Metabolic and Transcriptomic Responses of Weaned Pigs Induced by Different Dietary Amylose and Amylopectin Ratio

Starch is one of the major dietary energy sources for mammals. However, the nutritional value of starch largely depends on its amylose and amylopectin ratio. In this study, the overall metabolic and transcriptomic responses of weaned pigs fed with different dietary starches were assessed. Sixteen weaned pigs were randomly allotted to two experimental diets containing either of pure cassava starch (CS) or maize starch (MS) as the sole energy source (the amylose-amylopectin ratio were 0.25 and 0.43, respectively). Results indicated that the body weight gain was not affected by different dietary starches. However, a moderate fatty liver was observed in CS-fed group. Long-term ingestion of CS not only increased the total liver fat content, but significantly elevated the liver triglyceride and cholesterol content (P<0.05). In addition, the serum insulin and cholesterol concentrations were both elevated in CS-fed group (P<0.05). Microarray analysis led to the identification of 648 genes differentially expressed in liver (P<0.05), and a lot of them were involved in lipid and carbohydrate metabolism. Additionally, pathway analysis indicated that both the insulin and PPAR signaling pathways were acutely affected by dietary amylose-amylopectin ratio. Long-term ingestion of CS activated the transcription of lipogenic genes such as hmgr and fasn, but decreased the expression of lipolytic genes such as aox1, ppara and fbp. The microarray results correlated well with the measurements of several key enzymes involved in hepatic lipid metabolism. Our results suggested that both the metabolic and transcriptomic responses of weaned pigs were tightly regulated by dietary starch composition, and a high amylose ratio starch (i.e MS) may be more healthful for mammals as the long-term energy source by down-regulation of hepatic lipogenesis and steroidogenesis

Expression of endo-1, 4-beta-xylanase from Trichoderma reesei in Pichia pastoris and functional characterization of the produced enzyme

<p>Abstract</p> <p>Background</p> <p>In recent years, xylanases have attracted considerable research interest because of their potential in various industrial applications. The yeast <it>Pichia pastoris </it>can neither utilize nor degrade xylan, but it possesses many attributes that render it an attractive host for the expression and production of industrial enzymes.</p> <p>Results</p> <p>The Xyn2 gene, which encodes the main <it>Trichoderma reesei </it>Rut C-30 endo-β-1, 4-xylanase was cloned into the pPICZαA vector and expressed in <it>Pichia pastoris</it>. The selected <it>P. pastoris </it>strains produced as 4,350 nkat/ml β-xylanase under the control of the methanol inducible alcohol oxidase 1 (<it>AOX1</it>) promoter. The secreted recombinant Xyn2 was estimated by SDS-PAGE to be 21 kDa. The activity of the recombinant Xyn2 was highest at 60°C and it was active over a broad range of pH (3.0–8.0) with maximal activity at pH 6.0. The enzyme was quite stable at 50°C and retained more than 94% of its activity after 30 mins incubation at this temperature. Using Birchwood xylan, the determined apparent <it>K</it>_mand k_catvalues were 2.1 mg/ml and 219.2 S^-1, respectively. The enzyme was highly specific towards xylan and analysis of xylan hydrolysis products confirmed as expected that the enzyme functions as endo-xylanase with xylotriose as the main hydrolysis products. The produced xylanase was practically free of cellulolytic activity.</p> <p>Conclusion</p> <p>The <it>P. pastoris </it>expression system allows a high level expression of xylanases. Xylanase was the main protein species in the culture supernatant, and the functional tests indicated that even the non-purified enzyme shows highly specific xylanase activity that is free of cellulolytic side acitivities. Therefore, <it>P pastoris </it>is a very useful expression system when the goal is highly specific and large scale production of glycosyl hydrolases.</p

Paradigm of Time-sequence Development of the Intestine of Suckling Piglets with Microarray

The interaction of the genes involved in intestinal development is the molecular basis of the regulatory mechanisms of intestinal development. The objective of this study was to identify the significant pathways and key genes that regulate intestinal development in Landrace piglets, and elucidate their rules of operation. The differential expression of genes related to intestinal development during suckling time was investigated using a porcine genome array. Time sequence profiles were analyzed for the differentially expressed genes to obtain significant expression profiles. Subsequently, the most significant profiles were assayed using Gene Ontology categories, pathway analysis, network analysis, and analysis of gene co-expression to unveil the main biological processes, the significant pathways, and the effective genes, respectively. In addition, quantitative real-time PCR was carried out to verify the reliability of the results of the analysis of the array. The results showed that more than 8000 differential expression transcripts were identified using microarray technology. Among the 30 significant obtained model profiles, profiles 66 and 13 were the most significant. Analysis of profiles 66 and 13 indicated that they were mainly involved in immunity, metabolism, and cell division or proliferation. Among the most effective genes in these two profiles, CN161469, which is similar to methylcrotonoyl-Coenzyme A carboxylase 2 (beta), and U89949.1, which encodes a folate binding protein, had a crucial influence on the co-expression network

Improving the thermostability of Trichoderma reesei xylanase 2 by introducing disulfide bonds

