Protein profile analysis of Jilin white goose testicles at different stages of the laying cycle by DIA strategy.

BACKGROUND: Jilin white goose is an excellent local breed in China, with a high annual egg production and laying eggs mainly from February to July each year. The testis, as the only organ that can produce sperm, can affect the sexual maturity and fecundity of male animals. Its growth and development are affected and regulated by a variety of factors. Proteomics is generally applied to identify and quantify proteins in cells and tissues in order to understand the physiological or pathological changes that occur in tissues or cells under specific conditions. Currently, the female poultry reproductive system has been extensively studied, while few related studies focusing on the regulatory mechanism of the reproductive system of male poultry have been conducted. RESULTS: A total of 1753 differentially expressed proteins (DEPs) were generated in which there were 594, 391 and 768 different proteins showing differential expression in three stages, Initial of Laying Cycle (ILC), Peak of Laying Cycle (PLC) and End of Laying Cycle (ELC). Furthermore, bioinformatics was used to analyze the DEPs. Gene ontology (GO) enrichment, Clusters of Orthologous Groups (COG), Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction (PPI) network analysis were adopted. All DEPs were found to be implicated in multiple biological processes and pathways associated with testicular development, such as renin secretion, Lysosomes, SNARE interactions in vesicle trafficking, the p53 signaling pathway and pathways related to metabolism. Additionally, the reliability of transcriptome results was verified by real-time quantitative PCR by selecting the transcript abundance of 6 selected DEPs at the three stages of the laying cycle. CONCLUSIONS: The funding in this study will provide critical insight into the complex molecular mechanisms and breeding practices underlying the developmental characteristics of testicles in Jilin white goose.

Parental betaine supplementation promotes gosling growth with epigenetic modulation of IGF gene family in the liver.

Betaine is widely used as a feed additive in the chicken industry to promote laying performance and growth performance, yet it is unknown whether betaine can be used in geese to improve the laying performance of goose breeders and the growth traits of offspring goslings. In this study, laying goose breeders at 39 wk of age were fed basal (Control, CON) or betaine-supplemented diets at low (2.5 g/kg, LBT) or high (5 g/kg, HBT) levels for 7 wk, and the breeder eggs laid in the last week were collected for incubation. Offspring goslings were examined at 35 and 63 d of age. The laying rate tended to be increased (P = 0.065), and the feed efficiency of the breeders was improved by betaine supplementation, while the average daily gain of the offspring goslings was significantly increased (P < 0.05). Concentrations of insulin-like growth factor 2 (IGF-2) in serum and liver were significantly increased in the HBT group (P < 0.05), with age-dependent alterations of serum T3 levels. Concurrently, hepatic mRNA expression of the IGF gene family was significantly increased in goslings derived from betaine-treated breeders (P < 0.05). A higher ratio of proliferating cell nuclear antigen (PCNA)-immunopositive nuclei was found in the liver sections of the HBT group, which was confirmed by significantly upregulated hepatic expression of PCNA mRNA and protein (P < 0.05). Moreover, hepatic expression of thyroxine deiodinase type 1 (Dio1) and thyroid hormone receptor ß (TRß) was also significantly upregulated in goslings of the HBT group (P < 0.05). These changes were associated with significantly higher levels of global DNA 5-mC methylation, together with increased expression of methyl transfer genes (P < 0.05), including betaine-homocysteine methyltransferase (BHMT), glycine N-methyltransferase (GNMT), and DNA (cytosine-5-)-methyltransferase 1 (DNMT1). The promoter regions of IGF-2 genes, as well as the predicted TRß binding site on the IGF-2 gene, were significantly hypomethylated (P < 0.05). These results indicate that gosling growth can be improved by dietary betaine supplementation in goose breeders via epigenetic modulation of the IGF gene family, especially IGF-2, in the liver.

The goose industry plays important roles in economics, cultures, and ecosystems, yet the low laying and growth rates of many indigenous breeds hinders the development of the goose farming. Betaine, an important methyl donor, is commonly used as a feed additive in livestock and poultry to enhance animal growth. Dietary supplementation of betaine in laying hens or gestational sows has been reported to promote the growth of their offspring. Here, we sought to investigate whether and how dietary betaine supplementation affects the growth and development of offspring goslings. In this study, goose breeders, both male and female, were fed a basal diet supplemented respectively with 0, 2.5, or 5 g/kg betaine for 7 wk. Goslings hatched from the breeder eggs of different groups were raised under the same standard condition for assessing the growth performance. Parental betaine increases the growth rate of offspring goslings with decreased DNA methylation on the IGF-2 gene promoter and increased expression of the IGF-2 gene in the liver. These results provide scientific evidence for the inter-generational effect of betaine on gosling growth.

