Comparative Analysis of the Transcriptome and Metabolome in Leaves of Diploid and Tetraploid Fagopyrum tataricum

Tartary buckwheat(Fagopyrum tataricum)is a dual-purpose medicinal and food crop grown for its high contents of functional compounds and abundant nutrients.Although studies have shown the differences of total flavonoid content in Tartary buckwheat at different ploidy levels,the composition of flavonoid and its regulatory mechanisms are largely unknown.In this study,the leaf metabolome and transcriptome of diploid and tetraploid accessions of Tartary buckwheat were analyzed to gain insight into the impact of polyploidization on comparative secondary metabolite composition and molecular regulatory mechanism.Based on a widely targeted metabolomics analysis,a total of 792 metabolites were identified,including 127 flavonoids.The accumulation of 127 metabolites and expression of 3871 genes differed significantly between diploid and tetraploid Tartary buckwheat.Integrated metabolomics and transcriptome analysis revealed that chromosome doubling up-regulated the expression of upstream genes in the flavonoid biosynthesis pathway to promote the accumulation of flavonoids.The present results contribute to elucidation of the molecular mechanism of phenotypic variation associated with polyploidy in Tartary buckwheat.The findings provide a reference for further studies on phenotypic traits in polyploid Tartary buckwheat,the cloning of crucial regulatory genes,and utilization of genetic engineering technologies in the breeding of Tartary buckwheat.

Comparison Between a Tetraploid Turnip and Its Diploid Progenitor(Brassica rapa L.):The Adaptation to Salinity Stress

Polyploidy is pursued in plant breeding programs due mainly to its ability to yield larger vegetative or reproductive organs. In controlled growth chamber experiments, a tetraploid turnip （cv. Aijiaohuang, 4n） and its diploid progenitor （cv. Aijiaohuang, 2n） were evaluated for their tolerance to salinity stress via investigations on a group of physiological parameters. The results indicate that the tetraploid turnip exhibit better adaptation to a high concentration salt medium （200 mmol L-1）, as evidenced by a less-affected germination rate and a healthier morphological appearance at the seedling stage. Furthermore, an extension of salinity stress up to a certain period of time at the 5-7-leaf stage shows differences between the tetraploid turnip and its diploid progenitor. The former had a higher K＋/Na＋ ratio in the roots, higher glutathione concentration and antioxidant activities in the leaves, and smaller reductions in photosynthetic capacity in terms of leaf chlorophyll content. Studies on the differences between an autopolyploid and its respective relative, from which the autopolyploid originated, in terms of their tolerance to salinity and/or other abiotic stresses, have remained rather limited. The comparison is interesting due to a homogenous genetic background.

STUDY ON EMBRYONIC DEVELOPMENT AND EARLY GROWTH OF TRIPLOID AND GYNOGENETIC DIPLOID LEFT-EYED FLOUNDER, PARALICHTHYS OLIVACEUS (T. et S.)

The early effects of chromosomal manipulation of eggs and sperm on the yields of triploid and gynogenetic diploid larvae of Paralichthys olivaceus were investigated. Triploidy was achieved by cold shocking fertilized eggs at 0-2℃ for 45 minutes duration 5 minutes after fertilization, and the induced triploidy rates were 31.2%-50% and the relative hatching rates were 53.3%-99%. Gynogenetic diploids were obtained when eggs were inseminated with irradiated sperm and cold shocked at 0-2℃ for 45 minutes duration 5 minutes after fertilization. The induced gynogenetic diploid rates and the relative hatching rates were 94%-96% and 48.5%-68.5% respectively. The embryonic development of the triploid experimental group and of the gynogenetic diploid experimental group was delayed at first compared with the control group. But from the gastrula stage, it was not delayed anymore. There were no significant differences in the growth of the triploid experimental group larvae and the control group larvae, and in the growth of the gynogenetic diploid experimental group larvae and the control group larvae according to Student’s t test (α=0.05). The relationship between the early growth of the triploid experimental group larvae and that of gynogenetic diploid experimental group larvae was also studied.

