Dynamic changes of histone H3 lysine 9 following trimethylation in bovine oocytes and pre-implantation embryos

Objectives

We have examined dynamic changes of histone H3 lysine 9 following trimethylation (H3K9me3), the mRNA expression levels of SUV39H1 and SUV39H2 in bovine oocytes and the role in the development of in vitro fertilization (IVF) pre-implantation embryos.

Results

There were strong H3K9me3 signals in germinal vesicle (GV) oocytes but no signals in MII oocytes. H3K9me3 signals were maintained during IVF pre-implantation embryo development. SUV39H1 and SUV39H2 showed significantly higher mRNA expression levels in GV oocytes than MII oocytes (P < 0.01). SUV39H1 showed high mRNA expression level in two-cell embryos, however, SUV39H2 showed high mRNA expression level in four-cell embryos. In other development stage, SUV39H1 and SUV39H2 showed low expression levels.

Conclusion

Bovine IVF pre-implantation embryos maintain strong H3K9me3 signals and SUV39H1 and SUV39H2 are highly expressed at the early development stage of pre-implantation embryos.

     

Body mass index and basal androstenedione are independent risk factors for miscarriage in polycystic ovary syndrome

Background

There is limited literature investigating the effects of body mass index (BMI) and androgen level on in vitro fertilization (IVF) outcomes with a gonadotropin-releasing hormone (GnRH)-antagonist protocol in polycystic ovary syndrome (PCOS). Androgen-related variation in the effect of body mass index (BMI) on IVF outcomes remains unknown.

Methods

In this retrospective study, 583 infertile women with PCOS who underwent IVF using the conventional GnRH-antagonist protocol were included. Patients were divided into four groups according to BMI and androgen level: overweight- hyperandrogenism(HA) group, n?=?96, overweight-non-HA group, n?=?117, non-overweight-HA group, n?=?152, and non-overweight-non-HA group, n?=?218.

Results

A significantly higher number of oocytes were retrieved, and the total Gn consumption as well Gn consumption per day was significantly lower, in the non-overweight groups than in the overweight groups. The number of available embryos was significantly higher in the HA groups than in the non-HA groups. Clinical pregnancy rate was of no significant difference among four groups. Live-birth rates in the overweight groups were significantly lower than those in non-overweight-non-HA group (23.9, 28.4% vs. 42.5%, P<0.05). The miscarriage rate in overweight-HA group was significantly higher than that in non-overweight-non-HA group (45.2% vs. 14.5%, P<0.05). Multivariate logistic regression analysis revealed that BMI and basal androstenedione (AND) both acted as significantly influent factors on miscarriage rate. The area under the curve (AUC) in receiver operating characteristic (ROC) analysis for BMI and basal AND on miscarriage rate were 0.607 (P?=?0.029) and 0.657 (P?=?0.001), respectively, and the cut-off values of BMI and basal AND were 25.335?kg/m² and 10.95?nmol/L, respectively.

Conclusions

In IVF cycles with GnRH-antagonist protocol, economic benefits were seen in non-overweight patients with PCOS, with less Gn cost and more retrieved oocytes. BMI and basal AND were both significantly influential factors with moderate predictive ability on the miscarriage rate. The predictive value of basal AND on miscarriage was slightly stronger than BMI.

     

Probiotic Potential of a Lactobacillus Bacterium of Canine Faecal-Origin and Its Impact on Select Gut Health Indices and Immune Response of Dogs