The development rule of feathers and application of hair root tissue in sex identification of Yangzhou geese.

Accurate gender identification is crucial for the study of bird reproduction and evolution. The current study aimed to explore and evaluate the effectiveness of a noninvasive method for gender identification in Yangzhou geese. In this experiment, 600 goose eggs were collected. Hair root tissues were used for PCR amplification, molecular sequencing, and anal inversion for early sex recognition in goslings. According to the DNA amplification results for the feather pulp tissue of 2-wk-old geese, bands appeared at 436 bp (CHD1-Z) and 330 bp (CHD1-W) upon gel electrophoresis. This method considered the base of goose feathers to accelerate the process of gender recognition. By examining the sex of anatomized poultry for verification, the accuracy rate of PCR gel electrophoresis and molecular sequencing sex identification was 100%, whereas the average accuracy rate of anal inversion was 97.41%. In the comparison of feather growth trends at 0 to 18 wk of age, the feather root weight (FRW), feather root length (FRL), feather branch length (FBL), and feather shaft diameter (FSD) of Yangzhou goose of the same age were not significantly different between males and females (P > 0.05). At 6 wk of age, the FRW, FRL, and FSD in males and FRL in females increased rapidly; their growth increased by 84.43, 67.58, 45.10, and 69.42%, respectively. At 10 wk of age, the male FRL, male FBL, and female FBL increased by 37.31, 34.81, and 21.72, respectively. The Boltzmann model was found to be the best-fitting model for the feathers of male Yangzhou geese. Early sex identification based on feather growth trends between the sexes is not feasible. This study provides a convenient and reliable technical means for early sex identification of waterfowl and serves as an ecological strategy for protecting the reproduction of poultry populations.

miR-140-y targets TCF4 to regulate the Wnt signaling pathway and promote embryonic feather follicle development in Hungarian white goose.

Goose down feather has become one of the most important economical products in the goose breeding industry and it provides several essential physiological roles in birds. Therefore, understanding and regulating the development of skin and feather follicles during embryogenesis is critical for avian biology and the poultry industry. MicroRNAs are known to play an important role in controlling gene expression during skin and feather follicle development. In this study, bioinformatics analysis was conducted to select miR-140-y as a potential miRNA involved in skin and feather follicle development and to predict TCF4 as its target gene. This gene was expressed at significant levels during embryonic feather follicle development, as identified by qPCR and Western blot. The targeting relationship was confirmed by a dual-luciferase assay in 293T cells. Then, the miR-140-y/TCF4 function in dermal fibroblast cells was explored. The results showed that miR-140-y could suppress the proliferation of goose embryonic dermal fibroblast cells (GEDFs) by suppressing the activity of some Wingless-types (Wnt) pathway related genes and proliferation marker genes, while miR-140-y inhibition led to the opposite effect. Similarly, the inhibition of the TCF4 gene results in blocking the proliferation of GEDFs by reducing the activity of some Wnt pathway-related genes. Finally, the co-transfection of miR-140-y inhibitor and siRNA-TCF4 results in a rescue of the TCF4 function and an increase of the Wnt signaling pathway and GEDFs proliferation. In conclusion, these results demonstrated that the miR-140-y-TCF4 axis influences the activity of the Wnt signaling pathway and works as a dynamic regulator during skin and feather follicle development.

Phenotypic and morphometric characterization of domestic geese raised in northern Benin.

