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The male-sterility polymorphism of Silene vulgaris: analysis of genetic dat from two populations and comparison with Thymus vulgaris.

Results are given of genetic studies of male sterility using plants from two natural populations from Sussex, England. Both populations have substantial frequencies of females, approximately 0.25 in population 1 and 0.60 in population 3. As in the few other gynodioecious populations studied in detail, many genetic factors are present. In population 1, there are at least two, and more likely three, different cytoplasmic types, one of which appears to produce male sterility in progeny from any hermaphrodite pollen donor; in other words restorer alleles for this cytoplasm are rare or absent from the population. The other two populations can be carried in hermaphrodites that have the dominant restorers. In population 1, there are also probably three restorer loci with complementary recessive male-sterility alleles, as well as a locus with duplicate action, which cannot produce male sterility unless the plant is also homozygous for the recessive allele at another locus. The results from population 3 are quite similar, though there was no evidence in this population for an unrestored sterility cytoplasm. A similar joint nucleocytoplasmic model with multiple restorers fits data from Thymus vulgaris.

Genes, Plant↗

Depletion of a novel SET-domain protein enhances the sterility of mes-3 and mes-4 mutants of Caenorhabditis elegans.

Four maternal-effect sterile genes, mes-2, mes-3, mes-4, and mes-6, are essential for germline development in Caenorhabditis elegans. Homozygous mes progeny from heterozygous mothers are themselves fertile but produce sterile progeny with underproliferated and degenerated germlines. All four mes genes encode chromatin-associated proteins, two of which resemble known regulators of gene expression. To identify additional components in the MES pathway, we used RNA-mediated interference (RNAi) to test candidate genes for enhancement of the Mes mutant phenotype. Enhancement in this assay was induction of sterility a generation earlier, in the otherwise fertile homozygous progeny of heterozygous mothers, which previous results had suggested represent a sensitized genetic background. We tested seven genes predicted to encode regulators of chromatin organization for RNAi-induced enhancement of mes-3 sterility and identified one enhancer, called set-2 after the SET domain encoded by the gene. Depletion of SET-2 also enhances the sterile phenotype of mes-4 but not of mes-2 or mes-6. set-2 encodes two alternatively spliced transcripts, set-2(l) and set-2(s), both of which are enriched in the germline of adults. In the adult germline, SET-2(L) protein is localized in mitotic and mid-late-stage meiotic nuclei but is undetectable in early pachytene nuclei. SET-2(L) protein is localized in all nuclei of embryos. The localization of SET-2(L) does not depend on any of the four MES proteins, and none of the MES proteins depend on SET-2 for their normal localization. Our results suggest that SET-2 participates along with the MES proteins in promoting normal germline development.

Alleles↗

Genetics of a new male-sterility locus in pigeonpea (Cajanus cajan [L.] Millsp.).

A natural male-sterile mutant was found in the population of a short-duration pigeonpea (Cajanus cajan[L.] Millsp.) cultivar ICPL 85010. This mutant is characterized by light yellow anthers of reduced size that are devoid of pollen grains. This mutant was crossed with two pigeonpea cultivars to study its inheritance. The F1, F2, and test cross data of the two crosses suggested that this male sterility trait is genetic in origin and is controlled by a single recessivegene. The F1 (mutant x ICPL 85010) plants were crossed with translucent (ms1) and arrowhead type (ms2) genetic male steriles reported earlier to study their allelic relationships. Segregation in the three-way cross F1 and F2 populations revealed that the mutant male-sterile gene was nonallelic to ms1 and ms2 loci and it is designated ms3. The new male sterility sources in pigeonpea will help in producing high-yielding hybrids and populations in diverse phenological groups.

Alleles↗

Use of sterile insect releases in an IPM program for control of Hypoderma lineatum and H. bovis (Diptera: Oestridae): a pilot test.

