Genetic control of the nuda character complex in the genus Avena

1976 ◽  
Vol 86 (2) ◽  
pp. 329-334 ◽  
Author(s):  
H. S. Atiyya ◽  
Watkin Williams

SummaryThe inheritance of the units of the character complex which differentiates Avena nuda from Avena sativa was studied in F1 hybrids and in the F2 generation derived from inter-crossing five cultivars of A. saliva with four cultivars of A. nuda. The 14 derived F1 hybrids could be classified into four types depending on the level of dominance of the sativa or nuda character expression. Type-I hybrids involving the cultivar Milford as parent showed a high level of dominance of the sativa-type expression, whereas the F1 hybrid from the cross, Condor × China, type IV, had the character expression typical of the A. nuda parent. Segregation in the F2 generation indicated that the entire character complex was under the control of a major gene, and supported the suggestion from previous work that modifying genes interact with the major gene to alter the expression of the homozygous nuda genotype towards the heterozygous phenotypeHomozygous nuda and heterozygous genotypes were shown to exhibit a gradient in the expression of the nuda character complex from the apex to the base of the panicle, the nuda-type characters being most pronounced in the apical spikelets. It is suggested that the variation of character expression within single panicles of homozygous nuda and heterozygous genotypes indicates the operation of an inhibitor-type gene action rather than a mutation to loss of function.

Development ◽  
1974 ◽  
Vol 32 (3) ◽  
pp. 557-571
Author(s):  
T. Konishi ◽  
I. L. Kosin

Cytological analysis was carried out on the blastodermal cells of White Leghorn eggs ubjected to several pre-incubation treatments. These treatments were storage, ranging from0 days to 4 weeks, together with one or more of the following: (1) variation of ambient temperature (5 °C, 15·5 °C, 24 °C), (2) variation of carbon dioxide level (normal air, 1·5% CO2-enriched air), (3) increased humidity (wrapping in plastic bags). To facilitate analysis, the chromosomal configuration of metaphase cells was classified into four types, I–IV, according to their increasingly ‘abnormal’ appearance, which included condensation, dispersal and/or clumping of chromosomes. In interphase cells, the degree of ‘abnormality’ was rated on the staining capacity and shape of the nuclei. The study yielded the following results. (1) Temperature of storage was the most important single factor determining the state of ‘normality’ of the nuclei. The CO2 level in the storage chamber or the use of plastic bags (toprovide the eggs in storage with a special‘ mini-environment’, believed largely due to increased humidity) had little effect on the cytological picture of the affected blastoderms. (2) As the blastoderms of eggs stored at 15·5 °C aged, the proportion of Type IV chromosomal configurations steadily rose. At 24 °C the aging process frequently followed a different route: both metaphase and post-metaphase chromosomes often simply disintegrated; the progression from Type I to Type IV was not in evidence. Aging at 5 °C resulted in an early appearance of uniformly dark-stained, spherical or oval nuclei. These were similar to those observed in the terminal stages of retrogression seen in the interphase nuclei. (3) During extended storage at 15·5 °C, mitosis was shown to be blocked at metaphase. No active mitoses were observed in the blastoderms of eggs stored at 5 °C. At 24 °C however, limited mitotic activity was present, up to and including anaphase. (4) The presence or absence of a high level of mitotic activity during pre-incubation storage was not crucial to the survival of the blastoderm. However, an environment that permitted limited mitosis was important if the cells were to have the best possible chancefor remaining alive during storage. The CO2 content of the air or the use of plastic bags played no role in this respect. (5) Two explanations, at the nuclear level, are suggested for the observed chain of events in the blastoderm of a stored chicken egg.


2021 ◽  
Author(s):  
Nicolas Gisch ◽  
Katharina Peters ◽  
Simone Thomsen ◽  
Waldemar Vollmer ◽  
Dominik Schwudke ◽  
...  

