Genetic variation affects de novo translocation frequency

Translocation is one of the most frequently occurring human chromosomal aberrations. The constitutional t(11;22)(q23;q11), which is the only known recurrent non-Robertsonian translocation, represents a good model for studying translocations in humans. Here we demonstrate polymorphisms of the palindromic sequence at the t(11;22) breakpoint that affect the frequency of de novo translocations in sperm from normal males. A typical allele consists of a perfect palindrome, producing ~10-5 de novo t(11;22) translocations. Alleles with an asymmetric center do not form the t(11;22). Our data show the importance of genome sequence on chromosomal rearrangements, a class of human mutation that is thought to be random.     

Effect of maturation culture period of oocytes on the sex ratio of in vitro fertilized bovine embryos

It has been suggested that the maturational stage of oocytes at time of insemination influences the sex ratio of resulting embryos. However, there are very few reports concerning the relationship between the maturation culture period of oocytes and the sex ratio of resulting embryos. The objective of this study was to investigate the effects of in vitro maturation culture period for bovine oocytes on the sex ratio of in vitro produced blastocysts using a novel technique of loop-mediated isothermal amplification (LAMP). Cumulus-oocyte complexes were collected from the ovaries of slaughtered cows, and then matured in vitro for various periods (16, 22, 28, and 34 h). After maturation culture for each period, the oocytes were inseminated with frozen-thawed spermatozoa, and then cultured in vitro. Blastocysts were harvested on Day 7 after insemination, and the sex of the embryos was examined using the LAMP method. The rates of oocytes matured to the metaphase II stage were significantly lower (P < 0.05) in the 16-h maturation group than in the other groups. The proportion of blastocyst formation after insemination was significantly higher (P < 0.05) in the 22-h maturation group than in the other groups. The proportion of male blastocysts increased with the increase in maturation culture period. The proportion of male blastocysts derived from oocytes matured for 34 h was significantly higher (P < 0.05) than from oocytes matured for 16 and 22 h. These results indicate that the sex ratio of in vitro fertilized embryos is apparently influenced by the maturation culture period of the oocytes.     

Prediction of Specific Japanese Sponge Cake Volume Using Pasting Properties of Flour

In Japanese soft wheat (Triticum aestivum L.) breeding programs, protein content (PC), and specific surface area (SSA) of flour have been used as important factors for the baking quality of Japanese sponge cake. We proposed batter pasting viscosity (BPV) as a parameter to predict the baking quality of Japanese sponge cake. BPV was measured using a Rapid Visco‐Analyser (RVA) with a modified heating profile. Twenty soft wheat samples from the 2006‐07 season and 22 from the 2007‐08 season, including Japanese soft wheat cultivars, advanced breeders' lines, and Western White (WW) imported from the United States, were milled and evaluated for solvent retention capacity (SRC) values of four solvents, batter pasting properties, flour pasting properties, PC, SSA, and specific cake volume (SCV) to investigate their relationships. BPV was the most strongly correlated of the parameters to SCV (r = –0.90, P < 0.001). Stepwise multiple regression analysis selected BPV and minimum viscosity (MV) of flour pasting as significant independent variables to predict SCV (corrected R² = 0.848). The variability in BPV related to cake batter expansion was highly explained by PC and sucrose SRC (corrected R² = 0.854, P < 0.001). MV was correlated to SSA (r = 0.56, P < 0.001) and might be related to the prevention of sponge cake shrinkage during baking.     

DNA marker for resistance to Puccinia horiana in chrysanthemum (Chrysanthemum morifolium Ramat.) “Southern Pegasus”

White rust caused by Puccinia horiana Henn. adversely affects chrysanthemum (Chrysanthemum morifolium Ramat.) production. The breeding of resistant varieties is effective in controlling the disease. Here we aimed to develop DNA markers for the strong resistance to P. horiana. We conducted a linkage analysis based on the genome-wide association study (GWAS) method. We employed a biparental population for the GWAS, wherein the single nucleotide polymorphism (SNP) allele frequency could be predicted. The population was derived from crosses between a strong resistant “Southern Pegasus” and a susceptible line. The GWAS used simplex and double-simplex SNP markers selected out of SNP candidates mined from ddRAD-Seq data of an F₁ biparental population. These F₁ individuals segregated in a 1:1 ratio of resistant to susceptible. Twenty-one simplex SNPs were significantly associated with P. horiana resistance in “Southern Pegasus” and generated one linkage group. These results show the presence of a single resistance gene in “Southern Pegasus”. We identified the nearest SNP marker located 2.2 cM from P. horiana resistance locus and demonstrated this SNP marker-resistance link using an independent population. This is the first report of an effective DNA marker linked to a gene for P. horiana resistance in chrysanthemum.     

