Surgical treatment of nasopharyngeal cancer - a consensus recommendation from two Chinese associations.

BACKGROUND: Surgical treatment is playing an increasingly important role in the management of nasopharyngeal carcinoma (NPC). This consensus focuses on the indications for optimal surgery, and surgical methods in the whole process of treatment for NPC to provide a useful reference to assist these difficult clinical decisions. METHODOLOGY: A thorough review of available literature on NPC and surgery was conducted by the Association for the prevention and treatment of nasopharyngeal carcinoma in China, international exchange and promotion Association for medicine and healthcare, and the Committee on nasopharyngeal cancer of Guangdong provincial anticancer association. A set of questions and a preliminary draft guideline was circulated to a panel of 1096 experienced specialists on this disease for voting on controversial areas and comments. A refined second proposal, based on a summary of the initial voting and different opinions expressed, was recirculated to the experts in two authoritative medical science and technology academic groups in the prevention and treatment of NPC in China for review and reconsideration. RESULTS: The initial round of questions showed variations in clinical practice even among similar specialists, reflecting the lack of high-quality supporting data and resulting difficulties in formulating clinical decisions. Through exchange of comments and iterative revisions, recommendations with high-to-moderate agreement were formulated on general treatment strategies and details of surgery, including indications and surgical approaches. CONCLUSION: By standardizing the surgical indications and practice, we hope not only to improve the surgical outcomes, but also to highlight the key directions of future clinical research in the surgical management of NPC.

[Effect of dual fluorescence imaging in identifying central lymph nodes and parathyroid glands during thyroid cancer surgery].

Objective: To investigate the effect of dual fluorescence imaging in identifying central lymph nodes and parathyroid glands during thyroid cancer surgery. Methods: This study was a cross-sectional study. Patients who underwent surgery for papillary thyroid cancer (PTC) at the Department of Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University between January 2022 and September 2023 were included. All patients underwent thyroid lobectomy or total resection, and central lymph node dissection was performed at the same time. During the operation, tracing injection of mitoxantrone hydrochloride and 785 nm and 660 nm dual fluorescence imaging technique were used to measure the fluorescence intensity (FI) of parathyroid glands, central lymph nodes and background. After correcting to obtain the standardized FI, the paired t-test was used to compare the standardized FI of the parathyroid glands and central lymph nodes, and the Spearman's rank correlation analysis was used to analyze the relationship between the standardized FI and various clinical indicators. Results: The study included 30 patients (8 males and 22 females), with a mean age of (41.8±10.4) years. A total of 76 parathyroid glands and 234 central lymph nodes were identified under dual fluorescence imaging, and the standardized FI of parathyroid glands was less than that of central lymph nodes (44.7±16.8 vs 99.5±28.4, P<0.001). The visualization rate, false rate and miscut rate of parathyroid glands under 785 nm wavelength excitation light were 98.7% (76/77), 0 (0/77) and 1.3% (1/77), respectively (one case with no visualization and miscutting parathyroid gland was the encapsulated type). The visualization rate of central lymph nodes under 660 nm wavelength excitation light was 98.7% (234/237). There was no significant correlation between FI and clinical indicators such as gender, age, height, weight, body mass index, preoperative thyroid stimulating hormone, thyroglobulin antibody, thyroid microsomal antibody, serum calcium, parathyroid hormone level and surgical procedure (all P>0.05). Conclusion: Dual fluorescence imaging of central lymph nodes and parathyroid glands can improve the ability to identify parathyroid gland while assisting central lymph node dissection.

[Standardized and individualized treatment improves survival rate and quality of life for advanced thyroid cancer].

The overall prognosis of differentiated thyroid carcinoma is favorable, but some patients still progress to a locally advanced stage. At present, there are still some problems in the diagnosis and treatment of locally advanced thyroid cancer, which have not been completely clarified, and have caused some problems to the clinical treatment. This article provides a comprehensive analysis and elaboration on the selection of surgical methods for local advanced thyroid cancer, management of recurrent laryngeal nerve and trachea, timing selection of staging surgery, and targeted therapy, aiming at promoting standardized and individualized treatment for advanced thyroid cancer and improving the survival rate and quality of life.