A joint Canadian-U.S. pilot test study was conducted for 4 yr on about 3,800 km2 on the Montana-Alberta border to determine the effect of sterile male releases on Hypoderma lineatum (Villers) and H. bovis (L.) populations remaining after initial chemical treatments. Chemical treatments initially reduced populations, making sterile male releases more efficient. Insect material for release was obtained from yearling animals held in confinement, an expensive, labor-intensive method of production. Sterile males of H. lineatum were released in one-half of the study area and sterile males of H. bovis were released in the other half. The unsterilized species in each half served as a control. Although the number of sterile males released was limited (265-462 yr), each species was eliminated in its respective release area, whereas the control species was not.

Alberta↗

Post-PCR sterilization: development and application to an HIV-1 diagnostic assay.

We have developed an effective post-PCR sterilization process and have applied the procedure to a diagnostic assay for HIV-1. The method, which is based on isopsoralen photochemistry, satisfies both the inactivation and hybridization requirements of a practical sterilization process. The key feature of the technique is the use of isopsoralen compounds which form covalent photochemical adducts with DNA. These covalent adducts prevent subsequent extension of previously amplified sequences (amplicons) by Taq polymerase. Isopsoralens have minimal inhibitory effect on the PCR, are activated by long wavelength ultraviolet light, provide sufficient numbers of covalent adducts to impart effective sterilization, modify the amplified sequence such that it remains single-stranded, and have little effect on subsequent hybridization. The sterilization procedure can be applied to a closed system and is suitable for use with commonly used detection formats. The photochemical sterilization protocol we have devised is an effective and pragmatic method for eliminating the amplicon carryover problem associated with the PCR. While the work described here is limited to HIV-1, proper use of the technique will relieve the concern associated with carryover for a wide variety of amplicons, especially in the clinical setting.

Base Sequence↗

Sterility in honey bees caused by dimethyl sulfoxide.

Honey bee (Apis mellifera) semen was treated as follows: diluted in saline with 10 percent dimethyl sulfoxide (DMSO) and stored at -196 degrees C; same treatment but stored at 12 degrees C; diluted in saline and stored at 12 degrees C; and undiluted, unstored semen. Daughters (queens) produced from the treated spermatozoa were evaluated for total sterility. Only sterile eggs were produced from 3 percent of the queens in both groups that had DMSO (5/166 in group 1, and 6/234 in group 2). They were different (P less than 0.05) from groups 3 and 4 in which no queens were produced that laid only sterile eggs (0/151 and 0/137, respectively). These results demonstrate that, under the conditions used, a low level of sterility is induced by DMSO, and this F1 sterility raises questions about possible genetic damage by DMSO.

Animals↗

Feasibility of one-time use of sterile syringes: a study of active injection drug users in seven United States metropolitan areas.

OBJECTIVES: To assess the feasibility of advice to injection drug users (IDUs) to use a sterile syringe for each injection, we examined sources of syringes, syringe use and reuse, and barriers to and facilitators of compliance with the one-time use of syringes by active IDUs in seven U.S. metropolitan areas. METHODS: Brief, interviewer-administered surveys were completed by 593 active IDUs, defined as injection reported within the past 90 days, in seven U.S. metropolitan areas characterized by various restrictions on syringe acquisition and possession. RESULTS: Most of the IDUs interviewed were male (69%) and African American (74%). Overall, only 23% obtained the most recently used syringe from a reliable source of sterile syringes (i.e., pharmacy or syringe exchange program [SEP]). The median number of injections per most recently used syringe was 3 (mean=5.2); 21% used the syringe only once. IDUs were more likely to have used a reliable source for obtaining their most recent syringe in cities with a SEP (odds ratio [OR]=5.3; 95% confidence interval [CI] 3.3-8.5) or without restrictive paraphernalia laws (OR=0.1; 95% CI 0.1-0.3). To facilitate one-time use of sterile syringes, IDUs recommended the provision of free syringes (50.3%), access to a SEP (38.1%), and access to pharmacy purchase of syringes (24.0%). CONCLUSIONS: Restrictions on syringe availability and the beliefs and practices of IDUs are barriers to the public health recommendation of one-time use of sterile syringes for IDUs who cannot stop injecting. Increased access to legal, inexpensive sterile syringes and education about the merits of one-time use are needed.