Construction of a high-density reference linkage map of tea (Camellia sinensis)

A few linkage maps of tea have been constructed using pseudo-testcross theory based on dominant marker systems. However, dominant markers are not suitable as landmark markers across a wide range of materials. Therefore, we developed co-dominant SSR markers from genomic DNA and ESTs and constructed a reference map using these co-dominant markers as landmarks. A population of 54 F₁ clones derived from reciprocal crosses between ‘Sayamakaori’ and ‘Kana-Ck17’ was used for the linkage analysis. Maps of both parents were constructed from the F₁ population that was taken for BC₁ population. The order of most of the dominant markers in the parental maps was consistent. We constructed a core map by merging the linkage data for markers that detected polymorphisms in both parents. The core map contains 15 linkage groups, which corresponds to the basic chromosome number of tea. The total length of the core map is 1218 cM. Here, we present the reference map as a central core map sandwiched between the parental maps for each linkage group; the combined maps contain 441 SSRs, 7 CAPS, 2 STS and 674 RAPDs. This newly constructed linkage map can be used as a basic reference linkage map of tea.     

Long-Range Transport of Sulfur from Northeast Asia to Chengshantu, Shandong Peninsula: Measurement and Simulation

Observations of air pollutants were conducted at Chengshantu in January 1996 to clarify the extent of trans-boundary pollution from the Asian continent. A nested air quality prediction modeling system (NAQPMS), which included parameters on emission, transport, diffusion, deposition and transformation of sulfur oxides, was performed to compile sulfur concentrations over the observation site. The model calculation reproduced the observed variations of sulfur oxides and sulfate well, although the model calculations could not reproduce the extensively low sulfate concentrations. Using nesting improves the ability of the modeling system to capture peak episodes seen in the observations. Calculation of the origins of deposited sulfur in each country with the NAQPMS shows that the long-range transport of sulfur is very serious. For Japan, 49% of sulfur deposition was from other countries during the campaign period.     

Molecular cloning and characterization of oryzacystatin-III, a novel member of phytocystatin in rice (Oryza sativa L. japonica)

On the basis of cDNA sequences, we found that the calli of rice encodes an amino acid sequence that shares 56% and 89% identity, respectively, with oryzacystatin-I and oryzacystatin-II. This sequence differs from that of oryzacystatin-II in the N-terminal region (Gln(7)-Ala(19) in the oryzacystatin-III numbering), and this region contained a glycine residue (Gly(14)), which is evolutionarily conserved in the cystatin superfamily. We named this novel protein oryzacystatin-III. Nucleotide sequencing of the 5'-flanking region of the oryzacystatin-III gene showed that it is highly homologous to the oryzacystatin-II gene but distinct from the oryzacystatin-II locus. Oryzacystatin-III inhibited papain, ficin, and human cathepsin B. The inhibition constants for papain and ficin differ from those of oryzacystatin-I and -II, and cathepsin B activity is affected only by oryzacystatin-III, showing differences in the interaction of these inhibitors with enzymes. These data suggest that the above three inhibitors may play unique physiological roles in the regulations of rice cysteine proteinases.     

Antioxidant activity of polyphenols in carob pods.

We extracted polyphenols from carob (Ceratonia siliqua L.) pods, and evaluated the in vitro antioxidant activity of the crude polyphenol fraction (CPP). The total polyphenol content in CPP determined by the Folin-Ciocalteu method was 19.2%. The condensed tannin content determined by the vanillin and proanthocyanidin assay systems was 4.37% and 1.36%, respectively. beta-Carotene bleaching, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, inhibition of lipid peroxidation by the erythrocyte ghost, and microsomal assay systems were used to evaluate the antioxidant activity. CPP showed a stronger inhibitory effect against the discoloration of beta-carotene than other polyphenol compounds such as catechins and procyanidins. CPP had weaker antioxidant activity in the DPPH free radical scavenging, the erythrocyte ghost, and microsomal systems than authentic polyphenol compounds at the same concentrations. The activity adjusted by the polyphenol concentration was, however, comparable to that of authentic polyphenol compounds. Considering most carob pods are discarded and not effectively utilized at present, these results suggested that carob pods could be utilized as a functional food or food ingredient.