Genomic imprinting is a mechanism of differentially epigenetic modification that restricts monoallelic expression to either the maternally or paternally inherited copy of the gene during gametogenesis. Imprinted methylation undergoes a process of erasure, acquisition, and maintenance during gametogenesis and early embryogenesis. Disruptions in any of these steps may lead to imprinting disorders, resulting in the aberrant development of embryogenesis, placentation and postnatal growth. Recent studies have shown that maternal-effect proteins are important for the regulation of imprinted gene during the development of preimplantation embryos. In order to obtain a better understanding for the mechanism of maternal-effect proteins in the maintenance of genomic imprints, the recent study progress of maternal-effect proteins, such as DPPA3, ZFP57, TRIM28 and DNMT1, are summarized, and the regulation mechanism of these maternal-effect proteins for genomic imprints are discussed.
Purpose: Age-related increase in myelin loss may be responsible for brain atrophy, and the mechanism is not completely understood. We aim to comprehensively delineate oligodendrocyte heterogeneity in young and aged mice and to reveal the underlying mechanism for myelin loss during aging. Methods: Diffusion tensor imaging and immunofluorescent staining were performed to verify the demyelination in the aged brains of both rodents and human. Further, the single-cell RNA sequencing data of all brain cells from young and aged mice were deeply analyzed to identify the subsets of oligodendrocyte lineage cells. Cell-to-cell interaction analysis was performed to detect the mechanism of observed changes in oligodendrocyte generation. Results: Oligodendrocytes were observed to up-regulate several senescence associated genes in aged brain. Four clusters of oligodendrocyte precursor cells (OPCs) were identified in both young and aged brains. The number of those OPCs in basal state was significantly increased, while the OPCs in the procedure of differentiation were immensely decreased in aged brain. Furthermore, it was identified that activated microglia in the aged brain released inflammatory factors to suppress OPC differentiation. Stat1 might be a potential target to transform senescent microglia into tissue repair type to promote oligodendrocyte generation. Conclusion: These results provided a perspective on how age activated microglia could impede remyelination and might give a new therapeutic target for age-related remyelinating diseases. Keywords: remyelination, oligodendrocyte precursor cells, microglia, oligodendrocytes, single cell RNA sequencing
This study was conducted to investigate the effections of in ovo injection with Newcastle disease vaccine combined with Astragalus polysaccharide on the mucosal immunity of jejunum. Four hundred fertilized eggs were randomly divided into four groups (n=100/group), and embryonic immunization with solutions of APS, ND vaccine, ND vaccine combined with APS, and 0.9% physiological saline into their amniotic fluid on d 18.5 of incubation. Significant improvement of the mucosal immunity of jejunum was displayed in those vaccinated with ND vaccine combined with APS, manifested as enhanced villus height and the ratio of villus height to crypt depth. Moreover, chicks immunized with ND vaccine plus APS significantly elevated the levels of slgA in the jejunum during the embryonic period. Overall results indicated embryonic immunization with ND vaccine combined with APS could stimulate stronger humoral immunity in the jejunum of newly hatched chicks.
In this study, the effects of synbiotic inclusion at the intra-amniotic stage in layer chicks were evaluated with different parameters, such as performance, immunological function, intestinal development, and cecal microflora content. A total of 1,200 eggs with fertile embryos were allocated into four treatment groups. For every treatment, five replicates were used, and 60 eggs were included in each replicate. The following four treatment groups were established: the non-injected group, 0.9% physiological saline injection (saline) group, 1 × 10 6 CFU/egg Lactobacillus plantarum injection (probiotic) group, and 1 × 10 6 CFU/egg L. plantarum + 2 mg/egg Astragalus polysaccharide injection (synbiotic) group. In ovo injection was carried out at 18.5 days of incubation. The results showed that in ovo injection of probiotics or synbiotics did not affect the hatching or growth performance of the chicks but significantly increased their feed intake (FI), body weight (BW), and the feed conversion ratio (FCR). Additionally, in ovo injection of synbiotics enhanced the levels of serum interleukin-2 (IL-2), interferon-γ (IFN-γ), and secretory immunoglobulin A (SIgA) in intestinal lavage fluid and the histomorphological development of the small intestine. Our results also indicated that intra-amniotic synbiotic injection significantly increased Lactobacillus and Bifidobacterium colonization while decreasing the relative abundance of Escherichia coli in the chicken cecum ( P < 0.05). In summary, in ovo injection of synbiotics had positive impacts on the performance, immunological function, gut development, and microbiota of growing chicks.