The opportunistic pathogen Streptococcus mitis possesses, like other members of the Mitis group of viridans streptococci, phosphorylcholine (P-Cho)-containing teichoic acids (TAs) in its cell wall. Bioinformatic analyses predicted the presence of TAs that are almost identical with those identified in the pathogen S. pneumoniae, but a detailed analysis of S. mitis lipoteichoic acid (LTA) was not performed to date. Here we determined the structures of LTA from two S. mitis strains, the high-level beta-lactam and multiple antibiotic resistant strain B6 and the penicillin-sensitive strain NCTC10712. In agreement with bioinformatic predictions we found that the structure of one LTA (type IV) was like pneumococcal LTA, except the exchange of a glucose moiety with a galactose within the repeating units. Further genome comparisons suggested that the majority of S. mitis strains should contain the same type IV LTA as S. pneumoniae, providing a more complete understanding of the biosynthesis of these P-Cho-containing TAs in members of the Mitis group of streptococci. Remarkably, we observed besides type IV LTA an additional polymer belonging to LTA type I in both investigated S. mitis strains. This LTA consists of β-galactofuranosyl-(1,3)-diacylglycerol as glycolipid anchor and a poly-glycerol-phosphate chain at the O-6 position of the furanosidic galactose. Hence, these bacteria are capable of synthesizing two different LTA polymers, most likely produced by distinct biosynthesis pathways. Our bioinformatics analysis revealed the prevalence of the LTA synthase LtaS, most probably responsible for the second LTA version (type I), amongst S. mitis and S. pseudopneumoniae strains.


1991 ◽  
Vol 100 (3) ◽  
pp. 649-655
Author(s):  
A. Colige ◽  
B. Nusgens ◽  
C.M. Lapiere

The Hutchinson-Gilford syndrome (progeria) is a rare disorder in childhood characterized by premature and accelerated aging. This study reports the effect of a potent growth factor, EGF, on the proliferative capacities and extracellular matrix macromolecules and collagenase expression of two strains of progeria skin-derived cells. At low population doubling levels (PDL less than 10), confluent cultures of progeria fibroblasts made quiescent by lowering the concentration of serum in the medium did not respond to EGF while the mitotic activity of normal PDL-matched fibroblasts was almost maximally restored upon addition of EGF. No obvious difference between normal and low PDL progeria fibroblasts was observed in the number and in the affinity of the receptors measured by [125I]EGF binding. The synthesis of collagen and non-collagen proteins was similar in normal and affected cells at low and high serum concentration and both types of cells responded to EGF by a specific inhibition of collagen synthesis. Besides a normal level of mRNA coding for type I and type III collagens, collagenase and laminin, progeria fibroblasts expressed a high level of elastin and type IV collagen mRNA. Like normal fibroblasts, progeria cells responded to EGF by a decrease in the level of mRNA for fibrillar collagens and elastin. In contrast, a complete lack of response to EGF was observed for collagenase mRNA whereas the expression of this enzyme was strikingly induced by EGF in normal PDL-matched cells. The abnormal expression of type IV collagen was not significantly modified by EGF. At PDL greater than 10, progeria cells exhibited features of senescence. A significant reduction of collagen synthesis was observed and no further inhibition by EGF was recorded.


2016 ◽  
Vol 33 (S1) ◽  
pp. s257-s257
Author(s):  
S. Liu ◽  
Z. Li

IntroductionPeople with schizophrenia is a highly heterogeneous group. Identifying subtypes of people with schizophrenia before discharge may help develop targeted discharge plans.ObjectivesTo explore possible subtypes among people with schizophrenia before discharge by their self-management ability, self-efficacy and cognitive function status.AimsTo identify possible subtypes among people with schizophrenia before discharge.MethodsTotally, 150 Chinese people with schizophrenia before discharged from a tertiary psychiatric hospital in Beijing were assessed by Self-management Instrument for People with Schizophrenia and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Cluster analysis using SPSS 20.0 package was performed to categorize subjects based on their scores.ResultsFour different types of subjects were revealed. Type I low cognition with no participation (n = 25), patients’ self-management ability, self-efficacy and cognitive function were very poor; type II medium cognition with blind confidence (n = 42), patients’ self-efficacy was good, while self-management ability was poor and cognitive function is medium; type III high cognition with high level skill (n = 46), patients’ cognitive function, self-management ability and self-efficacy were good; type IV low cognition with medium level skill (n = 37), patients’ cognition was very poor, while self-management ability and self-efficacy were medium. These four types of subjects had significant differences in long-term use of antipsychotics and primary caregivers’ education level (P < 0.05).ConclusionsThe finding of different subtypes of people with schizophrenia presenting in this sample may help health professionals give effective screening and targeted discharge measures which can further promote patients’ recovery and reduce readmission rates.Disclosure of interestThe authors have not supplied their declaration of competing interest.


Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.


2020 ◽  
Vol 65 (1) ◽  
pp. e01948-20
Author(s):  
Dalin Rifat ◽  
Si-Yang Li ◽  
Thomas Ioerger ◽  
Keshav Shah ◽  
Jean-Philippe Lanoix ◽  
...  

ABSTRACTThe nitroimidazole prodrugs delamanid and pretomanid comprise one of only two new antimicrobial classes approved to treat tuberculosis (TB) in 50 years. Prior in vitro studies suggest a relatively low barrier to nitroimidazole resistance in Mycobacterium tuberculosis, but clinical evidence is limited to date. We selected pretomanid-resistant M. tuberculosis mutants in two mouse models of TB using a range of pretomanid doses. The frequency of spontaneous resistance was approximately 10−5 CFU. Whole-genome sequencing of 161 resistant isolates from 47 mice revealed 99 unique mutations, of which 91% occurred in 1 of 5 genes previously associated with nitroimidazole activation and resistance, namely, fbiC (56%), fbiA (15%), ddn (12%), fgd (4%), and fbiB (4%). Nearly all mutations were unique to a single mouse and not previously identified. The remaining 9% of resistant mutants harbored mutations in Rv2983 (fbiD), a gene not previously associated with nitroimidazole resistance but recently shown to be a guanylyltransferase necessary for cofactor F420 synthesis. Most mutants exhibited high-level resistance to pretomanid and delamanid, although Rv2983 and fbiB mutants exhibited high-level pretomanid resistance but relatively small changes in delamanid susceptibility. Complementing an Rv2983 mutant with wild-type Rv2983 restored susceptibility to pretomanid and delamanid. By quantifying intracellular F420 and its precursor Fo in overexpressing and loss-of-function mutants, we provide further evidence that Rv2983 is necessary for F420 biosynthesis. Finally, Rv2983 mutants and other F420H2-deficient mutants displayed hypersusceptibility to some antibiotics and to concentrations of malachite green found in solid media used to isolate and propagate mycobacteria from clinical samples.


Toxins ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 14
Author(s):  
Thamiris Santana Machado ◽  
Felipe Ramos Pinheiro ◽  
Lialyz Soares Pereira Andre ◽  
Renata Freire Alves Pereira ◽  
Reginaldo Fernandes Correa ◽  
...  

Hospitalizations related to Methicillin-resistant Staphylococcus aureus (MRSA) are frequent, increasing mortality and health costs. In this way, this study aimed to compare the genotypic and phenotypic characteristics of MRSA isolates that colonize and infect patients seen at two hospitals in the city of Niterói—Rio de Janeiro, Brazil. A total of 147 samples collected between March 2013 and December 2015 were phenotyped and genotyped to identify the protein A (SPA) gene, the mec staphylococcal chromosomal cassette (SCCmec), mecA, Panton-Valentine Leucocidin (PVL), icaC, icaR, ACME, and hla virulence genes. The strength of biofilm formation has also been exploited. The prevalence of SCCmec type IV (77.1%) was observed in the colonization group; however, in the invasive infection group, SCCmec type II was prevalent (62.9%). The Multilocus Sequence Typing (MLST), ST5/ST30, and ST5/ST239 analyses were the most frequent clones in colonization, and invasive infection isolates, respectively. Among the isolates selected to assess the ability to form a biofilm, 51.06% were classified as strong biofilm builders. Surprisingly, we observed that isolates other than the Brazilian Epidemic Clone (BEC) have appeared in Brazilian hospitals. The virulence profile has changed among these isolates since the ACME type I and II genes were also identified in this collection.


