12D Group Research Articles

Gut Microbiota Alleviates Intestinal Injury Induced by Extended Exposure to Light via Inhibiting the Activation of NLRP3 Inflammasome in Broiler Chickens.

Light pollution is a potential risk for intestinal health in humans and animals. The gut microbiota is associated with the development of intestinal inflammation induced by extended exposure to light, but the underlying mechanism is not yet clear. The results of this study showed that extended exposure to light (18L:6D) damaged intestinal morphology, downregulated the expression of tight junction proteins, and upregulated the expression of the NLRP3 inflammasome and the concentration of pro-inflammatory cytokines. In addition, extended exposure to light significantly decreased the abundance of Lactobacillus, Butyricicoccus, and Sellimonas and increased the abundance of Bifidobacterium, unclassified Oscillospirales, Family_XIII_UCG-001, norank_f__norank_o__Clostridia_vadinBB60_group, and Defluviitaleaceae_UCG-01. Spearman correlation analysis indicated that gut microbiota dysbiosis positively correlated with the activation of the NLRP3 inflammasome. The above results indicated that extended exposure to light induced intestinal injury by NLRP3 inflammasome activation and gut microbiota dysbiosis. Antibiotic depletion intestinal microbiota treatment and cecal microbiota transplantation (CMT) from the 12L:12D group to 18L:6D group indicated that the gut microbiota alleviated intestinal inflammatory injury induced by extended exposure to light via inhibiting the activation of the NLRP3 inflammasome. In conclusion, our findings indicated that the gut microbiota can alleviate intestinal inflammation induced by extended exposure to light via inhibiting the activation of the NLRP3 inflammasome.

Research Note: The effect of photoperiod on the NLRP3 inflammasome and gut microbiota in broiler chickens

The present study aimed to investigate the effect of photoperiod on the intestinal inflammation and gut microbiota. A total of 96 broiler chickens were divided into 2 groups and fed separately under 2 different photoperiods (12L:12D group and 23L:1D group) for 21 d. The results showed that the photoperiod of 23L:1D damaged duodenal tissue structure (intestinal villus erosion, mucosal epithelial cell detachment, and inflammatory cell infiltration), significantly increased the concentration of inflammatory cytokines (IL-1β, IL-18, IL-6, and TNF-α) and significantly increased the mRNA expression levels and protein expression levels of NOD-, LRR-, pyrin domain-containing protein 3 (NLRP3) and caspase1 (P <0.05) compared with 12L:12D, which indicating that extended photoperiod induced intestinal injury and activated NLRP3 inflammasome. 16S rRNA sequencing analysis revealed that Bacteroides was significantly decreased, Ruminococcus_torques_group, norank_f_Desulfovibrionaceae, GCA-900066575, Defluviitaleaceae_UCG-011, Lachnospiraceae_FCS020_group, norank_f_UCG-010 and norank_f_norank_o_Clostridia_vadinBB60_group and were significantly increased in the 23L:1D group, compared with the 12L:12D group (P < 0.05). The correlation analysis between differential microbial communities and intestinal inflammation showed that the relative abundance of Bacteroides was negatively correlated with the mRNA expression level of NLRP3 (P < 0.05) and the relative abundance of Ruminococcus_torques_group was positively correlated with the mRNA expression level of NLRP3 (P < 0.05). linear discriminant analysis (LDA) effect size (LEfSe) results (LDA > 4) showed that the relative abundance of Bacteroides was dramatically higher (P < 0.05) in the 12L:12D group, whereas the relative abundance of Ruminococcus_torques_group was noticeably higher (P < 0.05) in the 23L:1D group. By the comprehensive analysis of the gut microbiota, the interaction of gut microbiota (Bacteroides and Ruminococcus_torques_group) and NLRP3 inflammasome may contribute to the intestinal injury under the condition of extended photoperiod.

Altered circadian rhythms effects on anxiety, locomotor activity, serotonin and nitric oxide levels in the prefrontal cortex of juvenile and adult rats

AbstractBackgroundDementia and Alzheimer’s disease (AD) can be exacerbated by irregular sleep‐wake cycles, and age may be a risk factor. This study compared behavioral responses such as anxiety, motor coordination, and locomotion to altered circadian rhythms and serotonin, nitric oxide (NO), and malondialdehyde (MDA) levels in the prefrontal cortex of juvenile and adult rats.MethodA total of thirty female Wistar rats were grouped into three (n = 5) in the following juvenile (30‐45 days old) and adult (90‐120 days old) groups: (A) Control (12L:12D cycle),(B) 24‐hour LED light exposure(12L:12L cycle) and (C) 24‐hour dark cycle (12D:12D cycle). Experimental rats were kept in the stated cycle conditions using natural lighting, LED lighting, and a dark room, respectively, for 60 days. Data were analyzed using a two‐way ANOVA (GraphPad Prism 9), and statistical significance was measured at p&lt;0.05.ResultFindings from the study revealed progressive weight loss in the sleep‐deprived juvenile (12L:12L) rats compared to adults (p&lt;0.05) in the same and other groups. Also, anxiety‐like indices such as longer duration of time in the dark area of the light‐dark box, avoidance of open arm entries on the elevated plus maze, reduced line crossing activity in the open field box, etc. were markedly higher in the juvenile rats from the 12L:12L and 12D:12D groups respectively. When juvenile and adult 12L:12L and 12D:12D cycle rats data were compared to controls, severe depletion of serotonin (p&lt;0.0001) and nitric oxide (p&lt;0.01) levels were observed, while age‐dependent MDA levels were revealed across all groups.ConclusionA bi‐directional relationship was observed between age and circadian disruption effects with more severe outcomes in juveniles compared to adults and this hold interesting implications for the study of the biological clock mechanisms underlying anxiety, mood and sleep disorders in living systems.

