Anterograde monosynaptic transneuronal tracers derived from herpes simplex virus 1 strain H129

Abstract

BackgroundHerpes simplex virus type 1 strain 129 (H129) has represented a promising anterograde neuronal circuit tracing tool, which complements the existing retrograde tracers. However, the current H129 derived tracers are multisynaptic, neither bright enough to label the details of neurons nor capable of determining direct projection targets as monosynaptic tracer.MethodsBased on the bacterial artificial chromosome of H129, we have generated a serial of recombinant viruses for neuronal circuit tracing. Among them, H129-G4 was obtained by inserting binary tandemly connected GFP cassettes into the H129 genome, and H129-ΔTK-tdT was obtained by deleting the thymidine kinase (TK) gene and adding tdTomato coding gene to the H129 genome. Then the obtained viral tracers were tested in vitro and in vivo for the tracing capacity.ResultsH129-G4 is capable of transmitting through multiple synapses, labeling the neurons by green florescent protein, and visualizing the morphological details of the labeled neurons. H129-ΔTK-tdT neither replicates nor spreads in neurons alone, but transmits to and labels the postsynaptic neurons with tdTomato in the presence of complementary expressed TK from a helper virus. H129-ΔTK-tdT is also capable to map the direct projectome of the specific neuron type in the given brain regions in Cre transgenic mice. In the tested brain regions where circuits are well known, the H129-ΔTK-tdT tracing patterns are consistent with the previous results.ConclusionsWith the assistance of the helper virus complimentarily expressing TK, H129-ΔTK-tdT replicates in the initially infected neuron, transmits anterogradely through one synapse, and labeled the postsynaptic neurons with tdTomato. The H129-ΔTK-tdT anterograde monosynaptic tracing system offers a useful tool for mapping the direct output in neuronal circuitry. H129-G4 is an anterograde multisynaptic tracer with a labeling signal strong enough to display the details of neuron morphology.Electronic supplementary materialThe online version of this article (doi:10.1186/s13024-017-0179-7) contains supplementary material, which is available to authorized users.

WDR5 Facilitates Human Cytomegalovirus Replication by Promoting Capsid Nuclear Egress

“…The HCMV Towne strain (ATCC VR-977) and a recombinant HSV-1 H129 strain created in the Luo laboratory (84) were used in this study. HCMV and HSV-1 were propagated and titrated as described previously (44,(82)(83)(84)(85). Cells were synchronized by serum starvation prior to infection and then incubated with viral inocula for 2 h to allow for adsorption.…”

The BRAIN Initiative Cell Census Consortium: Lessons Learned toward Generating a Comprehensive Brain Cell Atlas

“…For retrograde monosynaptic tracing, i.e., labeling neurons directly presynaptic to a defined population, the original rabies virus -based system (Wickersham et al, 2007b) has been refined in ways that range from improvements in the complementing helper viruses (Kim et al, 2016; Kohara et al, 2014; Liu et al, 2017; Miyamichi et al, 2013; Wall et al, 2010) to the use of a rabies virus strain with reduced toxicity (Reardon et al, 2016) and the addition of a destabilization domain to the viral nucleoprotein (Ciabatti et al, 2017). Although there are fewer tools available, anterograde monosynaptic tracing – i.e., labeling neurons directly postsynaptic to a starting population – based on the vesicular stomatitis virus or herpes simplex virus has been described (Beier et al, 2011; Zeng et al, 2017). More recently, AAV serotype 1 and 9 were shown to cross synapses in the anterograde direction as well (Zingg et al, 2017).…”

Posterior basolateral amygdala to ventral hippocampal CA1 drives approach behaviour to exert an anxiolytic effect

“…Results a/pBLA innervates vCA1 along its superficial to deep axis. To map the innervation between aBLA or pBLA and vCA1, we first used trans-synaptic virus-delivered anterograde trackers 21 (GFP-H129-G4 and mCherry-H129-R4) to outline the circuits in physiological conditions. After injecting GFP-H129-G4 into aBLA and pBLA, respectively ( Supplementary Fig.…”