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2.
Environ Toxicol ; 2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34664771

RESUMO

Bisphenol A (BPA) is an estrogen-like compound, and an environmental hormone, that is commonly used in daily life. Therefore, it may enter the human body through food or direct contact, causing BPA residues in blood and urine. Because most studies focused on the analysis of BPA in reproductive cells or tissues, regarding evidence the effect of BPA on human retinal pigment epithelium (ARPE-19) cells unavailable. Accordingly, the present study explored the cytotoxicity of BPA on ARPE-19 cells. After BPA treatment, the expression of Bcl-XL an antiapoptotic protein, in the mitochondria decreased, and the expression of Bax, a proapoptotic protein increased. Then the mitochondrial membrane potential was affected. BPA changed in mitochondrial membrane potential led to the release of cytochrome C, which activated caspase-9 to promote downstream caspase-3 leading to cytotoxicity. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase 1 (HO-1) pathway play a major role in age-related macular degeneration. Our results showed that expression of HO-1 and Nrf2 suppressed by BPA. Superoxide dismutase and catalase, which Nrf2 downstream antioxidants, were degraded by BPA. AMP-activated kinase (AMPK), which can regulate the phosphorylation of Nrf2, and the phosphorylation of AMPK expression was reduced by BPA. Finally, BPA-induced ROS generation and cytotoxicity were reduced by N-acetyl-l-cysteine. Taken together, these results suggest that BPA induced ARPE-19 cells via oxidative stress, which was associated with down regulated Nrf2/HO-1 pathway, and the mitochondria dependent apoptotic signaling pathway.

3.
Eur J Histochem ; 65(s1)2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34595897

RESUMO

Distinguishing brain venules from arterioles with arteriolosclerosis is less reliable using traditional staining methods. We aimed to immunohistochemically assess the monocarboxylate transporter 1 (MCT1), a specific marker of venous endothelium found in rodent studies, in different caliber vessels in human brains. Both largeand small-caliber cerebral vessels were dissected from four autopsy donors. Immunoreactivity for MCT1 was examined in all autopsied human brain tissues, and then each vessel was identified by neuropathologists using hematoxylin and eosin stain, the Verhoeff's Van Gieson stain, immunohistochemical stain with antibodies for α-smooth muscle actin and MCT1 in sequence. A total of 61 cerebral vessels, including 29 arteries and 32 veins were assessed. Immunoreactivity for MCT1 was observed in the endothelial cells of various caliber veins as well as the capillaries, whereas that was immunenegative in the endothelium of arteries. The different labeling patterns for MCT1 could aid in distinguishing various caliber veins from arteries, whereas assessment using the vessel shape, the internal elastic lamina, and the pattern of smooth muscle fibers failed to make the distinction between small-caliber veins and sclerotic arterioles. In conclusion, MCT1 immunohistochemical staining is a sensitive and reliable method to distinguish cerebral veins from arteries.

4.
Front Chem ; 9: 757908, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34692647

RESUMO

The saturation of octahydrophenanthrene was the rate-determining step in the hydrogenation process from phenanthrene to perhydrophenanthrene, which was due to the steric hindrance and competitive adsorption of octahydrophenanthrene. In this work, a series of Ni/NiAlOx catalysts with a uniform electron-deficient state of Ni derived from the nickel aluminate structure was synthesized to overcome the disadvantage of noble catalyst and the traditional sulfided catalysts in the saturation hydrogenation process of phenanthrene. Results showed that the catalyst calcinated at 650°C possessed more Ni2+ (∼98%) occupying octahedral sites and exhibited the highest robs (1.53 × 10-3 mol kg-1 s-1) and TOF (14.64 × 10-3 s-1) for phenanthrene hydrogenation. Furthermore, its ability to overcome steric hindrance and promote the rate-determining step was proven by octahydrophenanthrene hydrogenation. Comparing the evolution of hydrogenation activity with the change in the electronic structure of surface Ni sites, it was shown that the increase of metallic electron deficiency hindered the π-back bonding between surface Ni and aromatic rings, which was unfavorable for aromatic adsorption. As a result, the phenanthrene hydrogenation saturation performance can be enhanced by stabilizing the electron-deficient state of surface Ni on an optimal degree.