Effects of different photoperiod conditions on survival, growth, and gonadal development of Takifugu rubripes adults

Photoperiod has a significant influence on fish. In this study, 2.5-year-old Takifugu rubripes (tiger puffer) adults were selected to evaluate the photoperiod impacts (8 h light (L):16 h dark (D), 12L:12D, 16L:8D) from September to January at 15–17 °C on their growth, gonadal development, and survival for a 100-day. The mortality rate of males and females tiger puffer differed among the different photoperiods, and the 8L:16D photoperiod was not suitable for survival of males. At the end of the experiment, the body length, weight gain rate, specific growth rate and condition factor of both males and females tiger puffer were similar among the three photoperiods (P > 0.05). Higher percentage of females had developed to later developing phase and males had developed to spawning capable phase in the 12L:12D treatment, respectively. In particular, 100% of males had testis at the spawning capable phase. The gonadosomatic index values of males and females in the 12L:12D group were significantly higher than those in the 16L:8D group (P < 0.05), but no significant differences between the 8L:16D and 12L:12D groups (P > 0.05). The serum testosterone (T) content of males and the serum estradiol-17β (E2) content of females were highest in the 12L:12D group. The expression of aralkylamine N-acetyltransferase 1a (aanat1a) in the diencephalon/midbrain (D/M) was elevated under 12L:12D treatment in both sex (P < 0.05). The expression level of iodothyronine deiodinase type 2 (dio2) in the saccus vasculosus in males was elevated under the 12L:12D photoperiod (P < 0.05). The levels of gonadotropin-releasing hormone 1 (gnrh1) and gnrh3 mRNA in the D/M of females at later developing stages in the 12L:12D treatment were significantly higher than those in of other treatment groups, and the level of gnrh3 in males under this photoperiod was significantly elevated (P < 0.05). The levels of gonadotropin-inhibiting hormone (gnih) mRNA under 12L:12D were significantly elevated in both males and females (P < 0.05). Under this photoperiod, the levels of follicle stimulating hormone b-subunit (fshb) and luteinizing hormone b-subunit (lhb) in the pituitary gland of females at later developing stages were significantly higher than those of the other two groups (P < 0.05). The expression levels of lhb in males in the 12L:12D and 8L:16D photoperiods were significantly higher than that at 16L:8D (P < 0.05). These results indicated that culture under the 12L:12D photoperiod from September prior to the spawning season could result in accelerated gonadal development of both male and female tiger puffer.

Early posthatch body temperature, haematology and growth performance in Transylvanian naked neck chicks hatched from eggs stored for different durations

Early posthatch physiological responses and growth performances were assessed in 80 chicks hatched from Transylvanian naked neck (TN) chicken eggs stored in a cold room for 0, 3, 6, 9, and 12d before incubation with four replicates per group. The rectal temperature (RT) of birds hatched from 0 and 3d stored eggs were significantly (P < 0.01) lower than in the 9–12d storage groups. There was (P < 0.001) an increase in skin temperature on the breast (STB) as the length of storage increased. Day-old chicks and 28d-old chickens from non-stored eggs had higher (P < 0.05) packed cell volume (PCV) and haemoglobin (Hb) concentration than eggs stored for 12d. Chickens in 0, 3 and 6d storage groups had (P < 0.01) higher platelet count values than in the 12d group. During d1-28, chicks from 0 to 6d egg storage had (P < 0.001) higher weight gain and final live weight than 9–12d storage. Feed consumption was (P < 0.01) lower in 3d than in 6–12d. Chicks from 0 to 6d storage recorded a lower (P < 0.001) feed conversion ratio than in 9–12d storage. In conclusion, prolonged storage of TN eggs resulted in higher RT and STB, lower PCV and Hb, and lower growth performance during early posthatch age.

The Effects of Different UVA Photoperiods on the Growth Performance, Immune Responses, Antioxidant Status and Apoptosis-Related Gene Expression of the Pacific White Shrimp (Penaeus vannamei).

