Effects of fermented sweet potato residue on nutrient digestibility, meat quality, and intestinal microbes in broilers.

This study aimed to investigate the effects of different proportions of dietary fermented sweet potato residue (FSPR) supplementation as a substitute for corn on the nutrient digestibility, meat quality, and intestinal microbes of yellow-feathered broilers. Experiment 1 (force-feeding) evaluated the nutrient composition and digestibility of mixtures with different proportions of sweet potato residue (70%, 80%, 90%, and 100%) before and after fermentation. In Experiment 2 (metabolic growth), a total of 420 one-day-old yellow-feathered broilers were randomly allocated to 4 groups and fed corn-soybean meal-based diets with 0, 5%, 8%, and 10% FSPR as a substitute for corn. The force-feeding and metabolic growth experiments were performed for 9 and 70 d, respectively. The treatment of 70% sweet potato residue (after fermentation) had the highest levels of crude protein, ether extract, and crude fiber and improved the digestibility of crude protein and amino acids (P < 0.05). Although dietary FSPR supplementation at different levels had no significant effect on growth performance and intestinal morphology, it improved slaughter rate, half-chamber rate, full clearance rate, and meat color, as well as reduced cooking loss in the breast and thigh muscles (P < 0.05). Dietary supplementation with 8% and 10% FSPR increased the serum immunoglobulin M and immunoglobulin G levels in broilers (P < 0.05). Furthermore, 10% FSPR increased the Shannon index and Ruminococcaceae_UCG-014, Ruminococcaceae_UCG-010 and Romboutsia abundances and decreased Sutterella and Megamonas abundances (P < 0.05). Spearman's correlation analysis showed that meat color was positively correlated with Ruminococcaceae_UCG-014 (P < 0.05) and negatively correlated with Megamonas (P < 0.05). Collectively, 70% sweet potato residue (after fermentation) had the best nutritional value and nutrient digestibility. Dietary supplementation with 8% to 10% FSPR as a substitute for corn can improve the slaughter performance, meat quality, and intestinal microbe profiles of broilers. Our findings suggest that FSPR has the potential to be used as a substitute for corn-soybean meals to improve the meat quality and intestinal health of broilers.

The complete mitochondrial genome of the Anas platyrhynchos Linnaeus, 1758 breed Longshengcui and its phylogenetic analyses.

Duck breed Longshengcui (Anas platyrhynchos Linnaeus, 1758 breed Longshengcui, LSC) is one of the famous native breed of the Guangxi Zhuang Nationality Autonomous Region in China. In this study, we report the complete mitochondrial genome of LSC. The mitogenome (GenBank accession no. MZ895120) has 16,602 bp in length and consisted of the well-known 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and the control region. The phylogenetic analysis showed that LSC and Zhijiang duck have highly similar genetic relationship. These results are helpful for the conservation of genetic resources and phylogeny of this species.

Characterization of myosin heavy chain (MYH) genes and their differential expression in white and red muscles of Chinese perch, Siniperca chuatsi.

Fish skeletal muscle is composed of two anatomically and functionally different fiber layers, white or fast and red or slow muscles. Myosin, the major structural protein of fish skeletal muscle, contains multiple myosin heavy chain (MYH) isoforms involved in the high plasticity of muscle in response to varying functional demands and/or environmental changes. In this study, we comparatively assayed the cellular and ultrastructural feature of white and red skeletal muscles. Then, a total of 28 class II myosin heavy chain genes were identified in by searching the Chinese perch genome database. Among them, 14 genes code for the fast-muscle-type myosin heavy chain, and 7 genes code for the slow-muscle-type myosin heavy chain. Further, the different isoform gene structures, function domains, phylogenetic relations, and muscle-fiber type-specific expression were characterized. This is the first systematic work on the molecular characterization of class II myosin heavy chain isoforms and the differential analysis of their expression in red and white muscle tissues in Chinese perch Siniperca chuatsi. Our work provided valuable information for a better understanding of myh genes and their molecular characteristics, and the correlations of multiple myosin isoforms with potential functions in response to varying functional demands and/or environmental changes.

