[Method for recording tension changes of small pulmonary artery and vein using the isolated vessel tension measurement system]

Objective: To establish a standardized method for isolated pulmonary artery and vein rings with different diameter, pressure and length, which could provide a more scientific method for in vitro study of pulmonary vessel diseases. Methods: Male SD rats were anesthetized, and the right ventricular systolic pressure were measured. Small pulmonary artery and vein rings with 200-400 μm in diameter and 2 mm in length were prepared by dissecting pulmonary arteries and veins. The pulmonary vessel rings were mounted in the organ bath by 2 stainless steel wires with diameter of 40 μm. Then the internal circumference of the vessel rings was increased gradually with 100 μm per step. At the same time the vascular tension was recorded by the Myograph System and Acknowledgement data acquisition system, and subsequently the passive length-tension exponential curve was made. The initial tension of the rings was set, equilibrated for another 30 min, and then stimulated with 60 mmol/L KCl 3 times, and the best contractile reactivity was achieved. The contractile reactivity of pulmonary artery rings and endothelial integrity were detected by exposure to 1 μmol/L phenylephrine(PE) and 10 μmol/L acetylcholine(Ach), while the contractile reactivity of pulmonary vein rings was detected by exposure to 1 μmol/L U46619 and 10 μmol/L papaverine. Results: The contraction and relaxation effects of the pulmonary artery rings reached 0.39 mg and 92% when they were stimulated by 1 μmol/L PE and 10 μmol/L Ach. The contraction and relaxation effects of pulmonary vein rings were up to 0.13 mg and 84% when they were exposed to 1 μmol/L U46619 and 10 μmol/L papaverine, respectively. Conclusion: Pulmonary artery and vein rings with appropriate basal tension and optimal vasodilator activity were prepared, and a standardized method of tension experiment for isolated pulmonary artery and vein rings established.

Characterization of the triple-component linoleic acid isomerase in Lactobacillus plantarum ZS2058 by genetic manipulation

AIM

To assess the mechanism for conjugated linoleic acid (CLA) production in Lactobacillus plantarum ZS2058.

METHODS AND RESULTS

CLA has attracted great interests for decades due to its health-associated benefits including anticancer, anti-atherogenic, anti-obesity and modulation of the immune system. A number of microbial CLA producers were widely reported including lactic acid bacteria. Lactobacillus plantarum ZS2058, an isolate from Chinese traditional fermented food, could convert LA to CLA with various intermediates. To characterize the genetic determinants for generating CLA, a cre-lox-based system was utilized to delete the genes encoding myosin cross-reactive antigen (MCRA), short-chain dehydrogenase/oxidoreductase (DH) and acetoacetate decarboxylase (DC) in Lact. plantarum ZS2058, respectively. Neither intermediate was detected in the corresponding gene deletion mutant. Meanwhile all those mutants could recover the ability to convert linoleic acid to CLA when the corresponding gene was completed.

CONCLUSIONS

The results indicated that CLA production was a multiple-step reaction catalysed by triple-component linoleate isomerase system encoded by mcra, dh and dc.

SIGNIFICANCE AND IMPACT OF THE STUDY

Multicomponent linoleic acid isomerase provided important results for illustration unique mechanism for CLA production in Lact. plantarum ZS2058. Lactobacilli with CLA production ability offer novel opportunities for functional food development.

Extract of Syzygium aromaticum suppress eEF1A protein expression and fungal growth

AIMS

Clove extract has therapeutic potential as an antifungal drug, yet the mechanism of action remains ambiguous. Current study aimed to address the molecular process of the antifungal activity exerted by clove extract.

METHODS AND RESULTS

The antifungal assay results showed that clove extract had some effects on all of the tested yeast. Propidium iodide staining assay showed cell membrane damage in Saccharomyces cerevisiae after treatment of clove extract for 30 h. Interestingly, SDS-polyacrylamide gel electrophoresis assays revealed that the protein expression of eukaryotic elongation factor 1 alpha (eEF1A) was suppressed significantly after treatment with clove extract (not pure eugenol). Transcriptional analyses revealed that the TEF1 and TEF2 genes (translation elongation factor EF-1 alpha) encoding eEF1A were not disturbed with the addition of clove extract; however, the expression of related genes EFB1 (translation elongation factor 1 subunit beta), ENO2 (phosphopyruvate hydratase ENO2), GSP1 (Ran GTPase GSP1), RPP0 (ribosomal protein P0), YEF3 (translation elongation factor EF-3), TEF4 (translation elongation factor EF1B gamma), and RPS2 (ribosomal 40S subunit protein S2) increased significantly.

