0~360日龄藏绵羊瘤胃真菌群落的动态演替

Dynamic Succession of the Rumen Fungal Community in Tibetan Sheep from 0 To 360 Days of Age

为研究放牧条件下藏绵羊从出生到成年瘤胃真菌群落的动态演替过程,采集9个时间点(0、2、7、14、28、42、56、70和360日龄)27只藏绵羊瘤胃液,进行ITS基因测序。结果表明:瘤胃真菌的动态演替过程与日龄和饮食因素有关,在门水平上占优势的真菌包括子囊菌门(Ascomycot),新鞭毛菌门(Neocallimastigomycota)和担子菌门(Basidiomycota)(>75%的总相对丰度)。在门水平上,子囊菌门(Ascomycot)和新鞭毛菌门(Neocallimastigomycota)丰度随日龄的增长显著变化。从D0~D360,子囊菌门(Ascomycot)相对丰度由75.4%下降到10%,新鞭毛菌门(Neocallimastigomycota)相对丰度由0.5%上升到86.1%。在属水平上,真菌群落呈现日龄相关性。D2的优势属为复膜孢酵母属(Saccharomycopsis)和分枝孢子菌属(Cladosporium),D70的优势属为新丽鞭毛菌属(Neocallimastix)。综上所述,绵羊瘤胃真菌的演替过程受饲养条件和日龄的显著影响,在出生后第1天未发育的瘤胃即出现真菌,研究结果为研究瘤胃真菌在放牧羔羊体内的定植过程提供了新的视角,有助于制定新的管理策略,促进目标真菌的定植,从而改善宿主的瘤胃消化代谢功能。

To investigate the dynamic succession process of the rumen fungal community in Tibetan sheep from birth to adulthood under grazing conditions,rumen fluid from 27 Tibetan sheep was collected for internal transcribed spacer(ITS)gene sequencing at nine time points(0,2,7,14,28,42,56,70,and 360 days(D)of age;n=3).The results showed that the succession of ruminal fungi was related to age and diet during adulthood,and the dominant fungi at the phylum level included Ascomycota,Neocallimastigomycota,and Basidiomycota(>75%total relative abundance).At the phylum level,the abundance of Ascomycota and Neocallimastigomycota varied greatly with increased age.From D0-D360,the relative abundance of Ascomycota was reduced from 75.4%to 10%and the relative abundance of Neocallimastigomycota was increased from 0.5%to 86.1%.At the genus level,the fungal communities were age-related.The dominant genera at D2 were Saccharomycopsis and Cladosporium,and the dominant genus at D70 was Neocallimastix.This study indicated that the succession process of rumen fungi was greatly affected by feeding conditions and the age of sheep,and the presence of fungi was detected in the undeveloped rumen on the first day after birth.This study provides a new perspective for studying the colonization process of rumen fungi in grazing lambs and may help to develop new management strategies promoting target fungal colonization that may improve the rumen function of the host.