2021 ◽  
pp. 1-12
Author(s):  
Meng Wu ◽  
Ming Li ◽  
Hong-Ju Xie ◽  
Hong-Wei Liu

Silicone implant-based augmentation rhinoplasty or mammoplasty induces capsular contracture, which has been acknowledged as a process that develops an abnormal fibrotic capsule associated with the immune response to allogeneic materials. However, the signaling pathways leading to the nasal fibrosis remain poorly investigated. We aimed to explore the molecular mechanism underlying the pathogenesis of nasal capsular contracture, with a specific research interest in the signaling pathways involved in fibrotic development at the advanced stage of contracture. By examining our recently obtained RNA sequencing data and global gene expression profiling between grade II and grade IV nasal capsular tissues, we found that both the RAP1 and JAK/STAT signaling pathways were hyperactive in the contracted capsules. This was verified on quantitative real-time PCR which demonstrated upregulation of most of the representative component signatures in these pathways. Loss-of-function assays through siRNA-mediated Rap1 silencing and/or small molecule-directed inhibition of JAK/STAT pathway in ex vivo primary nasal fibroblasts caused a series of dramatic behavioral and functional changes, including decreased cell viability, increased apoptosis, reduced secretion of proinflammatory cytokines, and synthesis of type I collagen, compared to control cells, and indicating the essential role of the RAP1 and JAK/STAT signaling pathways in nasal capsular fibrosis. Our results sheds light on targeting downstream signaling pathways for the prevention and therapy of silicone implant-induced nasal capsular contracture.


Author(s):  
Outi Mäkitie ◽  
M. Carola Zillikens

AbstractOsteoporosis is a skeletal disorder with enhanced bone fragility, usually affecting the elderly. It is very rare in children and young adults and the definition is not only based on a low BMD (a Z-score < − 2.0 in growing children and a Z-score ≤ − 2.0 or a T-score ≤ − 2.5 in young adults) but also on the occurrence of fragility fractures and/or the existence of underlying chronic diseases or secondary factors such as use of glucocorticoids. In the absence of a known chronic disease, fragility fractures and low BMD should prompt extensive screening for secondary causes, which can be found in up to 90% of cases. When fragility fractures occur in childhood or young adulthood without an evident secondary cause, investigations should explore the possibility of an underlying monogenetic bone disease, where bone fragility is caused by a single variant in a gene that has a major role in the skeleton. Several monogenic forms relate to type I collagen, but other forms also exist. Loss-of-function variants in LRP5 and WNT1 may lead to early-onset osteoporosis. The X-chromosomal osteoporosis caused by PLS3 gene mutations affects especially males. Another recently discovered form relates to disturbed sphingolipid metabolism due to SGMS2 mutations, underscoring the complexity of molecular pathology in monogenic early-onset osteoporosis. Management of young patients consists of treatment of secondary factors, optimizing lifestyle factors including calcium and vitamin D and physical exercise. Treatment with bone-active medication should be discussed on a personalized basis, considering the severity of osteoporosis and underlying disease versus the absence of evidence on anti-fracture efficacy and potential harmful effects in pregnancy.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Deepshikha Bhowmik ◽  
Shiela Chetri ◽  
Bhaskar Jyoti Das ◽  
Debadatta Dhar Chanda ◽  
Amitabha Bhattacharjee

Abstract Objective This study was designed to discover the dissemination of virulence genes in Methicillin-resistant Staphylococcus aureus from clinical, community and environmental settings. Results This study includes 1165 isolates collected from hospital, community and environmental settings. Among them sixty three were confirmed as MRSA with varied SCCmec types viz; type I, type II, type III, type IV, type V, type VI, type VII, type VIII and type XII. The virulence gene such as sea (n = 54), seb (n = 21), eta (n = 27), etb (n = 2), cna (n = 24), ica (n = 2) and tst (n = 30) was also revealed from this study. The study underscores coexistence of resistance cassette and virulence genes among clinical and environment isolates which is first of its kind from this part of the world.


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