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The arrestin domain containing proteins (ARRDCs) are crucial adaptor proteins assist in signal transduction and regulation of sensory physiology. The molecular localization of the ARRDC gene has been confined mainly to the mammalian system while in invertebrates the expression pattern was not addressed significantly. The present study reports the identification, tissue specific expression and functional characterization of an ARRDC transcript in earthworm, Eudrilus eugeniae.The coding region of earthworm ARRDC transcript was 1146 bp in length and encoded a protein of 381 amino acid residues. The worm ARRDC protein consists of conserved N-terminal and C-terminal regions and showed significant homology with the ARRDC3 sequence of other species. The tissue specific expression analysis through whole mount in-situ hybridization denoted the expression of ARRDC transcript in the central nervous system of the worm which includes cerebral ganglion and ventral nerve cord. Besides, the expression of ARRDC gene was observed in the epidermal region of earthworm skin. The functional characterization of ARRDC gene was assessed through siRNA silencing and the gene was found to play key role in the light sensing ability and photophobic movement of the worm.The neuronal and dermal expression patterns of ARRDC gene and its functional characterization hypothesized the role of the gene in assisting the photosensory cells to regulate the process of photoreception and phototransduction in the worm.

The oligochaete earthworm, Eudrilus eugeniae is capable of regenerating both anterior and posterior segments. The present study focuses on the transcriptome analysis of earthworm E. eugeniae to identify and functionally annotate the key genes supporting the anterior blastema formation and regulating the anterior regeneration of the worm. The Illumina sequencing generated a total of 91,593,182 raw reads which were assembled into 105,193 contigs using CLC genomics workbench. In total, 40,946 contigs were annotated against the NCBI nr and SwissProt database and among them, 15,702 contigs were assigned to 14,575 GO terms. Besides a total of 9389 contigs were mapped to 416 KEGG biological pathways. The RNA-Seq comparison study identified 10,868 differentially expressed genes (DEGs) and of them, 3986 genes were significantly upregulated in the anterior regenerated blastema tissue samples of the worm. The GO enrichment analysis showed angiogenesis and unfolded protein binding as the top enriched functions and the pathway enrichment analysis denoted TCA cycle as the most significantly enriched pathway associated with the upregulated gene dataset of the worm. The identified DEGs and their function and pathway information can be effectively utilized further to interpret the key cellular, genetic and molecular events associated with the regeneration of the worm.

Purpose Verminephrobacter is a genus of symbiotic bacteria that live in the nephridia of earthworms. The bacteria are recruited during the embryonic stage of the worm and transferred from generation to generation in the same manner. The worm provides shelter and food for the bacteria. The bacteria deliver micronutrients to the worm. The present study reports the genome sequence assembly and annotation of a new strain of Verminephrobacter called Verminephrobacter eiseniae msu. Methods We separated the sequences of a new Verminephrobacter strain from the whole genome of Eisenia fetida using the sequence of V. eiseniae EF01-2, and the bacterial genome was assembled using the CLC Workbench. The de novo-assembled genome was annotated and analyzed for the protein domains, functions, and metabolic pathways. Besides, the multigenome comparison was performed to interpret the phylogenomic relationship of the strain with other proteobacteria. Result The FastqSifter sifted a total of 593,130 Verminephrobacter genomic reads. The de novo assembly of the reads generated 1832 contigs with a total genome size of 4.4 Mb. The Average Nucleotide Identity denoted the bacterium belongs to the species V. eiseniae, and the 16S rRNA analysis confirmed it as a new strain of V. eiseniae. The AUGUSTUS genome annotation predicted a total of 3809 protein-coding genes; of them, 3805 genes were identified from the homology search. Conclusion The bioinformatics analysis confirmed the bacterium is an isolate of V. eiseniae, and it was named Verminephrobacter eiseniae msu. The whole genome of the bacteria can be utilized as a useful resource to explore the area of symbiosis further.