196 research outputs found
Duplication, divergence and persistence in the Phytochrome photoreceptor gene family of cottons (Gossypium spp.)
<p>Abstract</p> <p>Background</p> <p>Phytochromes are a family of red/far-red photoreceptors that regulate a number of important developmental traits in cotton (<it>Gossypium </it>spp.), including plant architecture, fiber development, and photoperiodic flowering. Little is known about the composition and evolution of the phytochrome gene family in diploid (<it>G. herbaceum</it>, <it>G. raimondii</it>) or allotetraploid (<it>G. hirsutum</it>, <it>G. barbadense</it>) cotton species. The objective of this study was to obtain a preliminary inventory and molecular-evolutionary characterization of the phytochrome gene family in cotton.</p> <p>Results</p> <p>We used comparative sequence resources to design low-degeneracy PCR primers that amplify genomic sequence tags (GSTs) for members of the <it>PHYA</it>, <it>PHYB/D</it>, <it>PHYC </it>and <it>PHYE </it>gene sub-families from A- and D-genome diploid and AD-genome allotetraploid <it>Gossypium </it>species. We identified two paralogous <it>PHYA </it>genes (designated <it>PHYA1 </it>and <it>PHYA2</it>) in diploid cottons, the result of a Malvaceae-specific <it>PHYA </it>gene duplication that occurred approximately 14 million years ago (MYA), before the divergence of the A- and D-genome ancestors. We identified a single gene copy of <it>PHYB</it>, <it>PHYC</it>, and <it>PHYE </it>in diploid cottons. The allotetraploid genomes have largely retained the complete gene complements inherited from both of the diploid genome ancestors, with at least four <it>PHYA </it>genes and two genes encoding <it>PHYB</it>, <it>PHYC </it>and <it>PHYE </it>in the AD-genomes. We did not identify a <it>PHYD </it>gene in any cotton genomes examined.</p> <p>Conclusions</p> <p>Detailed sequence analysis suggests that phytochrome genes retained after duplication by segmental duplication and allopolyploidy appear to be evolving independently under a birth-and-death-process with strong purifying selection. Our study provides a preliminary phytochrome gene inventory that is necessary and sufficient for further characterization of the biological functions of each of the cotton phytochrome genes, and for the development of 'candidate gene' markers that are potentially useful for cotton improvement via modern marker-assisted selection strategies.</p
De novo assembly and characterization of the transcriptome of the toxic dinoflagellate Karenia brevis
BACKGROUND: Karenia brevis is a harmful algal species that blooms in the Gulf of Mexico and produces brevetoxins that cause neurotoxic shellfish poisoning. Elevated brevetoxin levels in K. brevis cells have been measured during laboratory hypo-osmotic stress treatments. To investigate mechanisms underlying K. brevis osmoacclimation and osmoregulation and establish a valuable resource for gene discovery, we assembled reference transcriptomes for three clones: Wilson-CCFWC268, SP3, and SP1 (a low-toxin producing variant). K. brevis transcriptomes were annotated with gene ontology terms and searched for putative transmembrane proteins that may elucidate cellular responses to hypo-osmotic stress. An analysis of single nucleotide polymorphisms among clones was used to characterize genetic divergence. RESULTS: K. brevis reference transcriptomes were assembled with 58.5 (Wilson), 78.0 (SP1), and 51.4 million (SP3) paired reads. Transcriptomes contained 86,580 (Wilson), 93,668 (SP1), and 84,309 (SP3) predicted transcripts. Approximately 40% of the transcripts were homologous to proteins in the BLAST nr database with an E value ≤ 1.00E-6. Greater than 80% of the highly conserved CEGMA core eukaryotic genes were identified in each transcriptome, which supports assembly completeness. Seven putative voltage-gated Na(+) or Ca(2+) channels, two aquaporin-like proteins, and twelve putative VATPase subunits were discovered in all clones using multiple bioinformatics approaches. Furthermore, 45% (Wilson) and 43% (SP1 and SP3) of the K. brevis putative peptides > 100 amino acids long produced significant hits to a sequence in the NCBI nr protein database. Of these, 77% (Wilson and SP1) and 73% (SP3) were successfully assigned gene ontology functional terms. The predicted single nucleotide polymorphism (SNP) frequencies between clones were 0.0028 (Wilson to SP1), 0.0030 (Wilson to SP3), and 0.0028 (SP1 to SP3). CONCLUSIONS: The K. brevis transcriptomes assembled here provide a foundational resource for gene discovery and future RNA-seq experiments. The identification of ion channels, VATPases, and aquaporins in all three transcriptomes indicates that K. brevis regulates cellular ion and water concentrations via transmembrane proteins. Additionally, > 40,000 unannotated loci may include potentially novel K. brevis genes. Ultimately, the SNPs identified among the three ecologically diverse clones with different toxin profiles may help to elucidate variations in K. brevis brevetoxin production. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-888) contains supplementary material, which is available to authorized users
