Genetic comparison between torafugu <Emphasis Type="Italic">Takifugu rubripes</Emphasis> and its closely related species karasu <Emphasis Type="Italic">Takifugu chinensis</Emphasis>

Abstract:   Sequence analyses of mitochondrial (mt) and nuclear genes were performed for genetic comparison between two Takifugu pufferfish species: torafugu T. rubripes and karasu T.  chinensis . With a sequence coverage of 20% in mtDNA, 640, 308, 344, 522 and 697 bp encoding mt 16S ribosomal RNA (rRNA), adenosine triphosphatase 6 ( ATPase 6 ), nicotinamide adenine dinucleotide dehydrogenase subunit 4 ( ND4 ), ND5 and cytochrome b (cyt b ), respectively, among 24 wild torafugu, 24 wild karasu and six hybrid-like samples, 15% of the torafugu identified by external color patterns showed nucleotide sequences consistent with karasu. Meanwhile, sequences of 60% karasu were consistent with those registered for torafugu (AJ421455). As for the hybrid-like samples, two possessed karasu-specific sequences in some base positions while torafugu-specific sequences in others. The remaining hybrid-like samples possessed torafugu-specific sequences. On the other hand, the mt control region did not show such type of consistency. Analysis of nuclear melanocortin receptor genes ( MC1R , MC4R ) among 54 samples showed 99–100% inter- and intraspecific sequence identity. Partial nuclear 18S  rRNA, complete internal transcribed spacer 1 ( ITS1 ), partial 5.8S  rRNA and ITS2 genes showed similar levels of identity, indicating a very low level of variation in their respective gene fragments between the two Takifugu species.     

不同处理方法和贮藏时间对野生大豆种子萌发的影响

采用人工小刀破皮、低温冷冻和浓硫酸处理研究其对野生大豆种子发芽的影响，实验表明：-6——-10℃低温冷冻处理野生大豆种子1、3、5、7、9d可以一定程度的提高种子的发芽率；用体积分数为0．98的浓硫酸处理种子8—10min，对提高野生大豆种子的发芽率有明显的促进作用，发芽率可高达98％。室内贮藏1—4年的种子其发芽率没有明显差异。     

Changes in rheological properties of grass carp fast skeletal myosin induced by seasonal acclimatization

To elucidate the effects of seasonal temperature acclimatization on thermal gelation of grass carp myosin, myosins from fish in different seasons were prepared and investigated for the changes in dynamic viscoelastic parameters including storage modulus (G′), loss modulus (G″) and damping factor (tan δ) upon heating. Myosins from fish in spring and summer had a temperature region of 38–44°C for the first marked increase of G′ higher than that of myosins from fish in autumn and winter (28–33°C). The measurement temperature-dependent changes in dynamic viscoelastic parameters such as G″ and tan δ were also different among the four myosins. While gel formation was observed with the spring and summer myosins, apparently in two steps, three steps were found in the autumn myosin. Furthermore, the winter myosin exhibited more than three steps for gel formation. These differences in rheological properties among the four myosins were considered to be attributed to the differences in thermodynamic and structural properties of these myosins previously reported.     

Qualitative and quantitative changes of F<Subscript>o</Subscript>F<Subscript>1</Subscript>-ATPase in Japanese flounder and red sea bream associated with rearing temperatures

ABSTRACT:   Fast skeletal muscles of Japanese flounder Paralichthys olivaceus and red sea bream Pagrus major were examined for quantitative and qualitative changes of mitochondrial ATP synthase (F_oF₁-ATPase) in association with rearing temperatures. The specific activities of F_oF₁-ATPase from Japanese flounder reared at 10°C, 15°C and 25°C for 4 weeks were determined to be 81 ± 11, 74 ± 13 and 83 ± 11 nmol/min·mg mitochondrial protein, respectively. The corresponding activity from red sea bream reared at 8°C for 5 weeks was determined to be 65 ± 9 nmol/min·mg mitochondrial protein, which was higher than 33 ± 9 nmol/min·mg mitochondrial protein in fish reared at 23°C. The contents of α- and β-F₁-ATPase in total mitochondrial proteins were not significantly different between fish reared at different temperatures for the two fish species. However, the contents of β-F₁-ATPase in the total fast skeletal muscle extracts, prepared from Japanese flounder reared at 10°C, were 2.1- and 2.9-fold higher than those for fish reared at 15°C and 25°C, respectively. The corresponding content from red seabream reared at 8°C was 2.2-fold higher than that for fish reared at 23°C. Therefore, the changes in F_oF₁-ATPase depending on rearing temperatures were species-specific.     