UVA is the most common type of solar UV radiation in aquatic environments; however, the effects it causes in shrimp farming in recirculating water systems (RAS) is unclear. Thus, the growth performance, immune responses, antioxidant status and apoptosis-related gene expression in Pacific white shrimp, Penaeus vannamei (body weight 9.56 ± 0.10 g), reared with 12L: 12D full spectrum light as background light under five UVA (peak at 400 nm) photoperiods (0L: 24D, 2L: 22D, 4L: 20D, 8L: 16D and 12L: 12D) at a light intensity of 1 W/m2 were investigated. The results showed that the 2L: 22D and 4L: 20D UVA photoperiods enhanced the growth performance and reduced the feed conversion ratio and the shrimp mortality. Shrimp exposed to UVA (2L: 22D and 4L: 20D) also displayed higher levels of hepatopancreas catalase (CAT), superoxide dismutase (SOD), acid phosphatase (ACP), phenol oxidase (PO) and lysozyme (LZM) compared to the 8L: 16D and 12L: 12D groups. The malondialdehyde (MDA) levels increased in line with the extension of the UVA irradiation time. The mRNA expression of apoptosis-related genes in all the UVA treatments were significantly higher than with the control treatment, except for the 2L: 22D group. The results of the 2L: 22D and 4L: 20D treatments were significantly higher than those of the control group, except for LGBP. In conclusion, 2L: 22D and 4L: 20D UVA photoperiods increased growth performance and decreased FCR, improved the innate immunity and antioxidant response and reduced the mortality rate in adult shrimp.

Preliminary evaluation of the green microalga Dunaliella salina as a potential feedstock for biodiesel: effect of molasses on growth and lipid profile

This research aims to evaluate the effect of molasses as a source of organic carbon on the growth and lipid profile of Dunaliella salina cultivated under different light regimes to determine its strategy and potential use to produce biodiesel. Two sources of nutrients (F/2 medium, F/2; molasses, M) and two light conditions (12 h light: 12 h darkness, 12L:12D) conformed four treatments (F/2 12L:12D, F/2 D, M 12L:12D, and MD) that were investigated with three replicates each. The concentration of microalgae produced by the groups under light conditions was more than double that of those grown in darkness. The highest biomass produced (46.91 ± 6.47 g L -1 ) was obtained in the F/2 medium with 12L:12D treatment, while the lowest (18.99 ± 0.78 g L -1 ) was in the M 12L:12D group. Regardless of the culture conditions, the lipids were mainly composed of the C16:0 and C18 fatty acids. The use of molasses as a culture medium produced the highest amount of C18:1, regardless of the light regime. Molasses promoted the highest production of fatty acids methyl esters. Depending on the culture medium, D. salina cells showed different percentages of saturated (SFA), monounsaturated (MFA), and polyunsaturated (PUFA) fatty acids. The highest amount of saturated fatty acids was obtained in F/2 12L:12D. The highest amount of polyunsaturated fatty acids was presented in the mixotrophic culture (molasses and light). The cultures grown with molasses were rich in monounsaturated fatty acids. An inexpensive industrial by-product, Cane molasses could be a low-cost feedstock for biodiesel in cultivating D. salina .

Effects of lighting regimes on performance, pineal melanopsin expression and melatonin content in native laying hens aged from 19 to 34 weeks

Melanopsin, a key light sensitive pigment, plays an important role in the regulation of bio-rhythm and photo-adaptation in poultry. This study aimed to investigate the effects of different lighting regimes on performance, pineal melanopsin expression and melatonin content in a native chicken, Beijing You Chicken (BYC) aged from 19 to 34 wk. A total of 900 nineteen-wk-old BYC female chicken having no significant body weight differences were randomly allocated to 3 groups with 3 replicates each, 100 birds each replicate, reared in individually lit floor pens with separate outdoor areas. Three different lighting regimes were used, including continuous 16 h (16L:8D, 6:00–22:00) for group 1, intermittent 16 h (12L:2D:4L:6D, 6:00–18:00, 20:00–24:00) for group 2, and continuous 12 h (12L:12D, 6:00–18:00) for group 3, respectively. The performance was measured for 19 to 34 wk. Serum melatonin (Mel), prolactin (Prl), luteinizing hormone (LH), and 17-beta estradiol (E2) contents were measured at 24 wk, 29 wk, and 34 wk of age, the relative expression of pineal melanopsin gene (Opn4 mRNA) was measured on 1 d at 9:00, 13:00, 17:00, 21:00, 1:00, and 5:00 at 29 wk of age, and at the end of 29 wk and 34 wk. The results showed that the egg mass, egg-laying rate, and feed egg ratio of BYC were not affected by lighting regimes for 19 to 34 wk (P > 0.05), except for the average feed intake (AFI) (P < 0.05). The AFI in the 12L:12D group was significantly higher than that in the 16L:8D group (P < 0.05), but had no difference with that in the 12L:2D:4L:6D group. The pineal Opn4 mRNA level was significantly upregulated in the 12L:2D:4L:6D group and downregulated in the 12L:12D group when compared with 16L:8D group at 29 and 34 wks of age (P < 0.05). The Mel content in the 16L:8D group was lower than that in the other 2 groups at 29 wk of age (P < 0.05), there was no difference in Mel content between 16L:8D group and 12L:2D:4L:6D group at 34 wk of age (P > 0.05). The present study suggested that the pineal melanopsin expression of the birds in the intermittent 16 h lighting group was higher than in the continuous 16 h and 12 h lighting group, and a significant negative correlation was found between melanopsin expression and Mel content at 34 wk of age, which may interact to promote the photo-adaptation of the native chicken and affect the future laying performance.