5.
Nano Converg ; 8(1): 31, 2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34661769

RESUMO

It is highly important to sensitively measure the abundance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on various surfaces. Here, we present a nucleic acid-based detection method consisting of a new sample preparation protocol that isolates only viruses, not the free RNA fragments already present on the surfaces of indoor human-inhabited environments, using a graphene oxide-coated microbead filter. Wet wipes (100 cm2), not cotton swabs, were used to collect viruses from environmental surfaces with large areas, and viruses were concentrated and separated with a graphene oxide-coated microbead filter. Viral RNA from virus was recovered 88.10 ± 8.03% from the surface and free RNA fragment was removed by 99.75 ± 0.19% from the final eluted solution. When we tested the developed method under laboratory conditions, a 10-fold higher viral detection sensitivity (Detection limit: 1 pfu/100 cm2) than the current commercial protocol was observed. Using our new sample preparation protocol, we also confirmed that the virus was effectively removed from surfaces after chemical disinfection; we were unable to measure the disinfection efficiency using the current commercial protocol because it cannot distinguish between viral RNA and free RNA fragments. Finally, we investigated the presence of SARS-CoV-2 and bacteria in 12 individual negative pressure wards in which patients with SARS-CoV-2 infection had been hospitalized. Bacteria (based on 16 S DNA) were found in all samples collected from patient rooms; however, SARS-CoV-2 was mainly detected in rooms shared by two patients.

8.
Crit Rev Food Sci Nutr ; : 1-14, 2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34620005

RESUMO

Endometriosis is a chronic disorder characterized by the presence of endometrial glands and stroma outside the uterine cavity. It affects 8%-10% of women in their reproductive years, and represents a major clinical problem with deleterious social, sexual and reproductive consequences. Current treatment options include pain relief, hormonal intervention and surgical removal. However, these treatments are deemed unsatisfactory owing to varying success, significant side effects and high recurrence rates. Green tea and its major bioactive component, (-)-epigallocatechin gallate (EGCG), possess diverse biological properties, particularly anti-angiogenic, anti-proliferation, anti-metastasis, and apoptosis induction. In recent years, preclinical studies have proposed the use of green tea to inhibit the growth of endometriosis. Herein, the aim of this review is to summarize the potential therapeutic effects of green tea on molecular and cellular mechanism through inflammation, oxidative stress, invasion and adhesion, apoptosis and angiogenesis in endometriosis.

9.
Org Lett ; 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34623166

RESUMO

The catalytic enantioselective desymmetrizing bromoaminocyclization of prochiral cyclohexa-1,4-dienes has been achieved by using chiral anion phase-transfer catalysis, providing a range of enantioenriched cis-3a-arylhydroindoles bearing an all-carbon quaternary stereocenter in good yields (up to 78%) and excellent enantioselectivities (up to 97% ee). Furthermore, the potential application of this methodology to natural product total synthesis was demonstrated by the asymmetric synthesis of (+)-Mesembrane.

10.
Medicine (Baltimore) ; 100(35): e27136, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34477164

RESUMO

RATIONALE: Small cell neuroendocrine carcinoma of the nasal cavity and paranasal sinuses is a rare but aggressive neoplasm with a poor prognosis and a strong propensity for regional recurrence and distant metastasis. Diagnosis is challenging and relies on immunohistochemical study. Treatment includes surgical resection, radiation therapy, chemotherapy, or a combination of these modalities. However, the optimal therapeutic strategy is still controversial. Due to its rarity, the complexity of the histological diagnosis, and the variety of the treatment regimens, we presented a case of primary small cell neuroendocrine carcinoma in the nasal cavity with description of the clinical manifestation, pathology features, and our treatment regimen. PATIENT CONCERNS: An 82-year-old female patient with hypertension presented with right epistaxis on and off with nasal obstruction for several days. DIAGNOSIS: An exophytic mass over the posterior end of the right inferior turbinate was found on nasopharyngoscope. Biopsy was done and the pathology confirmed small cell carcinoma, strongly positive for cytokeratin (AE1/AE3) and insulinoma-associated protein 1 (INSM-1), scatteredly positive for chromogranin A, synaptophysin and CD56. The final diagnosis was small cell neuroendocrine carcinoma of right nasal cavity, pT1N0M0, stage I. INTERVENTIONS: The patient underwent wide excision of right intra-nasal tumor and post-operative radiotherapy with a dose of 6600 cGy in 33 fractions. OUTCOMES: No local recurrence or distant metastasis was noted during the 12 months of follow-up. LESSONS: Multimodality treatment remains the most common therapeutic strategy, although no proven algorithm has been established due to the rarity of this disease. Further investigation is needed for providing evidence to standardize the treatment protocol.


