野化培训与放归、野生大熊猫肠道菌群的组成和变化

Composition and variation of gut microbiome of trained, preparatory reintroduced, reintroduced and wild giant pandas

追踪采集1只亚成年大熊猫(Ailuropoda melanoleuca)在野化培训(N=4)、预放归(N=4)和放归(N=5)过程的粪样以及5个野生大熊猫粪样,基于高通量测序技术,研究大熊猫肠道细菌、真菌的组成和变化.结果发现,亚成年大熊猫肠道内细菌在门水平上以Firmicutes(61.33%)和Proteobacteria(35.09%)为主,在属水平上以Clostridium(39.68%)、Escherichia(20.94%)和Leuconostoc(8.75%)为主.真菌在门水平上以Ascomycota(81.56%),在属水平上以Humicola(26.43%)、Sphaerulina(12.42%)和Aspergillus(4.49%)为主.预放归大熊猫肠道细菌菌群的组成和放归大熊猫相似,但真菌菌群存在差异.随着培训—放归—野外的过程变化,细菌菌群丰富度和多样性差异不显著(P> 0.05),其中Chao-1指数呈上升趋势,而Shannon指数呈下降趋势.野外和培训大熊猫肠道真菌菌群的丰富度差异显著(P <0.05),Chao-1和Shannon指数均呈上升趋势.同时发现,在细菌菌群中Leuconostoc的比例持续上升,而Acinetobacter和Zea比例持续下降.真菌菌群中Stachybotrys、Fusarium、Retroconis和Debaryomyces的比例持续上升,Cryptococcus和Lulwoayna比例持续下降.Clostridium、Bacillus、Sphaerulina和Aspergillus在放归过程中比例最高.本研究结果表明预放归过程肠道菌群不稳定,且真菌菌群的变化较明显,建议放归过程中缩短预放归时间;总体而言,野化培训与放归大熊猫肠道菌群的多样性、丰富度和结构组成逐渐向野生大熊猫趋近,野化培训与放归有利于大熊猫肠道菌群的重建,提高放归大熊猫的存活率.(图6表2参37)

This study aims to investigate the composition and variation of gut bacteria and fungi of juvenile giant pandas (GPs) during different stages: training (N = 4), preparatory reintroduction (N = 4), and reintroduction (N = 5). The samples from the juvenile GPs as well as 5 feces samples from wild GPs were analyzed using high-throughput sequencing technology to investigate the relationship between the gut microbiome and the survival rate of GPs. The results showed that, at phylum level, the bacteria in juvenile giant pandas mainly consisted of Firmicutes (61.33%) and Proteobacteria (35.09%), and the fungi mainly consisted of Ascomycota (81.56%). At genus level, the bacteria mainly consisted of Clostridium sp.(39.68%), Escherichia sp.(20.94%) and Leuconostoc sp.(8.75%), while the fungi mainly consisted of Humicola sp.(26.43%), Sphaerulina sp.(12.42%) and Aspergillus sp.(4.49%). The composition of bacteria in preparatory reintroduced GPs was similar to that of reintroduced GPs, contrarily, the composition of fungal communities was opposite. The richness and diversity of bacteria showed no significant difference between trained, preparatory reintroduced, and wild GPs. Contrarily, the richness of fungi showed significant differences between wild vs. trained, and wild vs. preparatory reintroduced GPs. However, in bacterial communities, the proportion of Leuconostoc sp. increased continuously over the four stages, while Acinetobacter sp. and Zea sp. decreased. In fungal communities, the proportion of Stachybotrys sp., Fusarium sp., Retroconis sp., and Debaryomyces sp. displayed a continuous increase, while Cryptococcus sp. and Lulwoayna sp. decreased over the four stages. Additionally, the proportions of Clostridium sp., Bacillus sp., Sphaerulina sp., and Aspergillus sp. in reintroduced GPs were larger than those in other groups. The study showed that GPs gut microbiome fluctuated during the prejaratory reintroduction stage, especially fungi. Thus, we suggested shorter preparatory reintroduction stage. In general, the richness, diversity, and composition of the gut microbiome in trained and reintroduced GPs gradually approached that of wild GPs. Besides, training and reintroduction can help the GPs reestablish their gut microbiome and improve the survival rate.