Background: SAGA is a multiprotein complex that possesses histone acetyltransferase activity. Results: Fission yeast strains with deletions in the SAGA acetyltransferase subunit exhibited increased leucine uptake in a manner dependent on an amino acid permease gene. Conclusion: SAGA regulates amino acid uptake in fission yeast. Significance: Regulation of nutrient uptake by SAGA provides a potential link between cellular metabolism and chromatin regulation.

Uptake of poor nitrogen sources such as branched-chain amino acids is repressed in the presence of high-quality nitrogen sources such as NH4+ and glutamate (Glu), which is called nitrogen catabolite repression. Amino acid auxotrophic mutants of the fission yeast Schizosaccharomyces pombe were unable to grow on minimal medium containing NH4Cl or Glu even when adequate amounts of required amino acids were supplied. However, growth of these mutant cells was recovered in the vicinity of colonies of the prototrophic strain, suggesting that the prototrophic cells secrete some substances that can restore uptake of amino acids by an unknown mechanism. We identified the novel fatty acids, 10(R)-acetoxy-8(Z)-octadecenoic acid and 10(R)-hydroxy-8(Z)-octadecenoic acid, as secreted active substances, referred to as Nitrogen Signaling Factors (NSFs). Synthetic NSFs were also able to shift nitrogen source utilization from high-quality to poor nitrogen sources to allow adaptive growth of the fission yeast amino acid auxotrophic mutants in the presence of high-quality nitrogen sources. Finally, we demonstrated that the Agp3 amino acid transporter was involved in the adaptive growth. The data highlight a novel intra-species communication system for adaptation to environmental nutritional conditions in fission yeast.

This study was conducted to investigate the effects of supplementation with nicotinamide ( NAM ) and sodium butyrate (BA) on meat quality and expression of muscle development genes in broilers reared at a high stocking density. A total of 567, 21-day-old AA broilers were randomly assigned to 5 treatment groups and 2 control groups, with 7 replicates of each group. The control groups included a low stocking density ( LD ; 12.9 birds/m 2 ) and were fed a basal diet. The treatment groups were kept at a high stocking density (HD; 18.6 birds/m 2 ) and received either a low dose of NAM (50 mg/kg; treatment LN ), a high dose of NAM (100 mg/kg; treatment HN ), a low dose of BA (500 mg/kg; treatment LB ), a high dose of BA (1,000 mg/kg; treatment HB ), or a compound supplement (50 mg/kg NAM+500 mg/kg BA; treatment COMB ); broilers were reared till 42 D of age. The control groups were kept at HD or at LD (12.9 birds/m 2 ) and were fed a basal diet. The heterophil-to-lymphocyte ratio was significantly higher in the HD control group than that in the LD group; this ratio was significantly lower in treatments LN, HN, HB, and COMB than that in the HD control group. The lightness of breast muscles at 45 min and 24 h after slaughter was significantly higher in the HD group than that in the LD group, and the HD group showed the highest drip loss at 24 h and 48 h. Lightness and drip loss were lower in the HN, LB, and COMB treatments than those in the HD group. HD rearing significantly reduced gene expression of myogenic regulatory factor 5 ( MYF5 ) while significantly increased expression of the protein ubiquitin degradation genes FBXO9 , FBXO22 , and FBXO32 . All treatments significantly reduced FBXO9 and FBXO32 expression. Our results suggest dietary supplementation with NAM and BA can improve meat quality of broilers under high stocking density by upregulating the expression of myogenic genes, and inhibiting protein ubiquitination.

Understanding the occurrence and distribution of various Eimeria species in broiler farms is necessary to develop effective coccidiosis vaccines. In the current study, fecal samples were collected from broilers with subclinical signs at fifty small-scale farms in the Shandong province in eastern China. Oocysts purified from fecal samples were examined for morphology. The Eimeria genomic DNA extracted from each sample was subjected to PCR amplification with species-specific primers for the internal transcribed spacer sequence or the small RNA subunit sequence of each of the seven species of Eimeria found in chickens. The results showed that more than one Eimeria species existed in most fecal samples, and the infection rate of identified Eimeria spp. in these farms was 90%, 88%, 72%, 68%, 60%, 26%, and 8% for E. tenella, E. praecox, E. acervulina, E. maxima, E. mitis, E. necatrix, and E. brunetti, respectively. This indicates that E. tenella, E. praecox, E. acervulina, E. maxima, and E mitis are the predominant species in local Shandong province, so an effective coccidiosis vaccine applied in this area should contain at least these five Eimeria species.