The objective of the present study was to develop a probiotic of canine-origin for its potential application in pet nutrition. Accordingly, 32 lactic acid bacteria (LAB) strains were isolated from faeces of dogs, out of which 9 strains were short-listed for further in vitro testing based on the aggregation time and cell surface hydrophobicity. The results of acid-, bile- and phenol-tolerance tests indicated that out of the nine, isolate cPRO23 was having better resistance to these adverse conditions likely to be encountered in the gastrointestinal tract. The isolate also showed optimal enzymatic activities for amylase, lipase and protease. Further assessments also indicated its superiority in terms of co-aggregation and antagonistic activity against pathogenic strains of Salmonella typhimurium and Salmonella enteritidis. Subsequently, the isolate was identified through 16S rRNA sequencing and sequence homology, and designated as Lactobacillus johnsonii CPN23. The candidate probiotic was then evaluated in vivo using 15 adult Labrador dogs, divided into 3 groups, viz. CON (with no probiotics), dPRO (with Lactobacillus acidophilus NCDC 15 as a conventional dairy-origin probiotic) and cPRO (with L. johnsonii CPN23 as a canine-origin probiotic). Results of the 9-week study indicated that supplementation of cPRO improved (P < 0.05) the faecal concentration of acetate and butyrate with a concomitant reduction (P < 0.05) in faecal ammonia. The cell-mediated immune response, assessed as delayed-type hypersensitivity reaction to phytohaemagglutinin-P, was better (P < 0.05) in dogs fed cPRO as compared to the CON dogs. There were, however, no variations evident in the antibody response to sheep-erythrocytes among the three groups. It is concluded that the canine-origin L. johnsonii CPN23, in addition to possessing all the in vitro functional attributes of a candidate probiotic, also has the potential to be used as a probiotic in pet nutrition programs.     

Nuclear transfer of porcine embryos using cryopreserved delipated blastomeres as donor nuclei

Nuclear transfer protocol for the pig using cryopreserved delipated four- to eight-cell and morula stage embryos as nucleus donors was developed. Donor embryos, which had been delipated by micromanipulation following centrifugation for polarizing cytoplasmic lipid droplets, were cryopreserved with 1.5 M 1,2-propanediol and 0.1 M sucrose. Recipient cytoplasts were prepared from ovulated oocytes. Activation of oocytes could be induced more efficiently when electric stimulation was given 53 hr after the hCG injection or later (66–83%), compared with 52 hr or earlier (11–16%, P < 0.05), suggesting that aging after ovulation may be required for in vivo matured porcine oocytes to be activated by electric stimuli. Membrane fusion rates between donor blastomeres and enucleated oocytes were 88% (127/144) and 97% (56/58, P > 0.05) for the four- to eight-cell and morula stage embryos, respectively. In vitro developmental rates to the two-cell (53/100 vs. 35/65), four-cell (34/100 vs. 26/65), and morula stage (17/100 vs. 18/65) were the same between the nuclear transfer embryos with four- to eight-cell and morula nuclei. However, more embryos reconstituted with morula nuclei developed to blastocysts (15% vs. 6%, P < 0.05). These data demonstrated that blastomeres of cryopreserved, delipated porcine embryos can be used as donor nuclei for nuclear transfer. Frozen-thawed, delipated blastomeres can be efficiently isolated and fused, and therefore provide a useful source of donor nuclei. Mol. Reprod. Dev. 48:339–343, 1997. © 1997 Wiley-Liss, Inc.     

Effects of Zinc Supplementation During In Vitro Maturation on Meiotic Maturation of Oocytes and Developmental Capacity in Yak

