Fatty Acid Production by Enhanced Malonyl-CoA Supply in Escherichia coli.

The expression of exogenous genes encoding acetyl-CoA carboxylase (Acc) and pantothenate kinase (CoaA) in Escherichia coli enable highly effective fatty acid production. Acc-only strains grown at 37 °C or 23 °C produced an approximately twofold increase in fatty acid content, and additional expression of CoaA achieved a further twofold accumulation. In the presence of pantothenate, which is the starting material for the CoA biosynthetic pathway, the size of the intracellular CoA pool at 23 °C was comparable to that at 30 °C during cultivation, and more than 500 mg/L of culture containing cellular fatty acids was produced, even at 23 °C. However, the highest yield of cellular fatty acids (1100 mg/L of culture) was produced in cells possessing the gene encoding type I bacterial fatty acid synthase (FasA) along with the acc and coaA, when the transformant was cultivated at 30 °C in M9 minimal salt medium without pantothenate or IPTG. This E. coli transformant contained 141 mg/L of oleic acid attributed to FasA under noninducible conditions. The increased fatty acid content was brought about by a greatly improved specific productivity of 289 mg/g of dry cell weight. Thus, the effectiveness of the foreign acc and coaA in fatty acid production was unambiguously confirmed at culture temperatures of 23 °C to 37 °C. Cofactor engineering in E. coli using the exogenous coaA and acc genes resulted in fatty acid production over 1 g/L of culture and could effectively function at 23 °C.

Blood Taurine Dynamics in Captive Lions: Relationship with Feed and Bile Acid Composition.

Taurine is an essential nutrient for felines including lions. Various severe symptoms induced by taurine deficiency have been reported for domestic and captive felines. Particularly for captive lions in zoos, little information related to taurine requirements is available. Therefore, this study evaluated the relationship between blood taurine concentration and taurine content in prey feed given at zoos, as well as the composition, types, and conjugation properties of bile acids (BAs) in blood collected repeatedly from four lions housed at three zoos. Blood taurine concentrations in four lions were within the normal range, although individual differences and variations were found. Taurine was abundant in feed supplied at the zoos. A positive correlation between blood taurine concentration and feed amount was observed in lions housed at the same zoo. Approximately 70-80% of the total BA pool was cholic acid, with 50-70% being taurine-conjugated. Individual differences and variations were found. No correlation was found between blood taurine concentration and the compositions of BAs in the blood. Results showed that supply of taurine was sufficient for all lions fed the prey feed. Future studies must be conducted to clarify influences on individual differences, as well as individual variations in blood taurine concentration and blood BA composition.

Effect of diet composition on coenzyme A and its thioester pools in various rat tissues.

Three coenzyme A (CoA) molecular species, i.e., acetyl-CoA, malonyl-CoA, and nonesterified CoA (CoASH), in 13 types of fasted rat tissue were analyzed. A relatively larger pool size of total CoA, consisting of acetyl-CoA, malonyl-CoA, and CoASH, was observed in the medulla oblongata, liver, heart, and brown adipose tissue. Focusing on changes in the CoA pool size in response to the nutrient composition of the diet given, total CoA pools in rats continuously fed a high-fat diet for 4 weeks were significantly higher in the hypothalamus, cerebellum, and kidney, and significantly lower in the liver and skeletal muscle than those of rats fed a high-carbohydrate or high-protein diet. In particular, reductions in the liver were remarkable and were caused by decreased CoASH levels. Consequently, the total CoA pool size was reduced by approximately one-fifth of the hepatic contents of rats fed the other diets. In the hypothalamus, which monitors energy balance, all three CoA molecular species measured were at higher levels when rats were fed the high-fat diet. Thus, it was of interest that feeding rats a high-fat diet affected the behaviors of CoA pools in the hypothalamus, liver, and skeletal muscle, suggesting a significant relationship between CoA pools, especially malonyl-CoA and/or CoASH pools, and lipid metabolism in vivo.

Estimating body weight of pigs from posture analysis using a depth camera.

