Gene Evolution And The Analysis In Bioinformatics Based On CYP4 Gene Family Of Insect

We dealt with three questions about CYP4 family gene in this dissertation:⑴The gene evolution of CYP4s in fig wasps from Ficus Hispida;⑵Why Apis mellifera has the least gene number of CYP4 family?⑶Is CYP4G15 in Drosophila relate with aggression?The interaction between fig pollinators and their host figs is one of the textbook examples of obligate pollination mutualism and one of the best cases of co-evolution known. In most cases, pollinators of one species pollinate one fig species. Moreover, multiple character variations exist in this mutualism. Several morphological and behavior traits are supposed to be long-time evolutionary results of coadaptation between the two lineages. The relationships among them are complicated. Figs and their associated fig wasps have been a focus of research on coevolved mutualism, resource conflicts, sex ratio evolution, the evolution of virulence, coevolution, population genetics, host-parasitoid interactions, community ecology, historical biogeography, and conservation biology. CYP4s are more important in metabolizing endogenous compounds than other P450 genes including hormones, pheromones, odourant molecules etc. They also play important roles in pesticide and pollution resistance. The P450 enzymes of all four clades will undoubtedly reveal many facets of the highly successful physiological adaptations of insects to their varied food sources and environments. So it is very important to study the evolution of CYP4s in fig wasps, which will be very helpful to know the host specificity for fig wasps. CYP4s in fig wasps from Ficus hispida are in purifying selection, which means the functions of members in CYP4 are related and persertive. Although CYP4Gs exist in all fig wasps, we found CYP4Gs might not play important part in detoxifying toxins from their host. CYP4s in fig wasps and Ips paraconfusus are quiet similar, we discuss that similar environment may lead to similar genes, like CYP4s.P450 is one of the most important detoxifying enzymes. We compared all gene clades in P450 of Apis mellifera to Nasonia vitripennis, Tribolium castaneum, Drosophila melanogaster, Bombyx mori, Aedes aegypti, Anopheles gambiae, emphasizing on CYP4 family. Apis mellifera has only four CYP4 genes with housekeeping functions, much fewer than other insects. It seems likely that the scarcity of CYP4s in Apis mellifera reflects a loss of environmental response and detoxifying capability. Using GENETREE 1.3, we found Apis mellifera has 9 gene losses, no duplication. And Apis mellifera has lower rate of evolution than other insects by the selection analysis with MEGA3.1. No gene duplication, more gene losses and lower rate of evolution can explain the least gene number of CYP4s.Aggressive behavior is pervasive in the animal world, and yet very little is known about its molecular mechanism. Aggression is a complex social behavior influenced both by genetic and environmental factors, which is still poorly understood. A number of genes have been identified with effects on aggressive behavior, e.g., CYP6A20. If its expression level is higher, it is inferred that the aggressive level of this species is lower. We use codon adaptation index (CAI) value to evaluate the expression level of CYP6A20 in 7 Drosophila species. We found that the CAI values of CYP6A20 between closely species have little difference, and the variations of CAI value of CYP6A20 are consistent with phylogeny of 7 Drosophila species. Comparing the CAI value of CYP6A20 and CYP4G15, we find that CYP4G15 do not affect aggressive behavior.