Acute motor axonal neuropathy following anti-rabies human diploid cell vaccine:A rare case and review

Rationale:Guillain Barre syndrome(GBS)is an acute neurological illness leading to quadriparesis with respiratory involvement.It can be triggered by infections,vaccinations,surgery,trauma,transplantation and drugs.Anti-rabies cell culture vaccines introduced to overcome the high rate of neurological complications associated with tissue based rabies vaccine,can be very rarely associated with GBS.Patient concerns:A 50-year-old female presented with acute severe upper back pain evolving into pure motor quadriparesis following administration of human diploid cell vaccine for rabies.Diagnosis:Acute motor axonal neuropathy variant of GBS following anti-rabies human diploid cell vaccine.Interventions:Intravenous high dose steroids.Outcomes:Patient recovered completely within 1 month.Lessons:Although anti-rabies cell culture vaccines are highly immunogenic and safe,they are rarely associated with GBS.Clinicians should be aware of this link because prompt diagnosis and treatment can result in complete recovery and avoid complications.

Comparison of Taste Components between Triploid and Diploid Oyster

The main taste components of triploid and diploid oyster (Crassostrea gigas) were compared. Free amino acids, inosine monophosphate, succinate, trimethylamine oxide and betaine in fresh and boiled extractives were analyzed. The protein, lipids, glycogen, moisture and ash, which may affect the flavour, were evaluated. In boiled extractives, the amino acids were 394.1 mg(100 g) -1 in diploid and 183.5 mg(100 g) -1 in triploid. However, in fresh oyster extractives, they were 320.0 mg(100 g) -1 and 147.3 mg(100 g) -1 respectively. The inosine monophosphate in triploid was 44% more than that in diploid, and a little difference existed in the content of trimethylamine oxide between them. The contents of these taste components were the basis for taste flavour pattern determination.

Seasonal Variation of the Glycogen Enzyme Activity in Diploid and Triploid Pacific Oyster Gonad During Sexual Maturation

The glycogen content and the activities of two key enzymes in glycogen metabolism, glycogen phosphorylase and gly- cogen synthetase, in the gonad of diploid and triploid Pacific oysters (Crassostrea gigas) were compared during maturation. The glycogen content in the gonad of diploids decreased with gametogenesis (by 85.7%), but the glycogen content in the gonad of trip- loids did not vary significantly. Activity of glycogen phosphorylase (GP) in the gonad of diploids decreased with gametogenesis (by 55.5%), while GP activity of triploids did not vary significantly during maturation. Activity of glycogen synthetase (GS) in the gonad of diploids increased slightly with gametogenesis, reaching a peak in June. Activity of GS declined sharply from June to July, which might be due to gonad spawning. GS activity of triploid oysters in spawning time (July and August) was significantly higher than that in other months, which might be explained with a ‘compensating’ mechanism for the higher glycogen content in triploids.

Microsatellite-Centromere Mapping in Japanese Scallop(Patinopecten yessoensis) Through Half-Tetrad Analysis in Gynogenetic Diploid Families

Gene-centromere mapping is an essential prerequisite for understanding the composition and structure of genomes. Half-tetrad analysis is a powerful tool for mapping genes and understanding chromosomal behavior during meiosis. The Japanese scallop(Patinopecten yessoensis), a cold-tolerant species inhabiting the northwestern Pacific coast, is a commercially important marine bivalve in Asian countries. In this study, inheritance of 32 informative microsatellite loci was examined in 70-h D-shaped larvae of three induced meiogynogenetic diploid families of P. yessoensis for centromere mapping using half-tetrad analysis. The ratio of gynogenetic diploids was proven to be 100%, 100% and 96% in the three families, respectively. Inheritance analysis in the control crosses showed that 51 of the 53 genotypic ratios observed were in accordance with Mendelian expectations at the 5% level after Bonferroni correction. Seven of the 32 microsatellite loci showed the existence of null alleles in control crosses. The second division segregation frequency(y) of the microsatellite loci ranged from 0.07 to 0.85 with a mean of 0.38, suggesting the existence of positive interference after a single chiasma formation in some chromosomes in the scallop. Microsatellite-centromere distances ranged from 4 c M to 42 c M under the assumption of complete interference. Information on the positions of centromeres in relation to the microsatellite loci will represent a contribution towards the assembly of genetic maps in the commercially important scallop species.

