ABSTRACT
A 48-year-old Japanese woman was diagnosed with Budd-Chiari syndrome and transferred for possible living donor liver transplantation (LDLT). Examinations before LDLT revealed that the recipient had anti-Jra and preformed donor-specific anti-human leukocyte antigen (HLA) antibodies (DSA). Rituximab was administrated at 16 days prior to the patient's scheduled LDLT for the prophylaxis of antibody-mediated rejection by DSA. The clinical significance of anti-Jra has not been clearly established because of the rarity of this antibody, so we discussed blood transfusion strategy with the Department of Blood Transfusion Service and prepared for Jra-negative packed red blood cells (RBCs). Intraoperative blood salvage was used during LDLT procedures to reduce the use of packed RBCs. Although post-transplantation graft function was excellent, a total of 44 U of Jra-negative RBCs were transfused during the entire perioperative period. Because sufficient amounts of Jra-negative packed RBCs were supplied, Jra mismatched blood transfusion was avoided. The patient was discharged from our hospital on postoperative day 102 without clinical evidence of any blood transfusion-related adverse events. Although there are some controversies of blood transfusion related to anti-Jra antibodies, the current strategies of blood transfusion for liver transplantation with anti-Jra are as follows: (1) sufficient supply and transfusion of Jra-negative matched packed RBCs and (2) application of intraoperative blood salvage to reduce the total amount of rare blood type RBCs. These strategies may be changed when the mechanism of anti-Jra alloimmunization is fully understood in the future.
Subject(s)
Antibodies/blood , Blood Transfusion/methods , Erythrocytes/immunology , HLA Antigens/immunology , Transfusion Reaction/prevention & control , Antibodies/immunology , Budd-Chiari Syndrome/immunology , Budd-Chiari Syndrome/surgery , Female , HLA Antigens/blood , Humans , Immunologic Factors/administration & dosage , Liver Transplantation/methods , Living Donors , Middle Aged , Rituximab/administration & dosage , Transfusion Reaction/immunologyABSTRACT
BACKGROUND: Impaired exercise capacity and muscle weakness are important characteristics of liver transplantation recipients. Perioperative rehabilitation has been introduced to promote early mobilization of patients and to prevent postoperative pulmonary complications. However, it is unknown how physical status recovers during the hospital stay after a liver transplant. The purpose of this study was to evaluate the changes in clinical indicators that represent the functional exercise capacity and muscle strength before and after living donor liver transplantation (LDLT). METHODS: We retrospectively reviewed 21 consecutive patients who underwent LDLT with perioperative rehabilitation from April 2014 to December 2015. Twelve patients who were tested for 6-minute walk distance, hand-grip strength, and isometric knee extensor muscle strength before and 4 weeks after LDLT were enrolled. RESULTS: At the preoperative baseline, the 6-minute walk distance significantly correlated with the Model for End-stage Liver Disease score and pulmonary functions (vital capacity, forced vital capacity, and forced expiratory volume in 1 second of predictive values). Comparisons between the preoperative and postoperative values revealed significant decreases in weight, Barthel Index, hand-grip strength, and isometric knee extensor muscle strength. Changes in hand-grip strength and isometric knee extensor muscle strength after LDLT correlated with the preoperative Model for End-stage Liver Disease score. CONCLUSIONS: Physical functional status had not been fully recovered 4 weeks after LDLT. Further investigation regarding developing a strategy for prevention of muscle atrophy before LDLT and recovery of physical fitness after LDLT would be helpful.
Subject(s)
Liver Cirrhosis/physiopathology , Liver Transplantation/rehabilitation , Living Donors , Muscle Strength , Walk Test , Adult , Aged , Female , Forced Expiratory Volume , Hand Strength , Humans , Knee/physiopathology , Liver Cirrhosis/rehabilitation , Liver Cirrhosis/surgery , Liver Transplantation/methods , Male , Middle Aged , Muscle Strength/physiology , Physical Fitness/physiology , Postoperative Period , Preoperative Period , Retrospective Studies , Severity of Illness Index , Vital CapacityABSTRACT
Gene expression biomarkers can enable rapid assessment of physiological conditions in situ, providing a valuable tool for reef managers interested in linking organism physiology with large-scale climatic conditions. Here, we assessed the ability of quantitative PCR (qPCR)-based gene expression biomarkers to evaluate (i) the immediate cellular stress response (CSR) of Porites astreoides to incremental thermal stress and (ii) the magnitude of CSR and cellular homeostasis response (CHR) during a natural bleaching event. Expression levels largely scaled with treatment temperature, with the strongest responses occurring in heat-shock proteins. This is the first demonstration of a 'tiered' CSR in a coral, where the magnitude of expression change is proportional to stress intensity. Analysis of a natural bleaching event revealed no signature of an acute CSR in normal or bleached corals, indicating that the bleaching stressor(s) had abated by the day of sampling. Another long-term stress CHR-based indicator assay was significantly elevated in bleached corals, although assay values overall were low, suggesting good prospects for recovery. This study represents the first step in linking variation in gene expression biomarkers to stress tolerance and bleaching thresholds in situ by quantifying the severity of ongoing thermal stress and its accumulated long-term impacts.
