Type Of Sterility Research Articles

Effects of cold chemical (glutaraldehyde) versus autoclaving sterilization on the rate of coating loss of aesthetic archwires: A double-blind randomized clinical trial

The effect of any sterilization methods (cold chemical, or hot) on film removal from coated archwires has not yet been investigated. Thus, we assessed it. This double-blind randomized clinical trial was performed on 120 observations: 40 macroscopically intact coated archwires from 4 brands were purchased (n=10 archwires/brand). Five wires from each brand underwent cold and 5 underwent hot sterilization. Wires were applied in 40 non-extractions patients at alignment phase of treatment (one month). Afterwards, 3 inter-bracket segments from each wire were examined microscopically, and the percentage of coating loss was recorded for each segment. Coating losses of the 4 brands and 2 sterilization methods were compared using a two-way ANOVA and a Welch t-test (α=0.05). Surfaces were also evaluated using scanning electron microscopy. The mean surface coating loss of hot (autoclave) and cold (glutaraldehyde) sterilization methods was 25.6±28.7 and 28.1±30.8 percent respectively. The mean surface coating removal of the Ortho Organizers, American Orthodontics, SIA, and Gestenco brands were 24.1±28.4, 36.7±36.0, 23.0±24.4, and 23.6±28.0 percent, respectively. The two-way ANOVA indicated a lack of overall significant differences among wire brands (P=0.189) and between sterilization types (P=0.629). However, the interaction of sterilization and brands was significant (P=0.005). Within the limitations of this 1-month clinical trial limited to 4 coated NiTi archwire brands only, the average coating removal of examined brands might not differ much, amounting to about 26% within a month. Glutaraldehyde and autoclave sterilization might not affect the average speed of coating loss in all brands, although each sterilization method might be favourable for certain brands.

Types of sterilization in feed containing different lipidic sources for golden hamster (Mesocricetus auratus)

Abstract The Golden hamster has been gaining significance as a new experimental biomodel, finding use as a reliable diagnostic tool in biomedical research and for zoonosis. Authentic data in terms of digestibility, interactions among raw materials and essential nutrients, besides the influence exerted by various sterilization processes on animal behavior remain unclear. We aimed to assess the influence of sterilization, via autoclaving and irradiation, of pellet feeds prepared using salmon or linseed oil on the digestibility and plasma biochemical parameters in Golden hamsters. Randomized evaluations were conducted on 36 adult male Golden hamsters (Mesocricetus auratus), distributed in six treatments and six replications, namely: common salmon oil; radiated salmon; autoclaved salmon; common linseed oil; radiated linseed and autoclaved linseed. A remarkable effect of the sterilization was evident on the digestibility and protein solubility of the feed, which was lower for autoclaved diets. There was also a significant effect on blood parameters. Animals fed diets containing linseed oil showed lower blood glucose compared to the others. Thus, the inference reached was that while salmon and linseed oil can be used in laboratory hamster feeds, autoclaving disturbs the nutritional quality of the rations.

Exploration of sterilization method and type of media for in vitro propagation of bauhinia scandens

Exploration of sterilization method and type of media for in vitro propagation of bauhinia scandens

1788. The Utility of Next-Generation Sequencing for Detection of Candidate Pathogens in Bronchoalveolar Lavage Fluid from Pediatric Patients with Respiratory Failure

BackgroundIn the field of infectious diseases, identification of etiologic pathogen is essential for definitive diagnosis and decisions regarding appropriate management. Bronchoalveolar lavage fluid (BALF) is considered a sterile type of specimen that is suitable for detecting pathogens of respiratory infections. Recently, next-generation sequencing (NGS) has been applied in the field of infectious diseases and has enabled us to identify pathogenic microorganisms comprehensively. The aim of this study was to comprehensively identify pathogens using NGS in BALF samples from immunocompetent pediatric patients with respiratory failure.MethodsTen patients hospitalized in the pediatric intensive care unit with respiratory failure were included. BALF samples obtained in the acute phase were used to prepare DNA- and RNA-sequencing libraries. The libraries were sequenced on MiSeq, and the sequence data were analyzed using metagenome analysis tools.ResultsA mean of 2,041,216 total reads were sequenced for each library. A significant number of four types of bacterial reads was detected in three BALF samples with DNA-sequencing, whereas pathogenic respiratory viruses were detected in seven of 10 patients with RNA-sequencing.Candidate pathogens were detected in three patients in whom etiologic agents were not identified by conventional methods. A summary of the detected pathogens is listed in Table 1. Sequence coverage and depth of each reference bacterial and viral genome are shown in Figures 1 and 2, respectively. The complete genome of enterovirus D68 was identified in two patients without underlying diseases, and phylogenetic analysis suggested that both strains belong to subclade B3, which is an epidemic strain that has spread worldwide in recent years.ConclusionWe demonstrated the utility of the NGS-based approach for detection of candidate pathogens in BALF from pediatric patients with severe respiratory failure. Our results suggest that NGS can be applied for comprehensive molecular diagnostics as well as surveillance of pathogens in the field of infectious diseases. Disclosures All authors: No reported disclosures.

