The protein synthesised from the C/EBPβ gene interacts specifically with a C/EBP-recognition sequence and acts as a transcriptional activator. It plays a key role in lipometabolism and therefore is considered as a candidate gene for goose fat liver forming. In order to get the sequence, four pairs specificity primers were designed for amplification of C/EBPβ gene in Landes geese. The fragments of C/EBPβ gene in geese were obtained by PCR amplification and splicing. The length of the complete DNA sequence was 2130 bp (Genebank accession number GU068582), including the promoter regions and a 984 bp open reading frame coding 327 amino acid(aa) . High percentages of G and C nucleotides were found in the coding region and 5'flanking region comprising a CpG island. The corresponding mRNA is present at high levels in the liver and adipose tissue compared to others. This indicated that it was closely related with lipid metabolism. In liver, the expression of C/EBPβ mRNA was higher in geese overfed than that of control group (P<;0.01). Compared with the overfed groups, the geese that were fed the betaine supplemented diet showed the decreased expression on the transcriptive level in the livers.
MicroRNA-23a (miR-23a) is an endogenous small activating RNA (saRNA) involved in ovarian granulosa cell (GC) apoptosis and sow fertility by activating lncRNA NORHA transcription. Here, we reported that both miR-23a and NORHA were repressed by a common transcription factor MEIS1, which forms a small network regulating sow GC apoptosis. We characterized the pig miR-23a core promoter, and the putative binding sites of 26 common transcription factors were detected in the core promoters of both miR-23a and NORHA. Of them, transcription factor MEIS1 expression was the highest in the ovary, and widely distributed in various ovarian cells, including GCs. Functionally, MEIS1 is involved in follicular atresia by inhibiting GC apoptosis. Luciferase reporter and ChIP assays showed that transcription factor MEIS1 represses the transcription activity of miR-23a and NORHA through direct binding to their core promoters. Furthermore, MEIS1 represses miR-23a and NORHA expression in GCs. Additionally, MEIS1 inhibits the expression of FoxO1, a downstream of the miR-23a/NORHA axis, and GC apoptosis by repressing the miR-23a/NORHA axis. Overall, our findings point to MEIS1 as a common transcription repressor of miR-23a and NORHA, and develop the miR-23a/NORHA axis into a small regulatory network regulating GC apoptosis and female fertility.
Steroid receptor coactivator 1 (SRC-1) is the key coactivator because of its transcriptional activity. Previous studies have shown that SRC-1 is abundant in the hippocampus and has been implicated in cognition. SRC-1 is also related to some major risk factors for Alzheimer's disease (AD), such as a decline in estrogen and aging, however, whether SRC-1 is involved in the pathogenesis of AD remains unclear. In this study, we established SRC-1 knockout in AD mice by cross breeding SRC-1-/- mutant mice with APP/PS1 transgenic mice, and investigated the expression of some synaptic proteins, the amyloid β (Aβ) deposition, and activation of astrocytes and microglia in the hippocampus of APP/PS1×SRC-1-/- mice. The results showed that SRC-1 knockout neither affects the Aβ plaque and activation of glia, nor changes the expression of synaptic proteins in AD model mice. The above results suggest that the complete deletion of SRC-1 in the embryo exerts no effect on the pathogenesis of APP/PS1 mice. Nevertheless, this study could not eliminate the possible role of SRC-1 in the development of AD due to the lack of observation of other events in AD such as tau hyperphosphorylation and the limitation of the animal model employed.
Contents Follicle‐stimulating hormone receptor (FSHR) is an important G protein‐coupled receptor, which is required for steroidogenesis, follicular development and female infertility. Here, we report a novel polymorphism in the 3′‐UTR that strongly influences ovine FSHR mRNA decay. The partial 3′‐UTR sequence of Hu sheep FSHR gene was isolated and characterized, and a polymorphism (c.2327A>G) was identified. Luciferase assay and qRT‐PCR showed that c.2327A>G polymorphism in the 3′‐UTR exerts a strong regulatory role in FSHR transcription. This regulatory role is achieved by affecting FSHR mRNA decay. Furthermore, the c.2327A>G mutation in the 3′‐UTR influences ARE (AU‐rich element, a cis‐acting element promoting mRNA decay)‐mediated mRNA decay of Hu sheep FSHR gene. Together, our study identified a novel polymorphism and elucidated a new mechanism underlying transcriptional regulation of FSHR in mammals.