CONCLUSIONS

These results suggest that clove extract plays a role in disrupting growth and affecting yeast metabolism. eEF1A was affected by clove extract at the protein level but not at the transcriptional level.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is based on a detailed study of antifungal action exerted by clove extract, and proposed that down-regulation of eEF1A protein expression may contribute to its antifungal activity. These results may have clinical significance for future application of clove extract as a natural antifungal agent.

[Study on application of two risk assessment methods in coal dust occupational health risk assessment]

Objective: To evaluate the applicability of quantitative grading method (GBZ/T 229.1-2010) and occupational hazard risk index method in coal dust occupational health risk assessment. Methods: Taking 4 coal mines as the research object of risk assessment and making occupational health field testing and investigation. Based on two risk assessment methods, we analysed the health risk levels of 20 occupations which were exposed to coal dust in workplaces. Results: Coal dust working post had different risk levels in 4 coal mines, the post of higher risk level were mainly concentrated in the underground workplace of coal mine, especially the post of coal mining and tunneling system. The two risk assessment results showed that the risk levels of coal-mining machine drivers and tunneling machine drivers were the highest. The risk levels of coal dust working post used by two risk assessment methods had no significant difference (P>0.05) and were highly correlated (r=0.821, P<0.001) . Evaluation results of two risk assessment methods were supported by the field investigation and literatures. Conclusion: The two risk assessment methods can be used in coal dust occupational health risk assessment.

[Prognostic value of dynamic monitoring of RUNX1-RUNX1T1 transcript in pediatric acute myeloid leukemia]

Objective: To investigate the prognostic value of dynamic monitoring of RUNX1-RUNX1T1 transcript in pediatric patients with t (8;21) acute myeloid leukemia (AML) . Methods: The clinical features and RUNX1-RUNX1T1 transcript levels of 55 pediatric t (8;21) AML patients, newly diagnosed from Jan. 2010 to Apr. 2016, were analyzed retrospectively. The relationship between the minimal residual disease (MRD) and prognosis was analysed by dynamic monitoring of RUNX1-RUNX1T1 transcript levels using real-time quantitative PCR (RQ-PCR) technology. Results: The RUNX1-RUNX1T1 transcript levels in bone marrow cells at diagnosis was not related to relapse. After one course of induction therapy, patients with a more than 2 Log reduction of RUNX1-RUNX1T1 transcript levels (>2 Log) had lower 5 years cumulative incidence of relapse (CIR) [ (24.3±8.4) % vs (52.6±9.7) %, χ(2)=9.046, P=0.003], relapse-free survival (RFS) [ (71.6±12.7) % vs (48.1±13.2) %, χ(2)=5.814, P=0.016], and better overall survival (OS) [ (76.9±12.5) % vs (48.9±14.7) %, χ(2)=6.346, P=0.012], compared to patients with a less than 2 Log reduction (a<2 Log) . Multivariate Cox survival analysis suggested that a>2 Log reduction in RUNX1-RUNX1T1 transcript levels after a course of induction therapy was an independent prognostic factor for RFS (HR=0.263, 95%CI 0.081-0.851, P=0.026) and OS (HR=0.214, 95% CI 0.057-0.808, P=0.023) . During consolidation therapy and follow-up period, molecular relapse of 16 cases and hematologic relapse of 13 cases were identified by continuous dynamic monitoring of RUNX1-RUNX1T1 transcript levels, with a median interval of 4.0 (1.5-5.8) months from the molecular relapse to hematologic relapse. 2 cases of molecular relapse who received timely allogeneic hematopoietic stem cell transplantation did not experience hematologic relapse. Conclusion: Dynamic monitoring RUNX1-RUNX1T1 transcript levels by RQ-PCR technique can subdivide patients into relatively low and high risk group, early screen patients at high risk of relapse and provide a scientific basis for precision stratification and risk-adapted therapy for pediatric t (8;21) AML children.

