Heterogeneity and Polymorphism of Functionally Specialized Blood Proteins of Migratory Fish on the Example of the North Caspian Population of Russian Sturgeons during the Sea and River Periods of Life. 2. Hemoglobins

We carried out comparative studies of the heterogeneity and polymorphism of the most important functionally specialized blood proteins, hemoglobins. The fractional composition of hemoglobin proved to be identical during the sea and river periods of life for all main parameters (number of components, relative mobility, and protein content of each component). This puts the Russian sturgeon in a special position with reference to migratory teleostean fish, specifically salmonids, in which the specific weight of the protein of slow and fast hemoglobins undergoes changes upon change of the habitat.     

Genotypic and Functional Impact of HIV-1 Adaptation to Its Host Population during the North American Epidemic

HLA-restricted immune escape mutations that persist following HIV transmission could gradually spread through the viral population, thereby compromising host antiviral immunity as the epidemic progresses. To assess the extent and phenotypic impact of this phenomenon in an immunogenetically diverse population, we genotypically and functionally compared linked HLA and HIV (Gag/Nef) sequences from 358 historic (1979–1989) and 382 modern (2000–2011) specimens from four key cities in the North American epidemic (New York, Boston, San Francisco, Vancouver). Inferred HIV phylogenies were star-like, with approximately two-fold greater mean pairwise distances in modern versus historic sequences. The reconstructed epidemic ancestral (founder) HIV sequence was essentially identical to the North American subtype B consensus. Consistent with gradual diversification of a “consensus-like” founder virus, the median “background” frequencies of individual HLA-associated polymorphisms in HIV (in individuals lacking the restricting HLA[s]) were ∼2-fold higher in modern versus historic HIV sequences, though these remained notably low overall (e.g. in Gag, medians were 3.7% in the 2000s versus 2.0% in the 1980s). HIV polymorphisms exhibiting the greatest relative spread were those restricted by protective HLAs. Despite these increases, when HIV sequences were analyzed as a whole, their total average burden of polymorphisms that were “pre-adapted” to the average host HLA profile was only ∼2% greater in modern versus historic eras. Furthermore, HLA-associated polymorphisms identified in historic HIV sequences were consistent with those detectable today, with none identified that could explain the few HIV codons where the inferred epidemic ancestor differed from the modern consensus. Results are therefore consistent with slow HIV adaptation to HLA, but at a rate unlikely to yield imminent negative implications for cellular immunity, at least in North America. Intriguingly, temporal changes in protein activity of patient-derived Nef (though not Gag) sequences were observed, suggesting functional implications of population-level HIV evolution on certain viral proteins.     

Erratum to: Composition of Peripheral Blood Leukocytes of Pink Salmon Oncorhynchus gorbuscha and Chum Salmon O. keta (Salmonidae) during the Marine Life Period

Journal of Ichthyology - An Erratum to this paper has been published: https://doi.org/10.1134/S0032945222330025     

Effect of γ Irradiation on the Microflora of Freshwater Fish: III. Spoilage Patterns and Extension of Refrigerated Storage Life of Yellow Perch Fillets Irradiated to 0.1 and 0.2 Megarad1

Maximal shelf life was determined and microbial flora were compared for irradiated (0.1 and 0.2 Mrad) and nonirradiated yellow perch fillets stored at 1 C. Shelf life was estimated by organoleptic determinations. Microbiological studies included determination of the effects of irradiation on the total aerobic microbial population, lag phase, and rate of growth. Genera of organisms isolated from fillets through the course of microbial spoilage were identified, and the proteolytic activity of the organisms was determined. Plate counts for fish prior to irradiation showed the presence of approximately 10(6) organisms per g of sample. Irradiation to 0.1 and 0.2 Mrad produced 1.4 and 3 logarithm reductions of the initial count, respectively. Irradiation to 0.1 and 0.2 Mrad approximately doubled the product's shelf life. Organisms initially isolated from the nonirradiated fillets, in order of decreasing number, consisted of Flavobacterium, Micrococcus-Sarcina, Achromobacter-Alcaligenes-Mima, Pseudomonas, Microbacterium, Vibrio, Bacillus, Corynebacterium, Lactobacillus, Brevibacterium, and Aeromonas. By the 6th and 9th days of fillet storage, Pseudomonas and the Achromobacter group were the predominant organisms. All members of the genus Flavobacterium, but not all members of the genus Pseudomonas, were proteolytically active on raw fish juice-agar and skim milk-agar media. The Achromobacter group was found to be nonproteolytic on both media. Residual flora of fillets irradiated to 0.1 and 0.2 Mrad consisted of the Achromobacter group, Lactobacillus, Micrococcus-Sarcina, and Bacillus. Their sequence in predominance, however, varied with dose level. Not all proteolytic bacteria in the fillets were eliminated by 0.1 and 0.2 Mrad; proteolytic Micrococcus-Sarcina survived these treatments.     

Comparative Analysis of the Fatty Acid Profiles of Smolts of the Brown Trout <Emphasis Type="Italic">Salmo trutta</Emphasis> L. and Atlantic Salmon <Emphasis Type="Italic">Salmo salar</Emphasis> L. during Smoltification (Indera River,White Sea Basin)

The fatty acid status of the total lipids was studied in smolts of the brown trout and the Atlantic salmon collected in summer in the Indera River (White Sea basin). Higher 18:3ω-3/18:2ω-6, ω-3/ω-6, and 20:4ω-6/18:2ω-6 ratios were found in smolts of the Atlantic salmon in comparison to smolts of the brown trout. A higher amount of essential fatty acid 18:2ω-6 and an increased ratio of the sum of polyunsaturated fatty acids to the sum of saturated fatty acids in smolts of brown trout were observed. We have registered the differences in the ratios of the fatty acids, including physiologically active ones, which indicated species-specific physiological and biochemical processes during smoltification.