In livestock production, oxidative stress (OS) is ubiquitous, reducing animal productivity and product quality. Hence, investigating the mechanisms of oxidative stress in livestock and inhibiting oxidative stress-induced damage is crucial. Curcumin, a plant-derived bioactive compound, exhibits antioxidant and anti-apoptotic properties. Adipose-derived stem cells (ADSCs) from animal adipose tissue are easily accessible and possess multilineage differentiation potential. Therefore, this work utilized bovine ADSCs to establish an oxidative stress model and investigated the effects of curcumin on oxidative stress and apoptosis. Firstly, bovine ADSCs were isolated and cultured from fetal calf subcutaneous adipose tissue. Their surface markers were identified by immunofluorescence, confirming the expression of CD29, CD44, CD73, CD90, CD105 and Vimentin, but not CD34, indicative of mesenchymal stem/progenitor cell characteristics. Secondly, to explore the effects of curcumin on oxidative damage and apoptosis in bovine ADSCs, an oxidative stress model was induced using H2O2. CCK-8 assays showed significantly reduced cell viability and SOD activity, along with increased malondialdehyde (MDA) and reactive oxygen species (ROS) levels, indicating successful modeling. RT-qPCR further confirmed that 500 μM of H2O2 treatment for 24 h promoted apoptosis. Herein, CCK-8 assays indicated a significant reduction in cell viability at >8 μM of curcumin. Thirdly, using 4 μM and 8 μM of curcumin for pre-protection, 8 μM maintained SOD activity, reduced MDA and ROS, inhibited apoptosis-related gene changes (Bcl-2, Bax, Caspase-3), and suppressed apoptosis according to a TUNEL assay. Fourthly, curcumin’s autophagy-inducing potential was hypothesized, which was confirmed by increased LC3-II and decreased P62 expression upon co-treatment with 3-MA. 3-MA inhibited curcumin’s antioxidant and anti-apoptotic effects, suggesting that curcumin’s antioxidant and anti-apoptotic roles may involve autophagy induction. In conclusion, bovine ADSCs are abundant, easily accessible, and multipotent, making them suitable for in vitro expansion. Curcumin alleviated H2O2-induced oxidative stress in bovine ADSCs, with curcumin also inhibiting apoptosis, likely through autophagy induction. This study validates the protective role of curcumin in bovine ADSCs, with potential applications in livestock production.

The Nuclear receptor subfamily 5 group A member 2 (NR5A2) gene plays a pivotal role in ovarian development, ovulation, and reproductive traits. There is a lack of studies on its impact on ovarian traits and reproductive traits in cattle. This study aimed to explore NR5A2 gene polymorphisms associations with reproductive traits and investigate the distribution of NR5A2 gene polymorphisms across diverse bovine breeds worldwide. We identified a novel 17-bp deletion within the NR5A2 gene specifically in Chinese Holstein cows (n = 1033) leading to the observation of two genotypes DD and ID. Subsequent association analysis revealed a significant correlation between the ‘ID’ genotype at this locus and a larger number of corpus albicans (p = 0.042) in diestrus, as well as a higher number of mature follicles (p = 0.038) in estrus. In addition, we also found that the distribution of this deletion exhibits strong regionality across different cattle breeds globally. These findings indicate that the 17-bp deletion mutation within the NR5A2 gene is significantly associated with an increased corpus luteum diameter and a greater number of mature follicles, suggesting its potential utility as a valuable DNA marker for enhancing cow fertility.

EPAS1 (Endothelial PAS Domain Protein 1) gene is well-known for its function in plateau hypoxia adaptability. It encodes HIF-2 alpha, which involved in the induction of genes regulated by oxygen and then affects multiple physiological processes such as angiogenesis and energy metabolism. All of these indicate it may affect the development of animals. In this study, a 14-bp deletion in EPAS1 gene was uncovered in Shandong black cattle population (n = 502). Two genotypes (II and ID) were found and the frequency of the homozygous II genotype is higher than the heterozygous ID genotype. This population is consisted with HWE (p > 0.05). And more importantly, the 14-bp deletion was associated with outside flat (p = 0.003), brisket (p = 0.001), and knuckle (p = 0.032). These findings suggested that the 14-bp deletion is significantly associated with carcass traits, which could be served as a molecular marker applied to cow breeding.