40 MAPPING THE EFFECT-SIZE OF GENE DOSAGE ON GENERAL INTELLIGENCE ACROSS THE GENOME

Thermosensitive genic male sterility (TGMS) is a most comfortable type of male sterility for the production of two-line hybrids in rice. In TGMS system, genes responsible for male sterility and its reversibility is of great importance to create a new pathway for development of new male sterile lines in rice. In this study, genetic analysis based on F2 population derived from a cross between TNAU 60S and IET 21009 revealed that a single recessive gene controls male sterility in TNAU 60S. Marker analysis combined with bulked segregant analysis (BSA) was used and located the target gene on chromosome 2. Fine mapping with 86 SSR markers on chromosome 2 between 20.0 cM and 27.0 cM revealed that tms gene is located at 24.3 cM between two SSR markers RM12713 and RM12722. Among the six genes, two genes LOC_Os02g12420 and LOC_Os02g12680 which encodes receptor like kinase and cytochrome P450 respectively were considered as candidate genes for thermosensitive gene male sterility in TNAU 60S because of very high differential expression between sterile and fertile samples.

Metagenomic analysis using next-generation sequencing of pathogens in bronchoalveolar lavage fluid from pediatric patients with respiratory failure

Next-generation sequencing (NGS) has been applied in the field of infectious diseases. Bronchoalveolar lavage fluid (BALF) is considered a sterile type of specimen that is suitable for detecting pathogens of respiratory infections. The aim of this study was to comprehensively identify causative pathogens using NGS in BALF samples from immunocompetent pediatric patients with respiratory failure. Ten patients hospitalized with respiratory failure were included. BALF samples obtained in the acute phase were used to prepare DNA- and RNA-sequencing libraries. The libraries were sequenced on MiSeq, and the sequence data were analyzed using metagenome analysis tools. A mean of 2,041,216 total reads were sequenced for each library. Significant bacterial or viral sequencing reads were detected in eight of the 10 patients. Furthermore, candidate pathogens were detected in three patients in whom etiologic agents were not identified by conventional methods. The complete genome of enterovirus D68 was identified in two patients, and phylogenetic analysis suggested that both strains belong to subclade B3, which is an epidemic strain that has spread worldwide in recent years. Our results suggest that NGS can be applied for comprehensive molecular diagnostics as well as surveillance of pathogens in BALF from patients with respiratory infection.

Effect of sterilization methods on electrospun cellulose acetate butyrate nanofibers for SH-SY5Y cultivation

In the biomedical field, the sterilization of nanofibers is of particular importance because it can significantly affect their morphology, physicochemical properties and cytocompatibility. Here, we studied the effect of conventional sterilization with 70% ethanol or ultraviolet (UV) radiation on cellulose acetate butyrate (CAB) nanofibers. Scanning electron microscopy (SEM) revealed that short-term (30 min) UV sterilization had no influence on nanofiber morphology while 70% ethanol led to swelling and, thus, reduced porosity. Water contact angle (WCA) measurements confirmed an increase in wettability after sterilization with ethanol. Fourier transform spectroscopy (FTIR) and electrokinetic analyses indicated only slight changes in the chemical composition of the CAB nanofibers for both sterilization types. However, longer sterilization time (2 h) led to notable changes in the chemical structure of the scaffolds. In turn, X-ray photoelectron spectroscopy (XPS) revealed changes in the chemical composition, even after short-term sterilization. In combination with FTIR and XPS, differential scanning calorimetry (DSC) identified the hydrolysis of the ethanol-sterilized scaffold and degradation of UV-sterilized one. Human neuroblastoma cell (SH-SY5Y) cultivation on the CAB scaffolds demonstrated significant changes in cell morphology and viability depending on sterilization type. Sterilization of CAB with 70% ethanol was preferable for SH-SY5Y attachment, growth and migration.