[Application of near-infrared autofluorescence imaging-based convolution neural network in recognition of parathyroid gland].

Objective: To investigate the application value of near-infrared autofluorescence imaging-based convolution neural network (CNN) for automatic recognition of parathyroid gland. Methods: The data of 83 patients who underwent thyroid papillary cancer surgery in the Department of Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University from August 2020 to March 2022 were retrospectively analyzed, and a total of 725 autofluorescence images of parathyroid gland were collected during the surgery. Meanwhile, non-parathyroid fluorescence imaging videos in the operation area of 10 patients were also collected, and 928 non-parathyroid fluorescence images were captured from those videos. The fluorescence images of parathyroid and non-parathyroid glands were directly used as input features for deep learning to construct ResNet 34, VGGNet 16 and GoogleNet models for automatic parathyroid identification. The ability of different models to identify parathyroid glands was tested by indicators such as accuracy, specificity, sensitivity, precision, receiver operating characteristic curve and area under the curve (AUC). In addition, 30 fluorescence images of parathyroid and 35 fluorescence images of non-parathyroid glands in 13 patients with papillary thyroid cancer from March to May 2022 were collected to prospectively test the best performing CNN model. Results: Among the 83 patients, there were 25 males and 58 females, with the mean age of (46.7±12.4) years. In the binary classification (parathyroid gland and non-parathyroid gland), the ResNet 34 model performed the best in different CNN models, the accuracy, specificity, sensitivity and precision of the identification test set were 97.6%, 96.3%, 99.3% and 95.5%, and the AUC reached 0.978 (95%CI: 0.956-0.991). In the prospective test, the prediction accuracy of the ResNet 34 model reached 93.8%, and the AUC was 0.938 (95%CI: 0.853-0.984). Conclusion: The near-infrared autofluorescence imaging-based deep CNN has good application value in the automatic recognition of parathyroid gland, and can be used to assist the recognition and protection of parathyroid gland in thyroid cancer surgery.

[Preliminary analysis of neuroprotective effects of capillary fascia preservation recurrent laryngeal nerve anatomical method in right level â ¥ dissection].

Objective: To investigate the application and effect of capillary fascia preservation between the recurrent laryngeal nerve (RLN) and common carotid artery (fascia preservation method) in nerve protection when dissecting right level Ⅵ lymph nodes for patients with papillary thyroid carcinoma. Methods: A retrospective cohort study enrolling 195 patients with papillary thyroid carcinoma undergoing right level Ⅵ lymph node dissection in Beijing Tongren Hospital from March 2021 to August 2022 was carried out. The RLN was dissected by fascia preservation method in study group and by routine method in control group. The intraoperative electrical signal amplitude of the RLN, the number of dissected lymph nodes, and the postoperative complications were recorded and analyzed. Results: A total of 195 patients (study group: 94 cases, control group: 101 cases) were collected. There were 71 males and 124 females, with the median age of 32 (39, 51) years. In the study group, the total number of right level Ⅵ lymph nodes was significantly larger than the number of right Ⅵa level lymph nodes [8 (6, 11) vs 6 (4, 8), P<0.001]. There were no significant differences between the two groups in the number of level Ⅵa or level Ⅵb lymph nodes [Ⅵa: 6 (4, 8) vs 5 (3, 7), P=0.373; Ⅵb: 3 (1, 4) vs 2 (1, 4), P=0.337] and metastasis rate [Ⅵa: 51.1% (48/94) vs 52.5% (53/101), P=0.844; Ⅵb: 12.8% (12/94) vs 15.8% (16/101), P=0.541]. The ratio of electromyography (EMG) amplitude R2 in lower level Ⅵ and entry into larynx (grouped as>90%, 50%~90%,<50%) in the study group was significantly higher than that in the control group (P<0.001). No significant differences were detected between the two groups in temporary RLN paralysis [1.1% (1/94) vs 2.0% (2/101), P=1.000]. Conclusions: Fascia preservation method can decrease the stimulus and traction to RLN and preserve the capillary network serving RLN. It can thoroughly dissect lymph nodes and decrease the injury of RLN.

[Diagnosis and treatment of differentiated thyroid carcinoma: hot spots and controversies].

