Project description:The genus Desulfonema belongs to the deltaproteobacterial family Desulfobacteraceae and comprises marine, sulfate-reducing bacteria that form filaments and move by gliding. This study reports on the complete, manually annotated genomes of Dn. limicola 5ac10T (6.91 Mbp; 6,207 CDS) and Dn. magnum 4be13T (8.03 Mbp; 9,970 CDS), integrated with substrate-specific proteome profiles (8 vs. 11). The richness in mobile genetic elements is shared with other Desulfobacteraceae members, corroborating horizontal gene transfer as major driver in shaping the genomes of this family. The catabolic networks of Dn. limicola and Dn. magnum have the following general characteristics: 98 versus 145 genes assigned (having genomic shares of 1.7 vs. 2.2%), 92.5 versus 89.7% proteomic coverage, and scattered gene clusters for substrate degradation and energy metabolism. The Dn. magnum typifying capacity for aromatic compound degradation (e.g., p-cresol, 3-phenylpropionate) requires 48 genes organized in operon-like structures (87.7% proteomic coverage; no homologs in Dn. limicola). The protein complements for aliphatic compound degradation, central pathways, and energy metabolism are highly similar between both genomes and were identified to a large extent (69-96%). The differential protein profiles revealed a high degree of substrate-specificity for peripheral reaction sequences (forming central intermediates), agreeing with the high number of sensory/regulatory proteins predicted for both strains. By contrast, central pathways and modules of the energy metabolism were constitutively formed under the tested substrate conditions. In accord with their natural habitats that are subject to fluctuating changes of physicochemical parameters, both Desulfonema strains are well equipped to cope with various stress conditions. Next to superoxide dismutase and catalase also desulfoferredoxin and rubredoxin oxidoreductase are formed to counter exposure to molecular oxygen. A variety of proteases and chaperones were detected that function in maintaining cellular homeostasis upon heat or cold shock. Furthermore, glycine betaine/proline betaine transport systems can respond to hyperosmotic stress. Gliding movement probably relies on twitching motility via type-IV pili or adventurous motility. Taken together, this proteogenomic study demonstrates the adaptability of Dn. limicola and Dn. magnum to its dynamic habitats by means of flexible catabolism and extensive stress response capacities.
Project description:Purpose: With the advent of Next-generation sequencing (NGS), several novel genes/proteins and cellular pathways in wide varitey of tissues has discovered. The aim of this study are to perform transcriptome profiling (RNA-seq) of magnum to determine differently expressed genes in laying and non-laying hens and to further validate the expression of candidate genes using real-time quantitative reverse transcription polymerase chain reaction (qRT–PCR) in laying, non-laying and molting hens. Methods: Magnum mRNA profiles of 35-60 weeks-old laying and non-laying hens, three each, were generated with NextSeq 500 sequencer in single-end mode with a read length of 1x76 bp. Raw sequencing reads were cleaned and trimmmed with Prinseq tool and good reads were aligned against the chicken reference gemone (Galgal 5.0) in Array Studio. Differential gene expression analysis was performed by the DESeq2 algorithm as implemented in Array Studio. The genes with at least three-fold change (FC) and Benjamini and Hochberg q-value < 0.05 were called differentially expressed. Results: Using an optimized data analysis workflow, we mapped about 30.5 million reads from layers and 33.4 million reads from non-layers to the chicken genome. A total of 19,152 gene transcripts were annotated from Ensembl alignment which represents 50.24% of the chicken genome assembly. Differential gene expression analysis showed 540 were differentially expressed between layer and non-layer hens. 152 DEGs were significantly up-regulated and 388 were significantly down-regulated in the laying hens when compared to the non-laying hens. Conclusions: Our study reports the expression of several pre-discovered and many novel genes that may be involved in the transport of precurosor molecules for biosynthesis and secretion of the egg-white proteins in the magnum. These genes can be used as quantitative basis of selecting hens with an improved egg quality.