HYBRID VIGOUR EFFECT IN SORGHUM SELECTION

The authors see application of hybrid vigour in the hybrids obtained on the basis of mother lines with cytoplasmic male sterility as a promising way of sorghum selection. The selection is aimed at increasing sorghum productivity. Hybrid vigour is observed in the first generation of hybrids which was caused by interaction among genes (dominance and epistasis) and additive effect of dominant genes. Its effect is weakened in further generations. The paper explores the effect of heterosis of F1 hybrids obtained on the basis of CMC lines with A1, A2, A3, A4, M-35-1A, 9E types of sterility and productive pollinator varieties which are resistant to biotic and abiotic factors in the region. The experiment was carried out on the pilot plots of Research and Technological Institute of Sorghum and Corn “Rossorgo” in 2015-2016. The area of the plot was7.7 m2; frequency observed was three times; landfill location was random. The density of new hybrids, standards and parental forms was 100 thousand plants pro a hectare. The frequency of pure (superior to the superior parental form), hypothetical (superior to the average value of parental forms) and competitive (excess of the sign of hybrid F1 over the released hybrid) heterosis in terms of: plant height, inflorescence length, grain mass per panicle and 1000 grains, yield. Heterosis was more frequent in terms of plant height, inflorescence length, weight of 1000 grains, and less frequently (mainly in 2016) in terms of yield and weight of grain from a panicle. The authors indicate the prospective combinations of crosses with low effect of competitive heterosis in plant height and the highest yield as: A1 O-Yang 1/Avance, A1 O-Yang 1/Topaz, A3 Feterita 14/Mercury, A4 KP 70/Volzhskoe 4. These hybrids form the grain yield of 4.09-9.15 t/ha (2015-2016) and are characterized by the effect of competitive heterosis in2016 interms of grain yield from 2.1 to 71.4%. Hybrids A1 O-Yang 1/Volzhskoe 4 and A2 KVV 114/Avance differ in competitive heterosis by weight of 1000 grains (51.7-60.0%) and grains from one panicle (5.8-52.9%). The hybrids outlined are expected to be relevant for further tests.

Relation between emm types and virulence gene profiles among Bulgarian Streptococcus pyogenes clinical isolates

Background: The Streptococcus pyogenes emm gene, which encodes M protein, is an important epidemiological marker. The aim of this study is to determine the emm genotypes of Bulgarian clinical streptococccal isolates in 2014–2018 and to evaluate their relationship with virulence genes profiling and disease types.Methods: PCR and sequencing were used for emm genotyping of 182 S. pyogenes clinical isolates according to the protocol of the Centre for Disease Control and Prevention. PCR was used to investigate the virulence factors.Results: We identified 15 emm types and eight clusters. Five main clusters with eight emm types were predominant: cluster A-C3 (emm1) – 24.7%, A-C5 (emm3) – 19.2%, E1 (emm4) – 11.0%, A-C4 (emm12) – 11.0% and E4 (emm2,28,77,89) – 20.9%. There were two novel subtypes: emm3.132 and emm3.133. The investigated strains with emm3 genotypes were common in sterile site infections (invasive ones) and types emm4 and emm12, in skin and mucosal infections. More than 60% of the major cluster A-C3 (emm1; emm1.33; emm1.6) members possessed many genes for streptococcal pyrogenic exotoxins that act as super-antigens and bring about potentially higher virulence.Conclusion: The present study described two novel emm3 subtypes. To the best of our knowledge, this study is the first that describe the emm type spectrum of Bulgarian S. pyogenes clinical isolates and associated virulence factors. Monitoring of the S. pyogenes pathogenic potential and epidemiology can lead to better knowledge and higher possibility for prevention and eradication of complications of streptococcal infections.