Sequencing of a Cultivated Diploid Cotton Genome-Gossypium arboreum

Sequencing the genomes of crop species and model systems contributes significantly to our understanding of the organization,structure and function of plant genomes.In a `white paper' published in 2007,the cotton community set forth a strategic plan for sequencing the AD genome of cultivated upland cotton that initially targets less complex diploid genomes.This strategy banks on the high

Genetic Diversity of Italian Ryegrass Diploid Cultivars, Revealed by Electrophoretically Detected Genotypes in Phosphoglucose Isomerase （PGI）

Nine diploid cultivars of Italian ryegrass （Lolium multiflorum Lain.） from France （Fortyl, Vertyl and Jericho）, Germany （Ligrande）, United Kingdom （Aber Epic and Aber Mario）, Denmark （Cordelia）, Netherlands （Alamo） and Poland （Tur） were tested with horizontal gel electrophoresis according to one locus （with four alleles） of the PGI enzyme system. One of them, named P4 is typical for the species, therefore can serve as a good marker for hybrids identification. Each cultivar was characterized by frequencies of different phenotypes. They were highly polymorphic （Pg = 0.58 - 0.78） and showed differences in heterozygosity level. The variability within populations （GST = 0.055） was higher than among populations （DST = 0.032）.

SAR-3——a resource of diploid true breeding hybrid rice

In 1988, we found strain 9003 from compositehybridization of indica and japonica. 9003 pos-sesses characteristics of twin seedlings withfrequency of 15-20% of the investigated popu-lation. The highest frequency was 45.68%.Afterwards, we discovered that some twinseedlings had variabilities in chromosome set.As to a pair of twin plants, it may be 2n-1n,2n-3n, 3n-3n or 1n-1n. The changes in chro-mosome set also occurred in the plants devel-oped from mono-embryo seeds. All of thesevariants nearly account for 1% in our con-trolled experiment. We named the triploidplants SAR-3 and found that SAR-3 could be aresource of diploid true breeding hybrid rice.

Artificial induction of androgenetic diploid in Yellow catfish(Pelteobagrus fulvidraco)

Androgenesis was the especial zoogamy that the germ plasma of offspring was from the agnate. In this study the eggs of Yellow catfish （Pelteobagrus fulvidraco） were irradiated by UV suspending in the synthetic ovarian fluid （OF）, and the total dosage of UV irradiation was 220 mJ·cm^-2. Diploid could be induced by heat shock （40℃, 2 min, 3 min） with different time period after fertilization （15-37 min）. The result showed that heat shock with 2 min was better than 3 min; there were two apices of induction in 17-21 min and 27-31 min after fertilization. The highest hatching rate was 3.30% at 29 min after fertilization, and the difference between two apices of induction was unobvious.

Evaluation of some Newly Developed Diploid Hybrids and their Breeding Value in 4x-2x Crosses

The narrow genetic base in potato (Solanum tuberosum L.) limits the progress in cultivar development.The rich diploid germplasm in the origin center of potato provide a unique resource for improvement of tetraploid potatoes.Seven newly developed diploid hybrids with 2n pollen production,all of which have S. phureja background,were developed and evaluated for their value in potato breeding.They were crossed as male parnets to six tetraploid Solanum tuberosum cultivars,and seeds in large quantity from eleven crosses were obtained.Main agronomic traits,such as tuber yield,tuber number,mean tuber weight,tuber shape,eye depth,skin smoothness,flesh color,and specific gravity,were measured for 4x 2x tetraploid progenies in seedling generation,and their parents as well.All of the diploid hybrids had some merit for specific traits and the DH39 was more promising;high specific gravity trait in some diploid hybrids was successfully introgressed into tetroploid progenies via 4x 2x crosses.These diploid hybrids have potential value in potato breeding.

