Youshe Ren

Effects of selenium on the proliferation, apoptosis and testosterone production of sheep Leydig cells in vitro

The objective of this study was to investigate the effects of selenium (Se) on inxa0vitro proliferation, apoptosis and testosterone production of sheep Leydig cells and its underlying mechanism. Leydig cells were collected from 8-month-old sheep and divided into four treatment groups (0, 2.0, 4.0 and 8.0xa0μmol/L Se). After treatment with Se for 48xa0h, the MTT and flow cytometric assay were used to detect cell proliferation and apoptosis. Testosterone level in the culture medium was determined by ELISA. The mRNA expression and protein abundance of cell cycle, apoptosis and testosterone synthesis-related genes were detected using real-time PCR and western blot analysis. The results showed that the highest percentage of live and apoptotic cells was obtained in the 2.0 and 8.0xa0μmol/L group, respectively. In the Se treatment groups, the proliferation rate of Leydig cells and the expression of cell cycle-related genes were decreased with the increasing Se supplementation in the culture medium. The percentage of apoptotic cells was increased with the increasing Se level, which was consistent with the expression of pro-apoptosis genes. The highest GSH-Px activity and lowest ROS content were also observed in the 2.0xa0μmol/L group. Appropriate Se level (2.0xa0μmol/L) can significantly increase the expression of p-ERK1/2, StAR and 3β-HSD, and improve the testosterone synthesis. Compared with the control group, PD0325901 could significantly inhibit the production of testosterone and the protein abundance of p-ERK1/2, StAR and 3β-HSD. Se treatment can mitigate the inhibition effect of PD0325901 and the testosterone secretion between the 2.0xa0μmol/L and control group was not significantly different. These results demonstrate that Se can affect the proliferation and apoptosis of Leydig cells by regulating cellular oxidative stress and the expressions of cell cycle and apoptosis-related genes. Se can also enhance the testosterone production of Leydig cells by activating the ERK signaling pathway and the expression of its downstream genes (StAR and 3β-HSD), which could be closely related to the regulating roles of Se in male fertility and spermatogenesis.

Effects of dietary selenium on apoptosis of germ cells in the testis during spermatogenesis in roosters

The aim of this study was to determine the effects of dietary selenium (Se) supplementation on apoptosis of germ cells in the testis during spermatogenesis in roosters. Eighty 12-week-old Hy-Line Variety white roosters with an averaged body weight of 1.38xa0±xa00.2xa0kg were selected and randomly divided into four experimental groups. They were fed the basal diet (0.044xa0mg/kg Se dry matter) supplemented with 0 (control), 0.5, 1.0, or 2.0xa0mg/kg of Se dry matter (from sodium selenite). After the 45-day feeding experiment, testis samples were collected from the roosters of each treatment group to detect the population of apoptotic germ cells using the terminal deoxynucleotidy1 transferase dUTP nick end labeling assay. The protein expression of cell cycle-related genes and the messenger RNA (mRNA) expression of apoptosis and cell cycle-related genes had also been detected. The results show that the population of apoptotic germ cells in the control and 2.0xa0mg/kg groups was increased (Pxa0<xa00.05) compared with that in the 0.5xa0mg/kg and 1.0xa0mg/kg groups. Expressions of CDC2 and CCNB1 protein in the control and 2.0xa0mg/kg groups were lower (Pxa0<xa00.05) than those in the 0.5xa0mg/kg and 1.0xa0mg/kg groups. The mRNA level of CDC2 in the 0.5xa0mg/kg group was higher (Pxa0<xa00.05) than that in other groups. The lowest (Pxa0<xa00.05) mRNA expressions of apoptosis-related genes (BCL-2, CASPASE 3, CASPASE 8) were also obtained in the 0.5xa0mg/kg group. These results show that dietary Se of roosters can affect apoptosis of germ cells by regulating the mRNA expressions of apoptosis- and cell cycle-related genes in the testis during spermatogenesis.

