Biomedical subjects

Zhen Zhang

Publications and source records attributed to Zhen Zhang.

At least 37 records · Page 2Linked to original sources

PubMed2006

Mesodermal expression of Tbx1 is necessary and sufficient for pharyngeal arch and cardiac outflow tract development.

The development of the segmented pharyngeal apparatus involves complex interaction of tissues derived from all three germ layers. The role of mesoderm is the least studied, perhaps because of its apparent lack of anatomical boundaries and positionally restricted gene expression. Here, we report that the mesoderm-specific deletion of Tbx1, a T-box transcription factor, caused severe pharyngeal patterning and cardiovascular defects, while mesoderm-specific restoration of Tbx1 expression in a mutant background corrected most of those defects in the mouse. We show that some organs, e.g. the thymus, require Tbx1 expression in the mesoderm and in the epithelia. In addition, these experiments revealed that different pharyngeal arches require Tbx1 in different tissues. Finally, we show that Tbx1 in the mesoderm is required to sustain cell proliferation. Thus, the mesodermal transcription program is not only crucial for cardiovascular development, but is also key in the development and patterning of pharyngeal endoderm.

Animals↗

PubMed2006

Development of a chemiluminescent ELISA for determining chloramphenicol in chicken muscle.

An indirect competitive enzyme-linked immunosorbent assay (ELISA) with chemiluminescent (CL) detection for chloramphenicol (CAP) in chicken muscle was developed. CAP-specific polyclonal antibody was raised in rabbit with a CAP-succinate derivative conjugated with bovine serum albumin. Luminol solution was used as the substrate of horseradish peroxidase. The detection limit was 6 ng/L. The CL-ELISA was 10 times more sensitive compared to the colorimetric-ELISA. When CAP was spiked in chicken muscle at levels of 0.05-5 microg/kg, recoveries ranged from 97 to 118% with coefficients of variation of 6-22%. In an actual residue study, the results obtained by CL-ELISA correlated well with those obtained by gas chromatography with microcell electron capture detector. The residue levels of CAP in treated chicken decreased with time and dropped rapidly after the first 6 h from around 50 to 10 microg/kg. After 3 days, CAP was not detected in chicken muscle. The developed method is therefore suitable for screening of CAP in chicken muscle samples.

Animals↗

PubMed2006

The Wilms tumor gene, Wt1, is required for Sox9 expression and maintenance of tubular architecture in the developing testis.

Mutation of the transcription factor and tumor suppressor gene WT1 results in a range of genitourinary anomalies in humans, including 46,XY gonadal dysgenesis, indicating that WT1 plays a critical role in sex determination. However, because knockout of Wt1 in mice results in apoptosis of the genital ridge, it is unknown whether WT1 is required for testis development after the initial steps of sex determination. To address this question, we generated a mouse strain carrying a Wt1 conditional knockout allele and ablated Wt1 function specifically in Sertoli cells by embryonic day 14.5, several days after testis determination. Wt1 knockout resulted in disruption of developing seminiferous tubules and subsequent progressive loss of Sertoli cells and germ cells such that postnatal mutant testes were almost completely devoid of these cell types and were severely hypoplastic. Thus, Wt1 is essential for the maintenance of Sertoli cells and seminiferous tubules in the developing testes. Of particular note, expression of the testis-determining gene Sox9 in mutant Sertoli cells was turned off at embryonic day 14.5 after Wt1 ablation, suggesting that WT1 regulates Sox9, either directly or indirectly, after Sry expression ceases. Our data, along with previous work demonstrating the role of Wt1 at early stages of gonadal development, thus indicate that Wt1 is essential at multiple steps in testicular development.

Alleles↗

PubMed2006

Notch3 gene amplification in ovarian cancer.