Analysis on Genetic Background of Female Triploid and Male Diploid Individuals of Siraitia grosvenorii by Using RAPD Molecular Markers

In order to provide molecular biological basis for breeding of excellent seedless varieties of Siraitia grosvenorii, the genetic background of 28 female triploid and male diploid individuals of S. grosvenorii was analyzed by using RAPD molecular markers. The results showed that female triploid and male diploid individuals of S. grosvenorli had abundant genetic background, with great genetic similarity cecfficients and close genetic distance. Overall, the genetic background of female triploid and male diploid individuals of S. grosvenorii exhibited relatively low complexity. Therefore, it is necessary to take corresponding measures for germplasm innovation to enrich the genetic background of seedless parents of S. grosvenorii.

Allopolyploidization increases genetic recombination in the ancestral diploid D genome during wheat evolution

Genetic recombination produces new allelic combinations,thereby introducing variation for domestication.Allopolyploidization has increased the evolutionary potential of hexaploid common wheat by conferring the advantages of heterosis and gene redundancy,but whether a relationship exists between allopolyploidization and genetic recombination is currently unknown.To study the impact of allopolyploid ization on genetic recombination in the ancestral D genome of wheat,we generated new synthetic hexaploid wheats by crossing tetraploid Triticum turgidum with multiple diploid Aegilops tauschii accessions,with subsequent chromosome doubling,to simulate the evolutionary hexaploidization process.Using the DArT-Seq approach,we determined the genotypes of two new synthetic hexaploid wheats with their parents,F;plants in a diploid population(2 x,D_(1)D_(1)×D_(2)D_(2))and its new synthetic hexaploid wheatderived population(6 x,AABBD_(1)D_(1)×AABBD_(2)D_(2)).About 11%of detected SNP loci spanning the D genome of Ae.tauschii were eliminated after allohexaploidization,and the degree of segregation distortion was increased in their hexaploid offspring from the F_(1) generation.Based on codominant genotypes,the mean genetic interval length and recombination frequency between pairs of adjacent and linked SNPs on D genome of the hexaploid F;population were 2.3 fold greater than those in the diploid F_(2) population,and the recombination frequency of Ae.tauschii was increased by their hexaploidization with T.turgidum.In conclusion,allopolyploidization increases genetic recombination of the ancestral diploid D genome of wheat,and DNA elimination and increased segregation distortion also occur after allopolyploidization.Increased genetic recombination could have produced more new allelic combinations subject to natural or artificial selection,helping wheat to spread rapidly to become a major global crop and thereby accelerating the evolution of wheat via hexaploidization.

STUDY OF GENOTOXIC EFFECTS OF ARSENIC ON HUMAN DIPLOID CELLS

Epidemiological studies have shown thatarsenic compounds cause lung and skin cancerin human.Studies of effect of arsenic onDNA were still deficient.The results of thestudies were unreliable.It makes more diff-iculty to understand the mechanisms ofarsenic carcinogenesis.

Analysis of Seed Phenotypic and Metabolic Characteristics of Diploid and Tetraploid Tartary Buckwheat

Polyploid plants grow well,are stress tolerant,and are rich in nutrients and bioactive compounds.Thus,they are useful for improving crop quality and yield.In this study,we compared the seed characteristics and metabolite profiles of diploid and tetraploid tartary buckwheat,which was developed via an artificially induced chromosome doubling event.The length,width,area,and thousand-grain weight were greater for the tetraploid seeds than for the diploid seeds.However,the germination rate decreased for the tetraploid seeds.Additionally,there was a gap between the shell and kernel of the tetraploid seeds.Moreover,the water absorption rate was higher for the tetraploid than for the diploid seeds.Chromosome doubling increased the seed total flavonoid content and deepened the seed color.A principal component analysis of the ultrahigh-pressure liquid chromatography-high resolution mass spectrometry data revealed the clear separation between the diploid and tetraploid samples.An orthogonal partial least squares-discriminant analysis and other multivariate statistical analyses identified 83 differentially abundant compounds,with most of the flavonoid metabolites more abundant in the tetraploid than in the diploid seeds.Research on tartary buckwheat polyploidy may result in enhanced germplasm resources and may clarify the mechanism underlying the biosynthesis of bioactive compounds.