Effect of dietary Tartary buckwheat extract supplementation on growth performance, meat quality and antioxidant activity in ewe lambs

The objective of this study was to investigate the effect of dietary Tartary buckwheat extract (TBE) supplementation on animal growth performance, meat quality and antioxidative activity in the Longissimus thoracis et lumborum muscle of lambs. The results showed that dietary TBE increased body weight, average daily gain, carcass weight, dry matter intake, and digestive organ weight. Dietary TBE had no effect on the pH, color, shear force or intramuscular fat of Longissimus muscle examined, whereas the cooking loss was decreased. The total antioxidative capacity and glutathione peroxidase 4 (GPx4) activity of Longissimus muscle were increased in lambs fed TBE. The mRNA contents of superoxide dismutase, catalase, GPx4 and nuclear factor-like-2 factor (Nrf2) did not vary among the groups, and greater protein levels of GPx4 and Nrf2 were observed. Taken together, these results suggest that TBE can be used as a feed ingredient in lamb production to improve its growth performance, and relieve oxidative stress and increase water holding capacity of meat.

The effect of dietary grape pomace supplementation on epididymal sperm quality and testicular antioxidant ability in ram lambs

Wine grape pomace (WGP) contains a rich source of polyphenols that can act as powerful antioxidants. The objective of this study was to investigate the effect of dietary WGP supplementation on antioxidative activity and epididymal sperm quality in rams. The rams were raised either under free-range or pen conditions, and the pen-raised rams were fed a WGP-containing diet (0, 5% and 10% of dry matter basis) for 74 days. An increase in the concentrations of reactive oxygen species (ROS, Pxa0<xa00.05) and malondialdehyde (MDA, Pxa0<xa00.05) were observed in the testes of rams subjected to restraint stress, and dietary WGP supplementation effectively decreased their contents (Pxa0<xa00.05). Restraint stress reduced both weight and volume of testes, and impaired sperm quality. Dietary WGP supplementation increased testes weight, sperm concentration, motility and acrosomal integrity, and decreased sperm deformity in pen-raised animals (Pxa0<xa00.05). The total antioxidative capacity (T-AOC) and catalase activity were decreased in the testes of pen-raised lambs (Pxa0<xa00.05), and T-AOC, catalase, glutathione peroxidase 4 (GPx4) and superoxide dismutase (SOD) activity were increased when rams were fed the WGP-containing diet (Pxa0<xa00.05). With the exception of SOD and GPx4, the mRNA contents of catalase and nuclear factor-like-2 factor (Nrf2) did not vary among the groups, and greater protein levels of SOD, catalase and GPx4 were observed in WGP-treated lambs (Pxa0<xa00.05). Taken together, these results suggest that WGP can be used as a feed ingredient in rams to alleviate restraint induced oxidative stress and improve epididymal sperm quality.

Notch signaling pathway promotes the development of ovine ovarian follicular granulosa cells

The Notch signaling pathway regulates cell proliferation, differentiation and apoptosis involved in development of the organs and tissues such as nervous system, cartilage, lungs, kidneys and prostate as well as the ovarian follicles. This study aimed to investigate the mRNA expression and localization of NOTCH2, as the key factor in Notch signaling pathway. This was determined by PCR, real-time PCR and immunohistochemistry. Additionally, the effects of inhibiting Notch signaling pathway with different concentrations (5μM, 10μM and 20μM) of N-[N-(3, 5-Difuorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT), an inhibitor of Notch signaling pathway, on ovine granulosa cells was determined in vitro by detecting estradiol production using enzyme linked immunosorbent assay and expressions of the genes related to the cell cycle and apoptosis using real-time polymerase chain reaction (PCR). NOTCH2, the key member of Notch signaling pathway, was found in ovine follicles, and the expression of NOTCH2 mRNA was highest in the theca cells of the follicles in medium sizes (3-5mm in diameter) and granulosa cells of the follicles in large sizes (>5mm in diameter). Immunohistochemical results demonstrated that NOTCH2 protein was expressed in granulosa cells of preantral follicles, in both granulosa cells and theca cells of antral follicles. Compared with DAPT-treated groups, the control group had a higher number of granulosa cells (P<0.05) and a higher estradiol production (P<0.05). Compared with the control group, the mRNA abundances of HES1, MYC, BAX, BCL2 and CYP19A1 in DAPT-treated groups was lower (P<0.05), respectively; whereas, the expression of CCND2, CDKN1A and TP53 mRNA showed no remarkable difference compared with control group. Collectively, Notch signaling pathway could be involved in the ovine follicular development by regulating the growth and estradiol production of granulosa cells.

