Rabies Virus Pseudotyped with CVS-N2C Glycoprotein as a Powerful Tool for Retrograde Neuronal Network Tracing

Efficient viral vectors for mapping and manipulating long-projection neuronal circuits are crucial in structural and functional studies of the brain. The SAD strain rabies virus with the glycoprotein gene deleted pseudotyped with the N2 C glycoprotein(SAD-RV(DG)-N2 C(G)) shows strong neuro-tropism in cell culture, but its in vivo efficiency for retrograde gene transduction and neuro-tropism have not been systematically characterized.We compared these features in different mouse brain regions for SAD-RV-N2 C(G) and two other widely-used retrograde tracers, SAD-RV(DG)-B19(G) and r AAV2-retro. We found that SAD-RV(DG)-N2 C(G) enhanced the infection efficiency of long-projecting neurons by^10 times but with very similar neuro-tropism, compared with SAD-RV(DG)-B19(G). On the other hand, SAD-RV(DG)-N2 C(G) had an infection efficiency comparable with r AAV2-retro, but a more restricted diffusion range, and broader tropism to different types and regions of longprojecting neuronal populations. These results demonstrate that SAD-RV(DG)-N2 C(G) can serve as an effective retrograde vector for studying neuronal circuits.

Comparison of physicochemical characteristics and microbiome profiles of low-temperature Daqu with and without adding tartary buckwheat

There is increasing interest in the utilization of tartary buckwheat(TB)for making various fermented foods due to its unique starch structure and functional features.However,studies on Daqu starter produced with TB as a raw material are lacking.This study aimed to compare the differences between conventional low-temperature Daqu(NDQ;65%barley and 35%pea)and Daqu made with TB(BDQ;55%barley,30%pea,and 15%TB)in physicochemical properties,microbial communities,and volatile and nonvolatile metabolites.Compared with NDQ,BDQ exhibited higher saccharifying power,liquefying power,acid protease activity,and lower pH value.High-throughput sequencing revealed that the microbial community structure of NDQ and BDQ had significant differences.NDQ were enriched in Kroppenstedtia,Bacillus,Saccharomycopsis,Issatchenkia,Cladosporium,and Aspergillus,while BDQ were dominated by Kroppenstedtia,Comamonas,Pseudomonas,Acinetobacter,Rhizopus,and Saccharomycopsis.There were notable distinctions in volatile and nonvolatile metabolomic profiles between NDQ and BDQ.The physicochemical differences between NDQ and BDQ were driven by their different microbiota,which also led to the inconsistency of their metabolite profiles.The bacterial community was significantly correlated with pH and acid protease activity,whereas the fungal community was only strongly correlated with saccharifying power.In addition,the correlation network demonstrated that the resident dominant microbes in Daqu had strong connections to numerous important volatile and nonvolatile compounds.This study provided a detailed insight into the microbiome characteristics that differ between the NDQ and BDQ,and it can be helpful to develop a TB-based starter applied in making traditional fermented foods.