Gene amplification is one of the common mechanisms that activate oncogenes. In this study, we used single nucleotide polymorphism array to analyze genome-wide DNA copy number alterations in 31 high-grade ovarian serous carcinomas, the most lethal gynecologic neoplastic disease in women. We identified an amplicon at 19p13.12 in 6 of 31 (19.5%) ovarian high-grade serous carcinomas. This amplification was validated by digital karyotyping, quantitative real-time PCR, and dual-color fluorescence in situ hybridization (FISH) analysis. Comprehensive mRNA expression analysis of all 34 genes within the minimal amplicon identified Notch3 as the gene that showed most significant overexpression in amplified tumors compared with nonamplified tumors. Furthermore, Notch3 DNA copy number is positively correlated with Notch3 protein expression based on parallel immunohistochemistry and FISH studies in 111 high-grade tumors. Inactivation of Notch3 by both gamma-secretase inhibitor and Notch3-specific small interfering RNA suppressed cell proliferation and induced apoptosis in the cell lines that overexpressed Notch3 but not in those with minimal amount of Notch3 expression. These results indicate that Notch3 is required for proliferation and survival of Notch3-amplified tumors and inactivation of Notch3 can be a potential therapeutic approach for ovarian carcinomas.

Chromosomes, Human, Pair 19↗

PubMed2006

Studies of interaction between a new synthesized minor-groove targeting artificial nuclease and DNA.

Nuclease plays an important role in molecular biology, such as DNA sequencing. Synthetic polyamide conjugates can be considered as new tool in the selective inhibition of gene expression and as potential drugs in anticancer or antiviral chemotherapy. In this paper, a new synthesized minor-groove targeting artificial nuclease, oligopyrrol-containing peptide, was reported. It was found that this new compound can bind DNA in AT-riched minor groove with high affinity and site specificity. DNA binding behavior was determined by UV-vis and circular dichroism (CD) methods. It was indicated that compound 6 can enhance the Tm of oligomer DNA from 51.8 to 63.5 degrees C and possesses large binding constant (Kb=8.83x10(4)L/mol).

Animals↗

PubMed2006

Spermatogonial differentiation in juvenile spermatogonial depletion (jsd) mice with androgen receptor or follicle-stimulating hormone mutations.

The jsd mice experience a single wave of spermatogenesis, followed by an arrest of spermatogenesis because of a block in spermatogonial differentiation. Previous pharmacological and surgical studies have indicated that testosterone (T) and low scrotal temperatures but not FSH block spermatogonial differentiation in jsd mice. We sought to test these observations by genetic approaches by producing male jsd mutant mice with either defective androgen receptor (AR, Tfm mutation) or a deficiency of FSH (fshb(-/-)). In adult jsd-Tfm double-mutant mice, the tubule differentiation index was 95% compared with 14% in jsd littermates, suggesting that general ablation of AR function restored spermatogonial differentiation in jsd mice. The results indicated that this enhancement of differentiation was primarily a result of elevation of temperature caused by the cryptorchid position of the testis in jsd-Tfm double-mutant mice, which resulted from the lack of AR in the gubernaculum. The low levels of T were not a factor in the release of the spermatogonial differentiation block in the jsd-Tfm mice, but we were unable to determine whether inactivation of AR in the adult jsd testis had a direct effect on the restoration of spermatogonial differentiation because the elevated temperature bypassed the T-induced block in spermatogonial differentiation. Although spermatogonia were indeed present in adult jsd-fshb double-mutant mice and were capable of differentiation after androgen deprivation, these mice had a tubule differentiation index of 0%, ruling out the possibility that endogenous FSH inhibited spermatogonial differentiation in jsd mice. The results are consistent in support of the hypothesis that inhibition of spermatogonial differentiation in jsd mice is a result of T acting through the AR only at scrotal temperatures.

Animals↗

PubMed2006

High level expression of a synthetic gene encoding Peniophora lycii phytase in methylotrophic yeast Pichia pastoris.

Phytase is widespread in nature. It has been used as a cereal feed additive that can enhance the phosphorus and mineral absorption in monogastric animals to reduce the level of phosphorus output in manure. Phytase of Peniophora lycii is a 6'-phytase, which owns high specific activity. To achieve a high expression level of 6'-phytase in Pichia pastoris, the 1,230-bp phytase gene of P. lycii was synthesized and optimized for codon usage, G+C content, as well as mRNA secondary structures. The gene constructs containing wild type or modified phytase gene coding sequences under the control of the highly-inducible alcohol oxidase gene (AOX1) promoter, the synthetic signal peptide (designated MF4I), which is a codon-modified Saccharomyces cerevisiae mating factor alpha-prepro-leader sequence, were used to transform P. pastoris. The P. pastoris strain that expressed the modified phytase gene (phy-pl-sh) with MF4I sequence produced 12.2 g phytase per liter of fluid culture, with the phytase activity of 10,540 U ml(-1). The yield of the modified phytase gene, with bias codon usage and MF4I signal, is 4.4 times higher than that of the wild type gene with MF4I signal and 13.6 times higher than that of the wild type gene with wild type S. cerevisiae signal. The recombinant phytase had one optimum pH (pH 4.5) and an optimum temperature of 50 degrees C. The P. pastoris strain expressed the modified 6-phytase gene, with the MF4I signal peptide showing great potential as a commercial phytase production system.

