Evolutionary Genomics of Gene Families: A Case Study of Insect Gustatory Receptors.

Gene families, which are groups of genes that share common ancestry and are often functionally related, constitute a substantial proportion of the protein-coding sequences within eukaryotic genomes. In insects, genes involved in chemoperception belong to gene families characterized by numerous copies that arise from episodic bursts of gene duplication. This biological process is crucial for insect survival, as it enables the perception of environmental chemical cues. In this chapter, we analyze the gustatory receptors in the fire ant Solenopsis invicta and present a protocol for bioinformatic analyses. First, we employ BITACORA to identify and annotate gene family members in the genome assembly, providing tools for the annotation and subsequent validation. Then, we use GALEON to explore the genomic arrangement of gene family members in the chromosome-level assembly and visualize the distribution of gene clusters. To gain insights into the evolution and function of these genes, we conduct multiple-sequence alignment and reconstruct the phylogeny, incorporating data from two other insects. Finally, we integrate physical and evolutionary distances of the gustatory receptors to further understand the dynamics of this gene family.