Establishment of an Invasive Prostate Cancer Model in Transgenic Rats by Intermittent Testosterone Administration

We have established a transgenic rat for adenocarcinoma of the prostate (TRAP) model that features uniform adenocarcinoma development in prostatic lobes at high incidence within a short experimental period. However, no invasive carcinomas with reactive stroma characteristics similar to those in man were observed. We therefore have focused on a new model for invasive carcinoma of the prostate using TRAP rats. In experiment 1, male TRAP rats in groups 1 and 2 were treated with orchiectomy at day 0 of the experiment. Rats in groups 1–3 underwent testosterone propionate (TP) implantation from weeks 1 to 4 and from weeks 6 to 16. Rats in groups 1 and 3 were given 3,2’-dimethyl-4-aminobiphenyl (DMAB) after TP implantation. The rats of group 4 served as controls. In experiment 2, the rats were divided into three groups, none of which received DMAB or orchiectomy, treated with TP continuously or with the treatment withdrawn once or twice. In experiment 1, invasive adenocarcinomas with abundant collagenous stroma were found in the dorsolateral and anterior prostate, some of which showed perineural space invasion at week 16. The number of invasive carcinoma foci was most frequent in group 3. In experiment 2, invasive adenocarcinoma development in the lateral prostates was correlated with the number of TP administration/withdrawal cycles. In conclusion, our newly established rat model for invasive adenocarcinoma of the prostate could serve as a useful preclinical model for evaluating the in vivo efficacy of preventive and therapeutic agents targeting of the tumor microenvironment.     

冀东地区野生大豆愈伤组织诱导及其耐盐性

以冀东沿海及内地不同条件下生长的14个野生大豆为试验材料，选取下胚轴和子叶作为外植体，在四种不同成分的培养基上诱导愈伤组织，经继代观察愈伤组织的质量，同时，在含不同浓度NaCl(0,0.2%,0.4%,0.6%,0.8%,1.0%)的继代培养基上，观察愈伤组织的耐盐性，试验结果表明；诱导野生大豆愈伤组织的适宜培养基为MS 2，4-D2.0mg/L 6-BA0.5mg/L 蔗糖5% 琼脂0.8%；不同材料之间愈伤组织的耐盐性有明显差异；耐盐性强的可在0.8%NaCl浓度下生存低的只能忍耐0.2%NaCl含量；本试验确定野生大豆愈伤组织耐盐性鉴定适宜的浓度为0.6%左右；盐碱条件下生长的野生大豆一般耐盐性较强，非盐碱环境下生长的野生大豆耐盐性也存在着耐盐性较强的类型，说明生长环境与细胞水平的耐盐性之间并没有完全的对应关系。     

Changes in metabolite concentrations in the abdominal muscle of the kuruma shrimp Marsupenaeus japonicus in response to different salinities

Invertebrates change the metabolite concentrations in their bodies to adapt to environmental salinity. The kuruma shrimp Marsupenaeus japonicus is one such invertebrate. It lives in coastal areas and is also known to change free amino acid concentrations depending on environmental salinity. To examine the relationship between the concentrations of metabolites, including amino acids, in the kuruma shrimp with environmental salinity, metabolome analysis was performed on the abdominal muscle of shrimps acclimated at 17, 34 and 40‰ salinity for 24 h. Principal component analysis revealed that the accumulation patterns of metabolites using the 111 metabolites detected in the shrimps exposed to different salinities were depicted in a salinity-dependent manner. The concentrations of alanine and glutamine were increased following exposure to increasing levels of salinity, suggesting that these free amino acids function in intracellular osmoregulation of the kuruma shrimp. Furthermore, the concentration of glycolytic metabolites was significantly decreased at high salinity. The concentrations of most of the metabolites related to the tricarboxylic acid (TCA) cycle also tended to decrease at high salinity. Considering the levels of expression of the genes related to various metabolic pathways, it seems that glycolysis is accelerated at high salinity.