Yangzhou Goose Research Articles

The role of active immunization against inhibin α-subunit on testicular development, testosterone concentration and relevant genes expressions in testis, hypothalamus and pituitary glands in Yangzhou goose ganders

The present study was designed to investigate the potential role of immunization against inhibin on testicular development, plasma testosterone concentration and expression of relevant genes in hypothalamus, pituitary, Leydig and Sertoli cells in Yangzhou ganders. For this purpose, Yangzhou ganders, n = 30 were divided into groups A and B. Group B ganders were actively immunized against inhibin α-subunit, while group A ganders were immunized with bovine serum albumin (BSA), which served as control. Immunization against inhibin elevated testes weights. In addition, immunization against inhibin elevated GnRH, StAR, CYP11A1 and AMH mRNA transcription expressions as depicted by qRT-PCR. Furthermore, hypothalamic GnRH-I mRNA expressions were up regulated, while GnIH mRNA transcription expression showed reciprocal expression on day 227. LH-β mRNA transcription expression remained unaffected. In conclusion, our findings suggest that active immunization against inhibin affect spermatogenesis and testicular development through regulations of hypothalamic, pituitary and testicular genes expressions.

The identification, characterization, and function of two TREMs genes in Chinese Yangzhou goose (Anas cygnoides)

Triggering receptor expressed on myeloid cells (TREM) is a cell-surface receptor primarily expressed on macrophages. Here, two novel TREM genes, AcTREM1 and AcTREM2, were identified from Anas cygnoides. AcTREM1 cDNA contained a putative signal peptide, two IG domains, and a transmembrane domain. The deduced AcTREM2 sequence also contained a signal peptide, an IG domain, and a transmembrane domain. qRT-PCR, fluorescence in situ hybridization, and immunofluorescence experiments showed that AcTREM1 and AcTREM2 were mainly expressed in the liver and spleen, and both genes and proteins were mainly distributed in cytoplasm. AcTREM1 expression in the liver and spleen was significantly upregulated following lipopolysaccharide (LPS) challenge at an early stage of infection and then decreased at a later stage. Changes in AcTREM2 expression were reciprocal to those of AcTREM1 in the liver and spleen after LPS challenge. Our results indicate that AcTREM1 and AcTREM2 participate in the antibacterial immunity of A. cygnoides.

Induction of out-of-season egg laying by artificial photoperiod in Yangzhou geese and the associated endocrine and molecular regulation mechanisms

This study was carried out to induce out-of-season breeding, in the summer, and to achieve high reproductive performance using artificial photoperiod manipulation in the long-day breeding Yangzhou goose. Young geese were subject to a two-phase short-to-long (group A) or a three-phase (long-short-long; group B) photoperiod program February through October. Egg-laying was induced to start similarly in both groups in May, increased to a peak level in July, and then decreased gradually through to October. The peak and post-peak laying rates were higher with the three-phase than with the two-phase program. Plasma progesterone concentrations changed similarly in the two groups, increasing from low levels during the pre-lay periods until the peak laying stage, then decreasing with decline in the egg-laying rate. Plasma T3 concentrations increased from the beginning of the experiment to form the first peak under a short photoperiod, declined to a trough at peak lay and then progressively increased to high levels towards the end of the experiment. Plasma T4 concentrations increased throughout the experiment, showing little response to changes in photoperiod. GnIH mRNA expression level in the hypothalamus steadily decreased from high levels under the short photoperiod to a nadir at peak of lay, but was abruptly up-regulated by over a thousand-fold thereafter. This mRNA expression pattern was also shared by GnIHR, VIPR, TRHR, TSH, and PRL genes in the pituitary gland, and to lesser extent, by GnRH, VIP, and TRH genes in the hypothalamus. Pituitary GnRHR mRNA expression levels changed in a similar manner to that of reproductive activities of geese in both groups. FSH beta subunits mRNA expression levels increased to high levels after day 11 of the long photoperiod, and were higher in group B than in group A at peak laying. LH beta gene expression level was similarly upregulated by photoperiod and was higher in group B than in group A when used the multivariable and two-way analyses of variance. Taken together, photoperiod, through regulation of expression of an array of genes in the hypothalamus and pituitary gland, synchronized stimulation and refractoriness of the reproductive system in Yangzhou geese. The higher out-of-season egg laying performance following the three-phase photo-program treatment was mediated by higher FSH beta and LH beta subunit mRNA expression levels.