[Study of long non-coding RNA HOTAIR expression in middle ear cholesteatoma]

Objective:To discuss the different expression of some long-chain noncoding RNA between middle ear cholesteatoma epithelial tissue and normal external ear canal skin.Method:Real-time quantitative PCR was used to detect the expression of 6 kinds of lncRNA: HOTAIR, ANCR, TINCR, PRINS, BANCR, PICSAR in 25 cases of cholesteatoma epithelial tissues and 15 cases of normal external auditory canal skin tissue samples, respectively. And compared the expression level of lncRNA in patients with different degree of bone destruction.Result:Expression level of HOTAIR was significantly increased in cholesteatoma epithelial tissues compared with the normal external auditory canal skin tissues,and the difference is statistically significant (P< 0.01). While there was no statistically significant difference expression of the rest of the five kinds of lncRNA between middle ear cholesteatoma epithelial tissues and normal external ear canal skin (P> 0.05). And there was no statistically significant difference expression of HOTAIR in patients with different degree of bone destruction (P> 0.05).Conclusion:Expression level of HOTAIR was up-regulated in middle ear cholesteatoma epithelial tissue compared with the normal external auditory canal skin tissues, and the expression level of HOTAIR has no obvious correlation with degree of bone destruction in patients with cholesteatoma.

[Primary culture and functional identification of distal pulmonary artery smooth muscle cells in mice]

Objective: To establish a method of isolation and primary culture of mice distal pulmonary artery smooth muscle cells (PASMCs) and identify the functional properties. Methods: PASMCs were harvested from the distal pulmonary artery (PA) tissue of mice by enzymatic digestion of collagenaseⅠand papain; and the growth characteristics were observed under inverted microscope and identified by Immunofluorescence technique. Effects on the intracellular calcium ion concentration of distal PASMCs were detected by Fura-2-AM fluorescent probe tracer under a fluorescence microscope in Krebs solution containing clopiazonic acid (CPA) and nifedipin (Nif). Results: PASMCs density reached approximately to 80% in a typical valley-peak-like shape after 6 days. Cell α-smooth muscle actin (α-SMA) immunofluorescence identified that 95% of the cultured cells were PASMCs. More than 95% PASMCs responded well to calcium-potassium Krebs solution (potassium ion concentration of 60 mmol/L) and showed a rapid increase in basal [Ca(2+) ](i) after 1 minute's perfusion (Δ[Ca(2+) ](i)>50), which demonstrated that the voltage-dependent calcium channels (VDCC) of distal PASMCs were in good function; after the perfusion of calcium Krebs, calcium-free/calcium-Krebs containing CPA and Nif, distal PASMCs showed two typical peaks, indicated the full function of store-operated calcium channel (SOCC) in distal PASMCs. Conclusion: This experiment successfully established a stable and reliable mice distal PASMCs model and the study of pulmonary vascular diseases could benefit from its higher purity and better functional condition.

Role and timing of second-line therapies for patients with recurrent platinum-resistant ovarian epithelial cancer

OBJECTIVE

To explore the regimens and prognoses of second-line therapies for recurrent platinum-resistant ovarian epithelial cancer (OEC).

MATERIALS AND METHODS

The clinical profiles and second-line regimens were retrospectively analyzed for 65 recurrent platinum-resistant OEC patients treated at Zhejiang Provincial Tumor Hospital during January 2003 to January 2013. In conjunction with literature reviews, the second-line therapies for platinum-resistant recurrent OEC were discussed.

RESULTS

Their average age was 55.2 years. The stages were I (n=4), II (n=3), III (n=45), and IV (n=13). The predominant type was serous adenocarcinoma (n=47, 72.3%). Chemotherapy was refused (n=14) and resistant (n=5 1). One case was lost to follow-up and another three withdrew early. An average of four chemotherapeutic courses were offered in 61 cases. Among them, five cases selected chemotherapy after a second operation. The average therapy-free interval (TFI) was 3.5 months. The efficacies were evaluated for 61 cases. CR (n=5) and partial remission (PR, n=22). The overall survival (OS) rate was 43.6% and average progression-free survival (PFS) was 15.44 months.

CONCLUSION

The efficacy of second-line therapy for recurrent platinum-resistant OEC is rather poor and the feasibility and efficacy of second operation are to be further explored.

