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PubMed2006

Analysis of MS2Bnap genomic DNA homologous to MS2 gene from Arabidopsis thaliana in two dominant digenic male sterile accessions of oilseed rape (Brassica napus L.).

PCR technique was employed to isolate gene homologous to the MS2Bnap (X99922.1) from two rapeseed (Brassica napus L.) dominant digenic male sterile lines, namely 220A (male sterile) and 220B (male fertile), 6A (male sterile) and 6C (male fertile). The isolated 2,581 bp sequences from 220A (named 220A-gDNA, GenBank accession number AY288778), 220B (220B-gDNA, AY257490), 6A (6A-gDNA, DQ060318) and 6C (6C-gDNA, DQ060319) all contained six introns. Forty-one single nucleotide polymorphism (SNP) sites were detected by alignment of these four sequences, seven of them dispersed in the exon regions. Two SNPs (1247, 1656) were detected between 220A-gDNA and 220B-gDNA, and the one at nucleotide 1247 of 220A-gDNA with A replaced by C was a missense mutation, which may be the putative male sterility site in 220A. All eight SNPs identified between 6A-gDNA and 6C-gDNA were located in the third intron, so the proteins encoded by them are the same. The one SNP between 6A-/6C-gDNA and 220A-/220B-gDNA at nucleotide 2474 of 220A-/220B-gDNA with C replaced by G was a missense mutation. Mutation site of BNMS2PROT (CAA68190.1) encoded by MS2Bnap in 220A(254) and 6A/6C(584) is different, which indicated dominant digenic male sterile line 220AB and 6CA have some difference in the molecular level. Comparison of structure of MS2Bnap in B. napus with that of MS2 in Arabidopsis thaliana revealed that the similarity of exons between these two genes is higher than that of introns.

Amino Acid Sequence↗
PubMed2006

High-resolution fine mapping of ps-2, a mutated gene conferring functional male sterility in tomato due to non-dehiscent anthers.

Functional male sterility is an important trait for the production of hybrid seeds. Among the genes coding for functional male sterility in tomato is the positional sterility gene ps-2. ps-2 is monogenic recessive, confers non-dehiscent anthers and is the most suitable for practical uses. In order to have tools for molecular-assisted selection (MAS) we fine mapped the ps-2 locus. This was done in an F(2) segregating population derived from the interspecific cross between a functionally male sterile line (ps-2/ps-2; Solanum lycopersicum) and a functionally male fertile line (S. pimpinellifolium). Here we report the procedure that has led to the high-resolution fine mapping of the ps-2 locus in a 1.65 cM interval delimited by markers T0958 and T0635 on the short arm of Chromosome 4. The presence of many COS markers in the local high-resolution map allowed us to study the synteny between tomato and Arabidopsis at the ps-2 locus region. No obvious candidate gene for ps-2 was identified among the known functional male sterility genes in Arabidopsis.

Alleles↗
PubMed2025

Fine mapping of the dominant female sterility gene and novel model of hybrid seed production in cabbage (Brassica oleracea L. var. capitata).

Hybrid breeding based on male sterility requires the removal of male parents, which is time- and labor-intensive; however, the use of female sterile male parent can solve this problem. In the offspring of distant hybridization between Brassica oleracea and Brassica napus, we obtained a mutant, 5GH12-279, which not only fails to generate gynoecium (thereby causing female sterility) but also has serrated leaves that could be used as a phenotypic marker in seedling screening. Genetic analysis revealed that this trait was controlled by a single dominant gene. Further analysis revealed that Bo2g005230, an orthologous gene of LATE MERISTEM IDENTITY1 (LMI1) in Arabidopsis, was predicted as the candidate gene and was renamed BoLMI1c. Sequence analysis revealed that homoeologous exchange (HE) occurred within the BoLMI1c gene body of 5GH12-279, which resulted in the generation of a novel fusion transcript. Two pairs of primers, N5230-1F/1R and N5230-2F/2R, were designed and successfully used for the identification of different genotypes of BoLMI1c. Transcriptome analysis revealed that BoLMI1c orchestrates the expression of several related biological processes and transcription factors. Furthermore, we found that self-pollination with mason bees produced no seeds in 5GH12-279, whereas the near-isogenic line 5GH12-170 produced seeds that were normal. Therefore, a new labor-saving hybrid seed production system with no need to remove the male parents, which is especially important for mechanized harvest in the future, has been proposed. Our study provides a valuable source of dominant female sterility and suggests the potential utilization of the female sterile line in hybrid breeding for mechanized harvest.