本研究旨在探究根皮素(PT)对过氧化氢(H2O2)诱导的牛脂肪源性干细胞(ADSCs)氧化应激和凋亡的影响.试验选取牛脂肪组织,使用Ⅳ型胶原酶分离牛ADSCs,传代培养后利用免疫荧光对牛ADSCs表面标记蛋白CD29、CD44、CD73及Vimentin进行鉴定.用不同浓度(0、100、200、500、1000μmol/L)的过氧化氢(H2O2)处理牛ADSCs 24 h,通过CCK?8法检测细胞存活率,筛选构建牛ADSCs氧化应激模型的适宜H2 O2浓度.利用CCK?8法检测不同浓度(0、10、50、100μmol/L)PT作用4 h后牛ADSCs的存活率,确定PT对牛ADSCs进行预保护的适宜浓度.随后先用不同浓度(0、10、50μmol/L)PT预处理牛ADSCs 4 h,对牛ADSCs进行预保护;再利用500μmol/L H2 O2处理牛ADSCs 24 h.采用试剂盒检测牛ADSCs内氧化应激相关指标,包括丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性;荧光探针2′,7′-二氯二氢荧光素二乙酸酯(DCFH?DA)测定细胞内活性氧(ROS)含量;实时荧光定量PCR(qRT?PCR)检测细胞凋亡相关基因B细胞淋巴瘤/白血病-2相关X蛋白(Bax)、B细胞淋巴瘤/白血病-2(Bcl?2)及半胱天冬酶-3(Caspase?3)mRNA相对表达量.结果显示:500μmol/L的H2O2能引起牛ADSCs存活率极显著下降(P<0.01),可以用来诱导其发生氧化应激.10和50μmol/L的PT不会对牛ADSCs的存活率产生显著影响(P>0.05),而100μmol/L的PT会引起牛ADSCs的存活率显著下降(P<0.05),因此后续试验选用10、50μmol/L的PT处理牛ADSCs进行4 h的预保护.免疫荧光检测结果显示,牛ADSCs中CD29、CD44、CD73及Vimentin蛋白表达呈阳性;氧化应激相关指标检测结果显示,与空白组(0μmol/L PT预保护,0μmol/L H2 O2处理)相比,500μmol/L H2 O2极显著增加牛ADSCs内MDA含量(P<0.01),极显著降低牛ADSCs内SOD活性(P<0.01),说明500μmol/L H2O2处理牛ADSCs引起了氧化应激.与氧化应激组(0μmol/L PT预保护,500μmol/L H2O2处理)相比,10或50μmol/L PT与500μmol/L H2 O2共处理可以显著减少牛ADSCs内MDA含量(P<0.05),50μmol/L PT与500μmol/L H2 O2共处理可以显著增加牛ADSCs内SOD活性(P<0.05),说明适宜浓度的PT可以缓解H2 O2诱导的牛ADSCs氧化应激.ROS染色结果显示,10、50μmol/L PT与500μmol/L H2 O2共处理均可极显著降低牛ADSCs内ROS含量(P<0.01),同样说明适宜浓度的PT可以缓解H2 O2诱导的牛ADSCs氧化应激.此外,qRT?PCR检测结果显示,与空白组相比,500μmol/L H2 O2显著增加牛ADSCs内促凋亡基因Bax和Caspase?3 mRNA相对表达量(P<0.05),极显著减少牛ADSCs内抗凋亡基因Bcl?2 mRNA相对表达量(P<0.01),说明500μmol/L H2O2处理可以引起牛ADSCs凋亡.而10或50μmol/L PT与500μmol/L H2O2共处理时,牛ADSCs内凋亡相关基因mRNA相对表达量与氧化应激组没有显著差异(P>0.05),说明在本试验的条件下,PT不会缓解H2O2诱导的牛ADSCs凋亡.综上所述,适量的PT可以有效缓解H2O2诱导的牛ADSCs氧化应激.

Global classification of bovine genes is important for studies of biology and tissue-specific gene editing. Herein, we classified the tissue-specific expressed genes and uncovered an important variation in the promoter region of an adipose tissue-specific lncRNA gene. Statistical analysis demonstrated that the number of genes specifically expressed in the brain was the highest, while it was lowest in the adipose tissues. A total of 1,575 genes were found to be significantly higher expressed in adipose tissues. Bioinformatic analysis and qRT-PCR were used to uncover the expression profiles of the 23 adipose tissue-specific and highly expressed genes in 8 tissues. The results showed that most of the 23 genes have higher expression level in adipose tissue. Besides, we detected a 12 bp insertion/deletion (indel) variation (rs720343880) in the promoter region of an adipose tissue-specific lncRNA gene (LOC100847835). The different genotypes of this variation were associated with carcass traits of cattle. Therefore, the outcomes of the present study can be used as a starting point to explore the development of cattle organs and tissues, as well as to improve the quality of cattle products.