Study on anaerobic co-digestion of municipal sewage sludge and fruit and vegetable wastes: Methane production, microbial community and three-dimension fluorescence excitation-emission matrix analysis.

Constantly increased sewage sludge (SS) and fruit and vegetable wastes (FVW) are becoming the major organic solid wastes in human society. Thus, anaerobic digestion is employed as a low carbon energy strategy to reduce their environmental pollution risk. Anaerobic co-digestion system was developed based on the carbon to nitrogen ratio strategy. Results showed that the daily biogas production was higher in co-digester, and the volumetric biogas production rate (VBPR) significantly enhanced for 1.3 âˆ¼ 3 folds, and the highest VBPR was 2.04 L/L • day with optimal OLR of 2.083 Kg L-1 d-1. Analytic results indicated that co-digestion could improve the biodegradable of feedstocks, which transforming to more VFAs and biogas. Compared with mono SS digester, mixed substrates relieved ammonia nitrogen inhibition and enhanced the hydrolytic acidification and methanogenesis. Meanwhile, the excessive humification of organics was suppressed. This study supported the concepts of improving carbon recovery from SS and FVW.

Effects of short-term fasting on the rhythmic expression of core circadian clock and functional genes in skeletal muscle of goldfish (Carassius auratus).

Molecular oscillators exist in peripheral tissues like pacemaker cells. Food intake is a dominant zeitgeber for peripheral clocks in vertebrates. Fasting is a physiological stress that elicits well-known metabolic adaptations, however, little is known about the effects of the rhythmic expression of clock components in skeletal muscle following short-term fasting in goldfish. Here, we characterized the molecular clock components and their daily transcription in COSINOR, and assessed the effect of 7-day fasting on the circadian patterns of the candidate genes expression in goldfish skeletal muscle. For the core clock genes, clock, bmal1a, cry1, cry2, cry3, per1, per2 and per3 showed circadian rhythmicity in fed goldfish, but not for bmal1a, cry2 and per1 in the fasted state. Of the 8 candidate functional genes analyzed, igf1, igf2 and igfbp2 showed circadian rhythmicity in the fed state, but circadian pattern was only observed for mRNA of myog, igfbp2 and mstn in fasted goldfish. Additionally, Spelman's correlation analysis showed the circadian expression of the myog and mstn presented positive and negative correlation with the transcription pattern of clock and per2 genes in fasted goldfish, respectively. Our results demonstrated that the peripheral clocks might be reset to respond rapidly to withholding of food in teleost skeletal muscle.

Complete mitochondrial genome of the hybrid of Oreochromis niloticus (♀) × Oreochromis aureus (♂).

In this paper, the complete mitochondrial genome of the hybrid of Oreochromis niloticus (♀) × Oreochromis aureus (♂) was determined using PCR-based method. The mitogenome was 16,663 bp in length, containing the same gene order and an identical number of genes or regions with the other Cichlid fishes, including 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and 1 putative control region. The overall composition of the mitogenome was 30.92% C, 27.98% A, 25.54% T, 15.56% G, with a slight AT bias of 53.52% occurs in the hybrid mitogenome. All the protein-coding genes were initiated by typical ATG codon, except for COX1 gene with the initiation codon GTG. Eight genes end with the complete stop codon TAA or TAG, while the COX2, COX3, ND3, ND4 and Cytb genes terminated with an incomplete stop codon T. The complete mitochondrial genome of Oreochromis niloticus (♀) × Oreochromis aureus (♂) may provide important DNA molecular data for further elucidation of evolutionary mechanisms in the hybrid fish of Cichlidae.

Complete mitochondrial genome sequence of Procypris merus.