GENOTOXIC EFFECT OF CIGARETTE SMOKE CONDENSATE (CSC) ON HUMAN DIPLOID CELL 2BS STRAIN

A series of bioassays such as sister chromatid exchange frequencies ( SCE.), chromosomal aberration ( CA ), micronuclel rate (MN) and cell-cycle delay have been used to detecting the genotoxic effect of cigarette smoke condensate (CSC) on human diploid cell 2BS strain. The results suggested that a higher SCE, ( 17. 0/ cell) was observed In 2BS cells treated with CSC at 100 μg/ml, as compared with 6. 9/cell of the background (P<0. 001). CA rate was significantly increased from 4% to 36% In cells treated with 10 μg/ml CSC (P< 0.001). MN rate varied from 9 -26‰ In cells treated with CSC compared to that of control (6‰). Meanwhile, the cell-cycle of cells was markedly delayed by CSC. The survival rate of 2BS cells declined to 59. 6% for treatment with CSC at 200 μg/ ml. There was a dose-effect response In SCE., CA, MN rate. We proposed that active oxygen might responsible for genotoxiclty of CSC on cells.

The Frequency of Survivorship in Heterozygous Diploids of Cdc13-1exo1Δ Mutants of S. cerevisiae Is One Survivor Cell in 72 Cells/Generation at 36°C

Telomeres cap ends of eukaryotic chromosomes prevent them from degradation and ensure genomic stability. Cdc13 is an essential telomere recruitment and maintenance protein. A temperature-sensitive point mutation in cdc13 gene leads to telomere impairment, giving rise to cdc13-1 mutants that suffer lethality at enhanced temperatures. Deleting Exo1 gene from these mutants, however, leads to the emergence of temperature-tolerant mutants called survivors. Yeasts are known to exist as either diploids or haploids. These yeast genotypes generate survivors. The frequency of survivorship in the haploid genotype is one cell in 104 cells/generation at 36°C, however, the frequency at which they emerge in their diploid counterparts at the same temperature is not known. In this study, we investigated the frequency of Survivorship in heterozygous diploids of cdc13-1exo1Δ mutants of S. cerevisiae at 36°C. Diploids were constructed by mating haploid strains of opposite mating type cdc13-1 exo1:LEU strains with strains of cdc13-1 exo1:HIS. The crosses were 1296 × 3181, 2561 × 3182, 1296 × 3182 and 2561 × 3181. Genetic markers and phenotypic appearance were considered while mating the mutant cells. Using a stick, a smear of one haploid strain was made on each YEPD plate labelled C2, C8, C9, D1, D14, and D15. A smear of another opposite mating type was made on the previous strain. They were mixed and allowed to mate overnight, before culturing on media lacking Luecine and Histidine (-L and -H). Survivors were generated by culturing these diploids at 36°C. Using SPSS 20.0 software for windows SPSS, 2011, the frequency was determined as one Survivor cell in 72 cells/generation, as their frequency of survivorship averaged 5.9 × 10-5 ± 0.04.

Development of Permanent Mapping Populations RILs in Diploid A Genome

Recombinant inbred lines(RILs) serve as powerful tools for genetic mapping.RILs are obtained by crossing two inbred lines followed by repeated selfing or sib-mating to create a set of new

Comparative Genetics of Floral Morphology in Diploid and Allotetraploid Gossypium

The cultivated Gossypium A genome diploid species G.arboreum and G.herbaceum and the allotetraploid species G.hirsutum and G.barbadense share common morphology for various floral traits,