Plant Infertility↗
PubMed2005

Incidence and clinical impact of sterilized disease and minimal residual disease after preoperative radiochemotherapy for rectal cancer.

PURPOSE: In advanced rectal cancer, chemoradiation can induce downstaging until complete disappearance of the tumor or its persistence in minimal form. The complete sterilized and the minimal residual disease often are considered similar. We evaluated the specific incidence of these two conditions and analyzed their impact in terms of local recurrence, distant metastasis, and survival. METHODS: We studied 139 uT3/T4 N0/N+ rectal cancers, treated with preoperative chemoradiation and curative surgery after six to eight weeks. We evaluated ypTNM stage and tumoral regression, according to the five degrees proposed by Dworak, with special attention to 4 and 3 (sterilized and minimal residual disease). RESULTS: Tumor downstaging occurred in 65 patients (46.7 percent), including 25 sterilized lesions (17.9 percent) and 24 minimal residual disease (17.2 percent). In median follow-up of 30 months, none of the patients with sterilized disease developed local or distant recurrence. Among patients with minimal residual disease, none developed local recurrence, whereas two (8.3 percent) developed distant metastasis, and one died from disease. In patients with gross residual disease (Grade 2, 1, 0) the percentage of local recurrence was 8.8 percent, distant recurrence 26.6 percent, and 13.3 percent died from disease. The difference between three groups is statistically significant as regards local and distant recurrence. CONCLUSIONS: After preoperative therapy, the sterilized disease shows an excellent prognosis. The minimal residual disease has an important numeric incidence. Its outcome is different, with a not-negligible risk of distant recurrence. The minimal residual disease has a much better prognosis in comparison with the gross residual disease.

Adenocarcinoma↗
PubMed1993

Waves of extinction from sterile insect release.

Employing theoretical models, we show that the sterile insect release method (SIRM) can give rise to traveling waves of fertile insects. The velocity of these waves depends critically upon the density of sterile insects (and thus upon the rate at which sterile individuals are being released into the environment). When the sterile density is sufficiently low, the traveling wave advances, giving rise to an invasion. However, when the sterile density exceeds a critical threshold, the wave reverses direction, thereby retreating and giving rise to local extinction. Both analytical (regular perturbation) methods and numerical methods are used to determine wave velocities and wave profiles. This is the first time traveling wave solutions have been shown for the SIRM.

Animals↗
PubMed1986

Male sterility of the mouse t-complex is due to homozygosity of the distorter genes.

Evidence is presented that the male sterility produced by the mouse t-complex is due to interaction of at least three sterility factors. These factors are carried in the same partial haplotypes as the three distorter genes, Tcd-1, Tcd-2, and Tcd-3 and are suggested to be identical with them. When heterozygous, the distorter/sterility genes act on the wild-type form of the responder gene, rendering sperm carrying it nonfunctional, thus leading to high transmission of the t form of the responder. When homozygous, the harmful effects of the distorter genes are stronger and affect both forms of the responder, leading to sterility. If homozygous sterility is an inescapable part of ratio distortion, then the t-lethals confer a selective advantage in removing sterile males from the population. Thus, the relationship between the various properties of the t-complex can now be understood.

Animals↗
PubMed2006

The molecular biology of cytoplasmically inherited male sterility and prospects for its engineering.