Zinc (Zn) is an essential trace element that is required during mammalian developmental processes. The objective of this study was to investigate the effects of Zn supplementation during in vitro maturation (IVM) on the developmental capacity of yak (Bos grunniens) oocytes. Cumulus expansion, nuclear maturation, intracellular glutathione (GSH), reactive oxygen species (ROS) levels, superoxide dismutase (SOD) activity, subsequent embryonic development, and the expression of Zn transporters (ZnTs) and Zrt and Irt-like proteins (ZiPs) were evaluated. The Zn concentrations in yak plasma and follicular fluid were 0.740?±?0.012 and 0.382?±?0.009 μg/mL, respectively. The cumulus expansion did not show significant differences in COCs after matured with or without Zn supplementation (P?>?0.05). The intracellular GSH was higher in oocytes matured with 1 or 2 mg/L Zn than in control group (0 mg/L) (P?<?0.05). However, ROS levels of oocytes matured with 1 or 2 mg/L Zn were reduced significantly compared with the control and 0.5 mg/L groups (P?<?0.05). The SOD activity was increased significantly after Zn supplementation. The cleavage rate was not significantly different after Zn supplementation (P?>?0.05). Percentages of matured oocytes that developed into the blastocyst stage after IVF were 47.9, 50.5, 60.4, and 58.9% for 0, 0.5, 1, and 2 mg/L Zn groups, respectively. Gene expression analysis revealed that the expression patterns associated with Zn were changed after Zn supplementation. In conclusion, Zn supplementation to IVM improved yak oocyte maturation and subsequent development by increasing GSH and SOD activity, decreasing ROS in oocytes.     

Glioprotective Effects of Lingonberry Extract Against Altered Cellular Viability,Acetylcholinesterase Activity,and Oxidative Stress in Lipopolysaccharide-Treated Astrocytes

Altered astrocytic function is a contributing factor to the development of neurological diseases and neurodegeneration. Berry fruits exert neuroprotective effects by modulating pathways involved in inflammation, neurotransmission, and oxidative stress. The aim of this study was to examine the effects of the lingonberry extract on cellular viability and oxidative stress in astrocytes exposed to lipopolysaccharide (LPS). In the reversal protocol, primary astrocytic cultures were first exposed to 1 µg/mL LPS for 3 h and subsequently treated with lingonberry extract (10, 30, 50, and 100 μg/mL) for 24 and 48 h. In the prevention protocol, exposure to the lingonberry extract was performed before treatment with LPS. In both reversal and prevention protocols, the lingonberry extracts, from 10 to 100 μg/mL, attenuated LPS-induced increase in reactive oxygen species (around 55 and 45%, respectively, P?<?0.01), nitrite levels (around 50 and 45%, respectively, P?<?0.05), and acetylcholinesterase activity (around 45 and 60%, respectively, P?<?0.05) in astrocytic cultures at 24 and 48 h. Also, in both reversal and prevention protocols, the lingonberry extract also prevented and reversed the LPS-induced decreased cellular viability (around 45 and 90%, respectively, P?<?0.05), thiol content (around 55 and 70%, respectively, P?<?0.05), and superoxide dismutase activity (around 50 and 145%, respectively, P?<?0.05), in astrocytes at both 24 and 48 h. Our findings suggested that the lingonberry extract exerted a glioprotective effect through an anti-oxidative mechanism against LPS-induced astrocytic damage.     

Fluoride Exposure Aggravates the Testicular Damage and Sperm Quality in Diabetic Mice: Protective Role of Ginseng and Banaba

