Phylogenetic analysis of AGAMOUS sequences reveals the origin of the diploid and tetraploid forms of self-pollinating wild buckwheat,Fagopyrum homotropicum Ohnishi

Fagopyrum homotropicum Ohnishi is a self-pollinating wild buckwheat species indigenous to eastern Tibet and the Yunnan and Sichuan Provinces of China. It is useful breeding material for shifting cultivated buckwheat (F. esculentum ssp. esculentum Moench) from out-crossing to self-pollinating. Despite its importance as a genetic resource in buckwheat breeding, the genetic variation of F. homotropicum is poorly understood. In this study, we investigated the genetic variation and phylogenetic relationships of the diploid and tetraploid forms of F. homotropicum based on the nucleotide sequences of a nuclear gene, AGAMOUS (AG). Neighbor-joining analysis revealed that representative individuals clustered into three large groups (Group I, II and III). Each group contained diploid and tetraploid forms of F. homotropicum. We identified tetraploid plants that had two diverged AG sequences; one belonging to Group I and the other belonging to Group II, or one belonging to Group II and the other belonging to Group III. These results suggest that the tetraploid form originated from at least two hybridization events between deeply differentiated diploids. The results also imply that the genetic diversity contributed by tetraploidization of differentiated diploids may have allowed the distribution range of F. homotropicum to expand to the northern areas of China.     

Plasma Profiles of Glucose, Insulin and Lipids in the Male WBN/Kob-Lepr(fa) Rat, a New Model of Type 2 Diabetes with Obesity

Plasma profiles of glucose, insulin and lipids were examined in the male WBN/Kob-Lepr(fa) (fa/fa) rat, a new model of type 2 diabetes (T2D), in comparison with age-matched original male WBN/Kob (lean) rats. The fa/fa rats developed hypertriglycemia, obesity and hyperglycemia from 5, 7, and 9 weeks of age, respectively. Plasma insulin levels in fa/fa rats were significantly higher than those in lean rats at 5 weeks of age, but after 11 weeks of age gradually declined to the levels in lean rats. HOMA-IR, a measure of insulin resistance status, showed that fa/fa rats had insulin resistance. The fa/fa rat has the potential to become an important animal model of T2D with obesity.     

Comparison of the blood coagulation profiles of ferrets and rats

The aim of this study was to examine the blood coagulation profiles of ferrets and compare them with those of rats. The ferret activated partial thromboplastin time (aPTT) was slightly longer than the rat aPTT. In contrast, the ferret prothrombin time and thrombin time were profoundly shorter than the corresponding rat values. The fibrinogen level in ferret plasma was 2 times higher than that in rats. Heparin prolonged all blood coagulation times in a concentration-dependent manner in both ferret and rat plasma. A significantly (P<0.01) higher concentration of heparin was required to double the aPTT in ferrets than rats. These blood coagulation data for ferrets will be useful in experimental animal studies.     

Effect of oral administration of 3,3',4,4',5-pentachlorobiphyenl on the intestinal microbiota of Sprague–Dawley rats

The effect of the endocrine-disrupting chemical 3,3',4,4',5-pentachlorobiphyenl (PCB 126) on intestinal microbiota after oral administration, and the improvement of intestinal microbiota and feces quantity by the subsequent administration of Lactobacillus acidophilus or Lactobacillus reuteri was investigated. All the rats were given 100 μg/kg bodyweight of PCB 126. The changes in bacterial counts were confirmed using a culture method. The administration of PCB 126 tended to decrease the bacterial counts of lactobacilli (10^9.6−10^10.2 to 10^8.8−10^9.2) and bifidobacteria (10^5.3−10^6.1 to 10^3.6−10^4.2), and to increase those of Enterobacteriaceae (10^8.2−10^9.1 to 10^9.4−10^10.3) and staphylococci (10^6.6−10^7.4 to 10^7.2−10^8.4) compared to no PCB 126 administration. After administration of PCB 126, L. acidophilus or L. reuteri orally administered to rats caused Enterobacteriaceae and staphylococci counts to decrease, suggesting that the intestinal microbiota was improved by the lactobacilli. The administration of L. acidophilus and L. reuteri improved the balance of intestinal microbiota, and defecation volume returned to its normal level. L. acidophilus and L. reuteri have a remedial effect on intestinal microbiota affected by PCB 126 and can function to lessen accumulated PCB 126 volume.     