Documentation on the domestic geese (Anser anser) in Benin is scarce, making it objectively difficult to exploit. Its production depends on small flocks raised by livestock farmers in different areas. The aim of the study was to describe the phenotypic and morphometric characteristics of geese encountered in northern Benin. To this end, a total of 576 adult geese (353 males and 223 females) from 102 farms in 4 agro-ecological zones of northern Benin were evaluated for 11 quantitative and 5 qualitative body traits. There are 6 plumage colors with white (42.01%), white-brown magpie (24.65%) and white-grey magpie (17.19%) as dominant colors. The proportions of white-grey (75%) and multicolored (51.85%) in Far northern zone of Benin (FNZB) were higher (P < 0.05) than those in the cotton zone of northern Benin (CZNB), Food-producing zone of southern Borgou (FZSB) and West-Atacora Zone (WAZ). The red coloring of the tarsi was more dominant in the FZSB (63.09%) and the FZSB (61.79%) (P < 0.05). Orange (57.47%) and yellow (28.82%) colored beaks were dominant but did not vary (P > 0.05) from one agro-ecological zone to another. Quantitative traits such as body length, tarsus length, wing span and thoracic circumference of geese varied (P < 0.05) between 71.34 to73.22 cm, 10.08 to 10.6 cm, 131.95 to 135.42 cm and between 42.07 to 43.86 cm respectively. Males differed significantly from females (P < 0.05) for all morphometric traits. The live weight of geese in the FNZB showed higher values than those of other agro-ecological zones (P ˂ 0.05). In addition, white phenotype geese (3.76 kg) were heavier (P ˂ 0.05) than other phenotypes. All correlations between weight and body measurements of domestic geese were positive, but the correlations between live weight and wing span (r = 0.68) were the strongest. These correlations could be used to assess the live weight of the geese population studied and for selection based on live weight. This study provides a reference for morpho-biometric traits and will be complemented by molecular characterization.

Comparative transcriptomics analysis identifies crucial genes and pathways during goose spleen development.

As the largest peripheral lymphoid organ in poultry, the spleen plays an essential role in regulating the body's immune capacity. However, compared with chickens and ducks, information about the age- and breed-related changes in the goose spleen remains scarce. In this study, we systematically analyzed and compared the age-dependent changes in the morphological, histological, and transcriptomic characteristics between Landes goose (LG; Anser anser) and Sichuan White goose (SWG; Anser cygnoides). The results showed a gradual increase in the splenic weights for both LG and SWG until week 10, while their splenic organ indexes reached the peak at week 6. Meanwhile, the splenic histological indexes of both goose breeds continuously increased with age, reaching the highest levels at week 30. The red pulp (RP) area was significantly higher in SWG than in LG at week 0, while the splenic corpuscle (AL) diameter was significantly larger in LG than in SWG at week 30. At the transcriptomic level, a total of 1710 and 1266 differentially expressed genes (DEGs) between week 0 and week 30 were identified in spleens of LG and SWG, respectively. Meanwhile, a total of 911 and 808 DEGs in spleens between LG and SWG were identified at weeks 0 and 30, respectively. Both GO and KEGG enrichment analysis showed that the age-related DEGs of LG or SWG were dominantly enriched in the Cell cycle, TGF-beta signaling, and Wnt signaling pathways, while most of the breed-related DEGs were enriched in the Neuroactive ligand-receptor interaction, Cytokine-cytokine receptor interaction, ECM-receptor interaction, and metabolic pathways. Furthermore, through construction of protein-protein interaction networks using significant DEGs, it was inferred that three hub genes including BUB1, BUB1B, and TTK could play crucial roles in regulating age-dependent goose spleen development while GRIA2, GRIA4, and RYR2 could be crucial for the breed-specific goose spleen development. These data provide novel insights into the splenic developmental differences between Chinese and European domestic geese, and the identified crucial pathways and genes are helpful for a better understanding of the mechanisms regulating goose immune functions.

Molecular mechanisms of hypothalamic-pituitary-ovarian/thyroid axis regulating age at first egg in geese.