Assuntos
Carcinoma Neuroendócrino/patologia , Cavidade Nasal/patologia , Neoplasias Nasais/patologia , Idoso de 80 Anos ou mais , Carcinoma Neuroendócrino/radioterapia , Carcinoma Neuroendócrino/cirurgia , Feminino , Humanos , Neoplasias Nasais/radioterapia , Neoplasias Nasais/cirurgia
11.
Cancers (Basel) ; 13(17)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34503074

RESUMO

Thyroid cancer (TC) is the most common endocrine malignancy, and its global incidence has steadily increased over the past 15 years. TC is broadly divided into well-differentiated, poorly differentiated, and undifferentiated types, depending on the histological and clinical parameters. Thus far, there are no effective treatments for undifferentiated thyroid cancers or advanced and recurrent cancer. Therefore, the development of an effective therapeutic is urgently needed for such patients. Piperlongumine (PL) is a naturally occurring small molecule derived from long pepper; it is selectively toxic to cancer cells by generating reactive oxygen species (ROS). In this study, we demonstrate the potential anticancer activity of PL in four TC cell lines. For this purpose, we cultured TC cell lines and analyzed the following parameters: Cell viability, colony formation, cell cycle, apoptosis, and cellular ROS induction. PL modulated the cell cycle, induced apoptosis, and suppressed tumorigenesis in TC cell lines in a dose- and time-dependent manner through ROS induction. Meanwhile, an intrinsic caspase-dependent apoptosis pathway was observed in the TC cells under PL treatment. The activation of Erk and the suppression of the Akt/mTOR pathways through ROS induction were seen in cells treated with PL. PL-mediated apoptosis in TC cells was through the ROS-Akt pathway. Finally, the anticancer effect and safety of PL were also demonstrated in vivo. Our findings indicate that PL exhibits antitumor activity and has the potential for use as a chemotherapeutic agent against TC. This is the first study to show the sensitivity of TC cell lines to PL.

12.
Microb Genom ; 7(9)2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34516366

RESUMO

Chitinases are involved in multiple aspects of fungal life cycle, such as cell wall remodelling, chitin degradation and mycoparasitism lifestyle. To improve our knowledge of the chitinase molecular evolution of Ascomycota, the gene family of 72 representatives of this phylum was identified and subjected to phylogenetic, evolution trajectory and selective pressure analyses. Phylogenetic analysis showed that the chitinase gene family size and enzyme types varied significantly, along with species evolution, especially for groups B and C. In addition, two new subgroups, C3 and C4, are recognized in group C chitinases. Random birth and death testing indicated that gene expansion and contraction occurred in most of the taxa, particularly for species in the order Hypocreales (class Sordariomycetes). From an enzyme function point of view, we speculate that group A chitinases are mainly involved in species growth and development, while the expansion of genes in group B chitinases is related to fungal mycoparasitic and entomopathogenic abilities, and, to a certain extent, the expansion of genes in group C chitinases seems to be correlated with the host range broadening of some plant-pathogenic fungi in Sordariomycetes. Further selection pressure testing revealed that chitinases and the related amino acid sites were under positive selection in the evolutionary history, especially at the nodes sharing common ancestors and the terminal branches of Hypocreales. These results give a reasonable explanation for the size and function differences of chitinase genes among ascomycetes, and provide a scientific basis for understanding the evolutionary trajectories of chitinases, particularly that towards a mycoparasitic lifestyle.