Subject(s)
Anthozoa/radiation effects , Biomarkers , Gene Expression Profiling , Real-Time Polymerase Chain Reaction , Animals , Anthozoa/physiology , Stress, PhysiologicalABSTRACT
The extracellular calcium-sensing receptor (CaSR), a G protein-coupled cell receptor cloned from bovine parathyroid, has been demonstrated to play a regulatory role in various functions of the gastrointestinal tract. In the present study, we examined the effect of cinacalcet, a drug that acts as a calcimimetic through the allosteric activation of CaSR, on the loxoprofen-induced small intestinal lesions and investigated the mechanisms involved in the protective action. Male Sprague-Dawley rats were used without fasting. The animals were administered loxoprofen p.o. and euthanized 24 hours later and the intestinal mucosa was examined for lesions. Cinacalcet was given p.o. twice, 30 min before and 6 h after loxoprofen. Loxoprofen caused hemorrhagic lesions in the small intestine, accompanied by the upregulation of enterobacterial invasion, myeloperoxidase (MPO) activity and inducible nitric oxide synthase (iNOS)/tumor necrosis factor α (TNF-α) expression as well as the downregulation of Muc2 expression. Prior administration of cinacalcet dose-dependently and significantly reduced the severity of these lesions in response to loxoprofen, with concomitant suppression of the changes in bacterial invasion, iNOS/TNF-α as well as Muc2 expression, and myeloperoxidase activity. Cinacalcet also significantly reversed a decrease in mucus secretion and fluid secretion in the small intestine caused by loxoprofen, but had no effect on the intestinal hypermotility or prostaglandin E2 deficiency caused by loxoprofen. These results suggest that cinacalcet protects the small intestine against loxoprofen-induced damage, and this effect may be functionally associated with an increase in fluid secretion and a reversal of downregulation of Muc2 expression caused by loxoprofen, resulting in suppression of bacterial invasion and iNOS/TNF-α expression, the major pathogenic events in nonsteroidal antiinflammatory drugs-induced small intestinal ulceration.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Intestinal Diseases/prevention & control , Naphthalenes/therapeutic use , Phenylpropionates/adverse effects , Receptors, Calcium-Sensing/agonists , Animals , Bacterial Load , Cinacalcet , Dinoprostone/metabolism , Enterobacteriaceae/isolation & purification , Intestinal Diseases/chemically induced , Intestinal Diseases/metabolism , Intestinal Diseases/microbiology , Intestine, Small/drug effects , Intestine, Small/metabolism , Intestine, Small/microbiology , Male , Mucin-2/genetics , Naphthalenes/pharmacology , Nitric Oxide Synthase Type II/genetics , Oligopeptides/pharmacology , Peroxidase/metabolism , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Receptors, Calcium-Sensing/metabolism , Tumor Necrosis Factor-alpha/geneticsABSTRACT
INTRODUCTION: We report herein a new method of transumbilical laparoscopic surgery using a GelPort through an umbilical zigzag skin incision. The method involves collaborating with plastic surgeons to ensure the procedure was minimally invasive. MATERIALS AND SURGICAL TECHNIQUE: After marking a zigzag skin incision in the umbilical region, the skin was incised along this line. Then, a GelPort double-ring wound retractor was inserted through the incision, which enlarged the diameter of the fascial opening to 6 cm. The Gelport was latched on the wound retractor ring, following the inflation of the pneumoperitoneum by CO (2). One or more additional ports were inserted as necessary. All operations were performed in the standard fashion. The specimen was easily extracted from the abdomen through the umbilical incision, and anastomosis was performed. Using the above method, we performed the following procedures: one total gastrectomy, one distal gastrectomy, three gastric local resections, five right hemicolectomies, two high anterior resections, three cholecystectomies, and seven transabdominal preperitoneal hernioplasties. All cases were accomplished without any complications using this method. The wounds of the umbilical region were almost "scarless" in all cases. DISCUSSION: We developed an umbilical zigzag skin incision technique to perform abdominal laparoscopic operations using a GelPort, with a minimal number of skin incisions. We consider that our method reduces the technical difficulties associated with laparoscopic surgery and maintains cosmesis.