The current study was conducted to investigate the effects of dietary zinc oxide (ZnO) on the antioxidant capacity, small intestine development, and jejunal gene expression in weaned piglets. Ninety-six 21-day-old piglets were randomly assigned to three dietary treatments. Each treatment had eight replicates with four piglets per replicate. The piglets were fed either control diet (control) or control diet supplemented with in-feed antibiotics (300 mg/kg chlortetracycline and 60 mg/kg colistin sulfate) or pharmacological doses of ZnO (3000 mg/kg). The experiment lasted 4 weeks. Blood samples were collected at days 14 and 28, while intestinal samples were harvested at day 28 of the experiment. Dietary high doses of ZnO supplementation significantly increased the body weight (BW) at day 14 and average daily gain (ADG) of days 1 to 14 in weaned piglets, when compared to control group (P < 0.05). The incidence of diarrhea of piglets fed ZnO-supplemented diets, at either days 1 to 14, days 14 to 28, or the overall experimental period, was significantly decreased in comparison with those in other groups (P < 0.05). Supplementation with ZnO increased the villus height of the duodenum and ileum in weaned piglets and decreased the crypt depth of the duodenum, when compared to the other groups (P < 0.05). Dietary ZnO supplementation decreased the malondialdehyde (MDA) concentration at either day 14 or day 28, but increased total superoxide dismutase (T-SOD) at day 14, when compared to that in the control (P < 0.05). ZnO supplementation upregulated the messenger RNA (mRNA) expression of zonula occludens-1 (ZO-1) and occludin in the jejunum mucosa of weaned piglets, compared to those in the control (P < 0.05). The pro-inflammatory cytokine interleukin-lβ (IL-1β) mRNA expression in the jejunum mucosa was downregulated in the ZnO-supplemented group, compared with the control (P < 0.05). Both in-feed antibiotics and ZnO supplementation decreased the mRNA expression of interferon-γ (IFN-γ), but increased the mRNA expression of transforming growth factor-β (TGF-β), in the jejunum mucosa of piglets, when compared to those in the control (P < 0.05). In summary, supplemental ZnO was effective on the prevention of post-weaning diarrhea (PWD) in weaned piglets and showed comparative growth-promoting effect on in-feed antibiotics, probably by the mechanism of improvement of the antioxidant capacity, restoration of intestinal barrier function and development, and modulation of immune functions.     

Effects of Maternal Zinc Glycine on Mortality,Zinc Concentration,and Antioxidant Status in a Developing Embryo and 1-Day-Old Chick

This study was conducted to investigate the effects of maternal zinc glycine (Zn-Gly) supplementation as an alternative for zinc sulfate (ZnSO₄) on mortality, zinc (Zn) concentration, and antioxidant status in a developing embryo and 1-day-old chick. Six hundred 39-week-old broiler breeders were randomly assigned to 6 treatments, each treatment including 5 replicates with 20 birds each. Six treatments received a basal diet (control, 24 mg Zn/kg diet) or a basal diet supplemented with ZnSO₄ (80 mg Zn/kg) or Zn-Gly (20, 40, 60, or 80 mg Zn/kg), respectively. The experiment lasted for 8 weeks after a 4-week pre-experiment with a basal diet. At the last week, 100 eggs per replicate were randomly collected for incubation. Compared with the control treatment, Zn supplementation decreased (P < 0.05) embryo mortalities of the late stage and the whole period, increased (P < 0.05) liver Zn concentration in the embryo of d9, d19, and 1-day-old chick, and improved (P < 0.05) antioxidant status in the embryo of d19 and 1-day-old chick. Compared with the ZnSO₄ treatment, 80 mg Zn/kg Zn-Gly treatment significantly decreased (P < 0.05) the late stage embryo mortality and increased (P < 0.05) liver Zn concentration in the embryo of d9, d19, and 1-day-old chick. The 80 mg Zn/kg Zn-Gly treatment significantly increased (P < 0.05) copper-zinc superoxide dismutase activity in d19 embryo and 1-day-old chick, total superoxide dismutase activity in 1-day-old chick, and copper-zinc superoxide dismutase messenger RNA (mRNA) abundance of d9 embryo and 1-day-old chick than that in ZnSO₄ treatment. The liver metallothionein concentration of the developing embryo and 1-day-old chick and its mRNA abundance of d19 embryo were also significantly increased (P < 0.05) in the 80 mg Zn/kg Zn-Gly treatment in comparison with ZnSO₄ treatment. In conclusion, maternal Zn supplementation decreased embryo mortalities of the late stage and the whole period by increasing liver Zn concentration and antioxidant status in d19 embryo and 1-day-old chick, and 80 mg Zn/kg from Zn-Gly treatment was the optimum choice.     