First Report of Leaf Curl on Celery (Apium graveolens var. dulce) Caused by Colletotrichum fioriniae in New York

An outbreak of foliar disease on celery cultivar Tango was reported in Erie County, New York, in September 2018. Disease incidence was approximately 85%. Diseased plants were stunted and twisted, and older leaves were downward curling. Brown to orange-colored lesions were observed on the margins of leaves and stalks, and chlorotic spots were present on the upper surface of leaves. Microscopic observation of the lesions on the leaves and stems identified acervuli typical of Colletotrichum spp. Conidia from acervuli were spread on 2% water agar (plus 0.02% w/v ampicillin) and incubated at 20°C. Cultures were transferred onto potato dextrose agar (PDA; Difco Laboratories, Detroit, MI). After 7 to 10 days, gray-colored colonies with pink conidiomata typical of Colletotrichum spp. were observed (Damm et al. 2012). Twenty isolations were conducted from diseased celery leaves and stalks, resulting in the same fungus. Conidia (n = 50) of an isolate Cl18-03 were cylindrical, 8.84 μm (6.66 to 10.77 μm) long and 3.63 μm (2.86 to 4.22 μm) wide, and slightly tapered on one end. To confirm the identity of the isolate, polymerase chain reaction was performed to amplify the internal transcribed spacer (ITS) region, actin (ACT), and portions of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes using primer pairs ITS1/ITS4 (White et al. 1990), Act512F/Act738R (Carbone and Kohn 1999), and GDF1/GDR1 (Templeton et al. 1992), respectively. Pairwise alignment of the sequences showed 99.8% similarity within the ITS and 100% similarity to the GAPDH and ACT sequences of C. fioriniae ex holotype CBS128517. Sequences of the isolate Cl18-03 were deposited in GenBank with accession numbers MK558808 (ITS), MK558809 (ACT), and MK558810 (GAPDH). For pathogenicity testing, Cl18-03 was grown on 0.2× PDA at room temperature and a 16-h photoperiod. Conidia were harvested after 7 days by flooding the plate with sterile type I water (ultrapure). The conidial suspension was passed through double-layered cheese cloth. Spores were counted, and the suspension was diluted to 1 × 10⁶ (plus 0.01% polysorbate-20) spores/ml. Five celery plants of cultivar Tango were sprayed with the inoculum until run-off. After inoculation, the plants were covered with a plastic bag for 96 h. Similarly, noninoculated control plants were sprayed with 0.01% polysorbate-20 and bagged. Plants were placed in a misting chamber and exposed to alternating 25°C light/18°C dark temperatures with a 16-h photoperiod. Mist was applied for an hour every day to maintain at least 85% relative humidity. After 8 days, symptoms of leaf curl including marginal and necrotic spots on the petiole were observed on all inoculated plants with complete collapse in two of the five inoculated plants. No symptoms were observed in the control plants. Symptomatic leaves were detached and placed in a moist chamber for 2 days, and brown acervuli without setae were observed in 75% of the lesions. Spores isolated from the lesions showed similar morphology and dimensions to the original isolate. To our knowledge this is the first report of C. fioriniae on celery associated with leaf curl in New York. The pathogen appears to be emerging in importance and previously reported on garlic in New York (Hay et al. 2018). Leaf curl is also an emerging, serious disease of celery reported in surrounding states including Ontario (Canada; Reynolds et al. 2019), Pennsylvania (Pollok et al. 2012), and Michigan (Rodriguez-Salamanca et al. 2015) and in Australia (Heaton and Dullahide 1993; Wright and Heaton 1991), and considering the low tolerance of disease, it may represent a significant threat to celery production in New York.

Curing cytoplasmic male sterility via TALEN-mediated mitochondrial genome editing.

Sequence-specific nucleases are commonly used to modify the nuclear genome of plants. However, targeted modification of the mitochondrial genome of land plants has not yet been achieved. In plants, a type of male sterility called cytoplasmic male sterility (CMS) has been attributed to certain mitochondrial genes, but none of these genes has been validated by direct mitochondrial gene-targeted modification. Here, we knocked out CMS-associated genes (orf79 and orf125) of CMS varieties of rice and rapeseed, respectively, using transcription activator-like effector nucleases (TALENs) with mitochondria localization signals (mitoTALENs). We demonstrate that knocking out these genes cures male sterility, strongly suggesting that these genes are causes of CMS. Sequencing revealed that double-strand breaks induced by mitoTALENs were repaired by homologous recombination, and that during this process, the target genes and surrounding sequences were deleted. Our results show that mitoTALENs can be used to stably and heritably modify the mitochondrial genome in plants.