Subject(s)
Colectomy/methods , Gastrectomy/methods , Herniorrhaphy/methods , Laparoscopy/methods , Umbilicus/surgery , Cholecystectomy, Laparoscopic/instrumentation , Cholecystectomy, Laparoscopic/methods , Colectomy/instrumentation , Gastrectomy/instrumentation , Herniorrhaphy/instrumentation , Humans , Laparoscopy/instrumentationSubject(s)
Amyloidosis/immunology , Interleukin-1beta/immunology , Animals , Base Sequence , DNA Primers , Enzyme-Linked Immunosorbent Assay , Male , Mice , Mice, Inbred C3HABSTRACT
CsBr phosphor ceramics doped with different luminescence centres such as In2O3, Eu2O3, EuCl3, SmCl3, TbCl3, GdCl3 or NdCl3 as the candidate for a new optically-stimulable phosphor for medical X-ray imaging sensor were prepared using a conventional ceramic fabrication process. It was found that X-ray-irradiated Eu-doped CsBr (CsBr:Eu) exhibited intense optically stimulated luminescence (OSL). The peak wavelength of the OSL emission and stimulation spectra of CsBr:Eu phosphor ceramic sample were 450 and 690 nm, respectively. The dependence of OSL properties on the conditions of preparation of phosphor ceramic samples, such as Eu concentration, sintering temperature and sintering time, were studied. The optimum preparation conditions were also studied. It was found that the OSL intensity of CsBr:Eu phosphor ceramics fabricated under optimum preparation conditions is higher than that of commercially available imaging plates using BaFBr:Eu.
Subject(s)
Bromides/chemistry , Bromides/radiation effects , Cesium/chemistry , Cesium/radiation effects , Radiation Protection/instrumentation , Radiography/instrumentation , Thermoluminescent Dosimetry/instrumentation , Thermoluminescent Dosimetry/methods , Dose-Response Relationship, Radiation , Equipment Design , Equipment Failure Analysis , Europium/chemistry , Europium/radiation effects , Materials Testing , Optics and Photonics , Radiation Dosage , Radiation Protection/methods , Reproducibility of Results , Sensitivity and Specificity , Transducers , X-RaysABSTRACT
This study evaluated the effects of the commonly used hydrophilic organic solvents, acetonitrile, methanol, ethanol, 1-propanol, dimethyl sulfoxide (DMSO), N,N-dimethylformamide, polyethylene glycol and propylene glycol, on CYP3A in pooled human liver microsomes, using testosterone and midazolam as substrates. Furthermore, we examined the modulation effect of organic solvents on CYP3A inhibition by ketoconazole. Testosterone 6beta-hydroxylation activity was potently inhibited in the presence of DMSO and 1-propanol in a concentration-dependent manner. Midazolam 1'-hydroxylation activity, however, was weakly inhibited only by 1% of DMSO, the highest concentration used in this study. Moreover, the potency of ketoconazole to inhibit CYP3A activities was variable, depending on the organic solvent used as a dissolving solvent for ketoconazole. Our data indicate that each organic solvent had an effect on CYP3A4 activity, evaluated by both substrates with different magnitudes. Furthermore, it was shown that the effects of organic solvents on CYP3A activity are substrate-dependent. The present study also shows that methanol had little effect on either substrate.