In vitro clonal propagation and stable cryopreservation system for <Emphasis Type="Italic">Platycladus orientalis</Emphasis> via somatic embryogenesis

Platycladus orientalis is a widespread conifer, which is native in eastern Asia, and has recently attracted much attention due to its ornamental value for landscape and gardens. However, native P. orientalis populations have been in decline over the past century. Here, we established an in vitro propagation and cryopreservation system for P. orientalis via somatic embryogenesis (SE). Whole megagametophytes with four development stages (Early embryogeny: E1 and late embryogeny: L1, L2, and L3) of zygotic embryos from immature P. orientalis cones were used as initial explants and cultured on three different basal media such as initiation medium (IM), Litvay (LV), and Schenk and Hildebrandt (SH). Both the developmental stage of zygotic embryos and kind of basal medium had a significant effect on embryogenesis induction with IM (P?<?0.001, respectively). The highest frequency of embryogenic callus induction was obtained in megagametophytes with zygotic embryos at L2 stage, which ranged as high as 30%. The maturation medium containing IM basal salts, vitamins and amino acids, 15 g l^?1 abscisic acid (ABA), 50 g l^?1 maltose, and 100 g l^?1 polyethylene glycol 4000 (PEG) was found to be the suitable medium for production of somatic embryos. The frequency of somatic embryo formation from both non-cryopreserved and cryopreserved cell lines was also tested. There were no statistical differences on the production of somatic embryos between non-cryopreserved and cryopreserved cells (P?=?0.523). Genetic fidelity of the plantlets regenerated from non-cryopreserved and cryopreserved embryogenic cell lines was assessed by both random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) analysis. There was no genetic instability in the regenerated plantlets from cryopreserved embryogenic cell lines. Both the SE protocol and cryopreservation protocols described here have the potential to contribute the conservation and clonal propagation of P. orientalis germplasm.     

The relevance of <Emphasis Type="Italic">ABCA1</Emphasis> R219K polymorphisms and serum ABCA1 protein concentration to Parkinson’s disease pathogenesis and classification: a case–control study

To investigate the relevance of ABCA1 R219K polymorphisms and serum ABCA1 protein concentration to Parkinson’s disease (PD) pathogenesis and classification in Chinese population. Between June 2013 to January 2014, 108 patients diagnosed with PD at Department of Neurology, Tangshan People’s Hospital, Tangshan were enrolled in the PD group, and 123 healthy individuals, from Health Screening Center of the same hospital, with matched age, gender, and education were enrolled in the control group. Polymerase chain reaction–restriction fragment length polymorphism method was used to detect ABCA1 R219K polymorphisms and enzyme-linked immunosorbent assay used to measure serum ABCA1 concentrations. Frequencies of R/K and K/K genotypes, and K allele of ABCA1 R219K polymorphisms were significantly lower in the PD group than the control group (all P < 0.05). Significant differences existed in distributions of genotype frequencies, including R/R, R/K and K/K, between PD and control group of each classification (all P < 0.05). ABCA1 concentrations were significantly different in the PD and control group (P < 0.05); also ABCA1 concentrations were very different among PD patients with different genotypes (all P < 0.05). Serum concentrations of ABCA1were significantly different among PD patients in different classifications (all P < 0.05), suggesting the negative correlation between ABCA1 serum concentration and PD classification (r = ?0.776, P < 0.05). And serum concentrations of ABCA1 showed obvious differences among cases with three different genotypes in each classification (all P < 0.05). ABCA1 R219K polymorphisms and serum concentration were associated with pathogenesis and classification of PD, and K allele may be a protective genetic factor.     