Development, genetic mapping and QTL association of cotton PHYA, PHYB, and HY5-specific CAPS and dCAPS markers
BACKGROUND: Among SNP markers that become increasingly valuable in molecular breeding of crop plants are the CAPS and dCAPS markers derived from the genes of interest. To date, the number of such gene-based markers is small in polyploid crop plants such as allotetraploid cotton that has A- and D-sub-genomes. The objective of this study was to develop and map new CAPS and dCAPS markers for cotton developmental-regulatory genes that are important in plant breeding programs. RESULTS: Gossypium hirsutum and G. barbadense, are the two cultivated allotetraploid cotton species. These have distinct fiber quality and other agronomic traits. Using comparative sequence analysis of characterized GSTs of the PHYA1, PHYB, and HY5 genes of G. hirsutum and G. barbadense one PHYA1-specific Mbo I/Dpn II CAPS, one PHYB-specific Alu I dCAPS, and one HY5-specific Hinf I dCAPS cotton markers were developed. These markers have successfully differentiated the two allotetraploid genomes (AD(1) and AD(2)) when tested in parental genotypes of ‘Texas Marker-1’ (‘TM-1’), ‘Pima 3–79’ and their F(1) hybrids. The genetic mapping and chromosome substitution line-based deletion analyses revealed that PHYA1 gene is located in A-sub-genome chromosome 11, PHYB gene is in A-sub-genome chromosome 10, and HY5 gene is in D-sub-genome chromosome 24, on the reference ‘TM-1’ x ‘Pima 3–79’ RIL genetic map. Further, it was found that genetic linkage map regions containing phytochrome and HY5-specific markers were associated with major fiber quality and flowering time traits in previously published QTL mapping studies. CONCLUSION: This study detailed the genome mapping of three cotton phytochrome genes with newly developed CAPS and dCAPS markers. The proximity of these loci to fiber quality and other cotton QTL was demonstrated in two A-subgenome and one D-subgenome chromosomes. These candidate gene markers will be valuable for marker-assisted selection (MAS) programs to rapidly introgress G. barbadense phytochromes and/or HY5 gene (s) into G. hirsutum cotton genotypes or vice versa. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12863-016-0448-4) contains supplementary material, which is available to authorized users
Questions about the HELIX trial
In the HELIX study, Sudhin Thayyil and colleagues suggested that all low-income and middle-income countries (LMICs) should immediately suspend use of cooling in neonates. The reported absence of benefit and increased mortality in neonates who were cooled are in contrast to our experience and the findings in meta-analyses in LMICs.http://www.thelancet.com/lancetgham2022Immunolog
Human Leukocyte Antigen-A, B, C, DRB1, and DQB1 Allele and Haplotype Frequencies in a subset of 237 donors in the South African Bone Marrow Registry
Human leukocyte antigen- (HLA-) A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 allele and haplotype frequencies were studied in a subset of 237 volunteer bone marrow donors registered at the South African Bone Marrow Registry (SABMR). Hapl-o-Mat software was used to compute allele and haplotype frequencies from individuals typed at various resolutions, with some alleles in multiple allele code (MAC) format. Four hundred and thirty-eight HLA-A, 235 HLA-B, 234 HLA-DRB1, 41 HLA-DQB1, and 29 HLA-C alleles are reported. The most frequent alleles were A02:02g (0.096), B07:02g (0.082), C07:02g (0.180), DQB106:02 (0.157), and DRB115:01 (0.072). The most common haplotype was A03:01g~B07:02g~C07:02g~DQB106:02~DRB115:01 (0.067), which has also been reported in other populations. Deviations from Hardy-Weinberg equilibrium were observed in A, B, and DRB1 loci, with C~DQB1 being the only locus pair in linkage disequilibrium. This study describes allele and haplotype frequencies from a subset of donors registered at SABMR, the only active bone marrow donor registry in Africa. Although the sample size was small, our results form a key resource for future population studies, disease association studies, and donor recruitment strategies
Cocaine-induced granulomatosis with polyangiitis—an under-recognized condition
Objectives:
Cocaine and cocaine mixed with levamisole are increasingly used in the UK and result in significant direct nasal damage in addition to promoting vasculitis. Our aims were as follows: (1) to identify the main symptoms and presentation of cocaine-induced vasculitis; (2) to provide evidence regarding the best practice for the investigation and diagnosis of cocaine-induced vasculitis; and (3) to analyse the clinical outcomes of patients in order to understand the optimal management for the condition./
Methods:
