage map with a total length of 1,729 cM was constructed in the BC(1) using genetic markers found to segregate in the F(2) population. A QTL analysis was applied by means of interval mapping for locating such agronomic traits as hardness of rind, Brix of flesh juice, flesh color (red and yellow) and rind color. The relative order of markers in the BC(1) map was essentially the same as that on the linkage map in the F(2). A total of five QTLs for four agronomic traits was detected. The QTL for hardness of rind was mapped on group 4. The linkage group 8 contained the QTL for sugar content of the flesh as expressed in Brix of the juice. The QTL for red flesh color was detected on groups 2 and 8. The QTL for rind color mapped on the group 3. The present map and QTL analysis may provide a useful tool for breeders by introducing valuable wild watermelon genes to cultivars.