Interspecific variation and functional traits of the gut microbiome in spiders from the wild: The largest effort so far.

Spiders being one of the most diverse group in phylum arthropod are of great importance due to their role as predators, silk producer, and in medicinal applications. Spiders in prey-predator relationships play a crucial role in balancing the food-chain of any ecosystem; therefore it is essential to characterize the gut microbiota of spiders collected from natural environments. In the present work, the largest effort so far has been made to characterize the gut microbiota of 35 spider species belonging to four different families using 16S amplicon targeting sequencing. Further, we compared the gut microbiota composition including endosymbiont abundance in spider species collected from different geographical locations. The results obtained revealed the presence of genera like Acinetobacter (15%), V7clade (9%), Wolbachia (8%), Pseudomonas (5%), Bacillus (6%). Although comparative analysis revealed that the gut bacterial composition in all the spider families has a similar pattern, in terms of community richness and evenness. The bacterial diversity in the spider family, Lycosidae are more diverse than in Salticidae, Tetragnathidae and Araneidae. Furthermore, it was observed that the abundance of endosymbiont genera, i.e. Wolbachia and Rickettsia, leads to shift in the abundance of other bacterial taxa and may cause sexual alterations in spider species. Moreover, predicted functional analysis based on PICRUSt2 reveals that gut microbiota of spider species were involved in functions like metabolism of carbohydrates, cofactors and vitamins, amino acids; biosynthesis of organic compounds, fatty acids, lipids etc. Based on the results obtained, it can be said that different locations do not correlate with community composition of gut microbiota in spider species collected from natural environments.