We performed a retrospective case series analysis of patients presenting with cocaine-induced midline destructive lesions or vasculitis compatible with granulomatosis with polyangiitis (GPA) from two large tertiary vasculitis clinics between 2016 and 2021./
Results:
Forty-two patients (29 Birmingham, 13 London) with cocaine-induced midline lesions or systemic disease were identified. The median age was 41 years (range 23–66 years). Current cocaine use was common, and 20 of 23 samples provided were positive when routine urine toxicology was performed; 9 patients who denied ever using cocaine were identified as using cocaine based on urine toxicology analysis, and 11 who stated they were ex-users still tested positive. There was a high incidence of septal perforation (75%) and oronasal fistula (15%). Systemic manifestations were less common (27%), and only one patient had acute kidney injury. Fifty-six per cent of our patients were PR3-ANCA positive, with none testing positive for MPO-ANCA. Symptom remission required cocaine discontinuation even when immunosuppression was administered./
Conclusion:
Patients with destructive nasal lesions, especially young patients, should have urine toxicology performed for cocaine before diagnosing GPA and considering immunosuppressive therapy. The ANCA pattern is not specific for cocaine-induced midline destructive lesions. Treatment should be focused on cocaine cessation and conservative management in the first instance in the absence of organ-threatening disease
Establishment and Spread of a Single Parthenogenic Genotype of the Mediterranean arundo wasp, Tetramesa romana1, In the Variable Climate of Texas
As part of a biological control program for the invasive weed, Arundo donax L., several genotypically unique populations of the parthenogenetic stemgalling wasp, Tetramesa romana Walker (Hymenoptera: Eurytomidae), from Spain and France were released in an infested riparian zone along the Rio Grande from Brownsville to Del Rio, TX. An adventive population of the wasp of unknown origin with limited distribution in Texas was also discovered, evaluated, and released as part of the program. More than 1.2 million wasps representing the mixture of genotypes were aerially released from 2009 to 2011. Wasps dispersed from their original release locations and now have a continuous distribution along the Rio Grande from Brownsville to Del Rio, and have dispersed throughout most of Central Texas with satellite populations as far west as San Angelo (Tom Green County), north as far as Kaufman (Kaufman County), and east to Navasota (Grimes County). The most successful genotype (#4) represented 390 of the 409 wasps recovered and matched both an imported population from the Mediterranean coast of Spain and an adventive population established in Texas before the start of the biological control program. Several other European genotypes of the wasp released in the program apparently failed to establish. This result demonstrated the benefits of evaluating and releasing the maximum genetic diversity of the biological control agent in the introduced range. Abundance of T. romana on the Rio Grande from Laredo to Del Rio averaged 190% more in 2013-2014 compared to a similar study in 2008-2009 before release of the European wasps. A favorability index was developed that showed that conditions from 1969 to 1977 would have been adverse to the wasp; conditions after 2009 were more favorable. Climate matching predicts the wasp will disperse throughout the southern U.S. and Mexico
Leukocyte and serum S100A8/S100A9 expression reflects disease activity in ANCA-associated vasculitis and glomerulonephritis.
Antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) commonly results in glomerulonephritis, in which neutrophils and monocytes have important roles. The heterodimer calprotectin (S100A8/S100A9, mrp8/14) is a Toll-like receptor-4 ligand found in neutrophils and monocytes and is elevated in inflammatory conditions. By immunohistochemistry of renal biopsies, patients with focal or crescentic glomerular lesions were found to have the highest expression of calprotectin and those with sclerotic the least. Serum levels of calprotectin as measured by ELISA were elevated in patients with active AAV and the levels decreased but did not normalize during remission, suggesting subclinical inflammation. Calprotectin levels in patients with limited systemic disease increased following treatment withdrawal and were significantly elevated in patients who relapsed compared with those who did not. As assessed by flow cytometry, patients with AAV had higher monocyte and neutrophil cell surface calprotectin expression than healthy controls, but this was not associated with augmented mRNA expression in CD14(+) monocytes or CD16(+) neutrophils. Thus, serum calprotectin is a potential disease biomarker in patients with AAV, and may have a role in disease pathogenesis
Phytochrome RNAi enhances major fibre quality and agronomic traits of the cotton Gossypium hirsutum L
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