6-Phytase↗

PubMed2006

Fgf8 expression in the Tbx1 domain causes skeletal abnormalities and modifies the aortic arch but not the outflow tract phenotype of Tbx1 mutants.

Fgf8 and Tbx1 have been shown to interact in patterning the aortic arch, and both genes are required in formation and growth of the outflow tract of the heart. However, the nature of the interaction of the two genes is unclear. We have utilized a novel Tbx1(Fgf8) allele which drives Fgf8 expression in Tbx1-positive cells and an inducible Cre-LoxP recombination system to address the role of Fgf8 in Tbx1 positive cells in modulating cardiovascular development. Results support a requirement of Fgf8 in Tbx1 expressing cells to finely control patterning of the aortic arch and great arteries specifically during the pharyngeal arch artery remodeling process and indicate that the endoderm is the most likely site of this interaction. Furthermore, our data suggest that Fgf8 and Tbx1 play independent roles in regulating outflow tract development. This finding is clinically relevant since TBX1 is the candidate for DGS/VCFS, characterized clinically by variable expressivity and reduced penetrance of cardiovascular defects; Fgf8 gene variants may provide molecular clues to this variability.

Animals↗

PubMed2006

Quantification of fragments of human serum inter-alpha-trypsin inhibitor heavy chain 4 by a surface-enhanced laser desorption/ionization-based immunoassay.

BACKGROUND: Several proteolytically derived fragments from the proline-rich region (PRR) of human inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) have been identified by surface-enhanced or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS or MALDI-TOF-MS) as potential disease markers. METHODS: Previously, we developed a SELDI-based immunoassay that can simultaneously distinguish and quantify multiple isoforms/variants of a protein/peptide of interest. In this study, we used this high-throughput approach to quantify and characterize the extensive fragmentation within the PRR of human serum ITIH4 and determined its association with different disease conditions. The ITIH4-related fragments were first immunocaptured by use of beads coupled with peptide-specific antibodies. The eluates were then studied by SELDI-TOF-MS. In addition, freshly collected and immediately processed serum and plasma samples were used to analyze the ex vivo stability of these ITIH4 fragments. RESULTS: Human serum ITIH4 was shown to be extensively proteolytically processed within the PRR, and its fragmentation patterns were closely associated with different disease conditions. Fragmentation patterns were generally consistent with cleavages by endoprotease followed by exoprotease actions. Observed fragments changed little under different assay conditions or blood collection and processing procedures. CONCLUSIONS: The fragmentation patterns within the PRR of human serum ITIH4 are associated with different disease conditions and may hold important diagnostic information. These fragmentation patterns could be useful as potential biomarkers for detection and classification of cancer.

Adult↗

PubMed2006

Polarization and experimental configuration analyses of sum frequency generation vibrational spectra, structure, and orientational motion of the air/water interface.

Here we report a detailed study on spectroscopy, structure, and orientational distribution, as well as orientational motion, of water molecules at the air/water interface, investigated with sum frequency generation vibrational spectroscopy (SFG-VS). Quantitative polarization and experimental configuration analyses of the SFG data in different polarizations with four sets of experimental configurations can shed new light on our present understanding of the air/water interface. Firstly, we concluded that the orientational motion of the interfacial water molecules can only be in a limited angular range, instead of rapidly varying over a broad angular range in the vibrational relaxation time as suggested previously. Secondly, because different vibrational modes of different molecular species at the interface has different symmetry properties, polarization and symmetry analyses of the SFG-VS spectral features can help the assignment of the SFG-VS spectra peaks to different interfacial species. These analyses concluded that the narrow 3693 cm(-1) and broad 3550 cm(-1) peaks belong to C(infinityv) symmetry, while the broad 3250 and 3450 cm(-1) peaks belong to the symmetric stretching modes with C2v symmetry. Thus, the 3693 cm(-1) peak is assigned to the free OH, the 3550 cm(-1) peak is assigned to the singly hydrogen-bonded OH stretching mode, and the 3250 and 3450 cm(-1) peaks are assigned to interfacial water molecules as two hydrogen donors for hydrogen bonding (with C2v symmetry), respectively. Thirdly, analysis of the SFG-VS spectra concluded that the singly hydrogen-bonded water molecules at the air/water interface have their dipole vector directed almost parallel to the interface and is with a very narrow orientational distribution. The doubly hydrogen-bonded donor water molecules have their dipole vector pointing away from the liquid phase.