Transcriptome analysis of adipose tissues from two fat-tailed sheep breeds reveals key genes involved in fat deposition

BackgroundThe level of fat deposition in carcass is a crucial factor influencing meat quality. Guangling Large-Tailed (GLT) and Small-Tailed Han (STH) sheep are important local Chinese fat-tailed breeds that show distinct patterns of fat depots. To gain a better understanding of fat deposition, transcriptome profiles were determined by RNA-sequencing of perirenal, subcutaneous, and tail fat tissues from both the sheep breeds. The common highly expressed genes (co-genes) in all the six tissues, and the genes that were differentially expressed (DE genes) between these two breeds in the corresponding tissues were analyzed.ResultsApproximately 47 million clean reads were obtained for each sample, and a total of 17,267 genes were annotated. Of the 47 highly expressed co-genes, FABP4, ADIPOQ, FABP5, and CD36 were the four most highly transcribed genes among all the known genes related to adipose deposition. FHC, FHC-pseudogene, and ZC3H10 were also highly expressed genes and could, thus, have roles in fat deposition. A total of 2091, 4233, and 4131 DE genes were identified in the perirenal, subcutaneous, and tail fat tissues between the GLT and STH breeds, respectively. Gene Ontology (GO) analysis showed that some DE genes were associated with adipose metabolism. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that PPAR signaling pathway and ECM-receptor interaction were specifically enriched. Four genes, namely LOC101102230, PLTP, C1QTNF7, and OLR1 were up-regulated and two genes, SCD and UCP-1, were down-regulated in all the tested tissues of STH. Among the genes involved in ECM–receptor interaction, the genes encoding collagens, laminins, and integrins were quite different depending on the depots or the breeds. In STH, genes such as LAMB3, RELN, TNXB, and ITGA8, were identified to be up regulated and LAMB4 was observed to be down regulated.ConclusionsThis study unravels the complex transcriptome profiles in sheep fat tissues, highlighting the candidate genes involved in fat deposition. Further studies are needed to investigate the roles of the candidate genes in fat deposition and in determining the meat quality of sheep.

Effects of maternal dietary selenium (Se-enriched yeast) on testis development, testosterone level and testicular steroidogenesis-related gene expression of their male kids in Taihang Black Goats

To investigate the effects of maternal dietary selenium (Se-enriched yeast) on testis development, testosterone level and steroidogenesis-related gene expression in testis of their male kids, selected pregnant Taihang Black Goats were randomly allotted to four treatment groups. They were fed the basal gestation and lactation diets supplemented with 0 (control), 0.5, 2.0 and 4.0u202fmg of Se/kg DM. Thirty days after weaning, testes were collected from the kids. After the morphological development status of testis was examined, tissue samples were collected for analyzing testosterone concentration and histological parameters. Testosterone synthesis-related genes were detected using real-time PCR. Localization and quantification of androgen receptor (AR) in testis of goats were determined by immunohistochemical and western blot analysis. The results show that Se supplementation in the diet of dams led to higher (pu202f<u202f0.05) testicular weight, volume, length, width, transverse and vertical grith of their male kids. Excessive Se (4.0u202fmg/kg) can inhibit the development of testis by decreasing testicular weight and volume. The density of spermatogenic cells and Leydig cells in the Se treatment groups was significantly (pu202f<u202f0.05) higher than that in the control. Maternal dietary Se did not affect the thickness of testes, thickness of germinal epithelium and diameter of seminiferous tubule. Se supplemented in the diet of dams improved the testosterone level in testis tissue and serum, and promote the expression of testosterone-related genes. The mRNA expression of StAR, 3β-HSD and CYP11A1 was decreased with the increasing dietary Se levels of dams. Maternal dietary Se can improve the AR protein abundance in testis of their offspring. AR immunopositive product was detected in Leydig cells, peritubular myoid cells, perivascular smooth muscle cells, primary spermatocytes and spermatids. The expression of AR in spermatogenetic cells is stage specific. This study suggests that maternal dietary Se can influence the testis development and spermatogenesis of their male kids by modulating testosterone synthesis in goats. More attention should be given to the potential role of maternal nutrition in improving reproductive performance of their offspring.

