Telomere-to-telomere genome assembly of the goose Anser cygnoides.

Our study presents the assembly of a high-quality Taihu goose genome at the Telomere-to-Telomere (T2T) level. By employing advanced sequencing technologies, including Pacific Biosciences HiFi reads, Oxford Nanopore long reads, Illumina short reads, and chromatin conformation capture (Hi-C), we achieved an exceptional assembly. The T2T assembly encompasses a total length of 1,197,991,206 bp, with contigs N50 reaching 33,928,929 bp and scaffold N50 attaining 81,007,908 bp. It consists of 73 scaffolds, including 38 autosomes and one pair of Z/W sex chromosomes. Importantly, 33 autosomes were assembled without any gap, resulting in a contiguous representation. Furthermore, gene annotation efforts identified 34,898 genes, including 436,162 RNA transcripts, encompassing 806,158 exons, 743,910 introns, 651,148 coding sequences (CDS), and 135,622 untranslated regions (UTR). The T2T-level chromosome-scale goose genome assembly provides a vital foundation for future genetic improvement and understanding the genetic mechanisms underlying important traits in geese.

Identifying candidate genes and biological pathways in muscle development through multi-tissue transcriptome comparisons between male and female geese.

Males and females have long shown disparities in body weight and height; yet, the underlying mechanisms influencing growth and development remain unclear. Male and female Zhedong White Geese (ZDW) geese have long been selected for large body size and egg production, respectively. This led to a large difference in body weight between males and females, making them a unique model for studying the effects of sex on growth and development. This study aimed to elucidate these mechanisms by comparing the transcriptomes of muscle and pituitary tissues in male and female ZDW geese to identify the critical genes responsible for the effects of sex on growth performance. Our analysis revealed 1101 differentially expressed genes (DEGs) in leg musculature (507 upregulated, 594 downregulated), 773 DEGs in breast musculature (311 upregulated, 462 downregulated), and 517 DEGs in the pituitary gland (281 upregulated, 236 downregulated) between male and female geese. These DEGs were significantly enriched in gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways associated with endocrine metabolism (e.g., hormonal activities), muscle formation (e.g., sarcomere and myofibril), and bone formation (e.g., bone morphogenesis and cartilage formation). The upregulated genes in males were enriched in KEGG pathways involving nutrient digestion and absorption (vitamin and protein), as well as the secretion of digestive juices (gastric acid and bile). Through protein-protein interaction analyses, we also observed high-density gene networks related to muscle fiber development, calcium ion metabolism, mitochondrial respiratory chain, and bone development. Therefore, our multi-tissue transcriptome analysis provides a deeper understanding of the complex and systematic gender-driven effects on growth and development in geese. IGF1, GHRHR, and NCAPG-LCORL and pathways related to myogenesis might play vital roles in gender differences before hormones exert their effect.

The DNA methylation status of the vitamin A signaling associated with testicular degeneration induced by long-day photoperiods in Magang geese.

Magang geese are typical short-day breeders whose reproductive behaviors are significantly influenced by photoperiod. Exposure to a long-day photoperiod results in testicular regression and spermatogenesis arrest in Magang geese. To investigate the epigenetic influence of DNA methylation on the seasonal testicular regression in Magang geese, we conducted whole-genome bisulfite sequencing and transcriptome sequencing of testes across 3 reproductive phases during a long-day photoperiod. A total of 250,326 differentially methylated regions (DMR) were identified among the 3 comparison groups, with a significant number showing hypermethylation, especially in intronic regions of the genome. Integrating bisulfite sequencing with transcriptome sequencing data revealed that DMR-associated genes tend to be differentially expressed in the testes, highlighting a potential regulatory role for DNA methylation in gene expression. Furthermore, there was a significant negative correlation between changes in the methylation of CG DMRs and changes in the expression of their associated genes in the testes. A total of 3,359 DMR-associated differentially expressed genes (DEG) were identified; functional enrichment analyses revealed that motor proteins, MAPK signaling pathway, ECM-receptor interaction, phagosome, TGF-beta signaling pathway, and calcium signaling might contribute to the testicular regression process. GSEA revealed that the significantly enriched activated hallmark gene set was associated with apoptosis and estrogen response during testicular regression, while the repressed hallmark gene set was involved in spermatogenesis. Our study also revealed that methylation changes significantly impacted the expression level of vitamin A metabolism-related genes during testicular degeneration, with hypermethylation of STRA6 and increased calmodulin levels indicating vitamin A efflux during the testicular regression. These findings were corroborated by pyrosequencing and real-time qPCR, which revealed that the vitamin A metabolic pathway plays a pivotal role in testicular degeneration under long-day conditions. Additionally, metabolomics analysis revealed an insufficiency of vitamin A and an abnormally high level of oxysterols accumulated in the testes during testicular regression. In conclusion, our study demonstrated that testicular degeneration in Magang geese induced by a long-day photoperiod is linked to vitamin A homeostasis disruption, which manifests as the hypermethylation status of STRA6, vitamin A efflux, and a high level of oxysterol accumulation. These findings offer new insights into the effects of DNA methylation on the seasonal testicular regression that occurs during long-day photoperiods in Magang geese.