Effects of Synbiotic2000™ Forte on the Intestinal Motility and Interstitial Cells of Cajal in TBI Mouse Model

The main objective of this study was to investigate the effects of Synbiotic2000? Forte on the intestinal motility and interstitial cells of Cajal (ICC) in traumatic brain injury (TBI) mouse model. Kunming mice were randomly divided into sham operation group (S group), enteral nutrition group with TBI (E group), and Synbiotic2000? Forte group with TBI (P group). The contractile activity of the intestinal smooth muscle, densities and ultrastructure of the ICC, kit protein concentration, weight, and defecation of mice were monitored and analyzed. TBI markedly suppressed contractile activity of the intestinal smooth muscle (P < 0.01), which led to a reduction of defecation (P < 0.01) and weight (P < 0.01). However, application of Synbiotic2000? Forte significantly improved contractile activity of the small intestine (P < 0.01), which may be related to protective effects to the interstitial cells of Cajal, smooth muscle cells, and enteric neurons. TBI impaired ICC networks and densities (P < 0.01), events that were protected by the application of Synbiotic2000? Forte. Synbiotic2000? Forte may attenuate TBI-mediated inhibition of the kit protein pathway. Synbiotic2000? Forte may improve intestinal motility and protect the ICC in the TBI mouse. These findings provide a novel support for the application of Synbiotic2000? Forte in intestinal motility disturbance after TBI.     

Effects of Probiotics on Survival,Growth and Digestive Enzymes Activities in Freshwater Prawn <Emphasis Type="Italic">Macrobrachium rosenbergii</Emphasis> (De Man 1879)

A study was conducted to examine the effects of three probiotics, Lactobacillus sporogenes, Bacillus subtilis and Saccharomyces cerevisiae on the survival, growth and digestive enzymes activities of the freshwater prawn Macrobrachium rosenbergii post larvae (PL). The probiotics, L. sporogenes (4 %), B. subtilis (3 %) and S. cerevisiae (4 %) were taken and mixed with basal diet. Diet without probiotics served as control. These probiotics diets were fed to M. rosenbergii PL for a period of 60 days. After the feeding trail, the growth parameters such as survival, weight gain, specific growth rate and protein efficiency rate were found to be significantly (P < 0.05) higher in 4 % S. cerevisiae incorporated diet fed PL when compared with control. In the case of feed conversion rate just the reverse was seen (P < 0.05) at this concentration. This indicates its superior quality among different concentrations of probiotics tested. Activities of digestive enzymes, such as protease, amylase and lipase were significantly (P < 0.05) higher at this concentration (4 % S. cerevisiae). Some of essential and non-essential amino acids also significantly elevated in probiotics supplemented diet fed prawns. This study indicated that probiotics, S. cerevisiae incorporated diets were beneficial for M. rosenbergii in terms of increasing growth, enzyme and amino acid production.     

Resveratrol Inhibits Diabetic-Induced Müller Cells Apoptosis through MicroRNA-29b/Specificity Protein 1 Pathway

The aim of this study was to evaluate the anti-apoptosis effects of resveratrol (RSV) on diabetic rats retinal Müller cells in vivo and in vitro and to further investigate the roles of microRNA-29b (miR-29b)/specificity protein 1 (SP1) in the anti-apoptosis mechanism of RSV. Retina was obtained from normal and diabetic rats with or without RSV (5 and 10 mg/kg/day) treatments at 1–7 months. TdT-mediated dUTP-biotin nick end labeling (TUNEL) and Annexin V/PI staining were used to detect apoptosis. Immunofluorescence was used to assess distribution of SP1 in retina. MiR-29b and SP1 messenger RNA (mRNA) expression was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). SP1, Bax, and bcl-2 protein expression was evaluated by western blotting. Caspase-3 activity was detected by assay kit. Our study showed that the TUNEL-positive cells were mainly localized in the inner nuclear layer (INL) of retina and RSV administration effectively suppressed streptozotocin (STZ)-induced apoptosis of retinal cells in INL in vivo (P?<?0.001). Our study also showed that RSV administration effectively suppressed high glucose (HG)-induced retinal Müller cells’ apoptosis in vitro (P?<?0.001). Furthermore, our study revealed that the diabetes-induced downregulated expression of miR-29b and upregulated expression of SP1 could be rescued by RSV in vivo and in vitro (P?<?0.05). The anti-apoptosis effect and downregulated SP1 expression effect of RSV was prevented by miR-29b inhibitor (P?<?0.05). MiR-29b mimic increased the above-mentioned effects of RSV (P?<?0.001). These findings indicate that RSV is a potential therapeutic option for diabetic retinopathy (DR) and that miR-29b/SP1 pathway play roles in the anti-apoptosis mechanism of RSV.     