Fine mapping and expression analysis of thermosensitive genic male sterility gene (tms) in rice (Oryza sativa L.)

Thermosensitive genic male sterility (TGMS) is a most comfortable type of male sterility for the production of two-line hybrids in rice. In TGMS system, genes responsible for male sterility and its reversibility is of great importance to create a new pathway for development of new male sterile lines in rice. In this study, genetic analysis based on F2 population derived from a cross between TNAU 60S and IET 21009 revealed that a single recessive gene controls male sterility in TNAU 60S. Marker analysis combined with bulked segregant analysis (BSA) was used and located the target gene on chromosome 2. Fine mapping with 86 SSR markers on chromosome 2 between 20.0 cM and 27.0 cM revealed that tms gene is located at 24.3 cM between two SSR markers RM12713 and RM12722. Among the six genes, two genes LOC_Os02g12420 and LOC_Os02g12680 which encodes receptor like kinase and cytochrome P450 respectively were considered as candidate genes for thermosensitive gene male sterility in TNAU 60S because of very high differential expression between sterile and fertile samples.

Identification of Owen-Type Male Sterility Maintainers Carrying Resistance Against Rhizoctonia Crown and Root Rot (Rcrr) Disease in Sugar Beet Germplasm

Propagation and maintaining cytoplasmic male-sterile (CMS) lines are prerequisite of hybrid production programs in sugar beet. The identification of Owen-type (O-type) source materials is important to maintain CMS plants that accelerate crosses between single plants. The objectives of the present study were to assess a base beet germplasm (SB19) to identify O-type plants for use in hybrid production programs and test for resistance against rhizoctonia crown and root rot (Rcrr) disease. A family was developed from each two identified candidate monogerm O-types. A number of 100 plants of each family were crossed with FC708 (male sterile) in insulated cages, and the progenies of hybrids were tested for the frequency of male sterility. Progenies of candidate O-types crossed with FC708 revealed various levels of male sterility. Type I and Type II male sterility had lowest frequency, while completely sterile type was the most frequent. The results demonstrated that 6 plants in each family were fully male sterile and their parallels S1 were selected as O-type and male sterility maintainer. The mean for male sterility frequency was 10.5%. The mean disease index (DI) in the selected O-types was 2.22 that was lower than DI in SB19 as a resistant check. Mean comparison for Rcrr demonstrated that all O-types and SB19 plants were discriminated form Jolgeh as Rcrr-susceptible check. In conclusion, the identified O-types can be tested for combining ability for the development of Rcrr-resistant sugar beet hybrids with respect to root and sugar yield traits.

Hot Air Oven for Sterilization: Definition & Working Principle

A hot air oven is a type of dry heat sterilization. Dry heat sterilization is used on equipment that cannot be wet and on material that will not melt, catch fire, or change form when exposed to high temperatures. Moist heat sterilization uses water to boil items or steam them to sterilize and doesn't take as long as dry heat sterilization. Examples of items that aren't sterilized in a hot air oven are surgical dressings, rubber items, or plastic material. Items that are sterilized in a hot air oven include:  Glassware (like petri dishes, flasks, pipettes, and test tubes)  Powders (like starch, zinc oxide, and sulfadiazine)  Materials that contain oils  Metal equipment (like scalpels, scissors, and blades) Hot air ovens use extremely high temperatures over several hours to destroy microorganisms and bacterial spores. The ovens use conduction to sterilize items by heating the outside surfaces of the item, which then absorbs the heat and moves it towards the center of the item. The commonly-used temperatures and time that hot air ovens need to sterilize materials is 170 degrees Celsius for 30 minutes, 160 degrees Celsius for 60 minutes, and 150 degrees Celsius for 150 minutes. Hot air ovens sterilize equipment over long periods of time, so she has to be organized in determining what items will be sterilized at what time. This depends on when the equipment needs to be available again. Gina's manager now explains the different types of hot air ovens.

Induction of sterile type 2 inflammation.

Microparticle debris from prosthetic implants has been shown to induce a type 2 inflammatory response through a Bruton’s tyrosine kinase-dependent signalling pathway.

