Effect of photoperiod on serum hormone concentrations during the annual reproductive cycle in geese.

The poor egg-laying rate of geese hinders the development of the goose industry; therefore, the reproductive performance of geese is an important area of investigation. To evaluate the relationship between photoperiod, reproductive hormones, and reproductive activity during the egg-laying cycle in geese under natural conditions, we collected blood samples from Sichuan white geese and Xupu geese to quantify changes in prolactin (PRL), estradiol (E2), vasoactive intestinal polypeptide (VIP), follicle stimulating hormone (FSH), gonadotropin-inhibitory hormone (GnIH), and luteinizing hormone (LH). We also calculated the rate of egg laying for the two populations during the egg-laying cycle. We show that the egg-laying rate and the serum concentration of some hormones (PRL, E2, VIP, FSH, GnIH, and LH) differed significantly between the two populations during the pre-laying, laying, and ceased-laying periods. Serum LH concentrations may be associated with maturation of the ovary and oviducts, whereas FSH, PRL, and GnIH play important roles in egg laying. These results provide a useful resource for future studies examining the laying rate in geese.

Effects of feeding conditions on gene expression in chicken breast muscle.

Chicken meat quality is becoming increasingly important among breeders and consumers. To understand the effect of feeding conditions on chicken meat quality, we investigated the profiles of genes expressed in chicken breast muscle. Using RNA sequencing, we identified 336, 321, and 387 differentially expressed genes among Chengkou, Daninghe, and Qingjiaoma chickens under scatter- and captivity-feeding conditions. Twenty-two genes differentially expressed between different feeding conditions were shown to be common among the three breeds. Seven of these genes were assessed by real-time quantitative PCR, which confirmed the findings of RNA sequencing and suggested that the results were viable. The differentially expressed genes showed enrichment for a series of significant pathways, including energy metabolism, xenobiotics biodegradation and metabolism, and the immune system. These results provide a solid foundation for elucidating the molecular mechanisms underlying chicken meat quality.

Gene expression profiles in the pituitary glands of Sichuan White geese during prelaying and laying periods.

To better understand the molecular mechanism(s) underlying egg-laying in Sichuan white geese, the profiles of genes in the pituitary gland were investigated during the prelaying and laying periods. Total RNA was extracted from the pituitary glands of geese during prelaying or laying periods and cDNA was generated. After sequencing and annotation, 54 upregulated and 84 downregulated genes were obtained from gene libraries. These genes were related primarily to biosynthetic processes, cellular nitrogen metabolic processes, transport, cell differentiation, cellular protein modification processes, signal transduction, and small molecule metabolic processes. Eleven genes were selected for further analyses using quantitative real-time PCR, and the results were generally consistent with the profiling results. Among these genes, levels of gonadotropin-releasing hormone, gonadotropin-inhibitory hormone, vasoactive intestinal peptide and its receptor, follistatin, estrogen receptor beta, and the progesterone receptor were differentially overexpressed during the prelaying period compared with the laying period. These results provide a solid foundation for elucidating the molecular mechanism of egg-laying performance in Sichuan white geese.

Differential gene expression in pre-laying and laying period ovaries of Sichuan White geese (Anser cygnoides).

Geese are an economically important poultry species worldwide. Their superior meat production performance and meat qual-ity make them a popular food. However, they are not bred worldwide because their poor laying capacity increases farming costs. To gain a global view of the genes that are differentially expressed between pre-laying (P) and laying (L) periods and to develop a database for further studies, we performed large-scale transcriptome sequencing of ovarian tissue collected from Anser cygnoides. In total, 30,151,422 raw reads, with an average length of 151 bp and a total length of 4,552,864,722 bp, were obtained. After primers and adaptors were removed, 19,167,132 clean reads, with an average length of 134.5 bp and a total length of 2,577,297,281 bp, were obtained, among which 1,268,906,694 bp and 1,308,390,587 bp were from L and P ovarian tissue, respectively. The 16,605 assembled sequences were further functionally annotated by comparing their sequences to different protein and functional domain databases and assigning gene ontology (GO) terms. Of these, 511 as-sembled sequences were considered differentially expressed based on the 2-fold method, among which 396 were assigned at least one GO term. Digital expression analysis using the Kyoto encyclopedia of genes and genomes annotation identified 121 genes that were differ-entially expressed in the P vs L periods. Five of these are of special interest for further investigation of their roles in determining high re-productive performance. This study provides valuable information and sequence resources for uncovering genes determining high egg-laying performance and for future functional genomics analysis of geese.

