Functional analysis of differentially expressed circular RNAs in sheep subcutaneous fat.

BACKGROUND: Circular RNAs (circRNAs), as important non-coding RNAs (ncRNAs), are involved in many biological activities. However, the exact chemical mechanism behind fat accumulation is unknown. In this paper, we obtained the expression profiles of circRNAs using high-throughput sequencing and investigated their differential expression in subcutaneous fat tissue of Duolang and Small Tail Han sheep. RESULTS: From the transcriptomic analysis, 141 differentially expressed circRNAs were identified, comprising 61 up-regulated circRNAs and 80 down-regulated circRNAs. These host genes were primarily enriched in the MAPK and AMPK signaling pathways which is closely associated with fat deposition regulation. We identified circRNA812, circRNA91, and circRNA388 as vital genes in fat deposition by miRNA-circRNA target gene prediction. The functional annotation results of target genes of key circRNAs showed that the signaling pathways mainly included PI3K-Akt and AMPK. We constructed the competing endogenous RNA (ceRNA) regulatory network to study the role of circRNAs in sheep lipid deposition, and circRNA812, circRNA91, and circRNA388 can adsorb more miRNAs. NC_040253.1_5757, as the source of miRNA response element (MRE) among the three, may play an important role during the process of sheep fat deposition. CONCLUSIONS: Our study gives a systematic examination of the circRNA profiles expressed in sheep subcutaneous fat. These results from this study provide some new basis for understanding circRNA function and sheep fat metabolism.

Identification of differentially expressed genes between subcutaneous and intramuscular adipose tissue of Large White pig using RNA-seq.

To explore the molecular mechanisms of lipid accumulation in different types of adipose tissue, the transcriptomes of the subcutaneous and intramuscular adipose tissues from the Large White pig were determined using RNA-seq technology and bioinformatics methods. The differential gene expression profiles were identified and analyzed with the Gene Ontology, KEGG pathway and protein-protein interaction network strategies. There were 180 differentially expressed genes between the two adipose tissues. The genes up-regulated in the subcutaneous, as compared to intramuscular, adipose tissues were mainly involved in the biological processes related to lipid metabolism. The down-regulated genes were significantly enriched in MAPK signaling pathway, suggesting that this signaling pathway could have an important regulatory role(s) in adipocyte differentiation. In summary, differentially expressed genes between the subcutaneous and intramuscular adipose tissues were predominantly involved in lipid metabolism/accumulation and regulation of adipogenesis in the Large White pig.

Multiple rescattering processes in high-order harmonic generation from molecular system.

The molecular multiple rescattering processes have been theoretically investigated via solving the time-dependent Schrödinger equation. Not only has the physical model been established, but also the related rescatterings originating from recombination with parent nucleus and with neighboring nucleus have been distinguished. Moreover, it has shown that the rescatterings originating from recombination with parent nucleus are similar with those atomic rescatterings, while those rescatterings from recombination with neighboring nucleus both before and after reversing the direction of the laser field are more sensitive to the internuclear distance. With time-frequency distribution and classical electron dynamics, the underlying mechanisms are revealed.

[MicroRNAs in the regulation of brown adipocyte differentiation].

MicroRNAs (miRNAs), a class of endogenous non-coding RNA about 22 nucleotide long, regulate gene expression at the post-transcription level by inhibiting the translation or inducing the degradation of their target mRNAs in organisms. There are two types of adipose tissues: brown and white. White adipose tissues store energy in the form of triglycerides (TGs), while brown adipose tissues catabolize TGs to generate energy. Brown adipose tissues are of great importance to the research of obesity and related metabolic diseases due to their function of preventing people from obesity. A lot of studies have revealed that miRNAs play crucial roles in regulating brown adipocyte differentiation and are modulated by lots of transcription factors and environmental factors, which form a complex regulatory network maintaining the homeostasis of adipose tissues. In this review, we summarize the latest studies of miRNAs in brown adipocyte differentiation, which might provide new strategies for the treatment of obesity and other related diseases.