Effects of Chromium-Loaded Chitosan Nanoparticles on Glucose Transporter 4, Relevant mRNA,and Proteins of Phosphatidylinositol 3-Kinase,Akt2-Kinase,and AMP-Activated Protein Kinase of Skeletal Muscles in Finishing Pigs

The study was conducted to evaluate the effects of chromium-loaded chitosan nanoparticles (Cr-CNP) on glucose transporter 4 (GLUT4), relevant messenger RNA (mRNA), and proteins involved in phosphatidylinositol 3-kinase (PI3K), Akt2-kinase, and AMP-activated protein kinase (AMPK) of skeletal muscles in finishing pigs. A total of 120 crossbred barrows (BW 65.00 ± 1.26 kg) were randomly allotted to four dietary treatments, with three pens per treatment and 10 pigs per pen. Pigs were fed the basal diet supplemented with 0, 100, 200, or 400 μg/kg of Cr from Cr-CNP for 35 days. After the feeding trials, 24 pigs were slaughtered to collect longissimus muscle samples for analysis. Cr-CNP supplementation increased GLUT4 messenger RNA (mRNA) (quadratically, P < 0.01) and total and plasma membrane GLUT4 protein contents (linearly and quadratically, P < 0.001) in skeletal muscles. Glycogen synthase kinase 3β (GSK-3β) mRNA was decreased linearly (P < 0.001) and quadratically (P < 0.001). Supplemental Cr-CNP increased insulin receptor (InsR) mRNA quadratically (P < 0.01), Akt2 total protein level linearly (P < 0.01) and quadratically (P < 0.001), and PI3K total protein was increased significantly (P < 0.05) in 200 μg/kg treatment group. The mRNA of AMPK subunit gamma-3 (PRKAG3) and protein of AMPKα₁ was significantly increased (P < 0.001) with the addition of Cr-CNP. The results indicate that dietary supplementation of Cr-CNP may promote glucose uptake by leading to recruitment of GLUT4 to the plasma membrane in skeletal muscles, and these actions may be associated with the insulin signal transduction and AMPK.     

Effect of C-type natriuretic peptide pretreatment on in vitro bovine oocyte maturation

C-type natriuretic peptide (CNP) has been considered as a physiological meiotic inhibitor that stimulates the cGMP production by cumulus cell natriuretic peptide receptor 2 (NPR2), which inhibits oocyte phosphodiesterase type 3 activity and increases cAMP. In this study, we explored the effect of CNP pretreatment on the in vitro maturation (IVM) of bovine oocytes by examining changes in cleavage rate, blastocyst formation, mitochondrial DNA (mtDNA) copy number, reactive oxygen species (ROS) level, glutathione (GSH) content, and redox state. Our results showed that 200 nM CNP could effectively maintain meiotic arrest of bovine oocytes in vitro within 6 h. The two-step IVM system in which oocytes were pretreated with 200 nM CNP for 6 h and then cultured IVM for 28 h yielded a significantly (P < 0.05) increased blastocyst rate and cell number after in vitro fertilization (IVF) while compared to the conventional one-step IVM method. In addition, in comparison with the conventional 24-h matured oocyte, oocytes pretreated with 200 nM CNP for 6 h followed by 28 h IVM resulted in significantly (P < 0.05) higher mtDNA copy number and ROS levels in oocytes, while GSH level significantly (P < 0.05) decreased. Remarkably, regardless of treatment, no changes were observed in FAD++, NAD(P)H autofluorescence intensity, and redox ratio (FAD++/NAD(P)H) within the oocytes, maintaining a healthy metabolic equilibrium of redox throughout the two-step IVM. In conclusion, these results indicate that CNP pretreatment could dramatically improve the quality of bovine oocytes during in vitro maturation.     