Thyroid cancer is the most common endocrine tumor. Although the research on thyroid cancer has been studied in depth, there are still many problems remaining controversial. In this article, the routine screening and preoperative evaluation of differentiated thyroid carcinoma, surgical management and adjuvant therapy, and basic translational research were analyzed from multiple perspectives. Besides, the current hot spots and controversies in the field of thyroid cancer from basic to clinical research were reviewed, aiming to further promote the hierarchical management and precise diagnosis and treatment of thyroid tumors.

[Association of extranodal extension and lymph node ratio with radioactive iodine-refractory papillary thyroid cancer].

Objective: To investigate the related factors of radioiodine-refractory thyroid cancer (RAIR-DTC) and the increase of cumulative iodine treatment dose. Methods: The data of patients with papillary thyroid cancer who underwent surgery and iodine treatment for the first time in the Affiliated Cancer Hospital of Zhengzhou University from January 2015 to December 2017 were retrospectively analyzed. The related factors of RAIR-DTC and the increase of cumulative iodine treatment dose were explored. Results: A total of 650 patients were enrolled, including 217 males (33.4%) and 433 females (66.6%), aged 45 (34, 53) years. There were 123 patients (18.9%) over 55 years old, 171 patients (26.3%) with extranodal extension and 18 patients (2.8%) with distant metastasis. The median lymph node ratio was 0.22 (0.11, 0.33). Twenty patients (3.1%) had an accumulated iodine treatment dose>400 mCi and 19 patients (2.9%) had RAIR-DTC. Multivariate logistic regression analysis showed that extranodal extension (OR=19.833, 95%CI: 6.057-73.325, P<0.001) was related factors for the increase of cumulative iodine treatment dose. Age>55 years old (OR=3.322, 95%CI: 1.136-9.466, P=0.024), distant metastasis (OR=10.059, 95%CI: 2.508-38.888, P<0.001), extranodal extension (OR=5.278, 95%CI: 1.707-19.813, P=0.006) and lymph node ratio (OR=34.724, 95%CI: 2.749-384.575, P=0.004) were related factors for RAIR-DTC. Conclusions: Extranodal extension and lymph node ratio are related factors for RAIR-DTC. In clinical practice, more attention should be paid to the influence of different lymph node metastasis characteristics on the occurrence of RAIR-DTC and the cumulative therapeutic dose of iodine.

[Role of preoperative ultrasound-guided inferior parathyroid gland localization and new classification to assist intraoperative search and protection of parathyroid glands].

Objective: To investigate the role and significance of ultrasound-guided inferior parathyroid gland (IPTG) localization in searching and protecting parathyroid glands before thyroid surgery. Methods: A randomized controlled trial study was conducted. A total of 306 patients (433 cases of lateral parathyroidectomy) who underwent primary thyroidectomy and central lymph node dissection in Beijing Tongren Hosipital from March to October 2021 were enrolled. In order to locate IPTG more quickly and effectively, new IPTG classification and the definition of quadrant position were carried out. The patients were divided into the study group (n=228) and the control group (n=205). The study group underwent ultrasound-guided IPTG examination before operation and measured the distance between the IPTG and the lower pole of the thyroid and the midline of the trachea. During the operation, the IPTG was found and protected depending on the localization. The control group did not use any auxiliary preoperative positioning method. The distribution ratio of IPTG and the coincidence rate between intraoperative validation and ultrasound localization were calculated. Results: There were 306 patients enrolled in the final analysis (95 males and 211 females), with a median age of 41 years old (18-70). Type Ⅱ and Ⅲ IPTG accounted for 77.2% (176/228) of the total cases. The total coincidence rate ranged from 72.8% to 79.4% in different IPTG groups. Type Ⅲ and quadrant 2 IPTG had the highest coincidence rate [92.4% (73/79) and 92.9% (79/85), respectively]. The study group had better in situ retention rate [82.0% (187/228) vs 73.2% (150/205), χ2=4.896, P=0.027] and less implantation rate [8.8% (20/228) vs 16.1% (33/205), χ2=5.393, P=0.020] than those of the control group. The in situ retention rate were better in type Ⅲ IPTG group, compared with those of the control group [94.9% (74/78) vs 77.4% (48/62), χ2=7.898, P=0.005]. There was no permanent hypoparathyroidism in two groups and the temporary hypoparathyroidism rate was 32.0% (24/75) and 34.6% (18/52), respectively (χ2=0.095, P=0.758). Conclusion: Ultrasound-guided IPTG localization examination has important implications for searching and protecting IPTG during operation, which can significantly increase in situ retention rate of IPTG and decrease the implantation rate.