Background: Xylanases are considered one of the most important enzymes in many industries. However, their low thermostability hampers their applications in feed pelleting, pulp bleaching, and so on. The main aim of this work was to improve the thermostability of Trichoderma ressei xylanase 2 (Xyn2) by introducing disulfide bonds between the N-terminal and \u3b1-helix and the \u3b2-sheet core. Results: In this work, two disulfide bonds were separately introduced in the Xyn2 to connect the N-terminal and \u3b1-helix to the \u3b2-sheet core of Xyn2. The two disulfide bondswere introduced by site-directed mutagenesis of the corresponding residues. The half-life of the mutants Xyn2C14\u201352 (disulfide bond between \u3b2-sheets B2 and B3) and Xyn2C59\u2013149 (disulfide bond between \u3b2-sheets A5 and A6) at 60\ub0C was improved by approximately 2.5- and 1.8-fold compared to that of the wild type Xyn2. In addition, the enzyme's resistance to alkali and acid was enhanced. Conclusion: Our results indicated that the connection of the N-terminal and \u3b1-helix to the \u3b2-sheet core is due to the stable structure of the entire protein

Hadis-hadis Antropomorfisme: Analisis Terhadap Takwil Ibn Hajar Al-‘asqalânî Dalam Fath Al-bârî

: Anthropomorphism in Hadith: An Analysis of Ibn Hajar al- ‘Asqalânî\u27s Ta\u27wîl in Fath al-Bârî. In the history of Islamic theology, discussion on Quranic verses and the Prophetic traditions that deal with anthropomorphism has undergone long history starting from heated debate between literal hadith centrists with those of rationalists theologians and the Muktazilah. This essay attempts to elaborate Ibn Hajar\u27s view, as an advocate of tradition, in understanding the hadiths that describe the attributes similar to that of His creatures. In order to avoid potential error and confusion in understanding the attributes of God, Ibn Hajar utilized ta\u27wîl method and departed from his root due to socio-political condition and the prevailing theological teachings that led him to support the tenets of Asy‘ariyah. Conversely, he was very keen on safeguarding the Muslim\u27s creed from equating God\u27s attributes with His creatures

Antibiotic affects the gut microbiota composition and expression of genes related to lipid metabolism and myofiber types in skeletal muscle of piglets

Background: Early-life antibiotic administration is known to affect gut microbiota and host adiposity, but the effects of antibiotic exposure on skeletal muscle properties remain unknown. The present study evaluated the changes in skeletal muscle properties including myofiber characteristics and composition, as well as intramuscular fat (IMF) content in skeletal muscle of piglets when exposed to a tylosin-containing diet. Results: A total of 18 piglets (28 days of age) were randomly allocated into two groups: control basal diet (Control) and Control + 100 mg tylosin phosphate/kg of feed (Antibiotic). The trial lasted for 39 days. High-throughput amplicon sequencing revealed that no significant difference in initial gut microbiota composition was existed between Control and Antibiotic groups. Antibiotic administration increased body weight and growth rate and decreased feed to gain ratio of pigs (P < 0.05). The carcass lean and fat volumes of pigs were increased by the tylosin administration (P < 0.05). Antibiotic treatment increased myofiber density and the expression of genes related to type I and type IIb myofibers in longissimus muscle (P < 0.05). The IMF content in longissimus muscle was increased by antibiotic exposure (P < 0.05). Antibiotic administration increased expression of genes related to fatty acid uptake and de novo synthesis, and decreased expression of genes related to triglyceride hydrolysis (P < 0.05). Tylosin administration affected taxonomic distribution and beta diversity of the caecal and colonic microbiota of piglets. Conclusion: These results confirm that the growth performance, myofiber composition and muscle lipid metabolism are affected by antibiotic administration, which may be associated with an altered gut microbiota, suggesting that the gut microbiota could be served as a potential target for modulating skeletal muscle properties of host

l-Isoleucine Administration Alleviates Rotavirus Infection and Immune Response in the Weaned Piglet Model

Rotavirus (RV) infection is one of the main pathogenic causes of severe gastroenteritis and diarrhea in infants and young animals. This study aimed to determine how dietary l-isoleucine supplementation improves the growth performance and immune response in weaned piglets with RV infection. In cell culture experiment, after IPEC-J2 and 3D4/31 cells were treated by 8 mM l-isoleucine for 24 h, the gene expressions of β-defensins and pattern recognition receptors (PRR) signaling pathway were significantly increased. Then, in the in vivo experiment, 28 crossbred weaned pigs were randomly divided into two groups fed with basal diet with or without l-isoleucine for 18 days. On the 15th day, the oral RV gavage was executed in the half of piglets. Average daily feed intake and gain of piglets were impaired by RV infection (P &lt; 0.05). RV infection also induced severe diarrhea and the increasing serum urea nitrogen concentration (P &lt; 0.05), and decreased CD4+ lymphocyte and CD4+/CD8+ ratio of peripheral blood (P &lt; 0.05). However, dietary l-isoleucine supplementation attenuated diarrhea and decreasing growth performance (P &lt; 0.05), decreased the NSP4 concentration in ileal mucosa, and enhanced the productions and/or expressions of immunoglobulins, RV antibody, cytokines, and β-defensins in serum, ileum, and/or mesenteric lymph nodes of weaned piglets (P &lt; 0.05), which could be relative with activation of PRR signaling pathway and the related signaling pathway (P &lt; 0.05) in the weaned pigs orally infused by RV. These results indicate that dietary l-isoleucine could improve the growth performance and immune function, which could be derived from l-isoleucine treatment improving the innate and adaptive immune responses via activation of PRR signaling pathway in RV-infected piglets. It is possible that l-isoleucine can be used in the therapy of RV infection in infants and young animals