Subject(s)
Cytochrome P-450 Enzyme Inhibitors , Enzyme Inhibitors/pharmacology , Ketoconazole/pharmacology , Liver/drug effects , Solvents/pharmacology , Cytochrome P-450 CYP3A , Cytochrome P-450 Enzyme System/metabolism , Dose-Response Relationship, Drug , Drug Interactions , Humans , Hydroxylation , In Vitro Techniques , Liver/enzymology , Microsomes, Liver/drug effects , Microsomes, Liver/enzymology , Midazolam/metabolism , Steroid Hydroxylases/antagonists & inhibitors , Substrate Specificity , Testosterone/metabolismABSTRACT
The structural organization and evolution of two tandemly repeated families, Spelt1 and Spelt52, located in the subtelomeric regions of Aegilops speltoides chromosomes were studied. The Spelt1 family of sequences with a monomer length of 178 bp was characterized by cloning and sequence analysis of polymerase chain reaction (PCR) products. Members of the Spelt1 family revealed sequence similarities exceeding 95%. This conservation has remained despite divergence of species in Aegilops section Sitopsis and after independent multiple amplification events in the genome of Ae. speltoides. Sequences representing the Spelt52 family were cloned, sequenced and compared with other sequences in databases. The Spelt52 repeat family contains monomers of two types, Spelt52.1 and Spelt52.2. The two monomers share a homologous stretch of 280 bp and have two regions without sequence similarity of 96 bp and 110 bp, respectively. PCR analysis was conducted to 15 lines in Ae. speltoides Tausch., Ae. longissima Schw. & Mushc., Ae. sharonensis Eig., Ae. bicornis (Forssk) Jaub.&Sp., and Ae. searsii Feld.&Kis. using primers to the homologous and nonhomologous regions of Spelt52 family. Intraspecies and interspecies differences in the occurrence and abundance of combinations of Spelt52.1 and Spelt52.2 monomers were detected. The use of primers to telomeric and subtelomeric repeats followed by Southern hybridization, cloning, and sequence analysis demonstrated that Spelt1 and Spelt52 are localized close to each other and to telomeric repeats. The efficiency of a PCR approach for the analysis of telomeric/subtelomeric junction regions of chromosomes is discussed.
Subject(s)
Genome, Plant , Poaceae/genetics , Tandem Repeat Sequences , Polymerase Chain Reaction , Sequence Analysis, DNAABSTRACT
To develop an efficient means of enhancer trapping, a two-element system employing Ds and an Ac transposase (AcTPase) gene was tested in rice. We generated 263 transgenic rice plants, each of which harboured the maize transposable element Ds together with a GUS coding sequence under the control of a minimal promoter (Ds-GUS), and a gene that confers resistance to the herbicide chlorsulfuron. Among the 263 lines generated, 42 were shown to have a single copy of the Ds-GUS element. Four single-copy lines were crossed with each of six transgenic plants that carried the AcTPase gene. Excision of the Ds-GUS in leaves of F1 plants was detected in eight combinations out of seventeen examined. The frequency of transposition of Ds-GUS in germ cells in the F1 plants was examined using 10,524 F2 plants, and 675 (6%) were judged to be transposants. Their frequencies differed among F1 plants depending on the AcTPase x Ds-GUS cross considered, and also among panicles on the same F1 plant. This suggests that Ds-GUS tends to transpose during panicle development. Southern analysis with a GUS probe showed different band patterns among transposants derived from different panicles. Therefore, the transposants derived from different panicles must have arisen independently. Transposants showing tissue-specific GUS activities were obtained, and enhancers thus trapped by the Ds-GUS element were identified. These results demonstrate that the system is suitable for the isolation of large numbers of independent Ds-GUS transposants, and for the identification of various tissue-specific enhancers. The Ds-GUS lines generated in this study offer a potentially powerful tool for studies on the functional genomics of rice.
Subject(s)
DNA Transposable Elements , Enhancer Elements, Genetic/physiology , Gene Expression Regulation, Plant , Oryza/genetics , Plants, Genetically Modified , Zea mays/genetics , Blotting, Southern , Crosses, Genetic , Drug Resistance , Gene Frequency , Genome, Plant , Glucuronidase/genetics , Glucuronidase/metabolism , Herbicides/toxicity , Oryza/growth & development , Promoter Regions, Genetic , Sulfonamides/toxicity , Transposases , Triazines/toxicity , Zea mays/growth & developmentABSTRACT
To elucidate the genetic system that establishes homologous chromosome pairing in monocot plants, we have isolated an asynaptic mutant of rice, designated pair2 (homologous pairing aberration in rice meiosis 2), in which 24 completely unpaired univalents are observed at pachytene and diakinesis. The mutation was caused by an insertion of the retrotransposon Tos17, as demonstrated by complementation of the mutation by transformation with the corresponding wild-type gene. The gene in which the element was inserted is orthologous to the ASY1 gene of Arabidopsis thaliana and the HOP1 gene of Saccharomyces cerevisiae. Mature PAIR2 mRNA and several splicing variants were found to be highly expressed in wild-type reproductive tissues, and lower expression was also detected in vegetative tissues. In situ hybridization and BrdU incorporation experiments revealed that PAIR2 expression is specifically enhanced in male and female meiocytes, but not in those at pre-meiotic S phase or in the pollen maturation stages. The results obtained in this study suggest that the PAIR2 gene is essential for homologous chromosome pairing in meiosis, as in the case of the genes ASY1 and HOP1. The study also suggested the possibility that a highly homologous copy of the PAIR2 gene located on a different chromosome is in fact a pseudogene.