Hair cortisol concentration in pre‐ and postpartum dairy cows,and its association with body condition,hock health,and reproductive status

The objective of this study was to investigate the profiles of hair cortisol concentrations as an index of chronic stress in dairy cows in association with their health, nutrition, and reproductive parameters. For 25 Holstein dairy cows, hair was collected from the tail switch ?19.2 ± 11.4, 44.8 ± 11.9, 103.0 ± 9.9, and 168.0 ± 9.7 days postpartum (L0, L1, L2, and L3, respectively). Body condition scores were negatively correlated with hair cortisol concentrations (r = ?0.255), and hock health scores were positively correlated with hair cortisol concentrations (r = 0.236, p < 0.05). Hair cortisol concentrations during the postpartum period showed different patterns according to the time of first artificial insemination (AI) and fertility. Cows that were submitted to first AI by 86 days postpartum showed a peak hair cortisol concentration at L1, whereas cows with delayed first AI had a peak at L2. The hair cortisol concentrations of subfertile (≥168 days) cows were significantly higher at L1 and L2 compared with L0, whereas hair cortisol concentrations of fertile cows (<168 days) were not different among the sampling times. These results indicate that cows with health problems appear to experience greater chronic stress, which may impair their reproductive function.     

Synthesis and fungicidal activity against Pyricularia oryzae of 6-(1,2,4-triazol-4-yl) chromone and -1-thiochromone derivatives

A series of novel 6-(1,2,4-triazol-4-yl) chromone and -1-thiochromone (benzo[b]thiazin-4-one) derivatives was obtained by cyclisation via thiosemicarbazides which were prepared by reaction of hydrazines and the corresponding isothiocyanates. Their fungicidal activity was evaluated against the rice blast fungus Pyricularia oryzae. Of this series, 2,5,8-trimethyl-6-(1-propyl-5-thioxo-3-trifluoromethyl-1,2,4-triazol-4-yl) chromone, 6-(1-butyl-5-thioxo-3-trifluoromethyl-1,2,4-triazol-4-yl)-2,5,8-trimethylchromone, 6-(1-hexyl-3-methyl-5-thioxo-1,2,4-triazol-4-yl)-2,5,8-trimethylchromone and 6-(1-allyl-5-thioxo-3-trifluoromethyl-1,2,4-triazol-4-yl)-2,5,8-trimethylchromone were highly active (pEC₅₀>6·0). Structure–activity relationship studies using the capacity factor k′ as a hydrophobicity index suggested that the log k′ optimum for 2,5,8-trimethyl-chromone and -1-thiochromone derivatives was around 1·0, equivalent to a log P_ow value of c. 4·4. © 1998 SCI     

Maternal exposure to low doses of DES altered mRNA expression of hepatic microsomal enzymes in male rat offspring

Our previous studies demonstrated that prenatal diethylstilbestrol (DES) treatment disrupts steroidogenesis but induces high-level expression of androgen receptor (AR) mRNA to inhibit the disruption of spermatogenesis. This study examined which prenatal DES treatment influenced hepatic microsomal enzymes, CYP3A1, CYP2B1/2, CYP2C11, UGT2B1 (UDP-glucuronosyltransferase 2B1), and IGF-1 (insulin-like growth factor-1), in male rat offspring. DES treatment decreased the mRNA expression levels of CYP3A1 and CYP2B1/2, but did not alter the expression of CYP2C11. At 6 weeks, DES treatment increasd the mRNA expression levels of UGT2B1 and IGF-1. These results suggest that prenatal DES treatment alters two hepatic enzymes (CYP3A1 and CYP2B1/2) and IGF-1 mRNA expression levels to counteract the low level of testosterone, but this disrupted UGT2B1 mRNA expression reduces the testosterone level.     

Diversity of fimbrillin among Porphyromonas gulae clinical isolates from Japanese dogs

Porphyromonas gulae, a gram-negative black-pigmented anaerobe, is a pathogen for periodontitis in dogs. An approximately 41-kDa fimbrial subunit protein (FimA) encoded by fimA is regarded as associated with periodontitis. In the present study, the fimA genes of 17 P. gulae strains were sequenced, and classified into two major types. The generation of phylogenetic trees based on the deduced amino acid sequence of FimA of P. gulae strains along with sequences from several strains of Porphyromonas gingivalis, a major cause of human periodontitis, revealed that the two types of FimA (types A and B) of P. gulae were similar to type I FimA and types II and III FimA of P. gingivalis, respectively. A PCR system for classification was established based on differences in the nucleotide sequences of the fimA genes. Analysis of 115 P. gulae-positive oral swab specimens from dogs revealed that 42.6%, 22.6%, and 26.1% of them contained type A, type B, and both type A and B fimA genes, respectively. Experiments with a mouse abscess model demonstrated that the strains with type B fimA caused significantly greater systemic inflammation than those with type A. These results suggest that the FimA proteins of P. gulae are diverse with two major types and that strains with type B fimA could be more virulent.