Molecular cloning, alternative splicing and mRNA expression analysis of MAGI1 and its correlation with laying performance in geese

ABSTRACT1. In a previous study, a laying-related single nucleotide polymorphism (SNP) Record-106975 (A–G) was found in the intron of Membrane-associated Guanylate Kinase with Inverted Domain Structure-1 (MAGI1) gene by restriction site-associated DNA sequencing. This study was performed to further identify the function of MAGI1 on laying performance in Yangzhou geese.2. The complete MAGI1 cDNA sequence was cloned from the ovary of the Yangzhou goose. A total of 4 alternative splice variants were identified, and the characterisation of their nucleic acid and amino acid (AA) sequences were analysed. The AA sequence of goose MAGI1 was highly conserved with other avian species.3. MAGI1 was ubiquitously expressed in 11 tested tissues, with greater amounts of mRNA in the granulosa cell layer and ovary. GG (n = 14) and GA (n = 6) genotypes of SNP Record-106975 showed significantly lower MAGI1 mRNA levels than those of the AA genotype.4. Over-expression and knockdown experiments revealed that MAGI1 mRNA expression was associated with caspase-3 mRNA levels in granulosa cells, and may play a role in regulating apoptosis of granulosa cells.

Reproductive axis gene regulation during photostimulation and photorefractoriness in Yangzhou goose ganders

BackgroundThe Yangzhou goose is a long-day breeding bird that has been increasingly produced in China. Artificial lighting programs are used for controlling its reproductive activities. This study investigated the regulations of photostimulation and photorefractoriness that govern the onset and cessation of the breeding period.ResultsIncreasing the daily photoperiod from 8 to 12 h rapidly stimulated testis development and increased plasma testosterone concentrations, with peak levels being reached 2 months after the photoperiod increase. Subsequently, testicular activities, testicular weight, spermatogenesis, and plasma testosterone concentrations declined steadily and reached to the nadir at 5 months after the 12-hour photoperiod. Throughout the experiment, plasma concentrations of triiodothyronine and thyroxine changed in reciprocal fashions to that of testosterone. The stimulation of reproductive activities caused by the increasing photoperiod was associated with increases in gonadotropin-releasing hormone (GnRH), but decreases in gonadotropin-inhibitory hormone (GnIH) and vasoactive intestinal peptide (VIP) gene messenger RNA (mRNA) levels in the hypothalamus. In the pituitary gland, the levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) mRNA abruptly increased during the longer 12-hour photoperiod. The occurrence of photorefractoriness was associated with increased GnIH gene transcription by over 250-fold, together with increased VIP mRNA levels in the hypothalamus, and then prolactin and thyroid-stimulating hormone in the pituitary gland. FSH receptor, LH receptor, and StAR mRNA levels in the testis changed in ways paralleling those of testicular weight and testosterone concentrations.ConclusionsThe seasonal reproductive activities in Yangzhou geese were directly stimulated by a long photoperiod via upregulation of GnRH gene transcription, downregulation of GnIH, VIP gene transcription, and stimulation of gonadotrophin. Development of photorefractoriness was characterized by hyper-regulation of GnIH gene transcription in the hypothalamus, in addition of upregulation of VIP and TRH gene transcription, and that of their receptors, in the pituitary gland.