Effects of different photoperiods on growth performance and health status of largemouth bass (Micropterus salmoides) juveniles

This study investigated the effects of photoperiod duration on growth, heamatological and blood biochemical parameters, and antioxidant capacity of largemouth bass (Micropterus salmoides). Triplicate groups of juvenile fish (33.22 ± 4.68 g) were kept in a recirculating aquaculture system and exposed to five different photoperiods [light/dark (L/D), h] as follows: 8L:16D; 12L:12D; 16L:8D; 20L:4D and 24L:0D. All the fish were fed a commercial diet at a fixed ratio of 1% body mass with daily inspection of the consumed feed. The experiment lasted 16 weeks and fish growth was monitored at 4-week intervals. The results revealed the significant effect of photoperiod duration on growth rate and feed utilization. The constant light exposure (24L:0D) benefited weight gain (WG) only during the first four weeks while thereafter negative impacts were noticed. At the end of the feeding trial, the highest WG and specific growth rate were obtained in the 8L:16D group which significantly differed from those of the 12L:12D and 16L:8D groups. Although fish feed intake was not influenced by photoperiod duration, better feed conversion ratio was found in the 8L:16D group. Moreover, the same group exhibited the highest hepatosomatic and gonadosomatic indices, and haemoglobin concentration. The highest plasma total protein and globulin concentrations were recorded for the 16L:8D group. Plasma glucose concentration decreased by prolongation of light duration while opposite trends were observed for plasma ammonia concentration and creatinine kinase activity. The highest alanine aminotransferase and aspartate aminotransferase activities were found in 20L:4D and 12L:12D groups, respectively. Moreover, plasma alkaline phosphatase activity significantly decreased in 12L:12D and 16L:8D groups. Longer light duration led to remarkable increase of thiobarbituric acid reactive substances (TBARS) concentration in fish liver, brain and gill indicating the incidence of oxidative stress. Likewise, boosted antioxidant responses were found in liver [glutathione (GSH) and glutathione S-transferase (GST)], brain (GST) and kidney (superoxide dismutase) as light duration extended. These findings suggest that 8 L:16D is favouring better growth, organosomatic index and antioxidant capacity of largemouth bass juveniles reared in RAS.

Effect of photoperiod on eggshell quality and quality characteristics of tibia, femur, and ulna in laying ducks

We investigated the effect of photoperiod on eggshell quality, bone quality characteristics and bone metabolism related enzymes and factors in laying ducks. After adaption, 300 Jinding laying ducks (252-day-old) were randomly divided into 5 treatments, receiving 12L (hours of light):12D (hours of darkness), 14L:10D, 16L:8D, 18L:6D or 20L:4D, respectively. Each group had 6 replicates of 10 birds each. The feeding experiment lasted 8 wk. Compared with 12L:12D, the higher values of eggshell breaking strength occurred in ≥18 h photoperiods at the end of 6 wk, and in ≥16 h photoperiods at the end of 4 wk, with the common highest values in 18 h photoperiod (P ˂ 0.05). Besides, 18L:6D had higher values of ultimate load Fu and cortical cross-sectional area A in tibia, femur, and ulna (P ˂ 0.05), compared with 12L:12D. The higher values of proximal bone mineral content (BMC; tibia), distal BMC (ulna), total Ca (tibia), and cortical volumetric bone mineral density (vBMC; tibia and ulna) were observed in 16L:8D and 18L:6D treatments (P ˂ 0.05). Meanwhile, 18 h photoperiod group had the higher proximal BMC (femur) and total Ca in ulna (P ˂ 0.05). In serum, compared with 12L:12D group, the higher ALP activity occurred in ≥16 h photoperiods (0:00 and 18:00), with the highest values in 18L:6D treatment (P ˂ 0.05); the higher values of TGF-β (6:00) and OC (6:00 and 18:00) were simultaneously observed in 18 h photoperiod (P ˂ 0.05). Moreover, values of trACP activity, TNF-α and IL-6 contents decreased in ≥18 h photoperiods at 0:00 (P ˂ 0.05), compared with 12L:12D group. To sum up, an appropriate photoperiod could improve eggshell quality, bone strength and mineral content through increasing osteogenesis during the light time and decreasing resorption activity during the dark, and 18 h is an adequate photoperiod for the eggshell and bone quality of laying ducks.