Characterization of the mitochondrial genome of the MAX1 type of cytoplasmic male-sterile sunflower

BackgroundMore than 70 cytoplasmic male sterility (CMS) types have been identified in Helianthus, but only for less than half of them, research of mitochondrial organization has been conducted. Moreover, complete mitochondrion sequences have only been published for two CMS sources – PET1 and PET2. It has been demonstrated that other sunflower CMS sources like MAX1, significantly differ from the PET1 and PET2 types. However, possible molecular causes for the CMS induction by MAX1 have not yet been proposed. In the present study, we have investigated structural changes in the mitochondrial genome of HA89 (MAX1) CMS sunflower line in comparison to the fertile mitochondrial genome.ResultsEight significant major reorganization events have been determined in HA89 (MAX1) mtDNA: one 110 kb inverted region, four deletions of 439 bp, 978 bp, 3183 bp and 14,296 bp, respectively, and three insertions of 1999 bp, 5272 bp and 6583 bp. The rearrangements have led to functional changes in the mitochondrial genome of HA89 (MAX1) resulting in the complete elimination of orf777 and the appearance of new ORFs - orf306, orf480, orf645 and orf1287. Aligning the mtDNA of the CMS sources PET1 and PET2 with MAX1 we found some common reorganization features in their mitochondrial genome sequences.ConclusionThe new open reading frame orf1287, representing a chimeric atp6 gene, may play a key role in MAX1 CMS phenotype formation in sunflower, while the contribution of other mitochondrial reorganizations seems to appear negligible for the CMS development.

Comparative transcriptome analysis reveals that tricarboxylic acid cycle-related genes are associated with maize CMS-C fertility restoration

BackgroundC-type cytoplasmic male sterility (CMS-C) is one of the three major types of cytoplasmic male sterility (CMS) in maize. Rf4 is a dominant restorer gene for CMS-C and has great value in hybrid maize breeding, but little information concerning its functional mechanism is known.ResultsTo reveal the functional mechanism of Rf4, we developed a pair of maize near-isogenic lines (NILs) for the Rf4 locus, which included a NIL_rf4 male-sterile line and a NIL_Rf4 male fertility-restored line. Genetic analysis and molecular marker detection indicated that the male fertility of NIL_Rf4 was controlled by Rf4. Whole-genome sequencing demonstrated genomic differences between the two NILs was clustered in the Rf4 mapping region. Unmapped reads of NILs were further assembled to uncover Rf4 candidates. RNA-Seq was then performed for the developing anthers of the NILs to identify critical genes and pathways associated with fertility restoration. A total of 7125 differentially expressed genes (DEGs) were identified. These DEGs were significantly enriched in 242 Gene Ontology (GO) categories, wherein 100 DEGs were involved in pollen tube development, pollen tube growth, pollen development, and gametophyte development. Homology analysis revealed 198 male fertility-related DEGs, and pathway enrichment analysis revealed that 58 DEGs were enriched in cell energy metabolism processes involved in glycolysis, the pentose phosphate pathway, and pyruvate metabolism. By querying the Plant Reactome Pathway database, we found that 14 of the DEGs were involved in the mitochondrial tricarboxylic acid (TCA) cycle and that most of them belonged to the isocitrate dehydrogenase (IDH) and oxoglutarate dehydrogenase (OGDH) enzyme complexes. Transcriptome sequencing and real-time quantitative PCR (qPCR) showed that all the above TCA cycle-related genes were up-regulated in NIL_Rf4. The results of our subsequent enzyme-linked immunosorbent assay (ELISA) experiments pointed out that the contents of both the IDH and OGDH enzymes accumulated more in the spikelets of NIL_Rf4 than in those of NIL_rf4.ConclusionThe present research provides valuable genomic resources for deep insight into the molecular mechanism underlying CMS-C male fertility restoration. Importantly, our results indicated that genes involved in energy metabolism, especially some mitochondrial TCA cycle-related genes, were associated with maize CMS-C male fertility restoration.