Subject(s)
Chromosome Pairing/genetics , Gene Expression Profiling , Meiosis/genetics , Oryza/genetics , Retroelements/genetics , Amino Acid Sequence , Bromodeoxyuridine , DNA Primers , In Situ Hybridization , Molecular Sequence Data , Mutation/genetics , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sequence AlignmentABSTRACT
BACKGROUND AND OBJECTIVES: Trimethadione (TMO), an antiepileptic drug, may be used as a candidate for estimating hepatic drug-oxidizing activity. While TMO metabolism is mainly catalysed by CYP2C9, CYP2E1 and CYP3A4 the contribution of the different isoforms is unclear. In this study, we determined the percentage contribution of the three CYPs (CYP2C9, CYP2E1 and CYP3A4) to TMO N-demethylation. METHOD: We used human liver microsomes and human recombinant CYPs expressed in human B-lymphoblast cells and baculovirus-infected insect cells. RESULTS: The mean Km, Vmax and Vmax/Km values of TMO N-demethylation in human microsomes were 3.66 (mm), 503 (pmol/min/mg) and 2.61 (mL/h/mg), respectively. In the microsomes from human B-lymphoblast cells or baculovirus-infected insect cells, CYP 2C9, CYP 2E1 and CYP3A4 exhibited similar Km and higher Vmax in baculovirus-infected insect cells than B-lymphoblast cells. In baculovirus-infected insect cells, CYP2C9, CYP2E1 and CYP3A4 exhibited activities of 32, 286 and 77 pmol/min/pmol CYP, respectively. No CYP activity catalysed by CYP1A2 and 2D6 were detected in the two human cDNA expressed CYP isoforms. CONCLUSION: TMO is metabolized not only by CYP2E1 but also CYP3A4 and CYP2C9. The order of this metabolism is as follows: CYP2E1 >> CYP3A4 > CYP2C9.
Subject(s)
Anticonvulsants/metabolism , Aryl Hydrocarbon Hydroxylases/pharmacology , Cytochrome P-450 CYP2E1/pharmacology , Cytochrome P-450 Enzyme System/pharmacology , Microsomes, Liver/metabolism , Trimethadione/metabolism , Baculoviridae/drug effects , Baculoviridae/metabolism , Cytochrome P-450 CYP2C9 , Cytochrome P-450 CYP3A , Humans , Microsomes, Liver/drug effects , Microsomes, Liver/enzymologyABSTRACT
A 72-year-old female was admitted to our hospital for massive proteinuria. She had previously been diagnosed with hepatitis C virus (HCV) infection and macroglobulinemia. Renal histological examination demonstrated membranoproliferative glomerulonephritis (MPGN), and type 2 cryoglobulinemia was positive in her serum. It is generally recognized that MPGN is the most common nephritis associated with HCV infection and cryoglobulinemia, but this is the first report of an HCV-infected patient with macroglobulinemia associated with MPGN. After treatment with prednisolone and melphalan, proteinuria disappeared, but macroglobulinemia and cryoglobulinemia were not improved.
Subject(s)
Glomerulonephritis, Membranoproliferative/complications , Hepatitis C, Chronic/complications , Waldenstrom Macroglobulinemia/complications , Aged , Cryoglobulinemia/complications , Female , Glomerulonephritis, Membranoproliferative/diagnosis , Glomerulonephritis, Membranoproliferative/urine , Glomerulonephritis, Membranoproliferative/virology , Humans , Proteinuria , Waldenstrom Macroglobulinemia/diagnosisABSTRACT
Relatively selective in vivo substrate probes have been developed for several major CYP isoforms involved in oxidative drug metabolism. There are basically two in vivo methods for identifying the phenotype. One method, the selective (CYP-specific) phenotyping method, involves administering one single probe drug, whereas the other is a mixed phenotyping or "cocktail" method involving the simultaneous administration of multiple probe drugs, specific for the individual P450. At present, caffeine and chlorzoxazone are used most often as probe drugs for CYP1A2 and CYP2E1, respectively, but these are not necessarily the best probe drugs. Of the potential probe drugs for CYP2C9, CYP2C19, CYP2D6 and CYP3A4, none is really useful. Despite current limitations, the cocktail method for obtaining information about multiple CYP activities in a single experimental session is likely to be more widely used as a screening or phenotyping method for humans in the future.
