Deep Sequencing for Evaluation of Genetic Stability of Influenza A/California/07/2009 (H1N1) Vaccine Viruses

Virus growth during influenza vaccine manufacture can lead to mutations that alter antigenic properties of the virus, and thus may affect protective potency of the vaccine. Different reassortants of pandemic "swine" H1N1 influenza A vaccine (121XP, X-179A and X-181) viruses as well as wild type A/California/07/2009(H1N1) and A/PR/8/34 strains were propagated in embryonated eggs and used for DNA/RNA Illumina HiSeq and MiSeq sequencing. The RNA sequences of these viruses published in NCBI were used as references for alignment of the sequencing reads generated in this study. Consensus sequences of these viruses differed from the NCBI-deposited sequences at several nucleotides. 121XP stock derived by reverse genetics was more heterogeneous than X-179A and X-181 stocks prepared by conventional reassortant technology. Passaged 121XP virus contained four non-synonymous mutations in the HA gene. One of these mutations (Lys₂₂₆Glu) was located in the Ca antigenic site of HA (present in 18% of the population). Two non-synonymous mutations were present in HA of viruses derived from X-179A: Pro₃₁₄Gln (18%) and Asn₁₄₆Asp (78%). The latter mutation located in the Sa antigenic site was also detected at a low level (11%) in the wild-type A/California/07/2009(H1N1) virus, and was present as a complete substitution in X-181 viruses derived from X-179A virus. In the passaged X-181 viruses, two mutations emerged in HA: a silent mutation A₁₃₉₈G (31%) in one batch and G₇₅₆T (Glu₂₅₂Asp, 47%) in another batch. The latter mutation was located in the conservative region of the antigenic site Ca. The protocol for RNA sequencing was found to be robust, reproducible, and suitable for monitoring genetic consistency of influenza vaccine seed stocks.     

The Modern Status of Populations and Feeding Habits of the Longtail Dwarf Goby Knipowitschia longecaudata (Gobiidae) in the Don River Delta and the Eastern Part of Taganrog Bay

Journal of Ichthyology - The size and sex composition and feeding habits of the longtail dwarf goby Knipowitschia longecaudata have been studied in the Don River delta and in the eastern part of...     

Distribution of Ichthyoplankton in Relation to Specifics of Hydrological Regime off the Crimean coast (the Black Sea) in the Spring–Summer Season 2017

Journal of Ichthyology - The paper presents characteristics of the species composition, spatial distribution, and trophic interactions of ichthyoplankton and zooplankton in the spring–summer...     

Ichthyoplankton in the plankton community of the Crimean Peninsula shelf zone (Black Sea) in July 2010

Data on the species composition and quantitative distribution of ichthyoplankton, zooplankton, and jelly fish macroplankton from different areas of the Crimean Peninsula shelf zone in July 2010 are presented. It has been shown that the structure of species composition and the maximum abundance of ichthyoplankton are comparable to those in July 1988, i.e., until negative changes in the ecosystem of the Black Sea shelf, which took place in the 1990s. The average abundance of ichthyoplankton in July 2010 corresponds to the lowest long-term data obtained in July 1950s and 1960s. The effect produced by organochlorine contaminants and by the abundance of jelly fish macroplankton on the survival of pelagic fish eggs and fish larvae is studied. The prevalence of juvenile copepods in the guts of fish larvae, as well as the low proportion of fish larvae with empty stomachs (<10%), if compared to the data obtained in the 1990s (50–90%), point to the favorable trophical conditions for fish larvae in the area of investigation.     

State of the Ichthyoplankton Community along the Crimean Peninsula in August 2011

Data on species composition, spatial distribution of ichthyoplankton, and feeding of fish larvae in August 2011 are presented for the shelf and the open waters along the Crimean Peninsula from Kerch Strait to Karkinit Bay. In the ichthyoplankton, fish eggs and larvae represented 19 species from 16 families. The average egg abundance was 111 egg/m² and larvae abundance was 22 ind./m². The elimination ratio of the European anchovy Engraulis encrasicolus, which dominates in the plankton from the final stages of development to the prelarvae in 2011, was similar to that observed in 1957. The high number of larvae of the older age group in the western halistatic zone is explained by the peculiarities of the hydrological regime. Decrease in the pressure of predatory jelly macroplankton and an fodder zooplankton (zooplankton abundance) contribute to the survival of the fish larvae.