In addition, a stronger blockage occurred at n – 1 with Dpo4, compared with that using Kf-exo–.
To make a stronger blockage, we integrated a modified thymidine residue with biotin TEG (at position nt 6, from the 5′ ssDNA), which increases the oligo biotin distance to 15 atoms by using a triethyleneglycol (TEG) spacer.
Intrinsic mechanisms exist, which limit the escalation energetics even in case of a strong blockage confinement suppressing any fuel discharge and allowing on-going sloshing recriticalities.
Moreover, the Drosophila data suggest that it is possible to identify infected lines demonstrating strong blockage, strong cytoplasmic incompatibility and no apparent fitness effects on the host.
In subsequent experiments, this strain was shown to have very strong blockage of viral replication and disease transmission in laboratory assays (Moreira et al. 2009).
It is possible that Wolbachia infections that provide the strongest blockage of pathogen transmission might not spread easily into populations (Fig. 1).
In mosquitoes, Wolbachia presence in a variety of tissues through which a virus needs to pass to be transmitted may be crucial for generating strong transmission blockage; for instance, wMelPop which causes strong blockage is found in many tissues including the salivary glands of Ae. aegypti (Moreira et al. 2009).
Recent data for wMel feeding on blood from infected human patients also point to strong blockage of dengue in saliva but show some differences among serotypes (Ferguson et al. 2015).
The Drosophila data indicate that strains such as wAu with strong blockage, no deleterious effects, high densities and no cytoplasmic incompatibility exist in populations alongside strains such as wHa that cause strong cytoplasmic incompatibility, but no blockage or large deleterious effects.
A range of infections with different combinations of attributes occur in natural populations, including strains that might exhibit relatively strong blockage while also being able to easily spread in the absence of over replication after eclosion, and a high density in reproductive tissues to ensure strong cytoplasmic incompatibility and high maternal transmission.
The wMel infection was also transferred to Ae. albopictus where it causes strong blockage of chikungunya virus and dengue in laboratory assays, but has no apparent effects on longevity, hatch rates or other laboratory fitness parameters, despite generating strong cytoplasmic incompatibility (Blagrove et al. 2012, 2013).