Effects of light regime on the hatching performance, body development and serum biochemical indexes in Beijing You Chicken

The paper aimed to study the effects of light regime during the incubation on hatching performance, body development and serum biochemical indexes in Beijing You Chicken (BYC). A total of 1,408 BYC eggs were randomly allocated into 4 groups: 24 h dark as the control (Inc24D); 3 light regimes were 8 h light and 16 h dark group (Inc8L:16D); 12 h light and 12 h dark group (Inc12L:12D); 16 h light and 8 h dark group (Inc16L:8D), respectively. There were 352 eggs in each group, 4 replicates each group and 1 tray each replicate, 88 eggs each tray. Light-emitting diode (LED) strips, white light with temperature of 4,500 to 5,000 K, 150 to 200 lx were set up. The results showed that light regimes had no significant effects on hatching rate of eggs, hatching rate of fertile eggs and healthy rate of chicks (P > 0.05), but the hatching rate of eggs was the lowest in the Inc24D group (87.22%), and the highest in the Inc12L:12D group (93.64%); Lighted incubation significantly affected the incidence of leg problems of 1-day-old chicks (P < 0.05). The incidence rate of leg problems was the highest in the Inc24D group (4.21%), and was decreased in Inc12L:12D and Inc16L:8D groups (P < 0.05). Femur length in the Inc12L:12D group was greater than that in the Inc24D and Inc16L:8D groups (P = 0.011), but there were no differences between Inc8L:16D group and other three groups (P > 0.05). The relative brain weight of 1-day-old chicks was higher in Inc24D and Inc16L:8D groups than in Inc8L:16D group (P = 0.052), but had no difference with Inc12L:12D group. Light regimes during incubation had no effects on serum total protein, albumen, globulin, and urea nitrogen content of 1-day-old chicks (P > 0.05), while the globulin content in Inc12L:12D group was numerically greater than in other three groups (P = 0.063). Lysozyme content in Inc12L:12D group was higher than that in the Inc24D and Inc8L:16D groups (P < 0.05), but had no difference with that in Inc16L:8D group. Light regime had no effect on serum total antioxidant capability (T-AOC) (P > 0.05), but significantly affected the activities of glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) (P < 0.05). The GSH-Px and T-SOD activities in the Inc12L:12D group were higher than those in the Inc24D and Inc8L:16D groups. The MDA content of Inc24D was the highest (9.67 nmol/mL) compared to the others, which was very close to the significant level (P = 0.056). In conclusion, 12 h light and 12 h dark incubation has the potential to improve the hatching performance of BYC eggs, benefit for the long bone development, improve some serum immune and antioxidant indexes, and reduce the leg problems in 1-day-old chicks.

Expression of hypoxia-inducible factor-1 in mice infected with Toxoplasma gondii during pregnancy

To investigate the expression and possible role of hypoxia-inducible factor-1 (HIF-1) at the maternal-fetal interface following Toxoplasma gondii infection during early pregnancy. Twenty pregnant C57BL/6 mice, each weighing 16 to 20 g, were randomly divided into 4 groups, including the 12-d control group, 12-d infection group, 18-d control group and 18-d infection group. Mice in the 12-d and 18-d infection groups were injected intraperitoneally with 150 tachyzoites of the T. gondii PRU strain on day 6 of pregnancy, while mice in the 12-d control and 18-d control groups were injected with the same volume of phosphate buffered saline (PBS). Mice in the control and infection groups were sacrificed on days 12 and 18 of pregnancy, and the placental and uterine specimens of the pregnant mice in each group were sampled for pathological examinations. The mRNA expression of HIF-1α, HIF-1β and vascular endothelial growth factor (VEGF) was quantified using quantitative fluorescent real-time PCR (qPCR) assay in the placental and uterine specimens, and the correlation between HIF-1α and VEGF mRNA expression was examined. In addition, and the HIF-1α expression was detected using immunohistochemical staining in the placental and uterine specimens of pregnant mice. Compared with the 12-d and 18-d control groups, adverse pregnant outcomes were observed in mice in 12-d and 18-d infection groups, such as teratism and placental dysplasia. HE staining showed swelling and blood stasis of cells, sinusoid reduction and inflammatory cell infiltration in the labyrinth area of the placenta specimens of mice in 12-d and 18-d infection groups relative to 12-d and 18-d control groups, and columnar epithelial cell injury and inflammatory cell infiltration were seen in the mouse uterine specimens in both infection groups. qPCR assay detected significantly higher HIF-1α (F = 132.6, P < 0.05) and HIF-1β mRNA expression (F = 286.9, P < 0.05) in the placental specimens and lower HIF-1α (F = 111.5, P < 0.05) and HIF-1β mRNA expression (F = 55.2, P < 0.05) in the uterine specimens in the 12-d infection group than in the 12-day control group, and significantly lower HIF-1α and HIF-1β mRNA expression was detected in the placental and uterine specimens in the 18-d infection group than in the 18-day control group (F = 215.8, 418.9, 156.8 and 200.1; all P values < 0.05). Significantly lower VEGF-A (F = 426.2, P < 0.05), VEGF-B (F = 104.6, P < 0.05) and VEGF-C mRNA expression (F = 566.9, P < 0.05) in the placental specimens and higher VEGF-A (F = 426.2, P < 0.05), VEGF-B (F = 104.6, P < 0.05) and VEGF-C mRNA expression (F = 566.9, P < 0.05) in the uterine specimens were detected in the 12-d infection group than in the 12-d control group, and higher VEGF-A, VEGF-B and VEGF-C mRNA expression was found in the placental and uterine specimens in the 18-d infection group than in the 18-d control group (F = 521.9, 100.6, 275.9, 224.6, 108.2 and 333.4; all P values < 0.05). Immunohistochemical staining showed strongly and mildly positive HIF-1α expression in the mouse placental labyrinth area in the 12-d and 18-d infection groups relative to 12-d and 18-d control groups, while no HIF-1α expression was detected in mouse uterine specimens. HIF-1α expression appears a tendency towards a rise in the second trimester and a reduction in the third trimester in mice following T. gondii infection during early pregnancy, which is contrary to the changing tendency of VEGF-A, VEGF-B, and VEGF-C expression. It is hypothesized that HIF-1α inhibits placental angiogenesis in mice during pregnancy through suppressing VEGF expression, resulting in adverse pregnant outcomes.

