Question

You want to know whether the virulence genes present in Bordetella pertussis are evolutionarily related to genes in the less pathogenic species & bronchiseptica or if the virulence genes were acquired via horizontal gene transfer. What characteristics] would you compare to answer this question?

a. variations in ribosomal binding sites and intron sequences in the genes of interest
b. percentage of G+C content in the genes of interest compared to the rest of the genome
c. codon usage in the genes of interest compared to the rest of the genome
d. number of genes in the pan genome of the genus

Answer 1

The relationship between virulence genes in Bordetella pertussis and those in Bordetella bronchiseptica can be inferred by sequencing similarities and the presence of genes on mobile genetic elements like plasmids, as well as comparing the pan-genome of the genus.

Step-by-step explanation:

To determine whether virulence genes in Bordetella pertussis are evolutionarily related to those in Bordetella bronchiseptica or acquired through horizontal gene transfer, one approach would be to compare the sequence similarity of these genes in both species. A high sequence similarity would suggest an evolutionary relationship, whereas a low similarity could indicate acquisition through horizontal gene transfer. Moreover, the presence of virulence genes on mobile genetic elements like plasmids or phages in one species but not in the other could provide evidence for horizontal gene transfer.

Additionally, comparing the pan-genomes would reveal the number of shared and unique genes between species, enhancing our understanding of gene conservation and diversity within the genus. The pan-genome of a genus includes the core genome present in all species and the accessory genome found in one or several but not all species. If virulence genes are part of the core genome, it's more likely they were inherited vertically, while if they are part of the accessory genome, they might have been acquired laterally.