Age at first egg (AFE) has consistently garnered interest as a crucial reproductive indicator within poultry production. Previous studies have elucidated the involvement of the hypothalamic-pituitary-ovarian (HPO) and hypothalamic-pituitary-thyroid (HPT) axes in regulating poultry sexual maturity. Concurrently, there was evidence suggesting a potential co-regulatory relationship between these 2 axes. However, as of now, no comprehensive exploration of the key pathways and genes responsible for the crosstalk between the HPO and HPT axes in the regulation of AFE has been reported. In this study, we conducted a comparative analysis of morphological differences and performed transcriptomic analysis on the hypothalamus, pituitary, thyroid, and ovarian stroma between normal laying group (NG) and abnormal laying group (AG). Morphological results showed that the thyroid index difference (D-) value (thyroid index D-value=right thyroid index-left thyroid index) was significantly (P < 0.05) lower in the NG than in the AG, while the ovarian index was significantly (P < 0.01) higher in the NG than in the AG. Furthermore, between NG and AG, we identified 99, 415, 167, and 1182 differentially expressed genes (DEGs) in the hypothalamus, pituitary, thyroid, and ovarian stroma, respectively. Gene ontology (GO) analysis highlighted that DEGs from 4 tissues were predominantly enriched in the "biological processes" category. Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that 16, 14, 3, and 26 KEGG pathways were significantly enriched (P < 0.05) in the hypothalamus, pituitary, thyroid, and ovarian stroma. The MAPK signaling pathway emerged as the sole enriched pathway across all 4 tissues. Employing an integrated analysis of the protein-protein interaction (PPI) network and correlation analysis, we found GREB1 emerged as a pivotal component within the HPO axis to regulate estrogen-related signaling in the HPT axis, meanwhile, the HPT axis influenced ovarian development by regulating thyroid hormone-related signaling mainly through OPN5. Then, 10 potential candidate genes were identified, namely IGF1, JUN, ERBB4, KDR, PGF, FGFR1, GREB1, OPN5, DIO3, and THRB. These findings establish a foundation for elucidating the physiological and genetic mechanisms by which the HPO and HPT axes co-regulate goose AFE.

Transferability of Nikita and Sukkula retrotransposons in domestic goose (Anser anser domesticus) genome.

This article aimed to detect the existence of barley-specific Nikita and Sukkula retrotransposons in domestic geese samples and to evaluate the evolutionary relationships between these and other transposons belonging to the family Anatidae. Inter-retrotransposonamplified polymorphism-polymerase chain reaction (IRAP-PCR) method was performed for these retrotransposons movements in three diverse domestic goose populations (Chinese x Embden crossbred, Turkish White, and Turkish Multicolor). Polymorphism ratios were between 0 and 33% in all samples for Nikita and 0-73% in all samples for Sukkula. In addition, intrapopulation genetic polymorphism rates were also 0-15% in Chinese x Embden crossbred, 0-25% in Turkish White, 0-25% in Turkish Multicolor for Nikita; while 0-27% in Chinese x Embden, and 0-50% in Turkish Multicolor for Sukkula. There was no polymorphism for Sukkula among Turkish White samples. Moreover, the neighbour-joining method was used for phylogenetic tree construction using 38 sequences of different ducks, geese, and swans. In silico analyses supported the transitions of retrotransposons in the family Anatidae. It is concluded that transposon mobility among the phylogenetically distant species may lead to understanding evolutionary relationships. This report is one of the first studies investigating retrotransposon movements in domestic geese, revealing a new perspective on the goose genome regarding mobile genetic elements.

Transcriptome and lipidome integration unveils mechanisms of fatty liver formation in Shitou geese.

Geese evolved from migratory birds, and when they consume excessive high-energy feed, glucose is converted into triglycerides. A large amount of triglyceride deposition can induce incomplete oxidation of fatty acids, leading to lipid accumulation in the liver and the subsequent formation of fatty liver. In the Chaoshan region of Guangdong, China, Shitou geese develop a unique form of fatty liver through 24 h overfeeding of brown rice. To investigate the mechanisms underlying the formation of fatty liver in Shitou geese, we collected liver samples from normally fed and overfed geese. The results showed that the liver size in the treatment group was significantly larger, weighing 3.5 times more than that in the control group. Extensive infiltration of lipid droplets was observed in the liver upon staining of tissue sections. Biochemical analysis revealed that compared to the control group, the treatment group showed significantly elevated levels of total cholesterol (T-CHO), triglycerides (TG), and glycogen in the liver. However, no significant differences were observed in the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), which are common indicators of liver damage. Furthermore, we performed a combined transcriptomic and lipidomic analysis of the liver samples and identified 1,510 differentially expressed genes (DEGs) and 1,559 significantly differentially abundant metabolites (SDMs). The enrichment analysis of the DEGs revealed their enrichment in metabolic pathways, cellular process-related signaling pathways, and specific lipid metabolism pathways. We also conducted KEGG enrichment analysis of the SDMs and compared them with the enriched signaling pathways obtained from the DEGs. In this study, we identified 3 key signaling pathways involved in the formation of fatty liver in Shitou geese, namely, the biosynthesis of unsaturated fatty acids, glycerol lipid metabolism, and glycerophospholipid metabolism. In these pathways, genes such as glycerol-3-phosphate acyltransferase, mitochondrial (GPAM), 1-acylglycerol-3-phosphate O-acyltransferase 2 (AGPAT2), diacylglycerol O-acyltransferase 2 (DGAT2), lipase, endothelial (LIPG), lipoprotein lipase (LPL), phospholipase D family member 4 (PLD4), and phospholipase A2 group IVF (PLA2G4F) may regulate the synthesis of metabolites, including triacylglycerol (TG), phosphatidate (PA), 1,2-diglyceride (DG), phosphatidylethanolamine (PE), and phosphatidylcholine (PC). These genes and metabolites may play a predominant role in the development of fatty liver, ultimately promoting the accumulation of TG in the liver and leading to the progression of fatty liver.