A noninvasive method for estimating the body weight (BW) of a pig considering its posture using a low-cost depth camera (Kinect v2) was proposed. A total of 150 pigs were used, and 738 depth images (point clouds) were obtained for them. The pig "volume" was calculated from the pig point cloud, and it was found to have a very high correlation to BW. To evaluate the posture of a pig quantitatively, seven posture angles were calculated based on the "spine" extracted from a pig point cloud. We found the posture angles representing the height of the head position correlated with the accuracy of BW estimation using the "volume." Based on this finding, we proposed an "adjusted volume," which was adjusted based on the relationship between the posture angles and the estimation error. The BW of pigs was estimated using the simple regression model with the "adjusted volume," and the MAPE and RMSPE were 4.87% and 6.13%, respectively. The accuracy of the suggested model was similar to that of the volume-based estimation models of other studies that used only data with an appropriate pig posture for BW estimation.

Coenzyme A and Its Thioester Pools in Obese Zucker and Zucker Diabetic Fatty Rats.

Feeding behavior is closely related to hypothalamic malonyl-CoA level in the brain and diet-induced obesity affects total CoA pools in liver. Herein, we performed a comprehensive analysis of the CoA pools formed in thirteen tissues of Zucker and Zucker diabetic fatty (ZDF) rats. Hypothalamic malonyl-CoA levels in obese rats remained low and were almost the same as those of lean rats, despite obese rats having much higher content of leptin, insulin, and glucose in their sera. Regardless of the fa-genotypes, larger total CoA pools were formed in the livers of ZDF rats and the size of hepatic total CoA pools in Zucker rats showed almost one tenth of the size of ZDF rats. The decreased total CoA pool sizes in Zucker rats was observed in the brown adipose tissues, while ZDF-fatty rats possessed 6% of total CoA pool in the lean rats in response to fa deficiency. This substantially lower CoA content in the obese rats would be disadvantageous to non-shivering thermogenesis. Thus, comparing the intracellular CoA behaviors between Zucker and ZDF rats, as well as the lean and fatty rats of each strain would help to elucidate features of obesity and type 2 diabetes in combination with result (s) of differential gene expression analysis and/or comparative genomics.

Questionnaire investigation to clarify the occurrence rate and characteristics of maternal rejection behavior in Japanese black cattle (Bos taurus).

We conducted a questionnaire investigation among breeding farmers to clarify the actual conditions of maternal rejection in Japanese Black cattle. We asked keeping experience of maternal rejective cows and compared occurrence patterns, rejective behavior manners, birth assistance methods, colostrum feeding method for calves, parity and rearing conditions of the cows. We found that 24% of the farms had kept rejective cows and 6% of the cows in these farms indicated maternal rejections. The most common occurrence pattern was 'Occurred from the first birth (65.6%)' and behavior manner was performing no maternal grooming with aggressive behavior (75%). Almost all the farmers assisted in each parturition (P < 0.05). There was not a significant difference among the colostrum feeding methods, but a significant difference in the rearing conditions of the cows, except for the cows with no data (P < 0.005). The parity of the rejective cows did not significantly differ in association with rejective behavior manners, birth assistance methods, colostrum feeding methods or rearing conditions. These results suggest that the occurrence rate of maternal rejection in Japanese Black cattle was approximately 6% and many of the rejective cows continuously performed no maternal grooming with aggressive behavior.

The acute social defeat stress and nest-building test paradigm: A potential new method to screen drugs for depressive-like symptoms.

Psychosocial stress can cause mental conditions such as depression in humans. To develop drug therapies for the treatment of depression, it is necessary to use animal models of depression to screen drug candidates that exhibit anti-depressive effects. Unfortunately, the present methods of drug screening for antidepressants, the forced-swim test and tail-suspension test, are limiting factors in drug discovery because they are not based on the constructive validity of objective phenotypes in depression. Previously, we discovered that the onset of nest building is severely delayed in mice exposed to subchronic mild social defeat stress (sCSDS). Therefore, a novel paradigm combining acute social defeat stress (ASDS) and the nest-building test (SNB) were established for the efficient screening of drugs for depressive-like symptoms. Since ASDS severely delayed the nest-building process as shown in chronically social defeated mice, we sought to rescue the delayed nest-building behavior in ASDS mice. Injecting a specific serotonin 2a receptor antagonist (SR-46349B), the nest-building deficit exhibited by ASDS mice was partially rescued. On the other hand, a selective serotonin reuptake inhibitor (fluoxetine) did not rescue the nest-building deficit in ASDS mice. Therefore, we conclude that the SNB paradigm is an another potential behavioral method for screening drugs for depressive-like symptoms including attention deficit, anxiety, low locomotion, and decreased motivation.

