Ceria Nanoparticles-Decorated Microcapsules as a Smart Drug Delivery/Protective System: Protection of Encapsulated P. pyralis Luciferase

Russian Science Foundation project 17-73-1041

Mobile DNA elements in T4 and related phages

Mobile genetic elements are common inhabitants of virtually every genome where they can exert profound influences on genome structure and function in addition to promoting their own spread within and between genomes. Phage T4 and related phage have long served as a model system for understanding the molecular mechanisms by which a certain class of mobile DNA, homing endonucleases, promote their spread. Homing endonucleases are site-specific DNA endonucleases that initiate mobility by introducing double-strand breaks at defined positions in genomes lacking the endonuclease gene, stimulating repair and recombination pathways that mobilize the endonuclease coding region. In phage T4, homing endonucleases were first discovered as encoded within the self-splicing td, nrdB and nrdD introns of T4. Genomic data has revealed that homing endonucleases are extremely widespread in T-even-like phage, as evidenced by the astounding fact that ~11% of the T4 genome encodes homing endonuclease genes, with most of them located outside of self-splicing introns. Detailed studies of the mobile td intron and its encoded endonuclease, I-TevI, have laid the foundation for genetic, biochemical and structural aspects that regulate the mobility process, and more recently have provided insights into regulation of homing endonuclease function. Here, we summarize the current state of knowledge regarding T4-encoded homing endonucleases, with particular emphasis on the td/I-TevI model system. We also discuss recent progress in the biology of free-standing endonucleases, and present areas of future research for this fascinating class of mobile genetic elements

Changes to the Fossil Record of Insects through Fifteen Years of Discovery

The first and last occurrences of hexapod families in the fossil record are compiled from publications up to end-2009. The major features of these data are compared with those of previous datasets (1993 and 1994). About a third of families (>400) are new to the fossil record since 1994, over half of the earlier, existing families have experienced changes in their known stratigraphic range and only about ten percent have unchanged ranges. Despite these significant additions to knowledge, the broad pattern of described richness through time remains similar, with described richness increasing steadily through geological history and a shift in dominant taxa, from Palaeoptera and Polyneoptera to Paraneoptera and Holometabola, after the Palaeozoic. However, after detrending, described richness is not well correlated with the earlier datasets, indicating significant changes in shorter-term patterns. There is reduced Palaeozoic richness, peaking at a different time, and a less pronounced Permian decline. A pronounced Triassic peak and decline is shown, and the plateau from the mid Early Cretaceous to the end of the period remains, albeit at substantially higher richness compared to earlier datasets. Origination and extinction rates are broadly similar to before, with a broad decline in both through time but episodic peaks, including end-Permian turnover. Origination more consistently exceeds extinction compared to previous datasets and exceptions are mainly in the Palaeozoic. These changes suggest that some inferences about causal mechanisms in insect macroevolution are likely to differ as well

Ceria nanoparticles boost activity of aged murine oocytes

Oocyte meiotic maturation and viability of follicular granulosa cells in young and old experimental Balb/C and CBA mice in the presence of ceria nanoparticles were studied. Treatment of old Balb/c mice with ceria nanoparticles for three days once a day (at a dose of 45 mg/kg) leads to a positive effect on reproductive system. The number of oocytes in follicles increases and this effect is accompanied by an increase in the number of oocytes at metaphase Ⅰ and metaphase Ⅱ. The number of living granulosa cells increases, while percentage of the necrotic and apoptotic ones decreases relative to control group. Data obtained on CBA mice provided additional evidence for positive effect of ceria nanoparticles. Depending on the initial state of the reproductive system and dose of ceria nanoparticles the effectiveness of the treatment will vary. In case of old mice ceria nanoparticles protect ovarian cells against oxidative damage, working as anti-aging agent. The litter size in old mice treated with the CNs increases too