Identification, pathological, and genomic characterization of novel goose reovirus associated with liver necrosis in geese, China.

Since 2021, a novel strain of goose reovirus (GRV) has emerged within the goose farming industry in Guangdong province, China. This particular viral variant is distinguished by the presence of white necrotic foci primarily localized in the liver and spleen, leading to substantial economic losses for the poultry industry. However, the etiology, prevalence and genomic characteristics of the causative agent have not been thoroughly investigated. In this study, we conducted an epidemiological inquiry employing suspected GRV samples collected from May 2021 to September 2022. The macroscopic pathological and histopathological lesions associated with GRV-infected clinical specimens were examined. Moreover, we successfully isolated the GRV strain and elucidated the complete genome sequence of the isolate GD21/88. Through phylogenetic and recombination analysis, we unveiled that the GRV strains represent a novel variant resulting from multiple reassortment events. Specifically, the µNS, λC, and σNS genes of GRV were found to have originated from chicken reovirus, while the σA gene of GRV exhibited a higher degree of similarity with a novel duck reovirus. The remaining genes of GRV were traced back to Muscovy duck reovirus. Collectively, our findings underscore the significance of GRV as a pathogenic agent impacting the goose farming industry. The insights gleaned from this study contribute to a more comprehensive understanding of the epidemiology of GRV in Southern China and shed light on the genetic reassortment events exhibited by the virus.

Integrated analysis of whole genome and transcriptome sequencing uncovers genetic differences between Zi goose and Xianghai flying goose.

Zi goose is a famous indigenous breed originating from northeast China with high annual egg production. Xianghai flying goose is a composite breed and is bred by crosses of the wild swan goose and the Zi goose. Our previous study revealed significant differences in muscle fiber characteristics between the two populations. Here, we aimed to reveal the underlying genetic basis of the above phenotype differences through whole-genome and transcriptome analysis. A total of 20 blood samples (10 Zi geese and 10 Xianghai flying geese) were used for whole genome sequencing, and eight breast muscle tissue samples (four Zi geese and four Xianghai flying geese) were used for RNA sequencing. Using the FST and XP-EHH analysis, some highly differentiated genome regions annotated with egg production (RORB, WNT4, BMPR1B) and breast muscle development (WNT7B) between the two populations were detected. RNA-sequencing analysis revealed differentially expressed genes related to muscle development (IGF1, PAX7). Moreover, several genes were detected by both genome and transcriptome analysis, and some of them were reported to be associated with muscle growth (SLIT2, PREX1) and intramuscular fat (COL6A1). These findings will help researchers better understand the genetic basis related to egg production and muscle development in geese.

Genome-wide selective signatures mining the candidate genes for egg laying in goose.