Adipogenesis describes the proliferation, differentiation, and apoptosis of mature adipocytes from primary adipocytes and is regulated by post-transcriptional modifications. Circular RNAs (circRNAs) play critical roles in mammalian development and physiology. However, the circRNA-mediated regulation of adipogenesis remains poorly understood. We profiled circRNA expression during bovine primary adipogenesis, detecting 16 circRNA candidates, including circPPARγ, which was abundant in the adipose tissue. Overexpression (overexpression plasmids) and interference (small interfering RNAs) with circPPARγ in bovine primary adipocytes, and proliferation, differentiation, and apoptosis were analyzed using EdU (5-ethynyl-2'-deoxyuridine) cell proliferation, cell counting kit-8, flow cytometry, TdT-mediated dUTP nick-end labeling apoptosis assay, Oil Red O staining, quantitative real-time PCR, and western blotting assays, which showed that circPPARγ facilitates adipocyte differentiation and inhibits proliferation and apoptosis. Dual-luciferase reporter assay and RNA immunoprecipitation assays indicated that circPPARγ binds miR-92a-3p and YinYang 1 (YY1). A novel regulatory pathway regulating adipogenesis and adipose deposition was revealed.

As an important part of the circadian rhythm, the circadian regulation factor 2 of cryptochrome (CRY2), regulates many physiological functions. Previous studies have reported that CRY2 is involved in growth and development. However, the relationship between CRY2 gene polymorphism and cattle carcass traits remains unclear. The aim of this study was to detect the possible variations of the CRY2 gene and elucidate the association between the CRY2 gene and carcass traits in the Shandong Black Cattle Genetic Resource (SDBCGR) population (n = 705). We identified a 24-bp deletion variation (CRY2-P6) and a 6-bp insertion variation (CRY2-P7) in the bovine CRY2 gene. The frequency of the homozygous II genotype is higher than the heterozygous ID genotype in both two loci. In addition, CRY2-P6 was consistent with HWE (p > 0.05). Importantly, the CRY2-P6 variant was significantly associated with 12 carcass traits, including gross weight, ribeye, high rib, thick flank, etc. and the II was the dominant genotype. The CRY2-P7 site was also significantly correlated with five traits (gross weight, beef-tongue, etc.). Collectively, these outcomes indicated that the two Indel loci in the CRY2 gene could be used for marker-assisted selection of cattle carcass traits.

The proliferation and differentiation of preadipocytes is an important factor determining bovine fat development, which is closely related to the feed conversion ratio, carcass traits, and beef quality. The purpose of this study was to identify the effects of candidate circRNA and miRNA on the proliferation and differentiation of bovine preadipocytes in order to provide basic materials for molecular breeding in cattle. circRNA sequencing was performed on bovine adipocyte samples at different differentiation time points, and a total of 1830 differentially expressed circRNAs were identified. Among them, circBDP1, derived from the bovine BDP1 gene, has potential binding sites for miR-204 (known as a regulator of bovine fat development) and miR-181b, which gives us a hint that circBDP1 may regulate bovine fat development by adsorbing miR-204 and miR-181b. Here, our results revealed that circBDP1 overexpression promoted the proliferation and differentiation of bovine preadipocytes. The miRNA profile of bovine adipocytes at different differentiation time points was also analyzed using the small RNA sequencing method, and a total of 89 differentially expressed miRNAs were identified, including miR-204 and miR-181b. As expected, dual-luciferase reporter results showed that circBDP1 competitively adsorbed miR-181b and miR-204. Overexpression and interference of miR-181b in bovine preadipocytes and 3T3-L1 showed that miR-181b promoted the proliferation and differentiation of preadipocytes. Further results displayed that miR-181b and miR-204 simultaneously targeted the SIRT1 gene, and miR-204 also targeted the 3' UTR region of the TRARG1 gene. In summary, this study found that miR-181b and miR-204 were involved in fat development by targeting SIRT1 and TRARG1. The results of this study will lay a foundation for the research of fat development and beef cattle industry.