Potential regulator of meat quality in geese: C1QTNF1 implications on cell proliferation and muscle growth.

Goose creates important economic value depending on their enrich nutrients of meat. Our previous study investigates potential candidate genes associated with variations in meat quality between Xianghai Flying (XHF) Goose and Zi Goose through genomic and transcriptome integrated analysis. Screening of 5 differential expression candidate genes related to muscle development identified by the FST, XP-EHH and RNA-seq in breast muscle from various geese. Among them, C1QTNF1 (C1q and TNF related protein 1), a gene of unknown function in goose, which observed mutations in coding sequence regions in sequencing data. Its function was explored after overexpression and knockdown which designed depending on the genetic sequence of the goose, respectively. Results showed that over-expression of C1QTNF1 significantly enhances cell proliferation and viability. In addition, the expression levels of the fusion marker gene Myomaker and the differentiation marker gene MyoD are significantly upregulated in cells. Knock-down C1QTNF1 leads to down regulated Myomaker and MyoD which involved muscle formation. But, the expression level of muscle atrophy marker MuRF is not significantly changed among different transfection groups. Since protein structures and interactions are closely related to their functions, we further analyzed the C1QTNF1 for physicochemical properties, structural predictions, protein interactions and homology. It can be reasonably inferred that C1QTNF1 has a similar effect to collagen, which may affect muscle development. In summary, we first speculate that C1QTNF1 may play an important regulatory role in muscle growth and development and thereby contributes to the further understanding of the genetic mechanisms that underlie meat quality traits of goose.

Comprehensive analysis of the differential expression of mRNAs, lncRNAs, and miRNAs in Zi goose testis with high and low sperm mobility.

Sperm mobility (SM) is an objective index for measuring sperm motility; however, the mechanisms underlying its regulation in geese remain unclear. The present study sought to elucidate the genetic mechanism underlying SM traits in Zi geese (Anser cygnoides L.). To this end, three successive experiments were performed. In Experiment I, SM was determined in 40 ganders; the 3 ganders with the highest mobility and three with the lowest mobility were assigned to the high and low sperm mobility rank (SMR) groups, respectively. In Experiment II, the differences in fertility between the two SMR groups were assessed within two breeding flocks comprising the selected six ganders from Experiment I and 30 females (each flock had 3 ganders and 15 females). In Experiment III, the testes of the 6 ganders were harvested for histological observation and whole-transcriptome sequencing. Results revealed better fertility, well-developed seminiferous tubules, and abundant mature sperm in the high-SMR-flock compared to those of the low-SMR-flock (89 vs. 81%) (P < 0.05). Differential expression (DE) analysis identified 76 mRNAs, 344 lncRNAs, and 17 miRNAs between the SMR groups, with LOC106049708, XPNPEP3, GNB3, ADCY8, PRKAG3, oha-miR-182-5p, and ocu-miR-10b-5p identified as key mRNAs and miRNAs contributing to SM. Enrichment analysis implicated these DE RNAs in pathways related to ATP binding, cell metabolism, apelin signaling, Wnt signaling, and Adherens junctions. Additionally, competing endogenous RNA (ceRNA) networks comprising 9 DE mRNAs, 17 DE miRNAs, and 169 DE lncRNAs were constructed. Two ceRNA network pathways (LOC106049708-oha-miR-182-5p-MSTRG.2479.6 and PRKAG3-ocu-miR-10b-5p-MSTRG.9047.14) were identified as key regulators of SM in geese. These findings offer crucial insights into the identification of key genes and ceRNA pathways influencing sperm mobility in geese.

Comparative transcriptomic analyses reveal key genes underlying melanin distribution during embryonic development in geese (Anser anser).