In this study, the complete mitochondrianl genome of Procypris merus was sequenced. It was determined to be 16,581 bp and included 13 protein-coding genes, 22 tRNA genes, 2 ribosomal RNA genes and 1 non-coding region (D-loop). The descending order of the base composition on heavy strand was 31.91% A, 24.95% T, 27.39% C, 15.75% G, which is similar to other cyprinid fish mitochondrial genomes. All protein-coding genes had ATG as the start codon but the stop codons have three types. Night genes end with TAA or TAG, and COII, ND4, ND6 and Cytb genes terminate with an incomplete - -T. The complete mitochondrial genome may provide important DNA molecular data for further phylogenetic analyses for higher taxa of Cyprinidae.

The phylogenetic placement of Siniperca obscura base on complete mitochondrial DNA sequence.

Abstract The extant freshwater sinipercids represent a group of 12 species and they are endemic to East Asia. In this study, we cloned and sequenced the complete mitochondrial DNA of Siniperca obscura from the Lijiang River. The size of the complete mitochondrial genome is 16,492 bp. The organization of the mitochondrial contained 37 genes (13 protein-coding genes, 2 ribosomal RNA and 22 transfer RNAs) and a major non-coding control region as well as those reported sinipercid fishes. Among the 13 protein-coding genes, three reading-frame overlaps were found: ATP8 and ATP6 overlap by 10 nucleotides and ND4 and ND4L overlap by 7 nucleotides and ND5 and ND6 overlap by 5 nucleotides. Phylogenetic analyses using N-J and maximum parsimony (MP) computational algorithms showed that S. chuatsi and S. kneri are sister species, next joined by S. Obscura, based on combined 12 protein-coding genes (excluding DN6).

Selection of Reference Genes in Transcription Analysis of Gene Expression of the Mandarin Fish, Siniperca chuasti.

At present, transcription analysis of gene expression commonly uses housekeeping genes as control for normalization. In this study, the expression levels of three housekeeping genes including GAPDH, beta-actin, and 18S rRNA in six tissues and five developmental stages of the Mandarin fish Siniperca chuatsi were assayed with quantitative real-time PCR (qPCR). Differences in expression levels were analyzed using geNorm program. The results demonstrate that beta-actin is the most stable gene at developmental stages and GAPDH is the most stable in different tissues. While 18S rRNA expression during development is differentially regulated, which indicates it is suitable as an internal control for gene expression normalization at the developmental level. Overall, the data suggest that the two most stable housekeeping genes are enough to accurately calibrate gene expression in S. chuatsi. The significance of this study provided convincing references and methodology for housekeeping gene selection and normalization in gene expression analysis with regular PCR or qPCR.

[Single nucleotide polymorphism analysis on the 5' regulatory region of IGF2 gene in Wuzhishan pig].

Single nucleotide polymorphisms (SNPs) in partial 5' regulatory region of the insulin-like growth factor 2 (IGF2) gene were studied by DNA sequencing in 60 pigs from the Wuzhishan, Diannan small-ear, Xiang, Meishan and Large White pig breeds. Thirteen SNP sites were detected, including one transversion at T6029A, 4 A<---->G transitions (A5976G, G13520A, G13563A and G13669A) and 8 C<---->T transitions (C5872T, C5888T, C6010T, C6037T, C6043T, C6063T,C6112T, C6164T). These 13 SNPs formed 23 composite genotypes. The gene, genotype and composite genotype frequencies of every SNP site in the whole group and in each breed were calculated. Results showed that the predominant allele in 3 miniature pig breeds was G, T and A at A5976G, C6164T and G13669A sites respectively, but the A-C-G allele was pre-dominant in Meishan and Large White breeds. Moreover, H15 and H19 were the characteristic composite genotype for the large versus the miniature breeds, respectively. In addition, the C5888T SNP was analyzed in 123 Wuzhishan pigs by the PCR-RFLP method. Results showed that the predominant allele was C, and the predominant genotype was CC. chi2-test results indicated that the Wuzhishan pig breed was at Hardy-Weinberg equilibrium with respect to this SNP. These results provide the miniature pig breeds such as the Wuzhishan pig with certain genetic references on the regulation of growth and development, and the mechanism of its dwarfism.