Nucleocytoplasmic male sterilities are binary genetic systems driven by mitochondrial, maternally inherited genes that induce male sterility and a female phenotype and which are overcome by nuclear restorers of fertility. They contribute to the reproductive biology and evolution of natural populations and are valuable tools for the commercial production of hybrid seeds in crops. For species with no natural form of cytoplasmic male sterility, such sterility can in some cases be introduced from different, but related, species through sexual crosses or somatic hybridisation. Somatic hybridisation is the only technique currently available for manipulating plant mitochondrial genomes. Recent successes in plastid transformation have opened up entirely new perspectives for the engineering of cytoplasmic male sterilities in transplastomic plants.

Cell Nucleus↗
PubMed2006

Characterization of methods for determining sterilization efficacy and reuse efficiency of oxygen biosensor multiwell plates.

High-throughput screening (HTS) assays based upon fluorometric detection of oxygen consumption in microtiter plates were primarily developed for applications in drug discovery and ecotoxicology but have recently been adopted for use in microbial community-level physiological profiling assays (CLPP). The widespread use of oxygen biosensor systems for CLPP applications has, however, been hindered by the relatively high cost of oxygen biosensor reagent systems and limited access to microplate fluorometer instrumentation platforms. The ability to recycle and reuse oxygen biosensor system plates would expand their utilization for CLPP assays and other research applications in microbial ecology. Here, the efficacy and cost effectiveness of multiple procedures for sterilization of Oxygen Biosensor System (OBS; BD Biosciences) plates for reuse was evaluated. OBS plates were sterilized using ethylene oxide, ultraviolet radiation, and bleach treatments, then evaluated for biosensor response and plate life-cycle performance. Of the sterilization methods tested, ethylene oxide sterilization was most effective based on its low cost, high sterilization efficacy, and minimal impact upon OBS plate response.

Biosensing Techniques↗
PubMed2002

A mitochondrial dysfunction induces the expression of nuclear-encoded complex I genes in engineered male sterile Arabidopsis thaliana.

To study the effect of a mitochondrial dysfunction induced by the expression of the unedited form of the subunit 9 of ATP synthase gene (u-atp9) in Arabidopsis, we constructed transgenic plants expressing u-atp9 under the control of three different promoters: CaMV 35S, apetala 3 and A9. The size and shape of transgenic plants bearing the apetala3::u-atp9 and A9::u-atp9 genes looked normal while the 35S::u-atp9 transformed plants showed a dwarf morphology. All u-atp9 expressing plants, independent of the promoter used, exhibited a male sterile phenotype. Molecular analysis of male sterile plants revealed the induction of the mitochondrial nuclear complex I (nCI) genes, psst, tyky and nadh binding protein (nadhbp), associated with a mitochondrial dysfunction. These results support the hypothesis that the expression of u-atp9 can induce male sterility and reveal that the apetala3::u-atp9 and A9::u-atp9 plants induced the sterile phenotype without affecting the vegetative development of Arabidopsis plants. Moreover, male sterile plants produced by this procedure are an interesting model to study the global changes generated by an engineered mitochondrial dysfunction at the transcriptome and proteome levels in Arabidopsis plants.

Amino Acid Sequence↗
PubMed2000

Effects of recombinant human FSH (rhFSH), urinary purified FSH (uFSH), and hMG on small preantral follicles and tertiary follicles from normal adult and androgen-sterilized female mice.