Journal Article↗

PubMed2006

Cotransport of the heterodimeric small subunit of the Saccharomyces cerevisiae ribonucleotide reductase between the nucleus and the cytoplasm.

Ribonucleotide reductase (RNR) catalyzes the rate-limiting step in de novo deoxyribonucleotide biosynthesis and is essential in DNA replication and repair. Cells have evolved complex mechanisms to modulate RNR activity during normal cell cycle progression and in response to genotoxic stress. A recently characterized mode of RNR regulation is DNA damage-induced RNR subunit redistribution. The RNR holoenzyme consists of a large subunit, R1, and a small subunit, R2. The Saccharomyces cerevisiae R2 is an Rnr2:Rnr4 heterodimer. Rnr2 generates a diferric-tyrosyl radical cofactor required for catalysis; Rnr4 facilitates cofactor assembly and stabilizes the resulting holo-heterodimer. Upon DNA damage, Rnr2 and Rnr4 undergo checkpoint-dependent, nucleus-to-cytoplasm redistribution, resulting in colocalization of R1 and R2. Here we present evidence that Rnr2 and Rnr4 are transported between the nucleus and the cytoplasm as one protein complex. Tagging either Rnr2 or Rnr4 with a nuclear export sequence causes cytoplasmic localization of both proteins. Moreover, mutations at the Rnr2:Rnr4 heterodimer interface can affect the localization of both proteins without disrupting the heterodimeric complex. Finally, the relocalization of Rnr4 appears to involve both active export and blockage of nuclear import. Our findings provide new insights into the mechanism of DNA damage-induced RNR subunit redistribution.

Biological Transport, Active↗

PubMed2006

Dicer function is essential for lung epithelium morphogenesis.

DICER is a key enzyme that processes microRNA and small interfering RNA precursors into their short mature forms, enabling them to regulate gene expression. Only a single Dicer gene exists in the mouse genome, and it is broadly expressed in developing tissues. Dicer-null mutants die before gastrulation. Therefore, to study Dicer function in the later event of lung formation, we inactivated it in the mouse lung epithelium using a Dicer conditional allele and the Sonic Hedgehogcre (Shhcre) allele. Branching arrests in these mutant lungs, although epithelial growth continues in distal domains that are expanded compared with normal samples. These defects result in a few large epithelial pouches in the mutant lung instead of numerous fine branches present in a normal lung. Significantly, the initial phenotypes are apparent before an increase in epithelial cell death is observed, leading us to propose that Dicer plays a specific role in regulating lung epithelial morphogenesis independent of its requirement in cell survival. In addition, we found that the expression of Fgf10, a key gene involved in lung development, is up-regulated and expanded in the mesenchyme of Dicer mutant lungs. Previous studies support the hypothesis that precise localization of FGF10 in discrete sites of the lung mesenchyme serves as a chemoattractant for the outgrowth of epithelial branches. The aberrant Fgf10 expression may contribute to the Dicer morphological defects. However, the mechanism by which DICER functions in the epithelium to influence Fgf10 expression in the mesenchyme remains unknown.

Animals↗

PubMed2006

Nuclear localization of the Saccharomyces cerevisiae ribonucleotide reductase small subunit requires a karyopherin and a WD40 repeat protein.