Subject(s)
Cytochrome P-450 Enzyme System/metabolism , Liver/enzymology , Pharmaceutical Preparations/metabolism , Phenotype , Aryl Hydrocarbon Hydroxylases/genetics , Aryl Hydrocarbon Hydroxylases/metabolism , Cytochrome P-450 CYP1A2/genetics , Cytochrome P-450 CYP1A2/metabolism , Cytochrome P-450 CYP2C19 , Cytochrome P-450 CYP2C9 , Cytochrome P-450 CYP2D6/genetics , Cytochrome P-450 CYP2D6/metabolism , Cytochrome P-450 CYP2E1/genetics , Cytochrome P-450 CYP2E1/metabolism , Cytochrome P-450 CYP3A , Cytochrome P-450 Enzyme System/genetics , Female , Humans , Male , Mixed Function Oxygenases/genetics , Mixed Function Oxygenases/metabolism , Molecular Probes , Pharmacogenetics/methods , Polymorphism, GeneticABSTRACT
A methane fermentation system for treating swine wastes was developed and successfully demonstrated in a field test plant (0.5 m3/d). The system was composed of a screw-press dehydrator, a methanogenic digester, a sludge separator, an oxidation ditch (OD) and composting equipment. A performance evaluation was carried out regarding physical pre-treatment using the screw-press dehydrator, methane fermentation for pre-treated slurry, and post-treatment for digested effluent by OD. Total solids (TS) and chemical oxygen demand (CODCr) removal by the screw-press pre-treatment were 38% and 22%, respectively. Properties of the screenings were as follows: water content 57%, ignition loss 93%, specific gravity 0.33. The pretreated strong slurry was digested under mesophilic conditions. Digestion gas (biogas) production rate was 25 m3/m3-slurry (NTP) and methane content of the biogas was 67%. CODCr removal of 65% with methane fermentation treatment of the slurry operating at 35 degrees C was observed. No inhibition of methane fermentation reaction occurred at the NH4(+)-N concentration of 3,000 mg/l or less during methane fermentation by the system. Mass balance from the present pilot-scale study showed that 1 m3 of mixture of excrement and urine of swine waste (TS 90 kg/m3) was biologically converted to 25 m3/m3-slurry (NTP) of biogas (methane content 67%), 100 kg of compost (water content 40%, ignition loss 75%), and 0.80 m3 of treated water (SS 30-70 mg/l).
Subject(s)
Agriculture , Bioreactors , Manure , Methane/metabolism , Refuse Disposal/methods , Ammonia/analysis , Animals , Bacteria, Anaerobic/physiology , Fermentation , Gases , Oxygen/metabolism , SwineABSTRACT
The rice heterochronic gene plastochron1, pla1, shows shorter plastochron and ectopic expression of the vegetative program during the rice reproductive phase resulting in aberrant panicle formation. A genetic and physical map was constructed to isolate the causal gene for the pla1 syndrome. Small-scale mapping was carried out to determine the approximate map position of the pla1 locus, and then a high-resolution genetic map was made for pla1-1, one of the pla1 alleles, using an F(2) population comprising 578 pla1-1 homozygous plants. In a high-resolution genetic map, the pla1-1 locus was found to map between RFLP markers C961 and R1738A on chromosome 10, within a 3.6-cM genetic distance. A physical map encompassing the pla1-1 locus was constructed by overlapping Bacterial Artificial Chromosome (BAC) clones through chromosome walking. PCR-based RFLP markers from BAC-end clones were developed and mapped relative to the pla1 locus. Physical map construction using BAC clones indicated that a BAC clone, B44A10 (167-kb), contained the pla1 locus within 74-kb corresponding to a 0.52-cM genetic distance. Gene prediction of 74-kb region carrying the pla1 locus suggested several candidate genes for the pla1 gene. Identification of a candidate gene for pla1 will be made by sequence analysis of allele variation and cDNA screening.