1. Melanin distribution typically exhibits a gradient dilution along the dorsal-ventral axis of the body, including in domestic geese. However, the specific genes and molecular mechanisms responsible for this melanin distribution pattern remain incompletely understood.2. The transcriptomic comparisons were conducted at three embryonic stages, specifically on embryonic d 15 (E15), 22 (E22), and 29 (E29), between the pigmented dorsal skin and the depigmented distal foot.3. Differentially expressed genes (DEGs) associated with melanin synthesis were identified, particularly TYR, TYRP1, and EDNRB2, which exhibited significantly higher expression levels in the dorsal skin at E15 and E22. However, expression levels significantly decreased in later stages (E29).4. The ASIP gene showed remarkably high-expression levels in the distal feet compared to the dorsal skin post-E22 stage (log2FC: 5.31/6.88 at E22/E29). Gene Ontology (GO) enrichment analysis detected eight terms associated with melanin synthesis and melanosome formation (p < 0.05), including melanosome membrane (GO: 0033162) and melanin biosynthetic process (GO: 0042438). Additionally, KEGG pathway analysis showed significant enrichment of the melanogenesis pathway (hsa004916) at d 22 (E22).

Transcriptome analysis of sexual dimorphism in dorsal down coloration in goslings.

BACKGROUND: In day-old Hungarian white goose goslings, there is a noticeable difference in dorsal down coloration between males and females, with females having darker dorsal plumage and males having lighter plumage. The ability to autosex day-old goslings based on their dorsal down coloration is important for managing them efficiently and planning their nutrition in the poultry industry. The aim of this study was to determine the biological and genetic factors underlying this difference in dorsal down colorationthrough histological analysis, biochemical assays, transcriptomic profiling, and q‒PCR analysis. RESULTS: Tissue analysis and biochemical assays revealed that compared with males, 17-day-old embryos and day-old goslings of female geese exhibited a greater density of melanin-containing feather follicles and a greater melanin concentration in these follicles during development. Both female and male goslings had lower melanin concentrations in their dorsal skin compared to 17-day-old embryos. Transcriptome analysis identified a set of differentially expressed genes (DEGs) (MC1R, TYR, TYRP1, DCT and MITF) associated with melanogenesis pathways that were downregulated or silenced specifically in the dorsal skin of day-old goslings compared to 17-day-old embryos, affecting melanin synthesis in feather follicles. Additionally, two key genes (MC1R and MITF) associated with feather coloration showed differences between males and females, with females having higher expression levels correlated with increased melanin synthesis and darker plumage. CONCLUSION: The expression of multiple melanogenesis genes determines melanin synthesis in goose feather follicles. The dorsal down coloration of day-old Hungarian white goose goslings shows sexual dimorphism, likely due to differences in the expression of the MC1R and MITF genes between males and females. These results could help us better understand why male and female goslings exhibit different plumage patterns.

The effect of LINC9137 targeting miR-140-3p-NKAIN3 signal axis on the development of goose testis sertoli cells.

Sertoli cells (SC) are a type of important cells in the testes, which can provide transport proteins, regulatory proteins, growth factors, and other cytokines for the spermatogenic process. They participate in the regulation of the maturation and differentiation of spermatogenic cells and play an important supporting role in the migration, proliferation, and differentiation of germ cells at all levels in the testes. Previous studies found differential expression of LINC9137, miR-140-3p, and Sodium/Potassium Transporting ATPase Interacting 3 (NKAIN3) genesin high and low sperm motility goose testicular tissues. This study investigated the effects of the LINC9137-miR-140-3p-NKAIN3 signal axis on the proliferation and apoptosis of goose testicular sertoli cells at the cellular level, respectively. The results showed that through acridine orange staining, oil red O staining, Alkaline phosphatase (AKP) staining, and RT qPCR assay, it was comprehensively identified that the cultured testicular sertoli cells were purified in vitro. Through the dual luciferase activity detection test, it was found that LINC9137 has a targeted binding site with miR-140-3p and NKAIN3. In addition, this study found that overexpression of miR-140-3p significantly inhibited the expression of LINC9137 and NKAIN3 in sertoli cells, and their expression was significantly increased when miR-140-3p was interfered with. By measuring cell proliferation activity and apoptosis related gene expression, it was found that overexpression of LINC9137 decreased cell proliferation activity (P > 0.05), while the expression level of apoptosis factor Bcl2 Associated X Protein (Bax)/B-cell lymphoma-2 (Bcl2) increased (P > 0.05). On the contrary, when interfering with LINC9137, the cell proliferation activity of sertoli cells was significantly increased (P < 0.01), and the expression level of apoptosis factor Bax/Bcl2 was significantly reduced (P < 0.05); The effect of miR-140-3p on the proliferation and apoptosis of sertoli cells is opposite to that of LINC9137. Meanwhile, this study co transfected overexpressed LINC9137 and miR-140-3p plasmids into sertoli cells, and found that the effect of LINC9137 overexpression on supporting cell proliferation was weakened by miR-140-3p. This study elucidates the role and function of the LINC9137 miR-140-3p-NKAIN3 signaling axis in the development of goose testes and spermatogenesis, establishes a regulatory network related to spermatogenesis, and provides a theoretical basis for studying the genetic regulation of goose spermatogenesis.