OBJECTIVE: To examine the stage-specific follicular response to recombinant human FSH (rhFSH), urinary FSH (uFSH), and hMG preparations. SETTING: In vitro follicle culture. INTERVENTION(S): Small preantral and tertiary follicles isolated from adult normal BDF-1 mice and androgen-sterilized mice were cultured with rhFSH, uFSH, and hMG for 4 days. MAIN OUTCOME MEASURE(S): Follicular diameter. Immunoreactive inhibin, E2, and progesterone concentrations in cultured medium. RESULT(S): The minimal effective dose of rhFSH, uFSH, and hMG for the follicular growth of small preantral follicles from normal mice was 10 mIU/mL, 1 mIU/mL, and 0.1 mIU/mL, respectively. For tertiary follicles from normal mice, the minimal effective dose of rhFSH, uFSH, and hMG was 10 mIU/mL, 10 mIU/mL, and 1 mIU/mL, respectively. The minimal effective dose of hMG for the follicular growth of small preantral follicles from androgen-sterilized mice was 0.01 mIU/mL, and that of rhFSH and uFSH on tertiary follicles from androgen-sterilized mice was 1 mIU/mL and 10 mIU/mL, respectively. No significant increase was found in the follicular diameter of the tertiary follicles from androgen-sterilized mice as a result of stimulation by hMG, but an hMG dose of >10 mIU/mL produced a significant increase in progesterone secretion. CONCLUSION(S): Human menopausal gonadotropin preparation acts detrimentally on follicles from androgen-sterilized mice by increasing the sensitivity of small preantral follicles to FSH and by inducing the luteinization of tertiary follicles.

Age Factors↗
PubMed1998

Preoperative radiotherapy and surgery for endometrial carcinoma: prognostic significance of the sterilization of the specimen.

INTRODUCTION: We report a retrospective study on the analysis of the operative specimen after preoperative radiotherapy for FIGO (1971) stage I or II endometrial carcinoma. METHODS AND MATERIALS: From 1976 to 1996, 221 patients were treated with external radiotherapy (XRT) and/or low-dose-rate brachytherapy (BT) followed by surgery (S). Patients with cervical involvement (89 patients) or with high-grade tumors (49 patients) received XRT and BT. Patients stage FIGO Ia (89 patients) or with low-grade tumors (57 patients) received BT alone. Surgery was performed 5 to 6 weeks after irradiation. RESULTS: The mean follow-up is 78 months (12-216). The 5-year survival was 90% for FIGO Ia, 80% for FIGO Ib, and 84% for FIGO II (p = 0.51). According to the differentiation, 5-year survival was 87% for grade 1, 84% for grade 2, 84% for grade 3 (p = 0.10). Grade 3 complications were registered in 2% (no grade 4). The tumors were sterilized in 37 patients (17%), sterilized but with dystrophic glands in 34 patients (16%), only modified and altered in 21 patients (9.5%), with viable cells in 56 patients (26%). After preoperative radiotherapy, 37/148 specimens were sterilized (25%), 14/74 after brachytherapy and surgery (19%), 23/74 after external radiotherapy-brachytherapy and surgery (31%). According to the response of the specimen, 5-year survival was 87% when the tumor was sterilized, 96% when altered glands were present, 85% when modified, and 76% if residual tumor with viable cells was identified (p = 0.043). CONCLUSION: Preoperative radiotherapy followed by surgery is a safe and effective treatment of FIGO stage I or II endometrial carcinomas. BT with two uterine tubes seems to be of interest in the contribution of the treatment of the uterus to sterilize the specimen. The analysis of this new prognostic factor remains important to select a population with worst prognosis.

Adult↗
PubMed1997

Sterile versus clean technique in postoperative wound care of patients with open surgical wounds: a pilot study.

PURPOSE: This study was completed to determine whether there were differences between sterile versus clean dressing change technique for open surgical wounds in the postoperative period with respect to (1) rate of wound healing and (2) cost of supplies. METHODS: A two-group design was used for this pilot study. Of a sample of 30 patients undergoing elective gastrointestinal operations with wounds healing by secondary intention, 15 were men and 15 were women. Mean age was 40.6 years (SD 13.0 years). Patients were randomly assigned to receive clean or sterile dressings, and the intervention was begun on the first postoperative day and repeated three times a day until discharge from the hospital. Analysis of rate of healing was performed with the Mann-Whitney U test: cost analysis was completed with a t test. FINDINGS: Subjects were studied for 3 to 9 days. Groups were homogeneous of the start of treatment with respect to age, length of operation, wound volume, nutritional status, and perfusion. There was no difference in rate of wound healing between the clean and sterile groups. Mean cost was significantly less for the clean group than for the sterile group. CONCLUSION: These pilot study data show no difference in rate of wound healing with clean versus sterile technique, and clean technique is less expensive. These findings need to be confirmed with a larger sample; type II error cannot be ruled out.

