Transcriptome analysis reveals steroid hormones biosynthesis pathway involved in abdominal fat deposition in broilers

Excessive abdominal fat deposition reduces the feed efficiency and increase the cost of production in broilers.Therefore,it is an important task for poultry breeders to breed broilers with low abdominal fat.Abdominal fat deposition is a highly complex biological process,and its molecular basis remains elusive.In this study,we performed transcriptome analysis to compare gene expression profiles at different stages of abdominal fat deposition to identify the key genes and pathways involved in abdominal fat accumulation.We found that abdominal fat weight(AFW)increased gradually from day 35(D35)to 91(D91),and then decreased at day 119(D119).Accordingly,after detecting differentially expressed genes(DEGs)by comparing gene expression profiles at D35 vs.D63 and D35 vs.D91,and identifying gene modules associated with fat deposition by weighted gene co-expression network analysis(WGCNA),we performed intersection analysis of the detected DEGs and WGCNA gene modules and identified 394 and 435 intersecting genes,respectively.The results of the Gene Ontology(GO)functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses showed that the steroid hormone biosynthesis and insulin signaling pathways were co-enriched in all intersecting genes,steroid hormones have been shown that regulated insulin signaling pathway,indicating the importance of the steroid hormone biosynthesis pathway in the development of broiler abdominal fat.We then identified 6 hub genes(ACTB,SOX9,RHOBTB2,PDLIM3,NEDD9,and DOCK4)related to abdominal fat deposition.Further analysis also revealed that there were direct interactions between 6 hub genes.SOX9 has been shown to bind to proteins required for steroid hormone receptor binding,and RHOBTB2 indirectly regulates the steroid hormones biosynthesis through cyclin factor,and ultimately affect fat deposition.Our results suggest that the genes RHOBTB2 and SOX9 play an important role in fat deposition in broilers,by regulating steroid hormone synthesis.These findings provide new targets and directions for further studies on the mechanisms of fat deposition in chicken.

Advances in Trehalose Biosynthesis Pathways and Application of Molecular Biology Technique

This paper aims to provide better guidance for construction of trehalose-producing recombinant strains to further improve the yield of trehalose. The research progress on trehalose biosynthesis pathways and the application of molecular biology technique in trehalose study in recent 30 years, especially the last 10 years are reviewed. Results show that there are 5 pathways of trehalose synthesis. Although enzymes and genes of trehalose synthesis have been isolated and genetic engineering strains have increased gradually, the improvement of trehalose yield is still inadequate because most recombinant strains are limited to study the physicochemical properties of single enzyme. With the development of modern biological technology, especially the rapid development of DNA recombinant technology, metagenomics and synthetic biology, high expression of heterologous trehalose in recombinant strains would become a hot research topic in the future.

Expression Profile Analysis of Genes Involved in Brassinosteroid Biosynthesis Pathway in Cotton Fiber Development

Cotton(Gossypium hirsutum L.) is the leading fiber crop and one of the mainstays of the economy in the world.Cotton fibers,as the main product of cotton plants,are unicellular,linear

Advances in the Plant Isoprenoid Biosynthesis Pathway and Its Metabolic Engineering

Although the cytosolic isoprenoid biosynthetic pathway, mavolonate pathway, in plants has been known for many years, a new plastidial 1–deoxyxylulose-5-phosphate (DXP) pathway was identified in the past few years and its related intermediates, enzymes, and genes have been characterized quite recently. With a deep insight into the biosynthetic pathway of isoprenoids, investigations into the metabolic engineering of isoprenoid biosynthesis have started to prosper. In the present article, recent advances in the discoveries and regulatory roles of new genes and enzymes in the plastidial isoprenoid biosynthesis pathway are reviewed and examples of the metabolic engineering of cytosolic and plastidial isoprenoids biosynthesis are discussed.

Transcriptome analysis to identify candidate genes related to chlorogenic acid biosynthesis during development of Korla fragrant pear in Xinjiang

Korla fragrant pear(KFP)with special fragrance is a unique cultivar in Xinjiang,China.In order to explore the biosynthesis molecular mechanism of chlorogenic acid(CGA)in KFP,the samples at different development periods were collected for transcriptome analysis.High performance liquid chromatography analysis showed that CGA contents of KFP at 88,118 and 163 days after full bloom were(20.96±1.84),(12.01±0.91)and(7.16±0.41)mg/100 g,respectively,and decreased with the fruit development.Pears from these typical 3 periods were selected for de novo transcriptome assemble and 68059 unigenes were assembled from 444037960 clean reads.One‘phenylpropanoid biosynthesis’pathway including 57 unigenes,11 PALs,1 PTAL,64CLs,9 C4Hs,25 HCTs and 5 C3’Hs related to CGA biosynthesis was determined.It was found that the expression levels of 11 differentially expressed genes including 1 PAL,2 C4Hs,34CLs and 5 HCTs were consistent with the change of CGA content.Quantitative polymerase chain reaction analysis further showed that 8 unigenes involved in CGA biosynthesis were consistent with the RNA-seq data.These findings will provide a comprehensive understanding and valuable information on the genetic engineering and molecular breeding in KFP.