Monochromatic green light stimulation during incubation shortened the hatching time via pineal function in White Leghorn eggs

BackgroundEffect of monochromatic green light illumination on embryo development has been reported in chickens. The avian pineal gland is an important photo-endocrine organ formed by a mediodorsal protrusion during embryonic development. However, the involvement of pineal gland in the light transduction process remains to be elucidated. In the present study, we investigated the influence of monochromatic green light on hatching time and explored the possible mechanism via pineal function.ResultsA total of 600 eggs of White Leghorn (Shaver strain) were incubated under photoperiods of either 12 h of light and 12 h of darkness using monochromatic green light (12L:12D group) or 24 h of darkness (0L:24D group) for 18 d. Compared to 0L:24D group, the green light stimulation shortened the hatching time without extending the hatch window or impairing hatchability. The liver of embryos incubated in the 12L:12D light condition was heavier than those of the 0L:24D group on d 21 post incubation which may be linked to the observed increase in the serum concentration of insulin-like growth factor 1 (IGF-1); primary secretion of the liver. Histological structure analysis of pineal gland demonstrated that the light stimulation increased follicle area, wall thickness and lumen area on d 10 and d 12 post incubation. Rhythmic function analysis demonstrated that three clock related genes (brain and muscle ARNT-like-1, BMAL1; circadian locomotor output cycles kaput, CLOCK; and cryptochrome-1, CRY1) and a melatonin rate-limiting enzyme related gene (arylalkylamine N-acetyltransferase, AANAT) were rhythmically expressed in the pineal gland of the 12L:12D group, but not in the 0L:24D group. Simultaneously, the light stimulation also increased the concentration of melatonin (MT), which was linked to hepatocyte proliferation and IGF-1 secretion in previous studies.ConclusionsThe 12L:12D monochromatic green light stimulation during incubation shortened hatching time without impairing hatching performance. Pineal gland’s early histological development and maturation of its rhythmic function were accelerated by the light stimulation. It may be the key organ in the photo-endocrine axis that regulates embryo development, and the potential mechanism could be through enhanced secretion of MT in the 12L:12D group which promotes the secretion of IGF-1.

Effects of light cycle on motion behaviour and melatonin secretion in Haliotis discus hannai

The abalone Haliotis discus hannai is a typical nocturnal marine invertebrate. In this study, a quantitative analysis was performed on the motion behaviour characteristics of abalones exposed to different light cycles (0 L:24D, 12 L:12D, 24 L:0D) using infrared camera and behavioural analysis software. A preliminary analysis of the intrinsic correlations between melatonin secretion and abalone behaviour rhythms was also conducted. The results showed that the cumulative moving distance and duration of movement for abalone in the 0 L:24D group were significantly higher than those in the 12 L:12D and 24 L:0D groups (P < 0.05). The mean and maximum moving velocities of abalones in the 12 L:12D group were significantly higher than those in the 0 L:24D group (P < 0.05). The maximum cumulative moving distance and duration of movement for abalone in the 12 L:12D and 24 L:0D groups occurred between 00:00–03:00. In the 0 L:24D group, peak cumulative moving distance and duration movement were recorded between 00:00–03:00 and 15:00–18:00. According to the results of cosine analysis, melatonin content and expression levels of aralkylamine N-acetyl transferase (AANAT) and N-acetylserotonin O-methyltransferase (ASMT) in the 12 L:12D and 24 L:0D groups showed significant circadian cosine rhythms (P < 0.05) and tended to be higher during the day and lower at night. Compared with the variation trend of melatonin, the expression levels of melatonin receptor (MTR) in each group showed significant circadian cosine rhythms (P < 0.05). Especially in the 0 L:24D group, the expression levels of MTR also tended to be higher during the day and lower at night, indicating that MTR may mediate other factors which participate in the regulation of abalone circadian rhythms. The results of this study provide a quantitative description of the motion behaviour characteristics of abalone exposed to different light cycles. The intrinsic correlation between melatonin secretion and abalone motion behaviour rhythms was also examined in this study, which in turn provides a reference for light regulation and feeding strategies in aquaculture production.