Role of a liver fatty acid-binding protein gene in lipid metabolism in chicken hepatocytes.

This study investigated the role of the chicken liver fatty acid-binding protein (L-FABP) gene in lipid metabolism in hepatocytes, and the regulatory relationships between L-FABP and genes related to lipid metabolism. The short hairpin RNA (shRNA) interference vector with L-FABP and an eukaryotic expression vector were used. Chicken hepatocytes were subjected to shRNA-mediated knockdown or L-FABP cDNA overexpression. Expression levels of lipid metabolism-related genes and biochemical parameters were detected 24, 36, 48, 60, and 72 h after transfection with the interference or overexpression plasmids for L-FABP, PPARα and L-BABP expression levels, and the total amount of cholesterol, were significantly affected by L-FABP expression. L-FABP may affect lipid metabolism by regulating PPARα and L-BABP in chicken hepatocytes.

Feeding conditions and breed affect the level of DNA methylation of the mitochondrial uncoupling protein 3 gene in chicken breast muscle.

To investigate the effects of feed condition and breed on the level of DNA methylation for the uncoupling protein 3 (UCP3) gene, which is an important candidate gene for regulating intramuscular fat (IMF) content in chicken breast muscle, breast muscle of Daninghe (DNH) and Qingjiaoma (QJM) chickens under scatter-feed and captivity-feed conditions was analyzed. Using RNA sequencing, 47 and 113 candidate genes were determined to be related to feed conditions and breed, respectively, and 7 differentially expressed genes were confirmed by real-time quantitative PCR, including UCP3. The mRNA levels of UCP3 were significantly different between the 2 feed conditions. The DNA region from bp +1700 to +2459 of the UCP3 gene was studied using the bisulfite sequencing method and contained 46 methylation sites and 3 CpG islands. The results showed that the methylation level of this UCP3 region was lower in DNH chickens (0.77% to 0.88%, P = 0.012) and QJM chickens (0.88% to 0.91%, P = 0.20) under scatter-feed conditions than under captivity-feed conditions. The mean methylation level of UCP3 in DNH chickens was lower than that in QJM chickens under scatter-feed conditions (DNH to QJM, 0.77% to 0.88%, P = 0.007), which suggests that breed affects the mean methylation level of UCP3 under scatter-feed conditions. In summary, our findings suggest that feed condition and breed affect the methylation of UCP3 in chicken breast muscle.

Microarray analysis of differentially expressed genes in the liver between Bai'er layers and broilers.

In this study, we profiled gene expression in chicken liver and screened differentially expressed genes in the Bai'er layers and fat line broilers. Birds were derived from the 14th generation of Northeast Agricultural University fat broiler lines and Bai'er layers. Chicken genome arrays were used to screen differentially expressed genes in liver tissue from the Bai'er layers and fat line broilers. We screened 671 differentially expressed genes between broilers and layers at the ages of 2 and 4 weeks. We observed enrichment of a series of significant pathways, including the mitogen-activated protein kinase signaling pathway, cell cycle, mammalian target of rapamycin signaling pathway, and p53 signaling pathway. At 2 and 4 weeks, 94 shared differentially expressed genes were observed. We speculated that these genes regulate chicken lipid metabolism.

Comparison between transareola singlesite endoscopic thyroidectomy and minimally invasive video-assisted thyroidectomy.

OBJECTIVES: To compare surgical outcomes between transareola single-site endoscopic thyroidectomy (TASSET) and minimally invasive video-assisted thyroidectomy (MIVAT). METHODS: Patients with thyroid nodules were randomized to TASSET (n = 24) or MIVAT (n = 24). Surgical outcomes and patient-rated cosmetic results, based on numerical (0 [worst], 10 [best]) and verbal (1 [poor], 4 [excellent]) response scales, were compared. RESULTS: There were no significant differences between groups for age, sex, indication for operation, estimated blood loss, postoperative pain and length of postoperative stay. TASSET was associated with a significantly longer mean ± SD operative time than MIVAT (156.84 ± 41.42 vs. 66.38 ± 17.58 min), and significantly improved cosmetic results according to the numerical (9.63 ± 0.60 vs 7.90 ± 1.38) and verbal response (3.8 ± 0.5 vs 3.1 ± 0.7) scales. Postoperative complaints were comparable between the two approaches, although MIVAT involved a shorter operation time. CONCLUSIONS: Patients treated with TASSET had superior cosmetic results compared with those treated with MIVAT.