Genome-wide association studies (GWAS) have identified DENND1A as a potential candidate gene linked to the fertility-related phenotypes in dairy cows. However, to date, no studies have examined the association of the DENND1A insertion/deletions (indels) to bovine fertility on a large scale. Herein, two indel sites, including P4-del-26-bp and P8-ins-15-bp were identified in 1064 Holstein cows. The values of the minor allelic frequency (MAF) ranged between 0.471 (deletion) and 0.230 (deletion), respectively, and combined four different haplotypes by analyzing the haplotype combination. It is noteworthy that P4-del-26-bp is associated with the ovarian width (P = 0.0004) and corpus luteum diameter (P = 0.004). Meanwhile, P8-ins-15-bp was found to have a significant association with the ovarian width (P = 0.020), ovarian weight (P = 0.004), the number of mature follicles (P = 0.020), and diameter of the mature follicles (P = 0.016). Furthermore, the combinatorial analysis showed that the two indel combined-genotypes were significantly related to several reproductive traits (ovarian width, ovarian weight, etc.). Collectively, our findings indicated that these two novel indels and their combinations are correlated with the reproductive traits, and hence, they can serve in the marker-assisted selection (MAS) in cattle breeding. Nevertheless, further functional experiments are needed for understanding the mechanisms of these indels in cattle reproduction in a better way.

The precise functions and molecular mechanisms of microRNAs (miRNAs) in adipocytes are primarily unknown. Studies have demonstrated that miR-193b plays a pivotal role in the differentiation of preadipocytes. Herein, we evaluated the effects of bta-miR-193b on the growth and development of adipocytes, using the EdU cell proliferation method, flow cytometry analysis, CCK-8 assay, RT-qPCR, Western blotting, and oil red O staining. We observed that the overexpression of bta-miR-193b significantly affected the differentiation, proliferation, and apoptosis of adipocytes. The results of the dual-fluorescent reporter vector experiments demonstrated that bta-miR-193b directly targeted Acyl-CoA synthetase short-chain family member 2 (ACSS2). Additionally, the effects of ACSS2 overexpression on the proliferation and apoptosis in adipose cells were the opposite of those induced by bta-miR-193b. We also demonstrated that ACSS2 can significantly promote the expression of AKT and pAKT proteins. Therefore, this study presents a novel mechanism by which bta-miR-193b regulates adipocyte development by targeting ACSS2.

The down syndrome cell adhesion molecule like 1 (DSCAML1), is associated with the development of the nervous system and neurologic diseases. Previous Genome-wide association studies have shown that it is associated with sperm morphology, suggesting it has a critical role in fecundity. In this study, expression profiles of goat DSCAML1 mRNA were analyzed. The results showed that its expression in the testis differ significantly between the mitotic stage and meiotic stage. Three insertion/deletion (indel) variants of goat DSCAML1 were determined in the Shaanbei White Cashmere Goat (SWCG, n = 2162). Based on the association analysis, two indels (P2-16bp, P14-15bp) were significantly related to sperm quality (sperm motility and sperm density) in male goat and three loci were markedly related to the first-birth litter size in female goat (P = 4.0 × 10-6; P = 1.0 × 10-6; P = 4.7 × 10-2). In male goats, the different genotypes of P2-16bp and P14-15bp revealed a noticeable effect on the expression of DSCAML1. Moreover, the effects observed in the first-birth litter followed a similar trend, which may provide the basis for further research of DSCAML1 gene function and marker assisted selection (MAS) programs to improve reproductive traits.

Transcriptome sequencing analyses have suggested that sperm associated antigen 17 protein gene (SPAG17) may play important regulating roles in litter size. In this study, the expression profiles and genetic variations of the SPAG17 were studied in Shaanbei White Cashmere (SBWC) goats (n=1567). SPAG17 was highly expressed in testis and ovary of SBWC goats. At different developmental stages, it also continued to be highly expressed in testis. In addition, two variations of SPAG17, one indel locus and one copy number variation locus, were significantly associated with first-born litter size. Joint analysis results suggested that two polymorphic loci of the SPAG17 gene may regulate host gene expression in goat ovary and testis. Overall, the results indicated the important role of SPAG17 in the reproductive process of goats.