Subchronic and mild social defeat stress alter mouse nest building behavior.

Behavioral and physiological evaluations of animal models of depression are essential to thoroughly understand the mechanisms of depression in humans. Various models have been developed and characterized, and the socially defeated mouse has been widely used for studying depression. Here, we developed and characterized a mouse model of social aversion using a subchronic and mild social defeat stress (sCSDS) paradigm. Compared to control mice, sCSDS mice showed significantly increased body weight gain, water intake, and social aversion to dominant mice on the social interaction test. We observed nest building behavior in sCSDS mice using the pressed cotton as a nest material. Although sCSDS mice eventually successfully built nests, the onset of nest building was severely delayed compared to control mice. The underlying mechanism of this significant delay in nest building by sCSDS mice is unclear. However, our results demonstrate that nest building evaluation is a simple and useful assay for understanding behavior in socially defeated mice and screening drugs such as antidepressants.

How do visual and auditory cues influence calf stress reactions at weaning?

We investigated the effects of visual and auditory information related to cow and calf stress responses at weaning. Three weaning conditions were established with physical separation only (PS), physical and visual separation (VS), and physical, visual and auditory separation (VAS). Stress responses such as vocalization and self-grooming, and changes of three maintenance behaviors (lying, walking and grazing) were recorded for experimental cows and calves in the respective conditions. Comparison of the data revealed that the cow responses differed slightly among groups. However, the peak frequency of vocalization was higher in the PS calves than in those of either VS or VAS. Self-grooming frequency was significantly different in calves and was high in the order of VAS, VS and PS calves. Furthermore, the percentage of time spent lying down was greater, and that of walking was less, in VAS calves than in either VS or PS calves. These results demonstrate that different information at weaning might strongly affect the stress responses of calves but not those of cows. Relative impacts of different types sensory information on stressors must be considered to plan animal-friendly weaning.

Effects of chronic social defeat stress on MAP kinase cascade.

Chronic psychological and social stress can cause psychiatric disorders in humans. In this study, we analyzed the mitogen-activated protein kinase (MAPK) cascade in the hippocampus of chronically socially defeated rats. The rats that were subjected to social defeat every day for 5 weeks showed physiological and behavioral changes, including a reduced rate of weight gain, enlarged adrenal glands, and increased immobility in the forced swim test without concomitant changes in locomotor activity in the open field test. Altered body weight and enlarged adrenal glands are typical symptoms of human depression. Prolonged immobility in the forced swim test indicates behavioral despair, a well-established index of depression. Because the MAPK cascade plays a pivotal role in depression, we quantified the expression of these molecules in the hippocampus of chronically defeated rats using western blot analysis. We found that phospho-MAPK kinases 1/2 (MEK1/2) and phospho-extracellular signal-regulated kinases 1/2 (ERK1/2) were decreased, whereas MAPK phosphatase-1 (MKP-1) was increased in the hippocampus of chronically defeated rats compared to the control group. These results were consistent with findings in depressed patients and other animal models of depression. In conclusion, our findings suggest that chronic psychosocial stress in Wistar rats induced depression-like behavior and downregulated the MAPK cascade in the hippocampus.

Does the maternal grooming of cattle clean bacteria from the coat of calves?

The hygienic function of maternal grooming (MG) was investigated in beef cattle. Nine Japanese beef-type cow-calf pairs (six experimental pairs and three control pairs) were used in the fourth week after parturition. The bacteria on the calves' coats were compared numerically between before-MG samples of calves that had been deprived MG, and after-MG samples of those that had been allowed MG. Collected bacteria were incubated respectively on LB and DHL agars. In addition, the correlation between the quantity of MG and the decrement of bacteria was analysed. In the LB plate, bacteria were detected in all nine calves. The numbers of bacteria were significantly lower in the after-MG sample than in the before-MG sample (p<0.0001) in the experimental calves. In the DHL plate, bacteria were detected on two calves of experimental group in before-MG sample. In the after-MG sample, bacteria had mostly disappeared on the DHL plate. No correlation was observed between the quantity of MG and the decrement of bacteria. However, the decrement was greater than 90% in four calves and more than 70% in two calves in the experimental group. These results suggest that maternal grooming may have a bacteria-removal effect and contribute to hygienic maintenance of the calves' body.