BACKGROUND: Improving the egg production of goose is a crucial goal of breeding, because genetics is the key factor affecting egg production. Thus, we sequenced the genomes of 55 Chinese indigenous geese from six breeds, which were divided into the high egg-laying group (ZE, HY, and SC) and low egg-laying group (ZD, LH, and ST). Based on the results of the inter-population selection signal analysis, we mined the selected genome regions in the high egg-laying germplasm population to identify the key candidate genes affecting the egg-laying traits. RESULTS: According to the whole-genome sequencing data, the average sequencing depth reached 11.75X. The genetic relationships among those six goose breeds coincided with the breed's geographical location. The six selective signal detection results revealed that the most selected regions were located on Chr2 and Chr12. In total, 12,051 single-nucleotide polymorphism (SNP) sites were selected in all six methods. Using the enrichment results of candidate genes, we detected some pathways involved in cell differentiation, proliferation, and female gonadal development that may cause differences in egg production. Examples of these pathways were the PI3K-Akt signaling pathway (IGF2, COMP, and FGFR4), animal organ morphogenesis (IGF2 and CDX4), and female gonad development (TGFB2). CONCLUSION: On analyzing the genetic background of six local goose breeds by using re-sequencing data, we found that the kinship was consistent with their geographic location. 107 egg-laying trait-associated candidate genes were mined through six selection signal analysis. Our study provides a critical reference for analyzing the molecular mechanism underlying differences in reproductive traits and molecular breeding of geese.

Effects of essential oil mixtures on expression of genes involved in lipogenesis and fatty acid oxidation in geese (Anser anser).

The use of essential oils has recently increased in the poultry sector. The aim of this study was to investigate the effects of essential oil mixture (juniper, mint, oregano and rosemary oil) on fatty acid oxidation and lipogenic gene expression in geese. Research groups were formed as C (control; no additives), EK1 (0.4 ml/l essential oil mixture supplemented) and EK2 (0.8 ml/l essential oil mixture supplemented). Relative expression levels of genes included in lipogenesis (ACCα, ChREBP, FASN, LXRα and SREBP-1) expression levels of genes included in fatty acid oxidation (ACOX1, CPT1, CPT1A, PPARα and PPARγ) were measured using RT-qPCR. Group EK1 upregulates the mRNA expression levels of genes involved in lipogenesis such as ACCα, ChREBP and SREBP-1, while it downregulates the mRNA expression in levels of all genes involved in fatty acid oxidation. Group EK2 increases the mRNA expression levels of genes involved in lipogenesis such as ACCα, FASN and SREBP-1, while it decreased mRNA expression at the levels of all genes involved in fatty acid oxidation, as in the other group. In the study, adding an essential oil mixture to drinking water is predicted to increase fatty liver because it upregulates genes related to fat synthesis (lipogenesis) and downregulates genes related to fat degradation (fatty acid oxidation).

Association between Yili goose sperm motility and expression profiles of mRNA and miRNA in testis.

BACKGROUND: The study was conducted to find out the candidate microRNA (miRNA) and genes that associated with sperm motility of Yili goose through small RNA sequencing of testicular tissue of Yili goose, and provide a theoretical basis for the study of the regulation mechanism of sperm motility of Yili goose gander. RESULTS: In this study, five male geese with high sperm motility and five male geese with low sperm motility were slaughtered to obtain their testis tissues for small RNA sequencing, and biological information methods were used for data analysis. The results showed that a total of 1575 known miRNAs and 68 novel miRNAs were identified in the testis tissue of Yili goose, and 71 differentially expressed miRNAs and 660 differentially expressed genes were screened. GO functional analysis showed that miRNAs target genes were mainly involved in the binding, kinase activity, structural constituent of cytoskeleton and intermediate filament cytoskeleton. KEGG functional analysis showed that miRNAs target genes were significantly enriched in arginine and proline metabolism, glycolysis / gluconeogenesis, fructose and mannose metabolism and beta-Alanine metabolism and other pathways. miRNAs-mRNAs interaction network suggests miR-140/miR-140-3p/miR-140-3p-NKAIN3, let-7d-BTG1 and miR-145-5p/miR -145a-5p-CLEC2E may play an important role in testis development and spermatogenesis. CONCLUSIONS: The results of this study suggest that the sperm motility of Yili goose may be regulated by different miRNAs, and the target genes are significantly enriched in pathways related to sperm metabolism, indicating that miRNAs affect the sperm motility of Yili goose by regulating the metabolic process of sperm and the expression of related genes. This study can provide a reference for revealing the regulation mechanism of Yili goose sperm motility at the molecular level.

Circadian clock gene BMAL1 regulates STAR expression in goose ovarian preovulatory granulosa cells.