13.
BMC Geriatr ; 21(1): 488, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34493200

RESUMO

OBJECTIVE: This study was designed for the first time to analyze clinical efficacy of bone transport technology in Chinese older patients with infectious bone nonunion after open tibial fracture. METHODS: This study retrospectively analyzed 220 older patients with infectious bone nonunion after open tibial fracture. There were 110 patients receiving bone transport technology (Group A) and 110 patients receiving membrane induction technique with antibiotic bone cement (Group B). RESULTS: There were 164 male patients and 56 female patients, with an age range of 65 to 71 years and an average age of 67 ± 1.3 years. Traffic accident, high-fall injury and crush injury account for 45.5, 27.7 and 26.8%, respectively. Age, gender, histories, causes and fracture location had no significant difference between the two groups (P > 0.05 for all). Operation time in the Group A was significantly shorter than that in the Group B (P < 0.05). Linear and positional alignment (70.9 vs. 57.3), American Knee Society knee function score (167.7 ± 14.9 vs. 123.8 ± 15.7), Baird-Jackson ankle function score (89.9 ± 3.5 vs. 78.4 ± 4.9), bone healing index (43.0 ± 2.0 vs. 44.3 ± 3.0) and clinical recovery (8.2 vs. 4.5) of patients in the Group A were significantly better than those in the Group B (P < 0.05 for all). Wound infection in the Group A (7.3%) was significantly less than that in the Group B (16.4%; P < 0.05). There were neither a neurovascular complication nor a recurrence of infection in the two groups. CONCLUSION: Bone transport technology achieved better knee and ankle joint function recovery and superior bone healing and clinical efficacy than membrane induction technique with antibiotic bone cement, suggesting that bone transport technique is worthy of extensive promotion to improve clinical condition of older patients with infectious bone nonunion after open tibial fracture.


Assuntos
Fraturas da Tíbia , Idoso , China/epidemiologia , Feminino , Humanos , Masculino , Estudos Retrospectivos , Tecnologia , Fraturas da Tíbia/diagnóstico por imagem , Fraturas da Tíbia/cirurgia , Resultado do Tratamento
14.
Artigo em Inglês | MEDLINE | ID: mdl-34574858

RESUMO

The global prevalence of diabetes mellitus (DM) has reached 20%. Air pollutants with a particle size of less than 2.5 µm (PM2.5) are a globally recognized risk factor for diabetes and glaucoma. We examined whether the risk of glaucoma would decrease or increase when patients with DM were exposed to different PM2.5 concentrations. Data were obtained from the National Health Insurance Research Database (NHIRD) of Taiwan and the Air Quality Monitoring Network between 2008 and 2013. This nested case-control study involved 197 DM patients with glaucoma and 788 DM patients without glaucoma. Cases and controls were matched (1:4) by gender, age (±5 years), and index date (±6 months), and their data were entered in a logistic regression model adjusted for gender, age, urbanization level, income level, and comorbidities. The odds ratio (OR) of glaucoma at PM2.5 exposure concentration in the fourth quartile (Q4) compared with in the first quartile (Q1) was 1.7 (95% CI: 1.084-2.764). For glaucoma risk, the OR was 1.013 (95% CI: 1.006-1.020) at a PM2.5 exposure concentration in Q1, 1.004 (95% CI: 1.001-1.007) in the third quartile (Q3), and 1.003 (95% CI: 1.001-1.004) in Q4. In the subgroup analysis of patients living in non-emerging towns and non-agricultural towns, the OR for glaucoma in Q4 compared with in Q1 was 2.1 (95% CI: 1.229-3.406) and 1.8 (95% CI: 1.091-2.803), respectively (p trend = 0.001 and 0.011). For patients without migraine, the OR for glaucoma was 1.7 (95% CI: 1.074-2.782; p = 0.006). These results demonstrate that, for patients with DM, PM2.5 increased the risk of glaucoma and PM2.5 was an independent risk factor for glaucoma in patients with DM.

