Effects Of Intestinal Morganii On The Developmental Timing Of Drosophila Melanogaster

There are a large number of microorganisms,including fungi,bacteria,viruses and other microorganisms.These microorganisms provide the host with no need to evolve their own genetic and metabolic properties,which have an important impact on host nutritional metabolism,immune and other physiological activities.High throughput sequencing technology has revealed the human intestinal flora has the diversity and complexity,but on intestinal bacteria and host bacteria and how the interaction between the network and the molecular mechanism of host physiology remains unclear,so the intestinal microflora is becoming one of the hotspot.In order to solve the above problem,Drosophila melanogaster is becoming the host-symbiont interaction mode.in recent years,because the Drosophila intestinal colonization of microorganisms is relatively simple,easy to build gnotobiotes flies.First of all,we optimized the sterile Drosophila model to establish the protocol of germ free fly using Walch,hypochlorite and ethanol combined disinfection method,and eventually established a set of highly efficient sterile Drosophila technology and methods.A strain of bacteria was obtained from wild-captured fruit fly by Hungate roll tube technology,which was identified as Morganii Morganella.The bacteria stably colonized the intestinal tract of Drosophila,ranging from 10³ to 10⁵,and can be transferred in the progeny of D.melanogaster with the number of more than 10³,indicating that Morganii is a symbiotic bacteria of Drosophila.Morganii was required to promote the development of Drosophila.In the condition of poor nutrition?0.5%yeast?cases,conventional breeding of Drosophila pupae and eclosion time were 6 d and 11.7 d;sterile Drosophila pupae and eclosion time were delayed to 7.8 d and 18.9 d;Morganii-associatec pupae and fruit the eclosion time were 6.2 d and 12.1 d rescued the deficiency of germ-free?GF?developmental arrestment.Using immunofluorescence staining,we assayed the mitosis in intestinal cells.conventionally reared Drosophila midgut cell division is number 12.7 compared 1.1 in GF midgut;The number of Morganii bacteria group of Drosophila midgut cell division is 12.1,indicating that Morganii was promoting cellular proliferation of Drosophila intestine.in the further exploration of Morganii bacteria mechanism to promote the development of Drosophila,hormone conventional breeding Drosophila(a kind of induction The peak of the hormone from Drosophila to pupal stage was sixth day,and the peak value of gonadotropin releasing hormone?PTTH?in Drosophila melanogaster was in the range of ninth day,while that of the Morganii group was higher than that of germ-free group of Drosophila melanogaster can stimulate the secretion of PTTH to promote the growth and development of Drosophila.Through screening found that conventional breeding Drosophila insulin signal expression has been in a high level,while the expression of insulin signaling was very low in GF Drosophila.Morganii bacteria enhanced the Drosophila insulin signal expression of GF Drosophila,suggesting that insulin signal pathway contributed to the developmental timing of Drosophila..This paper focuses on the intestinal microecology,analysize the diversity and complexity of Drosophila intestinal bacteria emerging discipline,and explore the underpining mechanism of regulation of development in the host molecule of intestinal bacteria.This study has an important breakthrough in theory and technology,providing new insights for the human and microbial interaction and the prevention and treatment of human health and diseases.