Ribonucleotide reductase (RNR) catalyzes the reduction of ribonucleotides to the corresponding deoxyribonucleotides and is an essential enzyme for DNA replication and repair. Cells have evolved intricate mechanisms to regulate RNR activity to ensure high fidelity of DNA replication during normal cell-cycle progression and of DNA repair upon genotoxic stress. The RNR holoenzyme is composed of a large subunit R1 (alpha, oligomeric state unknown) and a small subunit R2 (beta(2)). R1 binds substrates and allosteric effectors; R2 contains a diferric-tyrosyl radical [(Fe)(2)-Y.] cofactor that is required for catalysis. In Saccharomyces cerevisiae, R1 is predominantly localized in the cytoplasm, whereas R2, which is a heterodimer (betabeta'), is predominantly in the nucleus. When cells encounter DNA damage or stress during replication, betabeta' is redistributed from the nucleus to the cytoplasm in a checkpoint-dependent manner, resulting in the colocalization of R1 and R2. We have identified two proteins that have an important role in betabeta' nuclear localization: the importin beta homolog Kap122 and the WD40 repeat protein Wtm1. Deletion of either WTM1 or KAP122 leads to loss of betabeta' nuclear localization. Wtm1 and its paralog Wtm2 are both nuclear proteins that are in the same protein complex with betabeta'. Wtm1 also interacts with Kap122 in vivo and requires Kap122 for its nuclear localization. Our results suggest that Wtm1 acts either as an adaptor to facilitate nuclear import of betabeta' by Kap122 or as an anchor to retain betabeta' in the nucleus.

Catalysis↗

PubMed2006

Serum markers in patients with resectable pancreatic adenocarcinoma: macrophage inhibitory cytokine 1 versus CA19-9.

PURPOSE: More accurate serum markers of pancreatic cancer could improve the early detection and prognosis of this deadly disease. We compared the diagnostic utility of a panel of candidate serum markers of pancreatic cancer. EXPERIMENTAL DESIGN: We collected preoperative serum from 50 patients with resectable pancreatic adenocarcinoma, as well as sera from 50 patients with chronic pancreatitis and 50 age/sex-matched healthy controls from our institution. Sera were analyzed for the following candidate markers of pancreatic cancer: CA19-9, macrophage inhibitory cytokine 1 (MIC-1), osteopontin, tissue inhibitor of metalloproteinase 1, and hepatocarcinoma-intestine-pancreas protein levels. RESULTS: By logistic regression analysis, MIC-1 and CA19-9 were significant independent predictors of diagnosis. Receiver operating characteristic curve analysis showed that MIC-1 was significantly better than CA19-9 in differentiating patients with pancreatic cancer from healthy controls (area under the curve is 0.99 and 0.78, respectively; P = 0.003), but not in distinguishing pancreatic cancer from chronic pancreatitis (area under the curve of 0.81 and 0.74, respectively; P = 0.63). Hepatocarcinoma-intestine-pancreas/pancreatitis-associated protein, osteopontin, and tissue inhibitor of metalloproteinase 1 serum levels did not provide additional diagnostic power. CONCLUSION: In the differentiation of patients with resectable pancreatic cancer from controls, serum MIC-1 outperforms other markers including CA19-9.

Adenocarcinoma↗

PubMed2006

Amino-catalyzed fragmentation characteristics of polyamides containing N-methylpyrrole and N-methylimidazole by electrospray negative ionization mass spectrometry.

Different negative fragmentations of synthesized polyamides containing N-methylpyrrole and N-methylimidazole were analyzed by electrospray ionization tandem mass spectrometry with low-energy collision-induced dissociation. An interesting rearrangement derived from amino catalysis of N-methylimidazole was observed. The observation is useful for the study of the correlations between the sequences of polyamides and their mass fragmentation pathways.

Catalysis↗

PubMed2006

Pulmonary Lophomonas blattarum infection in patients with kidney allograft transplantation.

The aim of the study was to analyse the clinical manifestation and management of pulmonary Lophomonas blattarum infection in four allograft transplantation recipients retrospectively. Four patients with pulmonary L. blattarum infection were diagnosed by using Fiberoptic bronchoscopy (FOB) and bronchoalveolar lavage (BAL) examination. Their clinical manifestation and management are summarized. Four cases of pulmonary L. blattarum were found during the period from the second month to the third month after transplantation. Concurring infection by other pathogens was found in three of them. Common initial symptoms included fever (>38 degrees C) without cough and breathlessness. Lower lobe shadowing could be found on chest X-ray. Body temperature decreased to the normal range in three patients and to 37.5 degrees C in the other one, after intravenous injection of metronidazole and tapering immunosuppressant. Radiological examination confirmed improved health condition of the patients afterwards. Two patients received repeated FOB and only dead L. blattarum was found. Pulmonary L. blattarum infection in allograft transplant recipients carry relatively obscure initial symptoms. Possible L. blattarum infection needs to be screened in post-transplantation pulmonary infection patients with similar symptoms, especially in those who respond poorly to anti-infection treatment. Microscopic examination of BAL fluid can help to identify pulmonary L. blattarum infection and metronidazole is an ideal treatment choice.