[Clinical characteristics and prognosis in papillary thyroid carcinoma patients with recurrent laryngeal nerve invasion].

Objective: To investigate the clinical characteristics and risk factors of postoperative recurrence in papillary thyroid carcinoma (PTC) patients with recurrent laryngeal nerve (RLN) invasion. Methods: The data of PTC patients with recurrent laryngeal nerve invasion treated in Beijing Tongren Hospital, Capital Medical University from January 2006 to December 2019 were retrospectively analyzed. The acoustic parameters were compared between different subgroups. Kaplan-Meier method was used to calculate the overall survival (OS) and the recurrence-free rate (RFS), and univariate and multivariate Cox regression analyses were performed to determine the risk factors for postoperative recurrence. Results: A total of 150 PTC patients were enrolled in the final analysis, including 102 females and 48 males, with an average age of (53.5±13.7) years, and 62 patients (41.3%) aged over 55 years. There were 88 cases with stage Ⅰ, and 62 cases with stage Ⅲ. Fifty-five patients presented with preoperative vocal cord paralysis. There were 75 cases appearing adhesion between tumor or lymph node and recurrent laryngeal nerve while 75 cases presented with direct invasion. The comparisons of acoustic parameters showed that patients with RLN invasion had higher jitter compared with patients without RLN invasion [2.3% (1.4%, 3.2%) vs 1.8% (0.8%, 2.6%), P<0.001]. Moreover, patients with preoperative vocal cord paralysis (VCP) had higher jitter[3.1% (2.2%, 4.6%) vs 2.0% (1.1%, 2.8%), P<0.001] and shimmer [7.1% (4.9%, 9.9%) vs 5.5% (4.2%, 7.3%), P<0.001] and shorter maximum phonation time (MPT) [8.0 (6.0, 10.0) s vs 12.0 (10.0, 15.3) s, P<0.001] compared with patients without preoperative VCP. However, there was no statistical difference in acoustic parameters between cases with RLN adhesion and RLN invasion (all P>0.05). Postoperative follow-up time ranged between 12-196 months, with an average of (65.0±35.9) months. Sixteen patients (10.7%) had recurrence or metastasis, and 8 cases (5.3%) died of recurrence or metastasis. The 5-year OS rate was 95.1%, and the 10-year OS rate was 92.8%. The 5-year RFS rate was 88.9%, and the 10-year RFS rate was 86.2%. Univariate Cox analysis showed that age of onset ≥ 55 years, preoperative recurrent laryngeal nerve palsy, laryngeal, trachea or esophageal invasion were the risk factors for postoperative recurrence of PTC with RLN invasion (all P<0.05). Multivariate Cox analysis showed that age of onset ≥ 55 years (OR=1.060, 95%CI: 1.011-1.110, P=0.015) was an independent risk factor. Conclusions: Age of onset ≥ 55 years is an independent risk factor for postoperative recurrence in PTC patients with RLN invasion. Preoperative acoustic parameters may provide reference for evaluation of RLN function.

[Quantitative dynamic contrast enhancement MR imaging parameters in the prediction and evaluation of the treatment response of malignant sinonasal tumors to chemotherapy:a preliminary result].