Genome-Wide Analysis of microRNAs Identifies the Lipid Metabolism Pathway to Be a Defining Factor in Adipose Tissue From Different Sheep.

microRNAs are a class of important non-coding RNAs, which can participate in the regulation of biological processes. In recent years, miRNA has been widely studied not only in humans and mice, but also in animal husbandry. However, compared with other livestock and poultry breeds, the study of miRNA in subcutaneous adipose tissue of sheep is not comprehensive. Transcriptome analysis of miRNAs in subcutaneous adipose tissue of Duolang sheep, and Small Tail Han sheep was performed using RNA-Seq technology. Differentially expressed miRNAs were screened between different breeds. Target genes were predicted, and then the joint analysis of candidate genes were conducted based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. Finally, the RNA-Seq data were verified by real-time quantitative polymerase chain reaction (qRT-PCR). Herein, we identified 38 differentially expressed miRNAs (9 novel miRNAs and 29 known miRNAs). In addition, a total of 854 target genes were predicted by miRanda software. GO and KEGG pathway analysis demonstrated that regulation of lipolysis in adipocytes plays a key role in the deposition of subcutaneous adipose tissue in Duolang sheep and Small Tail Han sheep. The miRNAs might regulate fat deposits by regulating genes involved in regulation of lipolysis in adipocytes. Specifically, NC_ 040278.1_ 37602, oar-mir-493-3p, NC_ 040278.1_ 37521 and NC_ 040255.1_ 11627 might target PTGS2, AKT2, AKT3, and PIK3CA, respectively, and then play critical regulatory role. In conclusion, all the results provide a good idea for further revealing the mechanism of subcutaneous adipose tissue deposition and improving the meat production performance of sheep, and lay a foundation for promoting the development of animal husbandry.

Production of transgenic mice carrying the Thanatin gene by intratesticular injection.

Transgenic animals have potential applications in medicine, life sciences, and biopharmacy. In this study, we developed a convenient, economic, and efficient method for gene transfer by transfection of male spermatogonial stem cells. Three fragments of the Thanatin gene, encoding an antibacterial peptide, were synthesized and amplified by overlap extension polymerase chain reaction (PCR). They were inserted into vector pIRES2-EGFP. The pIRES2-EGFP-Thanatin plasmid was mixed with liposomes and injected into the testes of male mice by a minimally invasive operation. Six weeks after injection, male mice were mated with normal female mice to produce an F1 generation. PCR and Southern blotting were performed to analyze F1 mice. Among those 52 F1 mice produced, 38.46% were found to be positive for the Thanatin gene by PCR and 30.77% by Southern blotting. Six positive mice were selected from the F1 generation and mated with normal females to an F2 generation, in which 36.36% were found to be positive for the Thanatin gene. Expression of the green fluorescence protein in the transgenic mice was confirmed by fluorescence imaging. These results showed that the Thanatin gene was integrated into the mouse genome. The study provides a useful method for the future development of disease-resistant animals and production of antibacterial peptides through transgenic animals.

[An update on the development of transgenic animal technology].

The animal transgenic technology has increasingly turned mature over several decades and promoted the research of transgenic technology to a new developmental phase. In this review, various kinds of transgenic technologies, including somatic cell nuclear transfer, gene transfer mediated by transposon, gene knockout mediated by RNA interference, and zinc-finger nucleases-gene targeting technology, are summarized. Recently, the success of induced pluripotent stem cells (iPS cells), which has provided an alternative way to derive pluripotent stem cells of large animals, will extend the field of transgenic animal studies. Here, we summarized the latest trends on the basis of previous studies. In addition, the characteristics of different kinds of transgenic methods in detail are discussed.

[Current progress and application prospects of induced pluripotent stem cells].

Induced pluripotent stem (iPS) cells can be directly generated from somatic cells by transduction of a few defined transcription factors. This technique avoids immunological rejection and ethical difficulties, which is a great revolution in life sciences. Like embryonic stem (ES) cells, iPS cells have the ability to self-renew through mitotic cell division and thus remain in its undifferentiated state and the ability to differentiate into not only all derivatives of the three primary germ layers: ectoderm, endoderm, and mesoderm, but also many mature cells in vitro. Therefore, iPS cells are important for theoretic study and therapeutic application. Here, we discuss recent advances in generating induced pluripotent stem cells, different reprogramming methods, and clinical applications of iPS cells. Finally, current problems of iPS cells and its prospects in transgenic animals are also discussed. This article is a summary of current research advances in reprogramming cells into induced pluripotent stem cells.

