Identifying Glucocorticoid Receptors in Planarians

As the G. tigrina genome has not been sequenced yet, we have performed a search for orthologous proteins of glucocorticoid receptors (hydrocortisone) in the genome of a closely relates species, namely Schmidtea mediterrana, using the SmedGD genomic database (https://planosphere.stowers.org/smedgd, accessed on 17 November 2022). We used the BLAST algorithm for this, which was also used previously to search for amino acid sequences based on similarity with the target protein receptors in humans (Homo sapiens), house mouse (Mus musculus), African clawed frog (Xenopus laevis), and fruit fly (Drosophila melanogaster). The search was performed both by the complete amino acid sequence and on the basis of ligand-binding domains.
The homologues found in the planarian genome were also compared in the GenBank database and the most similar sequences were selected. Domain analysis in the protein structure was determined using the NCBI Conserved domains database. Next, multiple alignment of amino acid sequences was performed with the ClustalW algorithm using an online service EMBL (European Molecular Biology Laboratory: //www.ebi.ac.uk/, accessed on 21 October 2022).
Phylogenetic comparisons of amino acid sequences were performed using an online service, EMBL (European Molecular Biology Laboratory: //www.ebi.ac.uk/, accessed on 21 October 2022).