Objective: To investigate the value of quantitative dynamic contrast enhancement MR imaging (DCE-MRI) parameters in the prediction and evaluation of the response to neoadjuvant chemotherapy in patients with malignant sinonasal tumors by comparing the parameter values before and after chemotherapy. Methods: DCE-MRI was performed in 14 patients (6 male cases, 8 female cases, 16-83 years) with malignant sinonasal tumors before chemotherapy in Beijing Tongren Hospital from January 2012 to December 2013 in which DCE-MRI was performed in 8 patients on the 7th, 21st and 42nd days after chemotherapy. The values of quantitative parameter including K(trans), K(ep), and V(e) of the tumor were assessed and the change rate of these quantitative parameter values after chemotherapy was calculated. Results: Response to chemotherapy of the tumor was found in 11 patients with malignant sinonasal tumors,whereas no response to chemotherapy of the tumor was confirmed in 3 patients. K(trans) ((0.75±0.28)/min) and K(ep) ((3.23±1.48)/min) values of the tumor before chemotherapy in patients with response to chemotherapy were significantly bigger than those ((0.43±0.41)/min, (1.34±0.42)/min) in patients with no response to chemotherapy (all P<0.01).There was no significant difference in V(e) values between two groups (P=0.165). Compared with K(trans) values of the tumor before chemotherapy,the change rate of K(trans) values decreased more than 40% on the 7th,21st and 42nd days after chemotherapy in the patients with treatment response,whereas the change rate did not decrease significantly in the patients without treatment response. Conclusion: The bigger K(trans) and K(ep) values of the tumor before chemotherapy,the better the treatment response of the tumor to chemotherapy.

Cloning and bioinformatic analysis of transcription factor MYB10 from the red-leaf peach.

In higher plants, the transcription factor MYB10 is an important regulator of anthocyanin biosynthesis. In order to study its role in the development of red coloration in peach leaves, the full-length MYB10 complementary DNA sequence of the red-leaf peach cultivar 'Tsukuba No. 5' (Prunus persica f. atropurpurea) was successfully cloned using reverse transcription-polymerase chain reaction. The sequence was assigned the GenBank accession No. KP315904. Bioinformatic analysis identified the complete MYB10 open reading frame, consisting of 678 bp encoding 225 amino acids. The predicted protein has a molecular weight of 26.56 kDa and a theoretical isoelectric point of 8.97. The secondary structure was found to comprise approximately 34.22% alpha helix, 15.11% extended strand, 10.67% beta turn, and 40% random coil. Subcellular analysis indicated that MYB10 may function in the cytoplasm. Assessment of the amino acid sequence suggested the presence of one serine and two threonine phosphorylation sites. Quantitative real-time polymerase chain reaction revealed that MYB10 expression positively correlated with anthocyanin content in red-leaf peach, indicating that this transcription factor plays a role in the biosynthesis of this pigment in peach trees.

Suppression of Inflammatory Responses by Dihydromyricetin, a Flavonoid from Ampelopsis grossedentata, via Inhibiting the Activation of NF-κB and MAPK Signaling Pathways.

Ampelopsis grossedentata, an indigenous plant in southern China, has been used for treating pharyngitis in traditional Chinese medicine for hundreds of years. In this study, we explored the anti-inflammatory activity of dihydromyricetin (1), its major bioactive component, and the underlying mechanism of this action. We demonstrated that 1 suppressed the levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) as well as increased the level of the anti-inflammatory cytokine interleukin-10 (IL-10) in lipopolysaccharide (LPS)-treated mice. Moreover, 1 was found to markedly inhibit the production of nitric oxide (NO) and the levels of TNF-α, IL-1ß, and IL-6, whereas it increased the level of IL-10 in LPS-induced RAW 264.7 macrophage cells. Compound 1 also reduced the protein expression of inducible nitric oxide synthase (iNOS), TNF-α, and cyclooxygenase-2 (COX-2) in macrophage cells. Furthermore, 1 suppressed the phosphorylation of NF-kappa B (NF-κB) and IκBα as well as the phosphorylation of p38 and JNK but not ERK1/2 in LPS-stimulated macrophages. Taken together, the present results suggest that 1 exerts its topical anti-inflammatory action through suppressing the activation of NF-κB and the phosphorylation of p38 and JNK. Thus, 1 may be a potentially useful therapeutic agent for inflammatory-related diseases.

Identification of apple cultivars on the basis of simple sequence repeat markers.