Molecular cloning of the SMAD4 gene and its mRNA expression analysis in ovarian follicles of the Yangzhou goose (Anser cygnoides)

Mothers against decapentaplegic homolog 4 (SMAD4) is an important protein in animal reproduction. It plays pivotal roles in cellular pathways, including apoptosis. The expression profile of the SMAD4 gene in goose ovarian follicles has not been reported.In this study, the SMAD4 coding sequence was cloned from the Yangzhou goose. A phylogenetic analysis was performed and mRNA expression was examined in various tissues using quantitative real-time PCR.An alternative splice form of SMAD4, SMAD4-b having 1656 bp, was identified. SMAD4-a mRNA was widely expressed in various healthy tissues, whereas SMAD4-b was very weakly expressed. SMAD4 mRNA in the ovary and oviduct was significantly higher than that in the pituitary and hypothalamus. SMAD4 mRNA expression analysis in hierarchical follicles showed that the level of SMAD4 mRNA was higher in large white follicles and post-ovulatory follicles than in the other follicles.The results indicate that SMAD4 might be involved in the recruitment of hierarchical follicles.

The effects of n-6:n-3 polyunsaturated fatty acid ratios on serum protein and immunoglobulins in the Yangzhou goose

The effects of n-6:n-3 polyunsaturated fatty acid ratios on serum protein and immunoglobulins in the Yangzhou goose

Effects of n-6:n-3 polyunsaturated fatty acid ratio on heterophil:lymphocyte ratio and T lymphocyte subsets in the peripheral blood of the Yangzhou gosling

The objective of this study was to determine the effects of dietary n-6:n-3 polyunsaturated fatty acid (PUFA) ratios on heterophil:lymphocyte (H:L) ratios and T cell subsets in the peripheral blood of the growing Yangzhou goose. A total of 160 healthy Yangzhou geese (0.407 ± 0.023 kg), aged 21 d, were randomly divided into 4 groups consisting of diets with different n-6:n-3 PUFA ratios: 12:1, 9:1, 6:1, and 3:1. White blood cell counts and H:L ratios were measured at 42, 56, and 70 d of age; T lymphocyte subsets were also analyzed using monoclonal antibodies and flow cytometry simultaneously. The results showed that differences were found in white blood cells between groups (P < 0.05) but not within groups (P > 0.05), and white blood cells of 70-d-old geese were significantly higher than those of other ages within the same group. The H:L ratios of all groups decreased as age increased, and differences were found in 6:1 and 3:1 groups between ages (P < 0.05). As for the comparison of H:L ratio between treatments, 6:1 and 3:1 were lower than the other 2 groups at 42 or 70 d of age (P < 0.05), and 3:1 was lower than the other 3 groups at 56 d of age (P < 0.05). Moreover, H:L ratios had a tendency to decrease with the decrease of n-6:n-3 PUFA ratios. Furthermore, cluster of differentiation (CD) 3+ and CD8+ increased gradually, whereas CD4+ and CD4+:CD8+ ratios first increased and then decreased as age increased. Differences were detected in T cell subsets among ages (P < 0.05). In addition, CD4+ and CD4+:CD8+ ratios were affected remarkably by n-6:n-3 PUFA ratios but CD3+ and CD8+ were not, and 6:1 had much higher CD4+ percentage and CD4+:CD8+ ratio compared with the other groups (P < 0.05). Taken together, diets containing low n-6:n-3 PUFA ratios could decrease H:L ratios in the peripheral blood. Additionally, CD4+ percentage and CD4+:CD8+ ratio were much higher in the 6:1 group, which could be relevant for improving positive immune responses for Yangzhou goslings from 42 to 70 d of age.

Uncovering the TREM-1-TLR connection

the innate immune system has several large genetically encoded receptor families that interact during the detection and elimination of pathogens. The Toll-like receptor (TLR) family recognizes a diverse group of evolutionarily conserved molecules including lipopolysaccharide (LPS), peptidoglycan,