Comparison of gamithromycin post-treatment intervals for beef cattle naturally affected with bovine respiratory disease

The primary objective of this study was to compare different gamithromycin post-treatment intervals (PTI) on clinical health outcomes in cattle naturally affected with bovine respiratory disease (BRD). Eight hundred cattle identified with BRD by pen riders, rectal temperature ≥ 104.0°F (≥ 40°C), and no previous treatments were randomized in a 1:1:1:1 ratio to 3-, 6-, 9-, or 12-day PTI within each lot. Cattle treated for BRD were returned to their home pen, and followed for 60 days (d) to monitor subsequent health outcomes. Cattle were categorized by type (dairy-beef or native). General and generalized linear mixed models were used for statistical analyses. First treatment success (P = 0.012) and BRD case fatality risk (P = 0.032) were different among PTI groups. The 9-d PTI group had the greatest first treatment success, which was different (P = 0.008) than the 3-d PTI. The 12-d PTI group had the poorest BRD case fatality risk, which was different (P = 0.071) than the 9-d PTI group. There were no significant differences between the 6- and the 9-d PTI groups. Dairy-beef cattle had an approximately 2-fold higher BRD case fatality risk (P = 0.012) than natives. Results will help practitioners to optimally use gamithromycin in the field.

The anti-caries efficacy of three fluoride compounds at increasing maturation of a microcosm biofilm

ObjectiveTo explore the anti-caries efficacy of three fluoride compounds at increasing maturation of a microcosm biofilm. DesignMicrocosm biofilm, obtained from saliva collected from three donors (IRB #1406440799), was grown on enamel samples (n = 18/group) for 24-h (Brain Heart Infusion; 0.2 % sucrose). Then, pH cycling model started. Three maturations were explored (4d, 8d, and 12d). The pH cycling consisted of daily 2 × 5 min treatments (NaF, SnF2, AmF: 287.5 ppm F, and de-ionized water [DIW]), 4 × 10 min remineralization (BHI, no sucrose, pH 7.0), and 3 × 2:15 h demineralization (BHI, 1% sucrose, pH 4.5). We analyzed the enamel (surface microhardness [VHNchange], integrated mineral loss [ΔZ], lesion depth [L]), and the biofilm (viability [log10 CFU/mL], lactic acid production [LDH], and exopolysaccharide [EPS] amount). Data were analyzed using two-way ANOVA (p = 0.05). ResultsThe interaction between tested variables was significant for VHNchange, viability, LDH, EPS (p = 0.0354, p = 0.0001, p < 0.0001, p < 0.0001), but not for L (p = 0.2412) or ΔZ (p = 0.6811). LDH and EPS analyses exhibited more tolerance of mature biofilm against NaF (LDH and EPS p < 0.0001); NaF-treated groups demonstrated significantly lower results than the control in the 12d group. The effect of SnF2 and AmF continued over time. VHNchange, L, and ΔZ: The effect of SnF2 and AmF was higher than NaF and DIW. L and ΔZ did not result in significant differences over time (all treatments). Within each maturation, fluoride compounds demonstrated statistically significantly lower L and ΔZ values than DIW. ConclusionsBiofilm’s maturation may influence the selection of fluoride compounds to achieve an optimum cariostatic effect.

Effects of Photoperiod Regime on Meat Quality, Oxidative Stability, and Metabolites of Postmortem Broiler Fillet (M. Pectoralis major) Muscles.

The objective of this study was to evaluate the effects of photoperiod on meat quality, oxidative stability, and metabolites of broiler fillet (M. Pectoralis major) muscles. A total of 432 broilers was split among 4 photoperiod treatments [hours light(L):dark(D)]: 20L:4D, 18L:6D, 16L:8D, and 12L:12D. At 42 days, a total of 48 broilers (12 broilers/treatment) was randomly selected and harvested. At 1 day postmortem, fillet muscles were dissected and displayed for 7 days. No considerable impacts of photoperiods on general carcass and meat quality attributes, such as carcass weight, yield, pH, water-holding capacity, and shear force, were found (p > 0.05). However, color and oxidative stability were influenced by the photoperiod, where muscles from 20L:4D appeared lighter and more discolored, coupled with higher lipid oxidation (p < 0.05) and protein denaturation (p = 0.058) compared to 12L:12D. The UPLC–MS metabolomics identified that 20 metabolites were different between the 20L:4D and 12L:12D groups, and 15 were tentatively identified. In general, lower aromatic amino acids/dipeptides, and higher oxidized glutathione and guanine/methylated guanosine were observed in 20L:4D. These results suggest that a photoperiod would result in no considerable impact on initial meat quality, but extended photoperiods might negatively impact oxidative stability through an alteration of the muscle metabolites.

Establishment and evaluation of a reversible two-kidney, one-clip renovascular hypertensive rat model.