[Hypoxia induced the remodeling of pulmonary arterial smooth muscles and increased the pulmonary artery smooth muscle Krüppel-like zinc-finger transcription factor 5 expression]

Objective: To study the effect of chronic hypoxia on pulmonary arterial remodeling and Krüppel-like zinc-finger transcription factor 5 (KLF5) protein expression in pulmonary artery smooth muscles in a hypoxia-induced pulmonary hypertension model. Methods: Totally 20 adult SD rats (200-250 g) were divided into a normoxia group and a chronic hypoxia group by the random number table. Rats in the chronic hypoxia group were put in an automatic hypoxia box for 21 days. After that, right ventricular systolic pressure (RVSP), mean right ventricular pressure (mRVP) and RV/(LV+ S) were measured. Lung tissue sections were made. The lumen area, ratio of wall thickness to radius of pulmonary artery were gauged by using the Image Pro Plus software. Primary PASMCs were cultured in oxygen-deficient environment (4% O₂)or normal oxygen environment (21% O₂)for 60 hours respectively, and then total protein or RNA were extracted for Western blotting and Q-PCR analysis.KLF5 protein expression in rat pulmonary arterial smooth muscle and pulmonary arterial smooth muscle cells was detected by Western blot. Results: Compared with the normoxia group(28.3±0.4), (11.3±1.0)mmHg (1 mmHg=0.133 kPa), the RVSP and mRVP in the chronic hypoxia group [(43.9±1.3), (26.5±2.3)mmHg] were significantly increased(P<0.05). The Rv/(LV+ S)of the chronic hypoxia group was(0.48±0.03), markedly higher than that of the normoxia group(0.27±0.01, P<0.05). The luminal area/total area of artery in the chronic hypoxia group decreased to (46.1±6.6)% compared with that in the normoxia group [(68.73±3.06)%, P<0.05]. The wall thickness/arterial radius(WT%)of the chronic hypoxia group increased up to (5.64±0.32)% as compared with (3.7±0.4)% of the normoxia group (P<0.05). The level of KLF5 protein in pulmonary arterial smooth muscles of the chronic hypoxia group was (21.6±7.2) times that of the normoxia group (P<0.05). Conclusion: Hypoxia induced the increase of RVSP, mRVP, RV/(LV+ S), accompanied with pulmonary arterial remodeling. The underlying mechanism of the artery change may be related to up-regulated expression of KLF5.

[Diagnostic utility of immunohistochemistry in differential diagnosis of renal tumors with oncocytic features]

Objective: To investigate the morphological features and immunophenotypes of eosinophilic renal tumors in order to provide references for the differential diagnosis of this tumor. Methods: A cohort of 75 cases of eosinophilic renal tumors were collected. The morphological features of the tumors were observed under microscope, and the immunophenotypes of the tumors were detected using tissue microarray and immunoshistochemistry. Results: There were some overlaps between the different types of eosinophilic renal tumors in morphology, but each had its distinct characteristics. Immunohistochemically, renal oncocytoma (RO) and eosinophilic chromophobe renal cell carcinoma (ChRCC) shared some common immumophenotypes, except for the expression of CK7, with the expression rates of 2/19 in RO and 17/20 in eosinophilic ChRCC, respectively. Eosinophilic clear cell renal cell carcinoma mainly showed positive immunostaining for Vimentin and CAⅨ, whereas negative for CK7 and CD117 in most cases (10/15). AMACR was diffusely expressed in the majority of eosinophilic papillary renal cell carcinoma (PRCC, 10/13). Furthermore, vimentin, CK7 and CD10 were positively expressed in eosinophilic PRCC with the expression rates of 8/13, 9/13 and 6/13, respectively; while CAⅨ, CD117 and TFE3 were all negatively expressed in eosinophilic PRCC.Epithelioid angiomyolipoma generally showed positive expression of vimentin, SMA and HMB45, but negative expression of CAⅨ and CK7. Vimentin, CD10, AMACR and TFE3 were strongly expressed in XP11.2 translocation renal cell carcinoma; on the contrary, CK7, CD117 and HMB45 were not expressed in the majority of the tumor. Conclusion: With full understanding of the morphology of different types of eosinophilic renal tumors, the immunostaining of vimentin, CAⅨ, CK7, CD10, AMACR, CD117, TFE3 and HMB45 could play a crucial role in the differential diagnosis of these tumors.

