The Effect Of Urbanization On Sarcophaga Intestinal Microbes

Urbanization is a process in which the population migrates from rural to urban areas.At the same time,it is manifested as changes in regional landscapes,industrial structure,production and lifestyle.Ecological problems such as habitat fragmentation,homogenization and environmental pollution caused by urbanization are important factors leading to the loss of biodiversity and directly affect the service functions of ecosystems.Insects are a major component of terrestrial ecosystem biodiversity and drive a variety of important ecosystem functions such as pollination,herbivore and pest control.Insect feeding,digestion and excretion are all done in the digestive tract,where the intestine is the most important functional area.Symbiotic microorganisms are ubiquitous in the intestinal tract of insects.Insects and microorganisms have established a variety of symbiotic relationships,playing a central role in host evolution and diversification.Sarcophaga are widely distributed and play an important role in consumers and decomposers in the ecosystem,and are closely related to human health.Therefore,this study takes Sarcophaga as the research object.Firstly,it investigates the changes in the species diversity of Sarcophaga under the urbanization gradient represented by urban areas,rural and forest.Based on this,it explores the different levels of urbanization on intestinal microbes.This study consists of two parts.The first part combines DNA barcodes with morphological taxonomy to determine the species of Sarcophaga,and compares the species diversity of Sarcophaga under the urbanization gradient.The results showed that the urbanization affected the species diversity of Sarcophaga,and the higher the degree of urbanization,the higher the species diversity of Sarcophaga.The second part is based on high-throughput sequencing technology to explore the impact of urbanization on the intestinal microbes of Sarcophaga,and draws the following conclusions:1.Intestinal microbes have a positive effect in the adaptation of Sarcophaga to urbanization;the microbial diversity of the intestines of forest habitats is significantly lower than that of urban and rural areas(p < 0.05),Firmicutes,Proteobacteria,Bacteroidetes is the dominant bacteria.The decrease in Cosenzaea in urban and rural areas may be antagonized by the bacteria ingested by Sarcophaga.2.Urbanization will cause the gut microbial community in Sarcophaga,which is a gradients trend from the higher order elements to the genus level.At the genus level,the community composition of the intestinal microbes in the rural is more similar to the urban area.3.Habitat changes brought about by urbanization will lead to an increase in the abundance of pathogenic bacteria in the intestines of the flies.At the phylum level,Actinobacteria is the most abundant in the bacteria;the genus has significant differences at the genus level.Conditional pathogens also have bacteria that are beneficial to the host.And the abundance is higher than 10 genera such as Pseudomnas.In view of the existing research and the above conclusions,we speculate that the abundance of pathogens in urban and rural areas may be due to the large amount of pathogens in the foods consumed by Sarcophaga and the pathogens in environmental foods are related to environmental changes brought about by urbanization.The increase of beneficial bacteria abundance in the intestines of the Sarcophaga in urban and suburban areas may be the defense mechanism produced by the host itself,and the bacterial community is balanced and regulated.This may be one of the microbial mechanisms for the adaptation of Sarcophaga to urbanization,and it also maintains the diversity of Sarcophaga in urban areas.