Abstract Backgroud: Newcastle disease virus (NDV) is considered one of the most important diseases among chickens. In this study, we generated recombinant surface-displayed Lactobacillus casei ( L.casei ) expressing the hemagglutinin-neuraminidase (HN) of NDV and a live vector pPG alone (named Lc-pPG-HN and Lc-pPG), and evaluated their effects on early growth development, intestinal health and protection against NDV challenge in chickens. 270 chickens were randomly divided into three groups: Lc-pPG-HN, Lc-pPG and physiological saline (control) group, and chickens from each group were respectively immunized with Lc-pPG-HN, Lc-pPG and physiological saline on 1 and 10 days. Results : Recombinant L.casei expressing the HN protein of NDV (Lc-pPG-HN) was successfully constructed. Orally immunized with Lc-pPG-HN could significantly increase body weight (BW) and immune organs index. Moreover, Lc-pPG-HN improved secretory immunoglobulin A (SIgA) in jejunum, the relative abundance of flora in cecum, histomorphological development of small intestine. In addition, the similar enhancement effects were also observed with hemaggluti-nation inhibition (HI) antibody titer and the expression of cytokines in the serum. The oral administration of Lc-pPG-HN also provided effective protection and alleviated the symptoms of NDV challenge. Conclusions: Thus, a recombinant L.casei vaccine expressing HN may be a potential therapeutic candidate against NDV and improve chickens growth and development.
Spitz nevus (SN) is a benign melanocytic lesion with cytologic and architectural atypia. It is sometimes difficult to distinguish SNs from atypical Spitz tumor (AST), Spitz melanoma, or conventional melanoma. SNs frequently develop in Caucasians and appear on the skin of the head and lower extremities. Lesions on the ear in Asian populations are rare. Here, we report a "red Spitz tumor" on the ear of a Chinese 18-year-old boy. Dermoscopic examination revealed possibly malignant features presented as polymorphous vessels along with central white area, pseudo-network depigmentation and atypical peripheral globular pattern. The results of histopathological examination strongly suggested that the neoplasm was a compound SN and no recurrences or metastases occurred during 1-year follow-up post-surgery. Further, we review the literature on 4 previously reported cases of SN on the ear and summarize the main points of SN diagnosis and differential diagnosis with atypical Spitz tumors and melanoma.
The lysine is considered as the most important essential amino acid, because it is the most limiting in the cereals grains. In this study, a lysine-rich (LR) gene, and the expression vector pcDNA3.1-LR and pBC1-LR were constructed. The LR was expressed in 293T cells driven by the vector pcDNA3.1-LR and checked by RT-PCR and WB. The mammary gland tissue-specific expression vector carrying the LR was injected directly into the lactating mammary glands of cows and the milk samples were checked by a complete amino acid analysis. The results showed that the LR protein was expressed successfully in cells and in cow milk; the expression of LR lasted for 6 d, and the lysine level of the injection group was significantly higher than that of negative controls (p Lass Than 0.05). This study provide a better understanding of how mammary gland expression systems increase the lysine content of milk that can be applied to transgenic dairy cow.
Summary TRIM28/KAP1/TIF1β was identified as a universal transcriptional co-repressor and is critical for regulating post-fertilization methylation reprogramming in preimplantation embryos. In this study, three siRNAs (si647, si742, and si1153) were designed to target the TRIM28 mRNA sequence. After transfection of the mixture of the three siRNA (siMix) into bovine fibroblast cells, the most effective one for TRIM28 knockdown was selected. By injecting RNAi directed against TRIM28 mRNA, we found that TRIM28 knockdown in oocytes had the most effect on the H19 gene, in which differentially methylated region (DMR) methylation was almost completely absent at the 2-cell stage (1.4%), while control embryos showed 74% methylation. In addition, global H3K9me3 levels at the 2-cell stage were significantly higher in the in vitro fertilization (IVF) group than in the TRIM28 knockdown group ( P <0.05). We further show that TRIM28 is highly expressed during oocyte maturation and reaches peak levels at the 2-cell stage. In contrast, at this stage, TRIM28 expression in somatic cell nuclear transfer (SCNT) embryos decreased significantly ( P <0.05), suggesting that Trim28 transcripts are lost during SCNT. TRIM28 is required for the maintenance of methylation imprints in bovine preimplantation embryos, and the loss of TRIM28 during SCNT may contribute to the unfaithful maintenance of imprints in cloned embryos.
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