[New advances in animal transgenic technology].

Animal transgenic technology is one of the fastest growing biotechnology in the 21st century. It is used to integrate foreign genes into the animal genome by genetic engineering technology so that foreign genes can be expressed and inherited to the offspring. The transgenic efficiency and precise control of gene expression are the key limiting factors on preparation of transgenic animals. A variety of transgenic techniques are available, each of which has its own advantages and disadvantages and still needs further study because of unresolved technical and safety issues. With the in-depth research, the transgenic technology will have broad application prospects in the fields of exploration of gene function, animal genetic improvement, bioreactor, animal disease models, organ transplantation and so on. This article reviews the recently developed animal gene transfer techniques, including germline stem cell mediated method to improve the efficiency, gene targeting to improve the accuracy, RNA interference (RNAi)-mediated gene silencing technology, and the induced pluripotent stem cells (iPS) transgenic technology. The new transgenic techniques can provide a better platform for the study of trans-genic animals and promote the development of medical sciences, livestock production, and other fields.

[Screening and identification of differentially expressed genes in Beijing fatty and broiler breast muscles].

mRNA differential display reverse-transcripton PCR(DDRT-PCR) was applied to identify differentially expressed genes in Arbor Acres broiler(AA) and Beijing fatty chicken breast muscles in order to find the mechanism which induces the differential gene expression at the molecular level. A total of 7 ESTs were found using reverse Northern dot blot, and all of them were compared with the nucleotide sequences in GenBank database using BLAST. S1 was highly similar to HMGN3; S3 was highly similar to ChEST294a8 with unknown functions; S4 and S5 were highly similar to PGM; S6 and S2 had highly similar nucleotide sequences with unknown functions in nucleotide databases; S7 had no significant similarity with existing genes or ESTs and was regarded as a new EST. The new EST was submitted to GenBank(Accession number: EU594549). This lays a foundation for further study on the mechanism of differential gene expression in Beijing fatty and AA breast muscles.

[Advances in the expression and regulation of MnSOD gene].

MnSOD, which is an important oxygen free radical scavenger in organisms, has an effect to resist oxidative stress and tumor. The expression and regulation of MnSOD gene is a complicated process, which includes many kinds of transcription factors, cell signal molecules and cell signal pathways. It refers to three aspects including transcription regulation, post-transcription regulation and translation regulation. Transcription regulation is the primary step for MnSOD gene expression and plays a key role during the expression of MnSOD gene. The activity of transcription factors, which controls MnSOD gene expression, such as SP-1, AP-2, AP-1, NF-kB and so on, can be changed in the course of transcription regulation. Drugs and metalions can also affect those transcription factors' activity. Furthermore some genes mutation and depletion also have an influence on the activity of those transcription factors. Post-transcription regulation is in a way of changing the stability of mRNA and its translation. Translation regulation is a process to regulate edition, modification, binding to metalion and site-specific of MnSOD polypeptide. Recently a kind of manganese trafficking factor for mitochondrial MnSOD called MTMl which is very important for activation of MnSOD has been discovered. Here, we review the advances in this field with an emphasis on transcription regulation and translation regulation of MnSOD gene. And at last, we discussed the prospect of MnSOD gene expression and regulation.

Monitoring the electron dynamics of the excited state via higher-order spectral minimum.

A pump-probe scheme for monitoring the electron dynamics of the excited state has been investigated by numerically solving the two-state time-dependent Schrödinger equation based on the non-Born-Oppenheimer approximation. By adjusting the delay time between a mid-infrared probe pulse and an ultra violet pump pulse, an obvious minimum can be seen in the higher-order harmonic region. With electron probability density distribution, ionization rate and classical simulation, the minimum can be ascribed to the electron localization around one nucleus at larger delay time and represents the electron dynamics of the excited state at the time of ionization. Moreover, the position of the minimum is much more sensitive to the nuclear motion.