Genome Sequence of a Marine Carotenoid Producing Yeast Rhodotorula mucilaginosa CYJ03

Carotenoids are valuable pigments that have been widely used in food,pharmaceutical,animal breeding and cosmetics industries.Due to the increasing demand for carotenoids of natural origin,the trend for production of carotenoids by red yeast has become popular.Strain Rhodotorula mucilaginosa CYJ03 was isolated from northern Yellow Sea of China for its carotenoid producing potential.It was found that the whole genome of CYJ03 was 19.03 Mb in size and contained 6301 protein-coding genes including a gene cluster for the carotenoids biosynthesis.The genome sequence would be valuable for exploring the potential biological properties of CYJ03,as well as for facilitating the molecular genetic analysis and the manipulation of carotenoids accumulation in this strain,and for the development of it as an engineered host for carotenoid production.

Heterologous biosynthesis of medicarpin using engineered Saccharomyces cerevisiae

Medicarpin is an important bioactive compound with multiple medicinal activities,including anti-tumor,anti-osteoporosis,and anti-bacterial effects.Medicarpin is associated with pterocarpans derived from medicinal plants,such as Sophora japonica,Glycyrrhiza uralensis Fisch.,and Glycyrrhiza glabra L.However,these medicinal plants contain only low amounts of medicarpin.Moreover,the planting area for medicarpin-producing plants is limited;consequently,the current medicarpin supply cannot meet the high demands of medicinal markets.In this study,eight key genes involved in medicarpin biosynthesis were identified using comparative transcriptome and bioinformatic analyses.In vitro and in vivo enzymatic reaction confirmed the catalytic functions of candidate enzymes responsible for the biosynthesis of medicarpin and medicarpin intermediates.Further engineering of these genes in Saccharomyces cerevisiae achieved the heterologous biosynthesis of medicarpin using liquiritigenin as a substrate,with a final medicarpin yield of 0.82±0.18 mg/L.By increasing the gene copy numbers of vestitone reductase(VR)and pterocarpan synthase(PTS),the final medicarpin yield was increased to 2.05±0.72 mg/L.This study provides a solid foundation for the economic and sustainable production of medicarpin through a synthetic biology strategy.

Terpenoid Indole Alkaloids Biosynthesis and Metabolic Engineering in Catharanthus roseus

Catharanthus roseus L. （Madagascar periwinkle） biosynthesizes a diverse array of secondary metabolites including anticancer dimeric alkaloids （vinblastine and vincristine） and antihypertensive alkaloids （ajmalicine and serpentine）. The multi-step terpenoid indole alkaloids （TIAs） biosynthetic pathway in C. roseus is complex and is under strict molecular regulation. Many enzymes and genes involved in the TIAs biosynthesis have been studied in recent decades. Moreover, some regulatory proteins were found recently to control the production of TIAs in C. roseus. Based on mastering the rough scheme of the pathway and cloning the related genes, metabolic engineering of TIAs biosynthesis has been studied in C. roseus aiming at increasing the desired secondary metabolites in the past few years. The present article summarizes recent advances in isolation and characterization of TIAs biosynthesis genes and transcriptional regulators involved in the second metabolic control in C. roseus. Metabolic engineering applications in TIAs pathway via overexpression of these genes and regulators in C. roseus are also discussed.

Metabolic Engineering of Tropane Alkaloid Biosynthesis in Plants

Abstract: Over the past decade, the evolving commercial importance of so-called plant secondary metabolites has resulted in a great interest in secondary metabolism and, particularly, in the possibilities to enhance the yield of fine metabolites by means of genetic engineering. Plant alkaloids, which constitute one of the largest groups of natural products, provide many pharmacologically active compounds. Several genes in the tropane alkaloids biosynthesis pathways have been cloned, making the metabolic engineering of these alkaloids possible. The content of the target chemical scopolamine could be significantly increased by various approaches, such as introducing genes encoding the key biosynthetic enzymes or genes encoding regulatory proteins to overcome the specific rate-limiting steps. In addition, antisense genes have been used to block competitive pathways. These investigations have opened up new, promising perspectives for increased production in plants or plant cell culture. Recent achievements have been made in the metabolic engineering of plant tropane alkaloids and some new powerful strategies are reviewed in the present paper.