Adult↗

PubMed2006

Template-assisted rational design of peptide inhibitors of furin using the lysine fragment of the mung bean trypsin inhibitor.

Highly active, small-molecule furin inhibitors are attractive drug candidates to fend off bacterial exotoxins and viral infection. Based on the 22-residue, active Lys fragment of the mung bean trypsin inhibitor, a series of furin inhibitors were designed and synthesized, and their inhibitory activity towards furin and kexin was evaluated using enzyme kinetic analysis. The most potent inhibitor, containing 16 amino acid residues with a Ki value of 2.45x10(-9) m for furin and of 5.60x10(-7) m for kexin, was designed with three incremental approaches. First, two nonessential Cys residues in the Lys fragment were deleted via a Cys-to-Ser mutation to minimize peptide misfolding. Second, residues in the reactive site of the inhibitor were replaced by the consensus substrate recognition sequence of furin, namely, Arg at P1, Lys at P2, Arg at P4 and Arg at P6. In addition, the P7 residue Asp was substituted with Ala to avoid possible electrostatic interference with furin inhibition. Finally, the extra N-terminal and C-terminal residues beyond the doubly conjugated disulfide loops were further truncated. However, all resultant synthetic peptides were found to be temporary inhibitors of furin and kexin during a prolonged incubation, with the scissile peptide bond between P1 and P1' being cleaved to different extents by the enzymes. To enhance proteolytic resistance, the P1' residue Ser was mutated to D-Ser or N-methyl-Ser. The N-methyl-Ser mutant gave rise to a Ki value of 4.70x10(-8) m for furin, and retained over 80% inhibitory activity even after a 3 h incubation with the enzyme. By contrast, the d-Ser mutant was resistant to cleavage, although its inhibitory activity against furin drastically decreased. Our findings identify a useful template for the design of potent, specific and stable peptide inhibitors of furin, shedding light on the molecular determinants that dictate the inhibition of furin and kexin.

Amino Acid Sequence↗

PubMed2006

Genetic relationships among fruiting-mei (Prunus mume Sieb. et Zucc.) cultivars evaluated with AFLP and SNP markers.

Genetic relationships among 50 fruiting-mei (Prunus mume Sieb. et Zucc.) cultivars from China and Japan were investigated, using 767 amplified fragment length polymorphism (AFLP) and 103 single nucleotide polymorphism (SNP) markers. The polymorphism among the cultivars was found to be 69.77%, based on EcoR I + Mse I AFLP primer pairs. The sequence alignment of 11 group sequences, derived from 50 samples, yielded 103 SNPs; the total length of genomic sequences was 3683 bp. Among these SNPs, 73 were heterozygous in the loci of different cultivars. The SNP distribution was 58% transition, 40% transversion, and 2% InDels. There was also 1 trinucleotide deletion. AFLP and SNP markers allowed us to evaluate the genetic diversity of these 50 fruiting-mei cultivars. The 2 derived cladograms did display some differences: all cultivars formed 2 subclusters (1A and 1B) in the cladogram based on AFLP polymorphisms, and formed 3 subclusters (2A, 2B, and 2C) in the cladogram based on SNP polymorphisms; and, in the cladogram based on AFLP polymorphisms, most cultivars from the Guangdong to Fujian provinces (G-F) in China, from the Yunnan, Hunan, and Sichuan provinces (Y-S-H) in China, and from Japan grouped in cluster 1A, and 18 (78.26%) of 23 cultivars from Jiangsu to Zhejiang provinces in China (J-Z) grouped in cluster 1B. The results demonstrate that mei cultivars from Japan are clustered with cultivars from China, and support the hypothesis that mei in Japan were introduced from China. Cultivars from the J-Z region of China have more genetic similarities. Cultivars from the G-F and Y-S-H regions have fewer genetic similarities and suggest more germplasm exchanges in the past.

Genetic Markers↗