DNA markers are useful tools that play an important role in plant cultivar identification. They are usually based on polymerase chain reaction (PCR) and include simple sequence repeats (SSRs), inter-simple sequence repeats, and random amplified polymorphic DNA. However, DNA markers were not used effectively in the complete identification of plant cultivars because of the lack of known DNA fingerprints. Recently, a novel approach called the cultivar identification diagram (CID) strategy was developed to facilitate the use of DNA markers for separate plant individuals. The CID was designed whereby a polymorphic maker was generated from each PCR that directly allowed for cultivar sample separation at each step. Therefore, it could be used to identify cultivars and varieties easily with fewer primers. In this study, 60 apple cultivars, including a few main cultivars in fields and varieties from descendants (Fuji x Telamon) were examined. Of the 20 pairs of SSR primers screened, 8 pairs gave reproducible, polymorphic DNA amplification patterns. The banding patterns obtained from these 8 primers were used to construct a CID map. Each cultivar or variety in this study was distinguished from the others completely, indicating that this method can be used for efficient cultivar identification. The result contributed to studies on germplasm resources and the seedling industry in fruit trees.

Identification of grapevine rootstock cultivars using expressed sequence tag-simple sequence repeats.

Grapevine (Vitis) rootstock varieties or cultivars are used to confer resistance and tolerance to insect and disease pests, unfavorable soil conditions, and other environmental conditions to cultivars that are susceptible to these conditions but otherwise have desired properties. The need to genotype and thoroughly identify grapevine rootstock varieties in the grape industry has become increasingly critical as more and more varieties are bred or selected. Although DNA markers have advantageous applications in plant identification, markers developed from classic DNA fingerprint analysis methods are not practical for plant cultivar identification. The manual cultivar identification diagram (MCID), which was previously developed in our research group, has been shown to select DNA markers that are relatively more exploitable in identifications of genotyped plant individuals. Using this MCID strategy and expressed sequence tag-simple sequence repeat (EST-SSR) markers, we identified 22 grapevine rootstock cultivars of diverse origin. All cultivars were clearly separated by fingerprints of seven pairs of EST-SSR primers and the grapevine rootstock CID (V-R-CID) generated is both practical and referable for the identification of any grapevine rootstock cultivars studied here. Furthermore, fewer primers can be used to distinguish all cultivars using this approach since the fingerprint from each primer pair could be used several times once it is generated. This initial version of V-R-CID can be made more informative with the identification and incorporation of more cultivars, thus providing better service to the grape industry.

Cloning and expression of UDP-glucose: flavonoid 3-O-glucosyltransferase gene in peach flowers.

To elucidate the connection between flower coloration and the expression of genes associated with anthocyanin biosynthesis, a gene encoding UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT) was isolated, and the expression of the last four genes in the anthocyanin biosynthetic pathway during peach flower development was determined. The nucleotide sequence of the peach UFGT (GenBank accession No. JX149550) is highly similar to its homologs in other plants. Total anthocyanin content initially increased during peach flower development, and then decreased over time. Expression of the four anthocyanin biosynthesis genes increased until the full-bloom stage, and then decreased during late florescence. Expression of F3H, DFR, and UFGT increased dramatically at the full-bloom stage, coinciding with an increase in anthocyanin concentration. The UFGT gene may not be the only gene of the anthocyanin pathway to be differentially controlled in red peach flower tissues. Further studies are needed to genetically and physiologically characterize these genes and enzymes in peach flowers and to gain a better understanding of their functions and relationships with flower coloration.

Characterization of EST-derived and non-EST simple sequence repeats in an F1 hybrid population of Vitis vinifera L.

Among different classes of molecular markers, expressed sequence tags (ESTs) are a new resource for developing simple sequence repeat (SSR) functional markers for genotyping and genetic mapping in F1 hybrid populations of Vitis vinifera L. Recently, because of the availability of an enormous amount of data for ESTs in the public domain, the emphasis has shifted from genomic SSRs to EST-SSRs, which belong to transcribed regions of the genome and may have a role in gene expression or function. The objective of this study was to assess the polymorphisms among 94 F1 hybrids from "Early Rose" and "Red Globe" using 25 EST-derived and 25 non-EST SSR markers. A total collection of 362,375 grape ESTs that were retrieved from the National Center for Biotechnology Information (NCBI) and 2522 EST-SSR sequences were identified. From them, 205 primer pairs were randomly selected, including 176 pairs that were EST-derived and 29 non-EST SSR primer pairs, for polymerase chain reaction amplification. A total of 131 alleles were amplified using 50 pairs of primers; 78 alleles were amplified using EST-derived SSR primers and 53 were from non-EST SSR primers. At most, 6 and 5 alleles were amplified by EST-derived and non-EST SSR primers, respectively. The EST-derived SSR markers showed a maximum polymorphic information content (PIC) value of 1 and a minimum of 0.33 while non-EST SSR markers had maximum and minimum PIC values of 1 and 0.25, respectively. The average PIC value was 0.56 for EST-derived SSR markers and 0.45 for non-EST SSR markers.