Effects of Zinc Glycinate on Productive and Reproductive Performance,Zinc Concentration and Antioxidant Status in Broiler Breeders

An experiment was conducted to investigate the effects of zinc glycinate (Zn-Gly) supplementation as an alternative for zinc sulphate (ZnSO₄) on productive and reproductive performance, zinc (Zn) concentration and antioxidant status in broiler breeders. Six hundred 39-week-old Lingnan Yellow broiler breeders were randomly assigned to 6 groups consisting of 4 replicates with 25 birds each. Breeders were fed a basal diet (control group, 24 mg Zn/kg diet), basal diet supplemented with 80 mg Zn/kg diet from ZnSO₄ or basal diet supplemented with 20, 40, 60 and 80 mg Zn/kg diet from Zn-Gly. The experiment lasted for 8 weeks after a 4-week pre-test with the basal diet, respectively. Results showed that Zn supplementation, regardless of sources, improved (P?<?0.05) the feed conversion ratio (kilogram of feed/kilogram of egg) and decreased broken egg rate, and elevated (P?<?0.05) the qualified chick rate. Compared with the ZnSO₄ group, the 80 mg Zn/kg Zn-Gly group significantly increased (P?<?0.05) average egg weight, fertility, hatchability and qualified chick rate, whereas it decreased (P?<?0.05) broken egg rate. The Zn concentrations in liver and muscle were significantly higher (P?<?0.05) in 80 mg Zn/kg Zn-Gly group than that in ZnSO₄ group. Compared with ZnSO₄ group, 80 mg Zn/kg Zn-Gly group significantly elevated (P?<?0.05) the mRNA abundances of metallothionein (MT) and copper-zinc superoxide (Cu-Zn SOD), as well as the Cu-Zn SOD activity and MT concentration in liver. Moreover, the 80 mg Zn/kg Zn-Gly group had higher (P?<?0.05) serum T-SOD and Cu-Zn SOD activities than that in the ZnSO₄ group. This study indicated that supplementation of Zn in basal diet improved productive and reproductive performance, Zn concentration and antioxidant status in broiler breeders, and the 80 mg Zn/kg from Zn-Gly was the optimum choice for broiler breeders compared with other levels of Zn from Zn-Gly and 80 mg/kg Zn from ZnSO₄.     

Identifying Morphological and Mechanical Traits Associated with Stem Lodging in Bioenergy Sorghum (<Emphasis Type="Italic">Sorghum bicolor</Emphasis>)

Stem lodging in Sorghum is a major agronomic problem that has far-reaching economic consequences. More rapid and reliable advances in stem lodging resistance could be achieved through development of selective breeding tools that are not dependent on post hoc data or dependent on abiotic or biotic environmental factors. Our objective was to use sorghum to examine how mechanical stability is achieved and lost, and to provide insights into the development of a rapid and reliable phenotyping approach. The biomechanical properties of the stems of six bioenergy sorghum genotypes were investigated using a three-point bending test protocol. Important morphometric data were also collected, and previously collected lodging scores were used to associate with morphological and mechanical traits. Nodes were two to three-folds stronger, stiffer, and more rigid than internodes. In general, internodes were numerically weakest and more rigid between internodes 3 and 6, corresponding to the area where higher stem lodging is observed. Internode strength was negatively correlated with diameter (r = ?0.77, P < 0.05) and volume (r = 0.96, P < 0.01), while stem lodging was positively correlated with flexural rigidity (r = 0.85, P < 0.05) and volume (r = 0.78, P < 0.05). The analysis revealed key functional traits that influence the mode and location of stem lodging. Moreover, these results indicate the potential of these methods as a selective breeding tool for indirect selection of stem lodging resistance in bioenergy sorghum.