The ovarian circadian clock plays a regulatory role in the avian ovulation-oviposition cycle. However, little is known regarding the ovarian circadian clock of geese. In this study, we investigated rhythmic changes in clock genes over a 48-h period and identified potential clock-controlled genes involved in progesterone synthesis in goose ovarian preovulatory granulosa cells. The results showed that BMAL1, CRY1, and CRY2, as well as 4 genes (LHR, STAR, CYP11A1, and HSD3B) involved in progesterone synthesis exhibited rhythmic expression patterns in goose ovarian preovulatory granulosa cells over a 48-h period. Knockdown of BMAL1 decreased the progesterone concentration and downregulated STAR mRNA and protein levels in goose ovarian preovulatory granulosa cells. Overexpression of BMAL1 increased the progesterone concentration and upregulated the STAR mRNA level in goose ovarian preovulatory granulosa cells. Moreover, we demonstrated that the BMAL1/CLOCK complex activated the transcription of goose STAR gene by binding to an E-box motif. These results suggest that the circadian clock is involved in the regulation of progesterone synthesis in goose ovarian preovulatory granulosa cells by orchestrating the transcription of steroidogenesis-related genes.

Genomic signatures reveal selection in Chinese and European domesticated geese.

The Swan goose and Greylag goose are species of geese native to East Asia and Europe, respectively, and are widely believed to be the ancestors of Chinese and European domesticated geese. The Yili goose (YL) and European domestic geese originated from the Greylag goose, but the history of domestication is unclear. In this study, we sequenced and analyzed the genome of the YL goose and the Hortobagy goose to combine with other previously sequenced goose populations for in-depth analysis. The population genetic variations in Stone geese, East Zhejiang White Geese, Taihu geese and Zi geese were also identified and compared. The results showed that admixture gene flow existed in the YL geese population, which was introgressed by Chinese geese, suggesting that gene flow events were frequent and widespread among domesticated geese. Further selected sweep analysis identified candidate genes and metabolic pathways that may be related to the differences in morphology. Several genes such as TGFBR3L, CMYA5, FOXD1, ARHGEF28 and SUCLG2 are associated with growth, reproduction and fertility traits. The results of this study will help to understand the genetic characteristics of domestic geese and the genes affecting important traits and provide a basis for the improved breed of domestic geese.

Base composition, adaptation, and evolution of goose astroviruses: codon-based investigation.

Goose astroviruses (GoAstVs) are causative agents that account for fatal infection of goslings characterized by visceral urate deposition, resulting in severe economic losses in major goose-producing regions in China since 2017. In this study, we sought to unravel the intrinsic properties associated with adaptation and evolution in the host environment of GoAstVs. Consistent results from phylogenetic analysis and correspondence analysis performed on the codon usage patterns (CUPs) reveal 2 clusters of GoAstVs, namely, GoAstV-1 and GoAstV-2. However, multiple similar compositional characteristics were found, despite the high divergence between GoAstV-1 and GoAstV-2. Studies on the base composition of GoAstVs reveal an A/U bias, indicating a compositional constraint, while natural selection prevailed in determining the CUPs in the virus genome based on our neutrality plot analysis, reflecting high adaptive pressure to fit the host environment. Codon adaptation index (CAI) analysis revealed a higher degree of fitness to the CUPs of the corresponding host for GoAstVs than avian influenza virus and betacoronaviruses, which may be a favorable factor contributing to the high pathogenicity and wide distribution of GoAstVs in goslings. In addition, GoAstVs were less adapted to ducks and chickens, with significantly lower CAI values than to geese, which may be a reason for the different prevalence of GoAstVs among these species. Extensive investigations on dinucleotide distribution revealed a significant suppression of the CpG and UpA motifs in the virus genome, which may facilitate adaptation to the host's innate immune system by evading surveillance. In addition, our study reported the trends of increasing fitness to the host's microenvironment for GoAstVs through increasing adaptation to host CUPs and ongoing reduction of CpG motifs in the virus genome. The present analysis deepens our understanding of the basic biology, pathogenesis, adaptation and evolutionary pattern of GoAstVs, and contributes to the development of novel antiviral strategies.

Genetic Diversity Analysis and Breeding of Geese Based on the Mitochondrial ND6 Gene.