The aim of the present study was to establish and evaluate a novel and reversible two-kidney, one-clip renovascular hypertensive rat model with a titanium vascular clip. A total of 40 male Sprague-Dawley rats were evenly and randomly divided into a sham-operated group, and 3, 7, 12 and 28D groups (namely removing the vascular clip in the renovascular hypertensive model after 3, 7, 12 and 28 days, respectively). The systolic blood pressure (SBP) and plasma renin activity (PRA) were measured, and color duplex imaging was conducted before placing the clips, as well as before and after removing them. After placing the vascular clips, SBP and PRA in the 3, 7, 12 and 28D groups were significantly increased (SBP: Sham-operated vs. 3D groups, P=0.020; 3 vs. 7D groups, P=0.008; 7 vs. 28D groups, P=0.019; 12 vs. 28D groups, P=0.039, and between other groups P<0.001. PRA: 3 vs. 7D groups, P=0.001; 7 vs. 12D groups, P=0.004; 12 vs. 28D groups, P=0.040, and between other groups, P<0.001). After removing the clips, SBP were significantly reduced in the 3 and 7D groups (P=0.023, 0.040, 0.066 and 0.314 in the 3, 7, 12 and 28D groups, respectively), but were still significantly higher than that before placing clips in the 7, 12 and 28D groups (P=0.067, P=0.005, P<0.001 and P<0.001 in the 3, 7, 12 and 28D groups, respectively). After removing the clips, PRA was significantly reduced in each group (P<0.001, P<0.001, P=0.012 and P=0.049 in 3, 7, 12 and 28D groups, respectively), but still higher than that before placing the clips (P<0.001, P=0.001, P=0.001 and P=0.003 in 3, 7, 12 and 28D groups, respectively). Vascular imaging also indicates this model has a reversible property. In conclusion, a reversible renovascular hypertension rat model is feasible, and provides a basis for research on clinical ischemic nephropathy and renal artery revascularization.

23 THE EFFECT OF WITHDRAWAL TIMING OF CONTROLLED INTERNAL DRUG RELEASE (CIDR) ON EWE REPRODUCTIVE PERFORMANCE

This study was carried out using 80 multiparous Awassi ewes during breeding season to compare the effects of controlled internal drug release (CIDR) withdrawal time on ewe fertility. Ewes were equally and randomly allotted into 4 groups (n = 20/group). Ewes had a CIDR inserted for 3, 6, 9, or 12 days with intramuscular administration of 300 IU of equine chorionic gonadotropin (eCG) at withdrawal time. Oestrus was detected using vasectomized ram starting 12 h after CIDR withdrawal and repeated every 12 h up to 84 h. Blood samples were collected from all groups at the time of CIDR withdrawal for measuring of oestradiol (E2) and progesterone (P4) serum concentrations using commercial ELISA kits and micro-titrimetric plates. Timed insemination was performed 48 h post CIDR withdrawal in all groups. Pregnancy was diagnosed by ultrasonography at day 23 post-insemination and confirmed at day 35. Comparisons among groups were evaluated using Chi Square (χ2) test in all measured parameters except hormones levels, which analysed by repeated-measures analysis of variance (ANOVA), using SAS (SAS Institute Inc., Cary, NC, USA). A difference was considered significant at P &lt; 0.05 level. The results revealed that the retention, vaginal discharge and drawstring breakage rates after CIDR removal were insignificantly differed between all groups. On the other hand, pregnancy rate was significantly (P ≤ 0.05) higher in 9-d and 6-d groups (68.4 and 60%, respectively) than the 3-d group. While, no significant difference was detected between 12d group and other groups. The heat detection rate was significantly (P ≤ 0.05) higher in 12d group (100%) than 6-d and 3-d groups (80 and 45%, respectively). While, no significant difference was detected between 12-d and 9-d groups in heat detection rate. P4 was significantly higher in the 12-d group (13.4 ± 3.06 ng mL−1) than other groups. While E2 was significantly lower in the 12-d group (1.6 ± 0.06 pg mL−1) than other groups. These results indicated that withdrawal of CIDR devices after 9 days are efficient in synchronizing oestrus in ewes and provided higher pregnancy rate.

Physiological metabolism ofHaliotis discus hannaiIno under different light qualities and cycles

The goal of this experiment was to examine the effects of different light qualities (red, white, blue) and cycles (12L:12D, 8L:16D, 4L:20D, 0L:24D, 16L:8D) on the survival, growth, metabolism and antioxidant defence system of Haliotis discus hannai Ino. Under red and white light at 4L:20D, the body weight-specific growth rate of abalones was significantly higher than that of the 0L:24D group (P < 0.05). At 16L:8D, succinate dehydrogenase activity decreased and lactate dehydrogenase and alanine aminotransferase activity and the lactic acid content significantly rose (P < 0.05) in the red and white light groups. Under blue light, reactive oxygen species and malondialdehyde content for each light cycle were significantly higher than those of the red and white groups (P < 0.05). Under blue, white and red light, total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, glutathione peroxidase (GPX) activity and reduced glutathione (GSH) content gradually rose with increased duration of light exposure. Under red light, significant differences in these parameters were detected between the 4L:20D and 16L:8D groups (P < 0.05). Under blue and white light at 16L:8D, values of T-AOC, SOD, GPX activity and GSH content were significantly lower than those of the 12L:12D group (P < 0.05). Overall, these results indicate that red light at light cycles of 4L:20D and 8L:16D is optimal for the culture and production of H. discus hannai, as these conditions promoted food intake, growth and health maintenance as well as normal physiological metabolism of the organism.