Black or African American↗

Effects of male sterility on female remating in the mediterranean fruitfly, Ceratitis capitata.

Mating-induced reductions in female receptivity are common in insects. These responses are of interest because of their utility in insect pest control. In addition, the control of receptivity is likely to be the subject of sexual conflict over remating frequency. We investigated the specific effect of male sterility on female receptivity in an important pest species, the Mediterranean fruitfly (medfly), in which sterile males are often used for population suppression. Sterile males performed less courtship, obtained significantly fewer first and second matings than fertile males, and reduced female receptivity significantly less effectively than did fertile males. We modelled the likelihood of fertile matings and show that the low mating success of sterile males represents a significant problem for medfly sterile insect technique (SIT) programmes.

Animals↗

Is cosmology compatible with sterile neutrinos?

By combining data from cosmic microwave background experiments (including the recent WMAP third year results), large scale structure, and Lyman-alpha forest observations, we constrain the hypothesis of a fourth, sterile, massive neutrino. For the 3 massless+1 massive neutrino case, we bound the mass of the sterile neutrino to ms<0.26 eV (0.44 eV) at 95% (99.9%) C.L., which excludes at high significance the sterile neutrino hypothesis as an explanation of the LSND anomaly. We generalize the analysis to account for active neutrino masses and the possibility that the sterile abundance is not thermal. In the latter case, the contraints in the plane are nontrivial. For a mass of >1 or <0.05 eV, the cosmological energy density in sterile neutrinos is always constrained to be omeganu<0.003 at 95% C.L., but for a mass of approximately 0.25 eV, omeganu can be as large as 0.01.

Journal Article↗

Effectiveness of certain sterilizing agents for seedling incubation in radiothymidine.

Failure of seed sterilization methods and breakdown in sterile technique can result in catabolism of thymidine by microorganisms during seedling incubation in radioisotope. The effectiveness of some sterilizing agents was monitored by microbiological methods and by thin layer chromatography for the presence of thymidine degradation products. Sodium hypochlorite and ethylene oxide each sterilized pea and sunflower seeds. Sodium hypochlorite failed to sterilize onion seeds while ethylene oxide was only occasionally effective and often retarded germination. Captan, commonly used before germination to prevent fungal blight of seedlings, did not reduce the bacterial flora of onion seeds.

Journal Article↗

Maize Mitochondria: Cytochromes of Fertile and Cytoplasmic Male-sterile Lines.

Cytochromes a + a(3), b, and c of mitochondria prepared from fertile and cytoplasmic male-sterile single- and double-cross maize (Zea mays L.) lines were examined by difference spectra at 25 C. The sterile lines contained the full complement of cytochromes, and absorption maxima were identical for each fertile-sterile combination. A small, but significant, increase of b cytochromes was detected in each sterile line, whereas the quantities of cytochromes a + a(3) and c were essentially unchanged. The yield of mitochondrial protein per gram of tissue was higher for the single-than for the double-cross, whereas the sterile cytoplasm did not affect ultimate mitochondrial yield.

Journal Article↗

Identification of a mitochondrial protein associated with cytoplasmic male sterility in petunia.

The petunia fused gene (pcf), which is associated with cytoplasmic male sterility (CMS), is composed of sequences derived from atp9, coxII, and an unidentified reading frame termed urfS. To determine whether the pcf gene is expressed at the protein level, we produced antibodies to synthetic peptides specified by the coxII and urfS portions of the pcf gene. Anti-COXII peptide antibodies recognized petunia COXII but no other mitochondrial proteins. Anti-URF-S peptide antibodies recognized a 20-kilodalton protein present in both cytoplasmic male sterile and fertile lines and a protein with an apparent molecular mass of 25 kilodaltons present only in cytoplasmic male sterile lines. The 25-kilodalton protein was found to be synthesized by isolated mitochondria and to fractionate into both the soluble and membrane portions of disrupted mitochondria, whereas the 20-kilodalton protein was found only in the membrane fraction. The abundance of the 25-kilodalton protein was much lower in fertile plants carrying the cytoplasmic male sterile cytoplasm and a single dominant nuclear fertility restorer gene, Rf. Thus, the pcf gene is correlated with cytoplasmic male sterility not only by its co-segregation with the phenotype in somatic hybrids, but also by the modification of its expression at the protein level through the action of a nuclear gene that confers fertility.

