Vol 517, No 1 (2024)

Fragments of two skulls of young cetotherium baleen whales have been described from the Fortep’yanka 2 locality (Russia, Republic of Adygea, Maikop district, Fortep’yanka river valley, Upper Miocene, Upper Sarmatian, Blinovskaya Formation). Based on the morphology of the posterior (mastoid) process of the petrous bone, the structure of the posterior edge of the temporal fenestra, and the S-shaped shape of the superoccipital ridges, the finds were attributed to Kurdalagonus maicopicus (Spasskii, 1951). The proportions of the skull and the degree of closure of the sutures of the skull made it possible to determine the individual age of these whales within a year. New findings significantly complement the data on the structure of the sutures of the lateral wall of the skull and age-related variability of cranial morphology in representatives of the genus Kurdalagonus.

For the first time, the hair cover and hair microstructure of an adult male Hydropotes inermis from the Primorsky region of Russia were studied using light and scanning electron microscopy. The absence of abundant underfur, sparse wool and its weak layering are characteristic of this inhabitant of the temperate monsoon and tropical zones, which does not need an effective thermal protection.The alveolar and lattice medulla of the hair is similar to that of other deer, is well developed, and increases the heat-protective properties of the hair, since seasonal and daily fluctuations in temperature and humidity can be significant. The cuticle pattern is similar to that of deer tribes Alceini and Capreolini. The hair serves as reliable protection for the water deer from mechanical damage when moving through thickets of bushes and grasses along the banks of rivers and swamps in the biotopes that this deer inhabits, which is facilitated by the significant thickness and length of the hairs on the back, sides and thighs. The knotty nature of the hairs protects the deer’s skin from the sharp growths of aquatic and marsh plants.

The content of N and P in the leaves of the following five families of monocots was studied: Poaceae, Cyperaceae, Orchidaceae, Iridaceae, Amaryllidaceae. It was found that species of different families of monocots had different N and P content and ratio in their leaves. N content was low in Iridaceae and high in Amaryllidaceae. P content was the lowest in Cyperaceae and Poaceae and the highest in Amaryllidaceae and Iridaceae. The minimum N/P ratio was in Iridaceae, the maximum in Poaceae. Thus, the content of N and P and their ratio is specific in different families of monocots.

More than 90% of the world’s population are carriers of herpes simplex virus type 1 (HSV-1). The infection manifests itself in the formation of blisters and ulcers on the face or genitals, and can cause blindness, encephalitis, and generalized infection. All modern first- and second-line antiherpetic drugs selectively inhibit viral DNA-polymerase. The purine-benzoxazine conjugate LAS-131 [(S)-4-[6-(purin-6-yl)aminohexanoyl]-7,8-difluoro-3,4-dihydro-3-methyl-2H-[1,4]benzoxazine], which we described earlier, uses the large subunit of the HSV-1 terminase complex as a biotarget and selectively inhibits its reproduction in vitro. For the first time, we have obtained fundamentally new results on the combined effect of LAS-131 on human herpesvirus infection with practically significant antiviral compounds – nucleoside analogues (acyclovir [ACV], penciclovir [PCV], ganciclovir [GCV], brivudine [BVDU], iododeoxyuridine [IDU], adenine arabinoside [Ara-A], as well as a nucleoside phosphonate analogue (cidofovir [CDV]) and a pirophosphate analogue (foscarnet [FOS]). Using a inhibition assay of cytopathic effect (CPE) induced by a virus, it was shown that when combined with LAS-131, the concentrations of the compounds in combinations providing inhibition of HSV-1-induced CPE by 50%, decreased by 2 times (additive effect, FOS) or more (synergistic effect, ACV, PCV, GCV, IDU, BVDU, Ara-A, CDV). Reducing the concentrations of agents creates non-permissive conditions for the reproduction of HSV-1 and opens up new real possibilities for controlling human herpesvirus infection.

Transvection is a phenomenon of interallelic communication in which enhancers can activate a specific promoter located on a homologous chromosome. Insulators play a significant role in ensuring functional interactions between enhancers and promoters. In the presented work, we created the model where two or three copies of the insulator are located next to enhancers and promoters localized on homologous chromosomes. Using the Su(Hw) insulator as model, we showed that the functional interaction between a pair of insulators promotes enhancer-promoter trans interactions. The interaction between the three insulators, on the contrary, can lead to the formation of chromatin loops that sterically hinder the full enhancer-promoter interaction. The results of the work suggest the participation of insulators in the regulation of homologous chromosome pairing and in communication between distant genomic loci.

Nucleoli shape inter-chromosomal contacts with genes controlling differentiation and cancer genesis. DUX4 genes specify transcription factor possessing two homeodomains. Previously, using Circular Chromosome Conformation Capture (4С) approach on population of cells, it was demonstrated that DUX4 gene clusters form frequent contacts with nucleoli. It was found also that these contacts are almost completely abolished after heat shock treatment. 4C approach as all ligation-mediated methods is capable to detect rather close interactions between chromatin loops in nuclei. In order to independently confirm the formation and the frequency of the contacts in single cells we used FISH approach. Here, we show that DUX genes in single cells form stable contacts in all tested HEK293T cells. The contacts after heat shock treatment reversibly retreat up to 1–3 μm distance. We conclude that inter-chromosomal contacts shaping by nucleoli are dynamic and stable providing both the initiation and maintenance of a differentiated state.