Genome-wide analysis of TCP family in tobacco

The TCP family is a transcription factor family, members of which are extensively involved in plant growth and development as well as in signal transduction in the response against many physiological and biochemical stimuli. In the present study, 61 TCP genes were identified in tobacco (Nicotiana tabacum) genome. Bioinformatic methods were employed for predicting and analyzing the gene structure, gene expression, phylogenetic analysis, and conserved domains of TCP proteins in tobacco. The 61 NtTCP genes were divided into three diverse groups, based on the division of TCP genes in tomato and Arabidopsis, and the results of the conserved domain and sequence analyses further confirmed the classification of the NtTCP genes. The expression pattern of NtTCP also demonstrated that majority of these genes play important roles in all the tissues, while some special genes exercise their functions only in specific tissues. In brief, the comprehensive and thorough study of the TCP family in other plants provides sufficient resources for studying the structure and functions of TCPs in tobacco.

Identification of altered pathways in Down syndrome-associated congenital heart defects using an individualized pathway aberrance score

The aim of this study was to identify disrupted pathways related to Down syndrome (DS), and DS-associated congenital heart defects (DS-CHD). The gene expression profile and pathway data of 10 human DS patients and 5 control samples in E-GEOD-1789 were recruited and analyzed by the individualized pathway aberrance score (iPAS) method, consisting of the data processing, gene-level statistics, pathway-level statistics, and significant measurement steps. The pre-processing step identified 12,493 genes and 1022 pathways (4269 genes). The pathway significant analysis identified eight pathways (adjusted P value <0.1) that differed between the disease and control samples. The cross-presentation of particulate exogenous antigen (phagosomes) and methionine salvage pathways showed the most significant differences among these. The gene expression levels of key pathway genes, such as CYBB and ADI1, were higher in disease samples than in normal controls. Based on our results, we predicted that the cross-presentation of particulate exogenous antigens (phagosomes) and the methionine salvage pathway could be good indicators of DS-CHD.

A highly conserved G-rich consensus sequence in hepatitis C virus core gene represents a new anti-hepatitis C target

G-quadruplex (G4) is one of the most important secondary structures in nucleic acids. Until recently, G4 RNAs have not been reported in any ribovirus, such as the hepatitis C virus. Our bioinformatics analysis reveals highly conserved guanine-rich consensus sequences within the core gene of hepatitis C despite the high genetic variability of this ribovirus; we further show using various methods that such consensus sequences can fold into unimolecular G4 RNA structures, both in vitro and under physiological conditions. Furthermore, we provide direct evidences that small molecules specifically targeting G4 can stabilize this structure to reduce RNA replication and inhibit protein translation of intracellular hepatitis C. Ultimately, the stabilization of G4 RNA in the genome of hepatitis C represents a promising new strategy for anti-hepatitis C drug development.

[Effects of hemoglobin J-Bangkok traits on measurements of glycated hemoglobin by five methods]

OBJECTIVE

To evaluate the interference of hemoglobin variants J-Bangkok on glycated hemoglobin (HbA(1)c) detected by five measurement systems.

METHODS

Seventy cases of blood samples were collected at Zhongshan Hospital of Sun Yat-sen University from July 2012 to January 2014, the blood samples were divided into the normal control group (40 cases) and Hb J-Bangkok variant group (30 cases), and the normal control group was divided into healthy control group (20 cases) and diabetic group (20 cases). HbA(1)c measurement systems were Primus Ultra2, Variant Ⅱ, Variant Ⅱ Turbo, Modular P and Leadman. Based on the standard of the American National Glycosylated Hemoglobin Standardization Program (NGSP), Primus Ultra2 was used as comparative system, and the other 4 systems were test systems. Comparative analysis and bias evaluation were conducted on the results from five detection systems in different groups, statistical analysis were used for evaluating the differences. The estimated average glucose (eAG) was calculated by HbA(1)c values and fasting plasma glucose (FPG) of Hb J-Bangkok variant group with the different detection systems. Deming regression analysis was used to determinate whether Hb J-Bangkok produced significant clinical effect on HbA(1)c results. HbA(1)c ± 10% and relative bias at 6% and 9% HbA1c were evaluation limits.

