Preliminary Study On Intestinal Microflora Of Wolf(Canis Lupus)and Dog(Canis Lupus Familiaris)by Metagenomics

Both wolves(Canis lupus)and dogs(Canis familiaris)belongs to the canine family.This species has a close relationship with humans,widely distributed in the world.The wolf living in china named Tibet wolf,or Mongolian wolf,this subspecies mainly distributed in China's Tibet,Inner Mongolia and other areas with the expansion of the scope of human activities and the hunting in the late 20^th century,the population and habitats of wolves are gradually reduced.Therefore,it is necessary to provide multiple protection for this species,and it is the first step to provide protection for this species from the macro and micro level.Some studies revealed that dogs were domesticated by wolves about 1.2 to 15,000 years ago.But recent findings suggest that domesticated dogs may have been domesticated as early as this time,dating back to the late Pleistocene.At present,there is no definite conclusion on the origin and time of domestication of domestic dogs.Influenced by human domestication,dogs and wolves have huge difference in the aspects of food and living environment.These changes also influenced their whole genome structure,digestion,and metabolism.Although the whole genome of wolves and dogs has been gradually studied,the study on the composition and function of intestinal flora between the two has not been carried out.Gut microbiota has great influence on hosts in many aspects such as health,digestion,and metabolism.Metagenomic technology could get more information about the composition and function of gut microbiota compared with other sequencing methods.In this study,we sequenced and compared the function and composition of the gut microbiota of dogs and wolves by using metagenomic technology in order to analyze the changes of gut microbiota structure of dogs caused by domestication.This analyzing will provide a new evidence of system evolution of dogs and wolves.The fecal samples in this study were collected from four wolves and three dogs which living in Harilar,Inner Mongolia of China.We got almost 45 Gb data with99.4%effective rates after sequencing.We found that the top 3 dominant phyla of dogs and wolves are Bacteroidetes,Firmicutes,and Fusobacteria according to this result.The top 3 dominant genera are Bacteroides,Fusobacterium,and Prevotella.We also found that there is some bacterium have significant difference between dogs and wolves although there is no significant difference between the dominant bacterium.These significantly different bacteriums may have a relationship with the digestion of starch and cellulose,such as Ruminococcaceae,Spirochaetaceae,Lactobacillaceae,and Desulfuromonadaceae in family level and Streptobacillus,Desulfuromusa,Ruegeria,Lactobacillus,Carnobacterium,Faecalibacterium,and Treponema in genus level.According to the annotation results of KEGG database and CAZy database,we found that there are some enzymes which have significant difference between dogs and wolves may have a relationship with digestion of starch and cellulose either,such as EC:4.4.1.1,EC:3.2.1.33,EC:2.4.1.25,EC:3.2.1.1,EC:2.4.1.18,EC:3.2.1.54,and EC:3.2.1.70,etc.The findings obtained in our study provided a special insight into the different function and composition of the gut microbiome between dogs and wolves and,increased the understanding of the bacterial ecosystems in the canid.