15.
Pharmaceutics ; 13(9)2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34575403

RESUMO

Gastric cancer (GC) is a fatal malignant tumor, and effective therapies to attenuate its progression are lacking. Nanoparticle (NP)-based solutions may enable the design of novel treatments to eliminate GC. Refined, receptor-targetable NPs can selectively target cancer cells and improve the cellular uptake of drugs. To overcome the current limitations and enhance the therapeutic effects, epigallocatechin-3-gallate (EGCG) and low-concentration doxorubicin (DX) were encapsulated in fucoidan and d-alpha-tocopherylpoly (ethylene glycol) succinate-conjugated hyaluronic acid-based NPs for targeting P-selectin-and cluster of differentiation (CD)44-expressing gastric tumors. The EGCG/DX-loaded NPs bound to GC cells and released bioactive combination drugs, demonstrating better anti-cancer effects than the EGCG/DX combination solution. In vivo assays in an orthotopic gastric tumor mouse model showed that the EGCG/DX-loaded NPs significantly increased the activity of gastric tumors without inducing organ injury. Overall, our EGCG/DX-NP system exerted a beneficial effect on GC treatment and may facilitate the development of nanomedicine-based combination chemotherapy against GC in the future.

16.
Chemosphere ; 287(Pt 3): 132305, 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34563770

RESUMO

BACKGROUND: Metal exposures are suspected to associate with the risk of hyperuricemia (HUA), but the current results are still conflicting. OBJECTIVE: To investigate the associations between multiple plasma metal exposures and HUA risk. METHODS: A cross-sectional study was conducted in 1406 Chinese Han adults who underwent routine physical examination in the Eighth Affiliated Hospital of Sun Yat-Sen University in Shenzhen. The plasma levels of 13 metals were measured by the inductively coupled plasma mass spectrometry (ICP-MS). Multivariable logistic, linear regression models, least absolute shrinkage and selection operator (LASSO) penalized regression analysis, and restricted cubic spline (RCS) models were applied to assess the associations. RESULTS: The median plasma uric acid concentration in HUA group (434 µmol/L) was significantly higher than that in non-HUA group (305 µmol/L). The multivariate-adjusted odds ratios (95% confidence intervals) of HUA were 1.62(1.08-2.43) for magnesium, 1.61(1.05-2.47) for copper, 1.62(1.06-2.49) for zinc, 1.87(1.26-2.81) for arsenic, 1.50(1.01-2.23) for selenium, and 1.70(1.16-2.49) for thallium based on the single-metal logistic regression models, comparing the highest versus the lowest quartile of metal levels. Further multi-metal logistic, linear regression models and the LASSO analysis all indicated positive associations of zinc, arsenic with HUA risk or uric acid levels. RCS model indicated an inverted V-shaped positive association between zinc levels and HUA risk (p for non-linearity = 0.048, p for overall association = 0.022), while arsenic levels showed a positive and linear dose-response relationship with HUA risk (p for non-linearity = 0.892, p for overall association<0.001). CONCLUSIONS: Higher plasma levels of zinc and arsenic might increase HUA risk and showed positive dose-response relationships. Further cohort studies in larger population are required to testify our findings.

17.
Diabetes Metab Res Rev ; : e3496, 2021 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-34537998

RESUMO

AIMS: We prospectively evaluated the association of circulating retinol-binding protein 4 (RBP4) levels in early pregnancy and risk of incident gestational diabetes mellitus (GDM) in pregnant women. METHODS: A nested case-control study was conducted among 332 women who developed GDM and 664 matched controls based on the Tongji-Shuangliu Birth Cohort. GDM was diagnosed during 24-28 weeks of gestation according to the International Association of Diabetes and Pregnancy Study Group criteria. Serum RBP4 levels in early pregnancy (6-15 weeks of gestation) were determined by ELISA assay. Multivariable conditional logistic regression models were used to analyse the association and generated the odds ratio (OR) and 95% confidence interval (CI). EMBASE and PubMed were searched up to 30 November 2020 to identify studies investigating the association between blood RBP4 levels in early pregnancy and incident GDM. RESULTS: In the multivariable model with adjustment of potential risk factors, the OR comparing the extreme quartiles of serum RBP4 levels was 2.26 (95% CI: 1.34, 3.81; p for trend <0.001), and each standard deviation (SD) increment of RBP4 was associated with 1.39-fold (95% CI: 1.15, 1.69) higher risk of GDM. The results were confirmed in a meta-analysis that included additional four studies with an overall OR of 1.47 (95% CI: 1.18, 1.83) per 1-SD increment of RBP4. CONCLUSIONS: Serum RBP4 levels in early pregnancy, independent of metabolic risk factors, are positively associated with the risk of GDM in pregnant women. Our findings may provide new insights into the mechanisms underlying the aetiology of GDM.