RESULTS

The differences of the 95% confidence interval (95%CI) between the test systems and the comparative system in control group were within ±0.7% HbA(1)c, bias were less than 6%, there were no statistically significant difference (P>0.05). In Hb J-Bangkok group, the eAG calculated from HbA(1)c measured by using Primus Ultra2, Modular P and Leadman were (8.14±2.99), (8.10±3.06) and (8.23±3.00)mmol/L, which had no statistically significant difference compared with FPG ((8.21±3.12)mmol/L, t=0.996, 1.091, 1.479, all P>0.05), and the differences of 95%CI between the results measured by Modular P and the comparative system were all within ±0.7% HbA(1)c, bias were -4.3%-0.4% and -5.2%-4.9%, there were no statistically significant difference (P>0.05). At 6% and 9% HbA(1)c concentrations, the mean differences of the results from the three detection systems were less than the clinically acceptable range. These results showed that the systems of Primus Ultra2, Modular P and Leadman were not affected by Hb J-Bangkok. However, the eAG values calculated from HbA(1)c of Variant Ⅱ and Variant Ⅱ Turbo were (5.58±2.12) and(5.00±2.13)mmol/L, which showed statistically significant lower results compared with FPG level (t=12.29, 13.23 , all P<0.001). Compared with Primus Ultra2, the differences of 95%CI were outside of ± 0.7% HbA1c, bias were -31.9%--12.0% and -42.0%- -17.6% , greater than 6%, showed a negative bias.At 6% and 9% HbA(1)c concentrations, the mean differences of the results were all greater than the clinical acceptable range. These results indicated that Hb J-Bangkok had significantly clinical interference on Variant Ⅱ and Variant Ⅱ Turbo systems.

CONCLUSION

Hb J-Bangkok has different interference on different HbA(1)c measurement systems, when performs the HbA(1)c test, clinical laboratory should pay attention to identify Hb variants, and select the appropriate methods to measure the HbA(1)c values in order to prevent the occurrence of interference by Hb variants.

Maximum-biomass concentration prediction for Bifidobacteria in the pH-controlled fed-batch culture

Our objective was to systematically study the relationship between maximum biomass concentration of different Bifidobacteria and total-acid anions accumulation, and develop a prediction equation for the maximum biomass concentration in the fed-batch culture at pH-controlled 7·0. The accumulation of acid anions and the consumption of nutrients of various strains were evaluated. In addition, minimum inhibitory concentrations (MICs) of acid anions on a range of strains were examined at pH 7·0. The inhibition of acid anions, which had the same MIC as sodium chloride, was due to the osmotic pressure under pH 7·0 conditions. Moreover, the concentration of total-acid anions completely inhibiting each strain in the fed-batch culture at pH-controlled 7·0 had no significant differences with the MIC of acid anions for the corresponding strains. The osmotic pressures under two conditions were not significantly different. Finally, the maximum biomass concentration of Bifidobacteria was found to be closely related to biomass yield per unit of acid anion produced (YX/P ) and MIC (C) which were needed for the prediction, and different strains exhibited marked correlation (P ˂ 0·01, R = 0·985). An equation for the prediction of the maximum biomass concentration was developed as follows: Xmax -X0  = (0·71 ± 0·03)·YX/P ·C.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides further insights into the inhibition of Bifidobacteria by dissociated acid anions (the dissociated form) at pH 7·0. The high correlation between different strains suggested that the equation established in this paper is appropriate for different strains of Bifidobacteria. The prediction equation could be used to guide practical production in the preparation of materials, the control of the end of fermentation and production plans for further products such as freeze-dried powder of Bifidobacteria or food fermentation.

Homology-based analysis of the GRAS gene family in tobacco

Members of the GRAS gene family are important transcriptional regulators. In this study, 21 GRAS genes were identified from tobacco, and were classified into eight subgroups according to the classification of Arabidopsis thaliana. Here, we provide a preliminary overview of this gene family in tobacco, describing the gene structure, gene expression, protein motif organization, phylogenetic analysis, and comparative analysis in tobacco, Arabidopsis, and rice. Using the sequences of 21 GRAS genes in Arabidopsis to search against the American tobacco genome database, 21 homologous GRAS genes in tobacco were identified. Sequence analysis indicates that these GRAS proteins have five conserved domains, which is consistent with their counterparts in other plants. Phylogenetic analyses divided the GRAS gene family into eight subgroups, each of which has distinct conserved domains and biological functions. Furthermore, the expression pattern of these 21 GRAS genes reveals that most are expressed in all six tissues studied; however, some have tissue specificity. Taken together, this comprehensive analysis will provide a rich resource to assist in the study of GRAS protein functions in tobacco.