Amino Acid Sequence↗

Mitochondrial modifications associated with the cytoplasmic male sterility in faba beans.

Isolated mitochondria of faba beans carrying two different determinisms of the cytoplasmic male sterility (cytoplasms 447 and 350) have been compared to fertile lines. 1. In addition to the major mitochondrial DNA, five small DNA species (in the range of 1000-2000 base pairs) were detected by agarose gel electrophoresis in the four cytoplasms. An additional small DNA species was found specifically in the cytoplasm 350. After endonuclease restriction of the mitochondrial DNA, the patterns obtained for both male-sterile cytoplasms were identical to each other but distinct by two to four fragments from the patterns obtained for male-fertile cytoplasms. 2. [35S]Methionine labeling in situ of the mitochondrial protein synthesis revealed an additional polypeptide (Mr = 25000) detected only in the two male-sterile cytoplasms. 3. The male-sterile cytoplasm 350 showed a decrease of the respiratory state 3 of oxygen uptake during oxidation of NADH or malate + pyruvate. This decrease is thought to reflect a smaller capacity of the respiratory chain. These specific mitochondrial modifications support the hypothesis of a mitochondrial localization of the cytoplasmic male sterility determinant in faba beans.

Cell Nucleus↗

The use of fibreoptic bronchoscopy with sterile catheter in the diagnosis of pneumonia.

The use of fibreoptic bronchoscopy with sterile catheter sampling of pulmonary secretions was evaluated in 70 patients with a provisional diagnosis of pneumonia. In 37 patients quantitative analysis of the sterile catheter isolates was performed (colony forming units (CFU) per ml). Potential bacterial pathogens were isolated in 37 patients and in the quantitative analysis, 14 of 22 isolates were grown in counts greater than or equal to 10(3) CFU/ml. Sterile catheter increased the bacterial isolation rate as in only 19 patients blood (2) or sputum (18) cultures yielded the same organisms. Sputum cultures showed a 25% false-positive rate in patients with no growth from sterile catheter. Quantitative analysis did not yield any further information in patients receiving antibiotics. Atypical or fungal pneumonia was diagnosed in 22 patients, while ten patients had other pathology simulating pneumonia. Sterile catheter sampling of pulmonary secretions at fibreoptic bronchoscopy proved to be a valuable tool in the diagnosis of bacterial pneumonia.

Adolescent↗

Use of acupuncture and sterile water injection for labor pain: a survey in Sweden.

BACKGROUND: Acupuncture and sterile water injections are nonpharmacological pain relief methods used for labor pain in Swedish delivery wards. Their use has changed over time, the reasons for which are unclear, and acupuncture is currently in more common use than sterile water injections. The aim of this study was to elucidate the clinical use of acupuncture and sterile water injections as pain relief and relaxation during childbirth in Sweden. METHODS: Twelve hundred questionnaires were sent out to all delivery wards in Sweden. Nine hundred sixty midwives fulfilled the inclusion criteria, and the response rate was 565 (59%). RESULTS: Acupuncture was used for both pain relief and relaxation, whereas sterile water injections were used almost exclusively for pain relief. The midwives' own choice of pain relief during childbirth for a possible future delivery was similar to their choice of method in clinical practice. CONCLUSIONS: Our study shows that acupuncture was used for both pain relief and relaxation, whereas sterile water injections were used almost exclusively for pain relief. The results also indicate a weakness in midwives' awareness and use of scientific knowledge and general recommendations about these methods.

Acupuncture Therapy↗

In vitro loss of tensile strength and elasticity of five absorbable suture materials in sterile and infected canine urine.