Although many circular RNAs (circRNAs) and long non-coding RNAs (lncRNAs) have been discovered in adipocytes, their precise functions and molecular mechanisms remain poorly understood. Based on existing circRNA and lncRNA sequencing data of bovine adipocytes, we screened for the differential expression of circFLT1 and lncCCPG1 in preadipocytes and adipocytes and further analyzed their function and regulation during adipogenesis. The overexpression of circFLT1 and lncCCPG1 together facilitated adipocyte differentiation and suppressed proliferation. Computationally, the RNA hybrid showed that circFLT1 and lncCCPG1 had multiple potential binding sites with miR-93. Additionally, luciferase reporting experiments verified that circFLT1 and lncCCPG1 may interact with miR-93. We also demonstrated that overexpressed miR-93 effectively suppresses the expression of lncSLC30A9. Signaling pathway enrichment analysis, luciferase activity assay, and expression analysis revealed that lncSLC30A9 inhibits proliferation by inhibiting the expression of AKT protein and promotes differentiation by recruiting the FOS protein to the promoter of peroxisome proliferator-activated receptor gamma (PPARG). In sum, our results elucidate the regulatory mechanisms of circFLT1 and lncCCPG1 as miR93 sponges in bovine adipocytes.

Adipogenesis is closely related to human health, livestock growth, and meat quality. A previous study identified that bovinelncFAM200Bpromoter has high activity in 3T3-L1 mice preadipocytes. Thus,lncFAM200Bwas a candidate gene for regulating adipogenesis. This study aimed to uncover the role oflncFAM200Bin bovine adipogenesis and identify novel genetic variations within the bovinelncFAM200Bgene. An expression analysis found thatlncFAM200Bwas expressed higher in fat than that in muscle, but the difference was not related to the total methylation level of the promoter active region. Moreover, the expression oflncFAM200Bexhibited a significant positive correlation with the expression ofC/EBPaduring bovine adipocyte differentiation. To uncover the function oflncFAM200B, the full-lengthlncFAM200Bwas cloned, and four kinds of transcript variants were found. Protein-coding potential prediction and prokaryotic expression system analysis showed that these four transcript variants were noncoding RNAs. The quantitative reverse-transcription polymerase chain reaction and 5-ethynyl-2 '-deoxyuridine assay showed that the transcript variants decreased the messenger RNA expression ofCyclin D1and inhibited the proliferation of bovine preadipocytes. Considering the important role oflncFAM200Bin adipogenesis, we identified genetic variations inlncFAM200B. Three single-nucleotide polymorphisms (SNPs) were revealed, and two of them (SNP1 and SNP3) were associated with Nanyang cattle body measurement traits. In conclusion, this study found that bovinelncFAM200Binhibited preadipocyte proliferation, and two genetic variations oflncFAM200Bcould be used in cattle breeding.

Sperm-associated antigen 17 (SPAG17) gene encodes a multifunctional cytoplasmic protein, which influences not only reproduction but also skeletal development related body measurement traits, especially body height. Thus, this study aimed to identify crucial insertion-deletion (indel) variations, which influence the body measurement traits of goats in large goat populations (n = 1725). As a result, two intronic indels (14 bp and 17 bp indel) were identified by sequencing. For the two indel loci, the distributions of genotypes and alleles were significantly different between the Shaanbei white cashmere goat (SBWC) and the Hainan black goat (HNBG). In SBWC goats, the different genotypes of the 14 bp indel were markedly associated with goat body height, chest width, body length and chest depth. The genotypes of the 17 bp indel were significantly related to body height and chest width. At the two loci, for all seven analyzed traits of SBWC goat, the growth data of DD homozygotes were the worst, which means that the 14 bp insertion and the 17 bp deletion were beneficial and detrimental variations, respectively. Moreover, the combined genotypes were significantly related to body height and chest width of SBWC goats and ten traits of HNBG. These results suggested that the 14 and 17 bp indels within SPAG17 can be used in goat growth related traits marker-assisted selection breeding, especially body height.

