水稻RFLP连锁图谱的构建及控制小穗不育和花粉不育的QTL分析

用台中65(粳稻)/ARC10313(籼稻)的重组近交系(F10)构建了RFLP连锁图谱, 含113个分布均匀的标记. 作成的图谱覆盖全基因组, 全图总长1462.4 cM, 图中标记位置与所使用的参照图谱基本符合. 利用该重组自交家系材料与亲本台中65回交得到BF1家系, 用于对小穗不育和花粉不育的QTL分析, 检测出3个小穗不育和1个花粉不育QTL, 且有一     

Long-lived volcanism on the lunar farside revealed by SELENE Terrain Camera

We determined model ages of mare deposits on the farside of the Moon on the basis of the crater frequency distributions in 10-meter-resolution images obtained by the Terrain Camera on SELENE (Selenological and Engineering Explorer) (Kaguya). Most mare volcanism that formed mare deposits on the lunar farside ceased at approximately 3.0 billion years ago, suggesting that mare volcanism on the Moon was markedly reduced globally during this period. However, several mare deposits at various locations on the lunar farside also show a much younger age, clustering at approximately 2.5 billion years ago. These young ages indicate that mare volcanism on the lunar farside lasted longer than was previously considered and may have occurred episodically.     

Growth of juvenile chub mackerel Scomber japonicus in the western North Pacific Ocean: with application and validation of otolith daily increment formation

The growth of juvenile chub mackerel Scomber japonicus collected in the western North Pacific Ocean in 2007 and 2009 was examined based on the evidence of otolith daily increment formation in captive specimens. There was a significant difference in the relationship between known age and number of increments in the frontal and sagittal planes. Repeated markings on the otolith using Alizarin complexone and the coefficient of variation in number of increments suggest that the increments in the frontal plane of the otolith are more suitable for age estimation than those in the long and short axes of the sagittal plane. The increments in the frontal plane formed daily, and the first ring was usually deposited 3 days after hatch. Age of wild juveniles ranged from 24 to 211 days after hatch based on the frontal plane method. The estimated hatching periods of specimens ranged from February to June, but the April-hatched specimens were collected throughout the sampling periods of 2007 and 2009. The Gompertz growth model showed a difference in growth pattern in specimens between 2007 and 2009. The juveniles in 2009 appeared to grow more quickly than those in 2007 until summer, but thereafter the 2009 specimens seemed to grow more slowly.     

Alkaloidal components in the poisonous plant,Ipomoea carnea (Convolvulaceae)

Natural intoxication of livestock by the ingestion of Ipomoea carnea (Convolvulaceae) sometimes occurs in tropical regions of the world. Polyhydroxylated alkaloids were isolated from the leaves, flowers, and seeds of the poisonous plant and characterized. Chromatographic separation of the leaf extract resulted in the isolation of swainsonine (1), 2-epi-lentiginosine (2), calystegines B(1) (3), B(2) (4), B(3) (5), and C(1) (6), and N-methyl-trans-4-hydroxy-l-proline (7). The contents of 1 in the fresh leaves and flowers were 0.0029 and 0.0028%, respectively, whereas the contents of 1, 3, and 4 in the seeds were approximately 10 times higher than those in the leaves and flowers. Alkaloids 3, 4, and 6 showed a potent inhibitory activity toward rat lysosomal beta-glucosidase, with IC(50) values of 2.1, 0.75, and 0.84 microM, respectively, and alkaloid 5 was a moderate inhibitor of alpha- and beta-mannosidases. Although alkaloid 1 is known as a powerful inhibitor of lysosomal alpha-mannosidase (IC(50) = 0.02 microM), alkaloid 2, which has been thought to be an intermediate in the biosynthesis of 1, was also a potent inhibitor of alpha-mannosidase with an IC(50) value of 4.6 microM.     

Otolith development and daily increment formation in laboratory-reared larval and juvenile black-spot tuskfish <Emphasis Type="Italic">Choerodon schoenleinii</Emphasis>

Microstructures of lapilli were examined for reared larvae and juveniles of black-spot tuskfish Choerodon schoenleinii. Lapilli of larvae at 1 day after hatching have one diffuse and obscure ring with an otolith radius of 4.3 ± 0.50 μm (mean ± SD, N = 8). The slope and intercept of the regression between the number of days after hatching and increment counts did not differ significantly from one and zero, respectively, indicating that lapillus increments were formed on a daily basis after hatching. There was an ontogenetic shift in the relative values of somatic and otolith growth, which corresponded to the transition from pelagic larvae to settlement stage. Simultaneously, the daily increment width reached the maximum value. These findings suggest that age at maximum value of increment width can be used as an indicator of the planktonic larval duration while settlement mark is not found. Since ontogenetic shift in the relationship between otolith radius and body size was observed, back-calculation of somatic growth in black-spot tuskfish using the otolith radius during the early life stages should be analyzed with caution, and the method requires further validation.     

Effect of maillard reaction on allergenicity of scallop tropomyosin

Scallop tropomyosin (TM), the major allergen of shellfish, was prepared from adductor muscles and reacted with four reducing sugars to investigate the effect of the Maillard reaction on the allergenicity of TM. The IgE-binding ability of TM increased significantly with the progress of the reaction with glucose, ribose, and maltose, but not with maltotriose. The allergenicity was enhanced at the early stage of the Maillard reaction, and the trend of the effect depended on the type of reducing sugar used. 2,4,6-Trinitrobenzenesulfonic acid treatment of the lysine residues in TM showed that the protein surface charge resulting from the Maillard reaction had no effect on the enhancement of the allergenicity. Thus, the change in the allergenicity would be closely related to the structural change caused by the Maillard reaction.     

Behaviors of D- and L-lactic acids during the brewing process of sake (Japanese rice wine)

The amounts of D- and L-lactic acids during the brewing process of sake were determined by capillary electrophoresis using 2-hydroxypropyl-beta-cyclodextrin as a chiral selector. Because L-lactic acid, which prevents the growth of nonuseful microorganisms, is a raw material of sake, the ratio of L-lactic acid to total lactic acid is almost 1.0 at the initial stage of sake brewing. During brewing, the ratio decreased gradually and finally reached 0.39. Yeast (Saccharomyces cerevisiae) for sake brewing produced D-lactic acid, but not L-lactic acid in a culture medium. These results suggest that the decrease in the ratio of L-lactic acid to total lactic acid during sake brewing resulted in D-lactic acid production by yeast. The ratios in 18 brands of sake obtained commercially ranged from 0.23 to 0.78. The levels of D-lactic acid in sake (140-274 mg/L) were in a narrower range than those of L-lactic acid (61-461 mg/L). Although the D-lactic acid level in sake did not correspond to total lactic acid level, the L-lactic acid level correlated well with total lactic acid level (R(2) = 0.867). These results suggest that the ratio of L-lactic acid to total lactic acid in sake reflected the amount of L-lactic acid added at the initial stage of sake brewing.