To explore the differences in body-weight traits of five goose breeds and analyze their genetic diversity and historical dynamics, we collected body-weight data statistics and used Sanger sequencing to determine the mitochondrial DNA of 100 samples of five typical goose breeds in China and abroad. The results indicated that Lion-Head, Hortobagy, and Yangzhou geese have great breeding potential for body weight. Thirteen polymorphic sites were detected in the corrected 505 bp sequence of the mitochondrial DNA (mtDNA) ND6 gene, accounting for approximately 2.57% of the total number of sites. The guanine-cytosine (GC) content (51.7%) of the whole sequence was higher than the adenine-thymine (AT) content (48.3%), showing a certain GC base preference. There were 11 haplotypes among the five breeds, including one shared haplotype. We analyzed the differences in the distribution of base mismatches among the five breeds and conducted Tajima's D and Fu's Fs neutral tests on the historical dynamics of the populations. The distribution of the mismatch difference presented an unsmooth single peak and the Tajima's D value of the neutral test was negative (D < 0) and reached a significant level, which proves that the population of the three species had expanded; the Lion-Head goose population tends to be stable. The genetic diversity of Lion-Head, Zhedong White, Yangzhou, and Taihu geese was equal to the average diversity of Chinese goose breeds. The Hortobagy goose is a foreign breed with differences in mating line breeding and hybrid advantage utilization.

Integrating genomics and transcriptomics to identify candidate genes for high egg production in Wulong geese (Anser cygnoides orientalis).

BACKGROUND: Wulong geese (Anser cygnoides orientalis) are known for their excellent egg-laying performance. However, they show considerable population differences in egg-laying behavior. This study combined genome-wide selection signal analysis with transcriptome analysis (RNA-seq) to identify the genes related to high egg production in Wulong geese. RESULTS: A total of 132 selected genomic regions were screened using genome-wide selection signal analysis, and 130 genes related to high egg production were annotated in these regions. These selected genes were enriched in pathways related to egg production, including oocyte meiosis, the estrogen signaling pathway, the oxytocin signaling pathway, and progesterone-mediated oocyte maturation. Furthermore, a total of 890 differentially expressed genes (DEGs), including 340 up-regulated and 550 down-regulated genes, were identified by RNA-seq. Two genes - GCG and FAP - were common to the list of selected genes and DEGs. A non-synonymous single nucleotide polymorphism was identified in an exon of FAP. CONCLUSIONS: Based on genome-wide selection signal analysis and transcriptome data, GCG and FAP were identified as candidate genes associated with high egg production in Wulong geese. These findings could promote the breeding of Wulong geese with high egg production abilities and provide a theoretical basis for exploring the mechanisms of reproductive regulation in poultry.

Phosphoproteome Reveals Extracellular Regulated Protein Kinase Phosphorylation Mediated by Mitogen-Activated Protein Kinase Kinase-Regulating Granulosa Cell Apoptosis in Broody Geese.

Geese have strong brooding abilities, which severely affect their egg-laying performance. Phosphorylation is widely involved in regulating reproductive activities, but its role in goose brooding behavior is unclear. In this study, we investigated differences in the phosphoprotein composition of ovarian tissue between laying and brooding geese. Brooding geese exhibited ovarian and follicular atrophy, as well as significant oxidative stress and granulosa cell apoptosis. We identified 578 highly phosphorylated proteins and 281 lowly phosphorylated proteins, and a KEGG pathway analysis showed that these differentially phosphorylated proteins were mainly involved in cell apoptosis, adhesion junctions, and other signaling pathways related to goose brooding behavior. The extracellular regulated protein kinase (ERK)-B-Cell Lymphoma 2(BCL2) signaling pathway was identified as playing an important role in regulating cell apoptosis. The phosphorylation levels of ERK proteins were significantly lower in brooding geese than in laying geese, and the expression of mitogen-activated protein kinase kinase (MEK) was downregulated. Overexpression of MEK led to a significant increase in ERK phosphorylation and BCL2 transcription in H2O2-induced granulosa cells (p < 0.05), partially rescuing cell death. Conversely, granulosa cells receiving MEK siRNA exhibited the opposite trend. In conclusion, geese experience significant oxidative stress and granulosa cell apoptosis during brooding, with downregulated MEK expression, decreased phosphorylation of ERK protein, and inhibited expression of BCL2.