SMAD7 disrupts the TGF‐β signaling pathway by influencing TGFBR1 stability and by blocking the binding of TGFBR1 to SMAD2/3. In this study, we showed that SMAD7 attenuated the TGF‐β signaling pathway in ovarian granulosa cells (GCs) by regulating TGFBR1 transcriptional activity. To function as a transcription factor, SMAD7 downregulated the mRNA levels of TGFBR1 via direct binding to the SMAD‐binding elements (SBEs) within the promoter region of pig TGFBR1. We also showed that SMAD7 enhanced porcine GC apoptosis by interrupting TGFBR1 and the TGF‐β signaling pathway. Interestingly, miR‐181b, a microRNA that is downregulated during porcine follicular atresia, was identified to be directly targeting SMAD7 at its 3′‐UTR. By inhibiting SMAD7, miR‐181b could inhibit GC apoptosis by activating the TGF‐β signaling pathway. Our findings provide new insights into the mechanisms underlying the regulation of the TGF‐β signaling pathway by SMAD7 and miR‐181b.
microRNAs (miRNAs) are well known to be important in mammalian female fertility. However, the genetic regulation of miRNAs associated with female fertility remains largely unknown. Here, we report that two single-nucleotide variants (SNVs) in the miR-23a promoter strongly influence miR-23a transcription and function in granulosa cell (GC) apoptosis. Two novel SNVs, g.-283G>C and g.-271C>T, were detected in the porcine miR-23a promoter by pooled-DNA sequencing. Furthermore, SNVs in the promoter region influenced miR-23a transcription in porcine GCs by altering its promoter activity. Functionally, SNVs in the promoter strongly influenced miR-23a regulation of early apoptosis in porcine GCs cultured in vitro. In addition, a preliminary association analysis showed that the combined genotypes of the two SNVs, rather than a single SNV, were tentatively associated with sow fertility traits in a Large White population. Overall, our findings suggest that the SNVs g.-283G>C and g.-271C>T in the miR-23a promoter are causal variants affecting GC apoptosis and miR-23a may be a potential small-molecule nonhormonal drug for regulating female fertility.
Abstract Background Vasa is a member of the DEAD-box protein family that plays an indispensable role in mammalian spermatogenesis, particularly during meiosis. Bovine vasa homology ( Bvh ) of Bos taurus has been reported, however, its function in bovine testicular tissue remains obscure. This study aimed to reveal the functions of Bvh and to determine whether Bvh is a candidate gene in the regulation of spermatogenesis in bovine, and to illustrate whether its transcription is regulated by alternative splicing and DNA methylation. Results Here we report the molecular characterization, alternative splicing pattern, expression and promoter methylation status of Bvh . The full-length coding region of Bvh was 2190 bp, which encodes a 729 amino acid (aa) protein containing nine consensus regions of the DEAD box protein family. Bvh is expressed only in the ovary and testis of adult cattle. Two splice variants were identified and termed Bvh - V4 (2112 bp and 703 aa) and Bvh - V45 (2040 bp and 679 aa). In male cattle, full-length Bvh ( Bvh - FL ), Bvh - V4 and Bvh - V45 are exclusively expressed in the testes in the ratio of 2.2:1.6:1, respectively. Real-time PCR revealed significantly reduced mRNA expression of Bvh - FL , Bvh - V4 and Bvh - V45 in testes of cattle-yak hybrids, with meiotic arrest compared with cattle and yaks with normal spermatogenesis (P < 0.01). The promoter methylation level of Bvh in the testes of cattle-yak hybrids was significantly greater than in cattle and yaks (P < 0.01). Conclusion In the present study, Bvh was isolated and characterized. These data suggest that Bvh functions in bovine spermatogenesis, and that transcription of the gene in testes were regulated by alternative splice and promoter methylation.
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