Adult↗
PubMed1994

Improvement of Minilaparotomy Technique to Allow for Reversal of Extensive Sterilization Procedures

In a previous study of outpatient reversal of tubal sterilization by a combined approach of laparoscopy and minilaparotomy, postoperative intrauterine pregnancy rates were 71%, and total costs were 40% lower than for those women undergoing anastomosis by a traditional laparotomy. However, the technique, which involved exteriorization of the uterus and adnexa, could not be easily applied when difficult cases with little remaining oviduct were encountered. With a modification of technique and the addition of a new retractor, it became feasible to consider more difficult cases for minilaparotomy outpatient reversal of sterilization. We prospectively studied 11 such patients with weight < IBW + 30% and < 4 cm of operable oviduct for technical feasibility, cost, complication rates, and reproductive outcome. A vaginal pack was used to elevate the uterus and a Babcock clamp was used to bring the fundus toward the incision by traction on the round ligament. A small self-retaining retractor designed for back surgery (Cloward retractor) was used for the abdominal wall. With the aid of an operating microscope a two-layer anastomosis was performed with 7-0 and 9-0 polydiaxone sutures. In all cases minilaparotomy reversal of tubal sterilization could be performed without prolonged technical difficulty. The mean age of the patients was 34.1 years (range 25-41 years) and operating time 110 minutes (87-158 min). There were no intraoperative or perioperative complications during the same day hospitalization. The mean time of follow-up was 16.7 months. Postoperatively, five women had ongoing or delivered pregnancies (45%) and one woman had two ectopic pregnancies. This study demonstrated a method for outpatient reversal of extensive tubal sterilization which was technically feasible in the 11 attempted patients. Based on the preliminary data from this study we encourage patients who have had extensive tubal sterilization procedures to consider both outpatient, minilaparotomy anastomosis and IVF as reasonable alternatives.

Journal Article↗
PubMed2001

Mass transfer resistance of sterile plugs in shaking bioreactors.

One of the mass transfer resistances for the gas exchange of shaking flasks is the sterile plug. The gas exchange through the sterile plug is described by an extended model of Henzler and Schedel [Bioprocess Eng. 7 (1991) 123]. Based on this model, a new method was developed to obtain the mass transfer resistance of various sterile closures. It consists of measuring the water evaporation rate of the shaking flask and is therefore very easily applied. Sterile plugs made of cotton, wrapped paper, urethane foam and fibreglass and caps made out of aluminium and silicone have been examined. Instead of the oxygen transfer coefficient (k(O(2))), which is commonly found in the literature, the carbon dioxide diffusion coefficient (D(CO(2))) is used to describe the mass transfer resistance of the sterile plug. The investigation revealed that this resistance is mainly dependent on the neck geometry and to a lesser extent on the plug material and density. The gas exchange of aluminium-caps was not reproducible.

Journal Article↗
PubMed2002

Double copulation of a female with sterile diploid and polyploid males recovers fertility in Bombyx mori.

Silkworm males produce dimorphic sperm, nucleate eupyrene sperm and anucleate apyrene sperm. Apyrene sperm have been speculated to have an assisting role in fertilisation. However, the coexistence of eupyrene and apyrene sperm in the testis and female reproductive organs has made it difficult to define the role of apyrene sperm. Polyploid males are highly sterile. Microscopic observation revealed that the elimination of eupyrene nuclei by peristaltic squeezing caused the sterility of polyploids. Heat-shock applied to pupae of Daizo males (DH) also induced high sterility due to the lack of normal apyrene sperm. When eupyrene sperm of sterile DH males and apyrene sperm of sterile polyploid males were mixed by double copulation, a remarkable increase in fertility of the double-mated females was observed. This finding strongly suggests that the apyrene sperm are indispensable in fertilisation of the silkworm and that polyploid apyrene sperm function as a substitute for diploid sperm. We established an experimental system in which we can separate the two types of sperm for further studies on their functions without chemical and/or mechanical treatments.