ABSTRACT
Genetic study of the reproductive barriers between related species plays an essential role in understanding the process of speciation. We developed a new method for mapping all possible factors causing deviations from expected Mendelian segregation ratios in F(2) progeny, which substantially contribute to reproductive isolation. A multiresponse nonlinear regression analysis of the allele frequencies of the markers covering an entire genome in the F(2) population was performed to estimate the map position and intensity of the reproductive barriers on each chromosome. In F(2) plants from a cross between a Japonica variety of rice, Nipponbare, and an Indica variety, Kasalath, the deviations of allele frequencies were well explained by 33 reproductive barriers. Of these, 15 reproductive barriers affected the allele transmission rate through the gametophyte and in 9 of these 15 cases, an Indica allele was transmitted at a higher frequency than a Japonica allele. The other 18 reproductive barriers altered the viability of the zygote via its genotype. Two zygotic reproductive barriers showed overdominance and 5 showed underdominance. The most pronounced reproductive barrier, mapped at 62.3 +/- 0.4 cM on chromosome 3, transmitted the Indica allele by 94% through the male gametophyte. The accuracy of the barrier position in the regression analysis was confirmed by progeny analysis. The regression analysis proved to be a powerful tool for detecting and characterizing every reproductive barrier, irrespective of whether it acted on the male or female gametophyte or the zygote.
Subject(s)
Genome, Plant , Oryza/genetics , Chromosome Mapping , Genetic Linkage , Hybridization, Genetic , Models, Genetic , Oryza/physiology , Regression Analysis , Species SpecificityABSTRACT
We produced transgenic rice calli, which constitutively express each of four KNOX family class 1 homeobox genes of rice, OSH1, OSH16, OSH15, and OSH71, and found that constitutive and ectopic expression of such genes inhibits normal regeneration from transformed calli, which showed continuous growth around their shoot-regenerating stages. Transgenic calli transferred onto regeneration medium began to display green spots, a sign of regeneration, but most of the transformants continued to propagate green spots at given stages. In the normal shoot-regeneration process of calli, expression of endogenous OSH1 was restricted in presumptive shoot-regenerating regions of calli and not observed in other areas. This restricted expression pattern should be required for further differentiation of the regenerating shoots. Thus our present results support the proposed function that KNOX family class 1 homeobox genes play a role in the formation and maintenance of the undetermined meristematic state of cells.
Subject(s)
Cell Differentiation/genetics , Genes, Homeobox/genetics , Genes, Plant/genetics , Oryza/cytology , Oryza/genetics , Cells, Cultured , Cloning, Molecular , Conserved Sequence/genetics , Gene Expression Regulation, Plant , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , In Situ Hybridization , Meristem/cytology , Meristem/genetics , Meristem/growth & development , Meristem/metabolism , Oryza/growth & development , Oryza/metabolism , Phenotype , Plant Proteins/genetics , Plant Proteins/metabolism , Plants, Genetically Modified , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Plant/genetics , RNA, Plant/metabolism , Trans-Activators/genetics , Trans-Activators/metabolism , Transformation, GeneticABSTRACT
The large-scale primary structure of the centromeric region of rice chromosome 5 was analyzed, the first example in a cereal species. The yeast artificial chromosome (YAC) and bacterial artificial chromosome (BAC) contigs aligned on the centromere of rice chromosome 5 (CEN5) covered a distance of more than 670 kb. Strong suppression of genetic recombination, one of the features of a functional centromere, occurred along the contig region. The most remarkable feature of CEN5 is the composition of the multiple repetitive elements. Oryza-specific RCS2 short tandem repeats were clustered along less than 100 kb at one end of the contig. At least 15 copies of the conserved domain of the 1.9 kb RCE1 centromeric repeats, which are similar to the long terminal repeats (LTRs) of gypsy-type retrotransposon RIRE7, were dispersed mainly in 320 kb stretches next to RCS2 tandem clusters. Many copies of the LTR-like sequences of RIRE3 and RIRE8, another gypsy-type retrotransposon, were also found throughout the contig. On the other hand, the gagpol region was less conserved in the contig. These results indicate that the rice centromere is composed of multiple repetitive sequences with the RCS2 tandem cluster probably being situated as the core of a functional centromere of some hundreds of kilobases to megabases in length.