A novel and efficient strategy for practical identification of tomato (Solanum lycopersicon) varieties using modified RAPD fingerprints.

Tomato breeding and variety development have led to the generation of a large number of varieties in many countries worldwide. This has created a growing and urgent need for an improved strategy for genotyping and identification since the traditional methods based on phenotype are growing unreliable. DNA markers could provide distinct benefits in tomato variety identification; however, DNA fingerprint analyses have not made DNA marker data readily usable for identification of varieties in tomato and other crops. A manual cultivar and/or variety identification diagram (MCID) strategy has been developed and has been found to make DNA markers more usable for the identification of genotyped plant individuals. We adopted this strategy, using modified RAPD markers to identify 42 tomato varieties from different geographical origins and seed merchants. All of the varieties were clearly separated and individually identified by reproducible fingerprints of only 6 RAPD primers. The tomato MCID that is generated is usable for the identification of any two or more tomato varieties. In addition, fewer primers can be used to make a distinction between varieties using this approach, since the selected fingerprints from each primer are used after they have been generated. The information in this first version of the tomato MCID can be enriched through identification and incorporation of more varieties and adaptation to other molecular markers in order to provide a more comprehensive tomato variety identification service for the horticultural industry.

Characterization of SNPs in strawberry cultivars in China.

Single nucleotide polymorphisms (SNPs) occur at high frequencies in both plant and animal genomes and can provide broad genome coverage and reliable estimates of genetic relationships. The availability of expressed sequence tag (EST) data has made it feasible to discover SNPs. DNA analysis is crucial in genetic studies not only for strawberry breeding programs but also for characterization of hybrids and species. We cloned 96 EST sequences, and 116 SNPs were discovered by comparing 16 strawberry cultivars grown in the region of Nanjing, China. Sequence alignment of 6 group sequences derived from 16 sample cultivars yielded 116 SNPs, within a total genomic sequence length of 1755 bp. The SNPs were discovered with a mean frequency of one SNP per 15 bp. These SNPs were comprised of 57% transitions, 32.7% transversions, 8.6% InDels, and 1.7% others, based on which a phylogenetic tree was constructed. Among the 116 SNPs, 75% were located within the open reading frame (ORF), while 25% were located outside the ORF. All 16 cultivars scattered well in dendrogram derived from the SNP data, demonstrating that SNPs can be a powerful tool for cultivar identification and genetic diversity analysis in strawberries.

Development of highly polymorphic EST-SSR markers and segregation in F1 hybrid population of Vitis vinifera L.

The objectives of this investigation were to develop and validate the expressed sequence tag (EST)-simple sequence repeat (SSR) markers from large EST sequences, and to study the segregation and distribution of SSRs within two grapevine parental lines. In total, 94 F1 lines crossed between "Early Rose" and "Red Globe" were studied. Approximately 2100 EST-SSR sequences of Vitis vinifera L. were searched for SSRs and analyzed for the design of polymerase chain reaction (PCR) primers amplifying the SSR-rich regions. Trinucleotide repeats were found to be the most abundant, followed by other nucleotide repeats. A total of 182 SSR primer pairs were first developed for the study on the parental polymorphism. Among the 182 SSR primers, 142 primer pairs (78%) could amplify the anticipated PCR products, among which only 52 primer pairs (36.62%) showed polymorphism between the two parents. These polymorphic bands were further surveyed among the 94 F1 lines, and the results showed that a total of 162 bands were amplified, and 98 of them were polymorphic in both parents (60.86% polymorphism), with an average of 1.88 polymorphic DNA bands for each primer pair. After testing with the chi-square test, 33 of the clearly amplified polymorphic bands followed a 3:1 ratio, and 37 followed a 1:1 ratio. The rest showed distorted segregation ratios.