Identification of potential candidate genes for the Huoyan trait in developing Wulong goose embryos by transcriptomic analysis.

1. The Wulong goose is a Chinese breed and a source of high-quality meat and eggs. A characteristic of the Wulong goose is that a proportion of the birds do not have eyelids, known as the Huoyon trait.2. Wulong geese exhibiting the Huoyan trait at embryonic stages of 9 days (E9), 12 days (E12) and 14 days (E14) were selected alongside those with normal eyelids for comprehensive transcriptome sequencing. Differentially expressed gene (DEG) and functional enrichment analyses were performed and finally, eight DEG were chosen to verify the accuracy of qPCR sequencing.3. Overall, 466, 962 and 550 DEG were obtained from the three control groups, D9 vs. N9, D12 vs. N12 and D14 vs. N14, respectively, by differential analysis (p < 0.05). CDKN1C, CRH, CROCC and TYSND1 were significantly expressed in the three groups. Enrichment analysis revealed the enrichment of CROCC and TYSND1 in pathways of cell cycle process, endocytosis, microtubule-based process, microtubule organising centre organisation, protein processing and protein maturation. CDKN1C and CRH were enriched in the cell cycle and cAMP signalling pathway.4. Some collagen family genes were detected among the DEGs, including COL3A1, COL4A5, COL4A2 and COL4A1. FREM1 and FREM2 genes were detected in both Huoyan and normal eyelids. There was a significant difference (p < 0.01) in FREM1 expression between ED9 and ED14 in female embryos, but this difference was not observed in male embryos.

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.

Transcriptome Profiling Unveils Key Genes Regulating the Growth and Development of Yangzhou Goose Knob.

Goose is one of the most economically valuable poultry species and has a distinct appearance due to its possession of a knob. A knob is a hallmark of sexual maturity in goose (Anser cygnoides) and plays crucial roles in artificial selection, health status, social signaling, and body temperature regulation. However, the genetic mechanisms influencing the growth and development of goose knobs remain completely unclear. In this study, histomorphological and transcriptomic analyses of goose knobs in D70, D120, and D300 Yangzhou geese revealed differential changes in tissue morphology during the growth and development of goose knobs and the key core genes that regulate goose knob traits. Observation of tissue sections revealed that as age increased, the thickness of the knob epidermis, cuticle, and spinous cells gradually decreased. Additionally, fat cells in the dermis and subcutaneous connective tissue transitioned from loose to dense. Transcriptome sequencing results, analyzed through differential expression, Weighted Gene Co-expression Network Analysis (WGCNA), and pattern expression analysis methods, showed D70-vs.-D120 (up-regulated: 192; down-regulated: 423), D70-vs.-D300 (up-regulated: 1394; down-regulated: 1893), and D120-vs.-D300 (up-regulated: 1017; down-regulated: 1324). A total of 6243 differentially expressed genes (DEGs) were identified, indicating varied expression levels across the three groups in the knob tissues of D70, D120, and D300 Yangzhou geese. These DEGs are significantly enriched in biological processes (BP) such as skin morphogenesis, the regulation of keratinocyte proliferation, and epidermal cell differentiation. Furthermore, they demonstrate enrichment in pathways related to goose knob development, including ECM-receptor interaction, NF-kappa B, and PPAR signaling. Through pattern expression analysis, three gene expression clusters related to goose knob traits were identified. The joint analysis of candidate genes associated with goose knob development and WGCNA led to the identification of key core genes influencing goose knob development. These core genes comprise WNT4, WNT10A, TCF7L2, GATA3, ADRA2A, CASP3, SFN, KDF1, ERRFI1, SPRY1, and EVPL. In summary, this study provides a reference for understanding the molecular mechanisms of goose knob growth and development and provides effective ideas and methods for the genetic improvement of goose knob traits.

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.

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.

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.

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.