Molecular and Biochemical Evidence for Phenylpropanoid Synthesis and Presence of Wall-linked Phenolics in Cotton Fibers

The mature cotton （Gossypium hirsutum L.） fiber is a single cell with a typically thickened secondary cell wall. The aim of this research was to use molecular, spectroscopic and chemical techniques to investigate the possible occurrence of previously overlooked accumulation of phenolics during secondary cell wall formation in cotton fibers. Relative quantitative reverse transcription-polymerase chain reaction analysis showed that GhCAD6 and GhCAD1 were predominantly expressed among seven gene homologs, only GhCAD6 was up-regulated during secondary wall formation in cotton fibers. Phylogenic analysis revealed that GhCAD6 belonged to Class I and was proposed to have a major role in monolignol biosynthesis, and GhCAD1 belonged to Class III and was proposed to have a compensatory mechanism for monolignol biosynthesis. Amino acid sequence comparison showed that the cofactor binding sites of GhCADs were highly conserved with high similarity and identity to bona fide cinnamyl alcohol dehydrogenases. The substrate binding site of GhCAD1 is different from GhCAD6. This difference was confirmed by the different catalytic activities observed with the enzymes. Cell wall auto-fluorescence, Fourier transform infrared spectroscopy （FTIR）, high-performance liquid chromatography （HPLC） and chemical analyses confirmed that phenolic compounds were bound to the cell walls of mature cotton fibers. Our findings may suggest a potential for genetic manipulation of cotton fiber properties, which are of central importance to agricultural, cotton processing and textile industries.

Targeting whole body metabolism and mitochondrial bioenergetics in the drug development for Alzheimer’s disease

Aging is by far the most prominent risk factor for Alzheimer’s disease(AD),and both aging and AD are associated with apparent metabolic alterations.As developing effective therapeutic interventions to treat AD is clearly in urgent need,the impact of modulating whole-body and intracellular metabolism in preclinical models and in human patients,on disease pathogenesis,have been explored.There is also an increasing awareness of differential risk and potential targeting strategies related to biological sex,microbiome,and circadian regulation.As a major part of intracellular metabolism,mitochondrial bioenergetics,mitochondrial quality-control mechanisms,and mitochondria-linked inflammatory responses have been considered for AD therapeutic interventions.This review summarizes and highlights these efforts.

Extensive sequence divergence between the reference genomes of Taraxacum kok-saghyz and Taraxacum mongolicum

Plants belonging to the genus Taraxacum are widespread all over the world,which contain rubber-producing and non-rubberproducing species.However,the genomic basis underlying natural rubber(NR)biosynthesis still needs more investigation.Here,we presented high-quality genome assemblies of rubber-producing T.kok-saghyz TK1151 and non-rubber-producing T.mongolicum TM5.Comparative analyses uncovered a large number of genetic variations,including inversions,translocations,presence/absence variations,as well as considerable protein divergences between the two species.Two gene duplication events were found in these two Taraxacum species,including one common ancestral whole-genome triplication and one subsequent round of gene amplification.In genomes of both TK1151 and TM5,we identified the genes encoding for each step in the NR biosynthesis pathway and found that the SRPP and CPT gene families have experienced a more obvious expansion in TK1151 compared to TM5.This study will have large-ranging implications for the mechanism of NR biosynthesis and genetic improvement of NR-producing crops.

Differentially Expressed Genes in Heads and Tails of Angelica Sinensis diels： Focusing on Ferulic Acid Metabolism

Objective： To explore the scientific connotation of the discrepant pharmaceutical activities between the head and tail of Angelica sinensis diels（AS）, an important herb extensively utilized in Chinese medicine, by the approach of transcriptome sequencing. Methods： Ten samples of AS were randomly collected in Min County, Gansu Province of China. Transcriptome sequencing of AS was accomplished in a commercial ILLumina Hi Seq-2000 platform. The transcriptome of each head and tail of AS were fixed in a gene chip, and detected under the procedure of Illumina Hi Seq-2000. Differentially expressed unigenes between the heads and tails of AS were selected by Shanghai Biotechnology Corporation（SBC） online analysis system, based on Gene Ontology, Kyoto Encyclopedia of Genes and Genomes and relevant bioinformatic database. Results： Totally 63,585 unigenes were obtained from AS by high-throughput sequencing platform. Among which 3359 unigenes were identified as differentially expressed unigenes between the heads and tails of AS by SBC analysis system scanning. Of which 15 differentially expressed unigenes participate in the metabolic regulation of phenylpropanoid biosynthesis（PB） pathway and ferulic acid metabolites, in response to the distinguished pharmaceutical actions of the heads and tails of AS. Conclusion： Different content of ferulic acid in the heads and tails of AS is related to the differentially expressed genes, particularly involved in the PB pathway.