Animals↗
PubMed2000

Validation of radiation sterilization dose for lyophilized amnion and bone grafts.

A limited number of grafts produced in one batch is the main constrain to validate radiation sterilization dose of amnion and bone grafts according to ISO standard. The validation experiments done were according to ISO 13409 with a slight modification in sampling method. The experiments were carried out three times by using 20 samples each, 10 for bio-burden enumeration and 10 for sterility test at verification dose. The average bio-burden with sample item portion (SIP) = 1 for amnion membranes were 98, 50 and 69 cfu respectively and 0 cfu for bone grafts. Verification dose experiments, were done at doses of 2.90 kGy for bone grafts and 5.13 kGy for amnion grafts and the results of sterility tests showed that amnion grafts got one positive and bone grafts got 0 positive. The results met the requirements of ISO 13409 so that the radiation sterilization dose, at sterility assurance level of 10(-6) was 25 kGy for both amnion and bone grafts. Viral contamination was excluded in this experiment.

Journal Article↗
PubMed2001

Selection and orientation of adjacent genes influences DAM-mediated male sterility in transformed maize.

Anther-targeted expression of E. coli DNA (Adenosine-N6-)-Methyltransferase (DAM) in maize was tested as a means to produce male-sterile plants. A high frequency of male-sterile plants with reduced anther size was observed when DAM was regulated by the maize anther-specific promoter 5126 (5126:DAM) and placed upstream of the herbicide resistance gene, pat, regulated by the cauliflower mosaic virus (CaMV) 35S promoter (35S:PAT). In contrast, placement of 5126:DAM upstream of a pat gene regulated by either the maize ubiquitin (UBI:PAT) or rice actin (rACTIN:PAT) promoters resulted in male-fertile plants. Based on these observed differences, DAM-mediated sterility was used as a phenotypic marker to assess the contribution of factors affecting gene expression such as orientation of the transcription units, choice of regulatory sequences mediating expression of adjacent genes, and effects of varying the anther-specific promoter regulating DAM. Constructs that place a portion of the CaMV 35S promoter, including the native AS-1 sequences, between 5126:DAM and UBI:PAT yielded a high frequency of male-sterile plants with reduced anther size. Significant differences in the frequency of male-sterile events and the associated anther size were also observed when the position of 35S:PAT was changed relative to 5126:DAM. These data provide evidence that gene expression in transformed maize plants can be impacted by simply altering the order, orientation or regulatory sequences of adjacent genes.

Acetyltransferases↗
PubMed2002

A new and distinctive male-sterile, female-fertile desynaptic mutant in soybean (Glycine max).

A spontaneous desynaptic mutation, affecting only microsporogenesis and causing pollen sterility, has been detected in BR97-12986H, a line of the official Brazilian soybean breeding program. In this male-sterile, female-fertile mutant, up to metaphase II, the meiotic behavior was similar to that described for the st series of synaptic mutants previously reported in soybean. Besides many univalents, few or total absence of bivalents were recorded in diakinesis. Bivalents presented one or two terminal chiasmata, while univalents retained the sister chromatid cohesion. Bivalents and most univalents congregated at the equatorial metaphase plate, although univalents frequently migrated to the poles prematurely. Laggards resulting from delay in chiasmata terminalization were also recorded. Distinctly different in their behavior from st series soybean mutants, telophase I-originated micronuclei of different sizes organized their own spindle in the second division. This behavior contributed towards an increase in genome fractionation. Several microspores and microcytes of different sizes were recorded at the end of meiosis. Pollen sterility was estimated at 91.2%. Segregation ratio for sterility in this line and its progenies reached 3:1. Allelism tests with st series of synaptic mutants are in progress. The importance of male-sterile, female-fertile mutations for soybean breeding programs is discussed.

Genes, Plant↗