Energy requirements for the maintenance and growth of Dorper-Jinzhong crossbred ram lambs

Abstract The sheep industry in China has been rapidly developing in recent years; however, the animals’ nutritional requirements under certain conditions have not been thoroughly defined. The objective of this study was to investigate the energy requirements of both the maintenance and growth of Dorper-Jinzhong crossbred ram lambs. Thirty 1/2 Dorperu2009×u20091/2 Jinzhong crossed F1 ram lambs (35u2009±u20090.5u2009kg of body weight, BW) were randomly selected and divided into five groups in a randomised design for a comparative slaughter trial. The lambs were offered one type of feed at 100%, 65% and 40% of the ad libitum intake. Another 15 lambs were used for the digestibility trial to estimate the metabolisable energy (ME) values of the diet at various feed intake levels. The net energy for maintenance (NEm) and the ME requirement for maintenance (MEm) were 286.68u2009kJ/kg0.75 of SBW and 437.80u2009kJ/kg0.75 of SBW, respectively; the energy efficiency for maintenance (km) was 0.655. The net energy for growth (NEg) values for varying average daily gain (100–350u2009g) in ram lambs grown from 35 to 50u2009kg increased from 1.31 to 5.93u2009MJ/d with an energy efficiency for growth (kg) of 0.457. Our results suggest that the energy requirements of Dorper-Jinzhong crossbred ram lambs are lower than the requirements recommended by the National Research Council (NRC) and Agricultural and Food Research Council (AFRC).

Effect of rare earth elements on feed digestibility, rumen fermentation, and purine derivatives in sheep

The experiment was conducted to evaluate the effect of rare earth elements (REE) on feed digestibility, rumen fermentation, and urinary purine derivatives (PDs) in sheep. Eight sheep (44.58±2.9 kg of body weight) fitted with ruminal cannulas were used in a replicated 4×4 Latin square design 20-day experiment. Sheep were fed a basal diet containing 100, 200 and 300 mg REE-citrate per kg dry matter (DM). Mixture of REE mainly consisted of cerium (56.8%), lanthanum (35.0%) and praseodymium (6.5%). Ruminal pH value was linearly (P<0.01) and quadratically (P<0.01) decreased, and ammonia N concentration (9.73 to 11.83 mg/100 mL) was quadratically (P<0.05) decreased, whereas total volatile fatty acids concentration was linearly increased with increasing REE supplementation (P<0.05). The ratio of acetate to propionate was linearly (P<0.01) and quadratically (P<0.01) decreased due to increase of propionate concentration (P<0.05). In situ ruminal neutral detergent fibre (aNDF) degradation of Leymus chinensis was improved (P<0.01), but the in situ ruminal crude protein (CP) degradation of soybean meal was decreased by feeding REE (P<0.01). Moreover, digestibility of DM, organic matter, aNDF, acid detergent fibre and CP in the total tract and urinary excretion of PD were also linearly (P<0.01) and quadratically (P<0.01) increased with increasing REE addition. In conclusion, supplementation of the basal diet with REE improved rumen fermentation and feed digestion in sheep. It was suggested that REE stimulated rumen microbial activity, digestive microorganisms or enzyme activity in a dose-dependent manner. The optimum supplemental dose of REE was about 200 mg/kg dietary DM in sheep.