18.
Int J Mol Sci ; 22(18)2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34576028

RESUMO

Lung cancer is one of the most common cancers and the leading cause of death in humans worldwide. Non-small-cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer cases and is often diagnosed at a late stage. Among patients with NSCLC, 50% die within 1 year after diagnosis. Even with clinical intervention, the 5-year survival rate is only approximately 20%. Therefore, the development of an advanced therapeutic strategy or novel agent is urgently required for treating NSCLC. Berberine exerts therapeutic activity toward NSCLC; therefore, its activity as an antitumor agent needs to be explored further. In this study, three terpenylated-bromide derivatives of berberrubine were synthesized and their anti-NSCLC activities were evaluated. Each derivative had higher anti-NSCLCs activity than berberrubine and berberine. Among them, 9-O-gernylberberrubine bromide (B4) and 9-O-farnesylberberrubine bromide (B5) showed greater growth inhibition, cell-cycle regulation, in vitro tumorigenesis suppression, and tumor migration reduction. In addition, some degree of apoptosis and autophagic flux blocking was noted in the cells under B4 and B5 treatments. Our study demonstrates that the berberrubine derivatives, B4 and B5, exhibit impressive anti-NSCLC activities and have potential for use as chemotherapeutic agents against NSCLC.


Assuntos
Berberina/análogos & derivados , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células A549 , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Berberina/síntese química , Berberina/química , Berberina/farmacologia , Brometos/química , Carcinogênese/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/patologia , Humanos , Terpenos/síntese química , Terpenos/farmacologia
19.
Org Biomol Chem ; 19(38): 8377-8383, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34528986

RESUMO

2-Alkenyl-tetrahydropyrans belong to a rare class of natural products that exhibit broad antifungal activities. Their structural instability and rareness in nature have restrained their discovery and drug development. In this study, the heterologous expression of a single highly reducing polyketide synthase (HR-PKS, App1) from Trichoderma applanatum in Aspergillus nidulans leads to the formation of seven 2-alkenyl-tetrahydropyran derivatives including one known compound virensol C (1) and six new compounds (2-7). However, introducing App1 into Saccharomyces cerevisiae resulted in the identification of additional two 2-alkenyl-tetrahydropyrans lacking the hydroxyl or methoxyl group at the C-2 position (8 and 9). The structures of the isolated compounds were elucidated by extensive spectroscopic analysis using NMR and HR-ESI-MS.

20.
Hortic Res ; 8(1): 183, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34465765

RESUMO

As one of the largest families of angiosperms, the Orchidaceae family is diverse. Dendrobium represents the second largest genus of the Orchidaceae. However, an assembled high-quality genome of species in this genus is lacking. Here, we report a chromosome-scale reference genome of Dendrobium chrysotoxum, an important ornamental and medicinal orchid species. The assembled genome size of D. chrysotoxum was 1.37 Gb, with a contig N50 value of 1.54 Mb. Of the sequences, 95.75% were anchored to 19 pseudochromosomes. There were 30,044 genes predicted in the D. chrysotoxum genome. Two whole-genome polyploidization events occurred in D. chrysotoxum. In terms of the second event, whole-genome duplication (WGD) was also found to have occurred in other Orchidaceae members, which diverged mainly via gene loss immediately after the WGD event occurred; the first duplication was found to have occurred in most monocots (tau event). We identified sugar transporter (SWEET) gene family expansion, which might be related to the abundant medicinal compounds and fleshy stems of D. chrysotoxum. MADS-box genes were identified in D. chrysotoxum, as well as members of TPS and Hsp90 gene families, which are associated with resistance, which may contribute to the adaptive evolution of orchids. We also investigated the interplay among carotenoid, ABA, and ethylene biosynthesis in D. chrysotoxum to elucidate the regulatory mechanisms of the short flowering period of orchids with yellow flowers. The reference D. chrysotoxum genome will provide important insights for further research on medicinal active ingredients and breeding and enhances the understanding of orchid evolution.

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