Membrane-associated ring-CH-type finger 1 (MARCH1), which mediates the ubiquitination of CD86 and MHC class II proteins, plays crucial roles in ruminant fecundity. To completely explore the functions of MARCH1 in goat reproduction, the mRNA expression of this gene were investigated in different tissues of goats. Moreover, we analyzed the association of three insertions and deletions (indels) within MARCH1 with litter size in a large population of Shaanbei white cashmere goats (n = 2844). It showed that MARCH1 was expressed in all examined tissues, including the spleen, brain, lungs, liver, muscles, and testis, of 14- and 56-day-old male goats and in the ovary tissues of female goats. However, MARCH1 expression levels in the testis and lungs were significantly different between the 14- and 56-day-old male goats. Therefore, we examined MARCH1 expression levels in the testis of male goats belonging to different developmental age groups, i.e., 0-, 14-, 28-, 42-, and 56-day-old male goats. Our results indicated a potential association between MARCH1 expression and mitosis-to-meiosis transition. Furthermore, we identified three novel 7-, 15-, and 18-bp indels in MARCH1 in the Shaanbei white cashmere goat population. The presence of the three indels significantly affected MARCH1 expression in the testis and ovary. Statistical analyses indicated that these indels were associated with first-born litter size (P < 0.05). A significant difference was observed in the genotype distribution of the three indels between single- and multi-lamb female goats (P < 0.05). Together, these findings suggest that MARCH1 plays a crucial role in fertility and that the three novel indels in the goat MARCH1 can be used as effective molecular markers for marker-assisted selection of goats for breeding in the future.

Runt-related transcription factor 2 (Runx2) is characterized by its critical functions in osteoblastic and ovulatory processes. The goal of this study was to explore the insertion/deletion (indel) variants of this gene and to evaluate their association with productive traits. Herein, a 12?bp and 6?bp insertion within the Runx2 gene was uncovered in Shaanbei white cashmere goats (SBWC; n?=?1200). Chi-square analysis revealed that the 12?bp insertion was related to litter size (p?<?0.01). Further association analysis also found this insertion was significantly associated with litter size (p?=?1.1E-5). Interestingly, this insertion was also significantly associated with chest circumference (p?=?0.018). Additionally, the 6?bp insertion was associated with body length (p?=?0.003), chest width (p?=?0.011), and chest circumference (p?=?0.005). Furthermore, diplotype associations also uncovered that the combined genotypes of these two indels also significantly affected litter size and growth traits (p?<?0.05). These findings suggested that these two insertions within the Runx2 gene were significantly associated with reproduction and growth traits, which would make them beneficial functional DNA markers that can be used in goat breeding.

The paired-like homeodomain 2 (PITX2) gene plays a critical role in regulating development, reproduction, and growth traits in ruminants. Hence, the objective of this study was to explore the polymorphisms of this gene and to evaluate their associations with quantitative traits. Herein, a novel insertion in the promoter region of the PITX2 gene was reported in Shaanbei white cashmere (SBWC) goats (n = 1012). The genotype distributions between mothers of single-kid and multi-kid groups within SBWC goats were significantly different (P < 0.01), implying that this indel mutation might affect the litter size. Furthermore, association analysis found that this indel mutation was significantly associated with litter size (P = 0.001). Individuals with genotype DD had a significantly smaller litter size than those with other genotypes (P < 0.01). Besides, this indel was significantly associated with the body length (P = 0.042) and the chest width (P = 0.031). Especially, the individuals with genotype DD had a significantly lower body length than those with genotype II (P < 0.05), which was consistent with the trend in litter size. These findings suggested that the new 22 bp indel mutation within the PITX2 gene is significantly associated with litter size and growth traits; this can be utilized as a functional molecular marker in goat breeding.

DNA methylation (DNAm), a major element of epigenetics, plays critical roles in individual development. Reduced representation bisulfite sequencing (RRBS) is an effective and economical method for analyzing the DNA methylation of a single base. The aims of this study were to determine the DNAm profiles of the methylation contexts (CGs and non-CGs) of lactation and dry periods of goat mammary glands using the RRBS, and to identify potential milk-related genes. The proportion of CG was the highest among all the sequence contexts. The highest CG levels (72.44% to 75.24%) occurred in the 3' UTR region, followed by the gene body region (61.14% to 65.45%). The non-CG levels were low compared to the CG levels. Bioinformatic analysis demonstrated that the CGs were mainly enriched at high methylation levels (>90%), while non-CGs were enriched at low methylation levels. Methylation levels of 95 and 54 genes in the lactation period were up- or downregulated, respectively, relative to the dry period, such as PPARα, RXRα and NPY genes. The bisulfite sequencing PCR results showed that the methylation level of goat PPARα gene during the lactation period was significant lower than in the dry period, while the methylation level of the RXRα gene was lower in the dry period than in the lactation period. Meanwhile, the methylation levels of human PPARα and NPY genes were significantly higher in MCF-7 than in MCF-10A cells. These findings provide essential information for DNA methylation profiles of goat mammary gland and detect some potential milk-related genes in dairy goats.