The loss of breaking strength and elasticity of five absorbable suture materials (polydioxanone [PDS-II], polyglycolic acid [PGA], polyglactin 910 [PG-910], polyglyconate [GTMC], and chromic gut) after in vitro incubation in sterile, Escherichia coli- and Proteus mirabilis-inoculated canine urine was studied. Biomechanical testing, in a controlled environment, was performed during the 28-day study period. Polydioxanone and chromic gut retained greater than 90% of their original strengths after 28 days of incubation in sterile urine and 87% of original strengths in E. coli-inoculated urine. Polyglyconate retained 24% and 18% of original strength, respectively, after incubation in sterile and E. coli-inoculated urine for 28 days. Polyglycolic acid and PG-910 retained less than 30% of original strength in sterile urine and only 7% in E. coli-inoculated urine after 21 days of incubation. In P. mirabilis-inoculated urine, loss of tensile strength and elongation was significant for all suture materials. Polyglycolic acid and PG-910 lost all strength after 24 hours of incubation. Polydioxanone lost all strength after 7 days of incubation, whereas GTMC retained 19% at day 7. Chromic gut retained 78% at day 7 and 16% after 21 days of incubation, however, the absence of normal phagocytic destruction of chromic gut in this in vitro study may have artificially elevated these values. In sterile urine with chemically modified pH, loss of strength and elongation was greater in alkaline urine than in neutral or acidic urine for all types of suture materials.

Animals↗

Pituitary responsiveness to LH-RH in intact and ovariectomized androgen-sterilized rats.

Serum LH changes in response to LH-RH injection were measured in intact and ovariectomized, steroid-treated female rats which were androgenized neonatally with 1,250 microgram testosterone propionate (TP) on day 5. At a dose of 20 ng LH-RH/100 g b.w., serum LH levels in intact rats increased over pre-injection levels, and at a dose of 100 ng LH-RH/100 g b.w., LH concentrations 15 min after injection were higher in nembutal-blocked proestrous rats than in androgen-sterilized rats. However, the ovulation response was not different between the groups. In ovariectomized estradiol benzoate (EB)-treated, androgen-sterilized rats, serum LH concentrations 15 and 60 min after LH-RH injection were lower than in similarly treated control rats. This effect was not secondary to the anovulatory state of the animal, since it also occurred in ovariectomized EB-treated prepuberal rats and in rats ovariectomized prepuberally and treated with EB in adulthood. Also, after treatment with 5alpha-dihydrotestosterone propionate (5alpha-DHTP), pituitary responsiveness to LH-RH in androgen-sterilized rats was lower than in control rats, which suggests that the subnormal response in the estrogen-treated rats was not due to a relative insensitivity to estrogen in the androgen-sterilized rats. The relatively high pituitary responsiveness to LH-RH in intact androgen-sterilized rats is probably due to the high circulating estrogen levels. The subnormal pituitary responsiveness to LH-RH after ovariectomy and estradiol treatment suggests, in addition to an effect on the hypothalamus, also a direct effect of neonatal androgen administration on the pituitary.

Animals↗

Non-inflatable sterile sheath for introduction of the flexible nasopharyngolaryngoscope.

Since the inception of the flexible nasopharyngolaryngoscope, sterility has been a primary concern. The increased incidence of hepatitis, tuberculosis, and acquired immunodeficiency syndrome has raised the fear of cross-contamination. Sterilization requires the use of ethylene oxide, which is economically disadvantageous, forcing most practitioners to disinfect rather than sterilize their nasopharyngolaryngoscopes. A presterilized, disposable sheath was designed in 1993. The system was cumbersome, because it required an air pump. Thus, it was not adopted by the majority of physicians. As a result, the manufacturer developed a new system, which I evaluated. It is cost-effective, smoother-surfaced, 70% thinner-walled, and much simpler to use. The disposable, single-use sheath is sterile, with no need for a pump or any additional device, and can be used anywhere at any time. I believe it will become the standard method for sterile introduction of the nasopharyngolaryngoscope.

Disinfection↗