DNA MARKERS IN ONION (Allium cepa L.) CYTOPLASMIC MALE STERILITY STUDY

The work is carried out in the framework of the onion F1 breeding program. The practical purpose of the work is to carry out genetic selection of onion forms using molecular genetic markers of male sterility in the course of obtaining the maternal line for heterotic selection of F1 hybrids. The scientific component of these studies was the study of the population-genetic basis of various types of male sterility in onions of the Belarusian genmplasma. We used belarusian varieties Vetraz and Skarb litvinov and a collection of other varieties and hybrids. Markers of the mitochondrial genes orfA501, cob and the nuclear alleles Ms/ms, cosegregating with genes of fertility restorer/S-sterility maintainer genes, were studied. It has been shown that in the Vetraz variety are observed plants with the N- or T-cytotype in N-cytoplasm (TN-). The belarusian variety Scarb litvinov contains plants with the cytotypes N-, S, TN-, SN-, STN-. As a result, it was concluded that the male sterility of the Vetraz variety is T-type, and in the Scarp litvinov variety is complex, and is caused by the cytoplasmic alleles S- and T-. In both varieties: Vetraz and Scarb litvinov the sources of the ms locus causing the S-type of male sterility have been identified. Less than one-fifth of the number of world collection of varieties and hybrids was detected as Scytotype. This value is smaller than the value given in the scientific literature. However it may reflect the significant spread of the original S-cytoplasm of a single plant of the shortday Italian Red variety in the world onion germplasm.

Mitochondrial genomes organization in alloplasmic lines of sunflower (Helianthus annuus L.) with various types of cytoplasmic male sterility.

BackgroundCytoplasmic male sterility (CMS) is a common phenotype in higher plants, that is often associated with rearrangements in mitochondrial DNA (mtDNA), and is widely used to produce hybrid seeds in a variety of valuable crop species. Investigation of the CMS phenomenon promotes understanding of fundamental issues of nuclear-cytoplasmic interactions in the ontogeny of higher plants. In the present study, we analyzed the structural changes in mitochondrial genomes of three alloplasmic lines of sunflower (Helianthus annuus L.). The investigation was focused on CMS line PET2, as there are very few reports about its mtDNA organization.MethodsThe NGS sequencing, de novo assembly, and annotation of sunflower mitochondrial genomes were performed. The comparative analysis of mtDNA of HA89 fertile line and two HA89 CMS lines (PET1, PET2) occurred.ResultsThe mtDNA of the HA89 fertile line was almost identical to the HA412 line (NC_023337). The comparative analysis of HA89 fertile and CMS (PET1) analog mitochondrial genomes revealed 11,852 bp inversion, 4,732 bp insertion, 451 bp deletion and 18 variant sites. In the mtDNA of HA89 (PET2) CMS line we determined 27.5 kb and 106.5 kb translocations, 711 bp and 3,780 bp deletions, as well as, 5,050 bp and 15,885 bp insertions. There are also 83 polymorphic sites in the PET2 mitochondrial genome, as compared with the fertile line.DiscussionThe observed mitochondrial reorganizations in PET1 resulted in only one new open reading frame formation (orfH522), and PET2 mtDNA rearrangements led to the elimination of orf777, duplication of atp6 gene and appearance of four new ORFs with transcription activity specific for the HA89 (PET2) CMS line—orf645, orf2565, orf228 and orf285. Orf228 and orf285 are the atp9 chimeric ORFs, containing transmembrane domains and possibly may impact on mitochondrial membrane potential. So orf228 and orf285 may be the cause for the appearance of the PET2 CMS phenotype, while the contribution of other mtDNA reorganizations in CMS formation is negligible.

The chimeric mitochondrial gene orf182 causes non-pollen-type abortion in Dongxiang cytoplasmic male-sterile rice.

D1-cytoplasmic male sterility (CMS) rice is a sporophytic cytoplasmic male-sterile rice developed from Dongxiang wild rice that exhibits a no-pollen-grain phenotype. A mitochondrial chimeric gene (orf182) was detected by mitochondrial genome sequencing and a comparative analysis. Orf182 is composed of three recombinant fragments, the largest of which is homologous to Sorghum bicolor mitochondrial sequences. In addition, orf182 was found only in wild rice species collected from China. Northern blot analysis showed that orf182 transcripts were affected by Rf genes in the isocytoplasmic restorer line DR7. Western blot analysis showed that the ORF182 product was localized in the mitochondria of the CMS line. An expression cassette containing orf182 fused to a mitochondrial transit peptide induced the maintainer line of male sterility, which lacked pollen grains in the anthers. Furthermore, the invivo expression of orf182 also inhibited the growth of Escherichia coli, with lower respiration rate, excess accumulation of reactive oxygen species and decreased ATP levels. We conclude that the mitochondrial chimeric gene orf182 possesses a unique structure and origin differing from other identified mitochondrial CMS genes, and this gene is connected to non-pollen type of sporophytic male sterility in D1-CMS rice.