Figure 6.

Carbohydrases present in the genome of Rhyzopertha dominica. (A). Neighbor-joining tree of α-amylases in R. dominica and in the genomes of other beetles. Sequences with >40% similarity to those annotated in R. dominica were downloaded from NCBI for phylogenetic analysis. Proteins were aligned with MUSCLE in MEGA X, and a bootstrap consensus tree was constructed using 500 bootstrap pseudoreplicates. Evolutionary distances were computed using the JTT distance matrix, and rate variation was modeled with a gamma distribution (shape parameter = 1). Accession numbers of proteins used in the tree are presented, and numbers on nodes indicate bootstrap support. (B). An expansion of glucose dehydrogenases on scaffold 4 in R. dominica. An array of 10 gene models for glucose dehydrogenases was found between two maltase genes. Although similar arrays of glucose dehydrogenases can be found in the genomes of other beetles, none were flanked by maltase gene models. Whether adjacent models can be used to infer putative gene function has not yet been widely investigated in insect genomes. (C). A deletion in a gene model coding for a GH 9 enzyme in R. dominica. One gene coding for a putative GH 9 enzyme was identified in the R. dominica genome. However, an ~25-amino-acid deletion was noted relative to other beetle endoglucanses, suggesting it may have a different function. (D). An insertion in a gene model coding for a putative GH 9 enzyme in all beetles genomes. A large ~50-amino-acid insertion was observed in all sequenced beetles relative to the consensus Pfam sequence. Notably, although many GH 9 gene models code for endoglucanses, many beetle GH 9 enzymes are thought to have different substrate preferences. This large insertion suggestions that these enzymes may no longer act on cellulose and may have different functions even in wood-feeding insects, such as Anoplophora glabripennis.