Peculiarities of the molecular composition of heterochromatin associated with pronucleoli in mouse embryos

The nucleus of pre-implantation mammalian embryos is characterized by peculiar structural organization. At the initial stages of cleavage, the nucleus of the embryo contains the so-called nucleolus precursor bodies (NPBs) or pronucleoli rather than functionally active nucleoli. The NPBs are fibrillar electron-dense structures inactive in RNA synthesis. The vast majority of NPBs are surrounded by a ring-shaped zone of transcriptionally inactive heterochromatin. Intriguingly, these zones contain not only tri-methylated histone Н3K9me3 as an epigenetic mark of repressed chromatin but also acetylated histone H4K5ac, a well-known marker of active chromatin. Immunocytochemical data suggest that the molecular composition of this ‘ring heterochromatin’ in mouse embryos changes during the realization of embryonic genome activation events, as well as during artificial suppression of transcription. In zygotes, some factors of mRNA biogenesis including splicing factor SC35 (SRSF2) and basal transcription factor TFIID are detectable in the ring chromatin. At later stages of development, other nuclear proteins such as Y14, a core component of the exon-exon junction complex (EJC), as well as the proteins involved in chromatin remodeling (ATRX, Daxx) are also detectable in this area. A typical component of the ‘ring heterochromatin’ is actin. Anti-actin immunocytochemical labeling is most expressed at the two-cell cleavage stage after activation of the embryonic genome. Indicatively, the molecular composition of the ‘ring heterochromatin’ associated with different NPBs may differ significantly even in the same nucleus. This seems to reflect the functional heterogeneity of morphologically similar NPBs according to their competence to the process of nucleologenesis. Here, we discuss briefly some peculiarities of the molecular composition and possible functions of the NPB-associated heterochromatin in mouse early embryos

Histological characteristics and functional properties of red and white parts of m. semitendinosus of slaughter pigs

A unique muscle of pigs (Sus scrofa domesticus) is m. semitendinosus, which contains the “red” (dark) part located mainly in the depth of the leg cut and the “white” (light) part located in the close proximity to the subcutaneous fat layer. Differences in the characteristics of its “red” and “white” parts can exert a significant effect on quality and economic indicators of meat products. The aim of this research was to study histological features of the microstructure and technological properties of muscle tissue from different parts of m. semitendinosus, obtained from slaughter pigs of Russian production. M. semitendinosus was excised from chilled porcine carcasses (N=20) 24 hours after slaughter in the process of deboning. Histological examination showed that the dark part of the muscle was characterized by a higher package density of fibers, higher number of capillaries and higher sarcomere length. On the contrary, the light part was characterized by a higher diameter of muscle fibers. Analysis of muscle fiber types showed that the proportion of type I, intermediate and type IIb fibers was higher by 9.3, 5.2 and 4.1%, respectively, in the dark part. Significant differences between the dark and light parts of m. semitendinosus were revealed in terms of the number and size of giant fibers: the light part was characterized by a larger number (by more than 5 times) of giant fibers with the fibers of a larger size (almost by 11%). The samples of minced meat from the dark and light parts showed significant (р<0.05) differences in the mean values of lightness, redness and yellowness (L*, a* and b*) by 6.00, 4.68 and 3.01 units, respectively, in raw samples, and by 6.53, 2.99 and 1.81, respectively, after curing with the nitrite mixture and cooking (р<0.05). The dark part of m. semitendinosus had higher pH values (р<0.05) both for raw and cooked samples. The consistency of the samples from the light part was less elastic, looser and more crumbly than that in the samples produced from the dark part of m. semitendinosus, which was confirmed by the structural-mechanical investigations. Therefore, this study showed significant differences between the dark and light parts of m. semitendinosus by microstructural and functional-technological characteristics. Significant variability by muscle fiber diameter, which was observed in the light part of this muscle, apparently should be taken into account in breeding work and quality assessment of pork from slaughter animals

Project Activity - the Road to Forming an Environmental Culture

The article considers a study devoted to the analysis of project activities. The study was conducted with students of the Department of Cultural Studies and Design of the 1-4th year of full-time education (bachelor’s degree) at the Ural Federal University, during which the attitude of students to project activities and their involvement in it was studied. The views of students about project activities, their implementation at the university is considered, and the further possibility of the impact of project activities on the development of the ecological culture of a modern student is assessed.В статье рассмотрено исследование, посвященное анализу проектной деятельности. Исследование проведено со студентами кафедры культурологии и дизайна 1–4 курса очной формы обучения (бакалавриат) в Уральском федеральном университете, в ходе которого изучено отношение студентов к проектной деятельности и их вовлеченность в неё. Рассмотрены представления студентов о проектной деятельности, осуществлении ее в вузе, а также оценена дальнейшая возможность влияния проектной деятельности на развитие экологической культуры современного студента

Postslaughter state of muscle tissue of pigs depending on the duration of pre-slaughter fasting

Changes in the muscle tissue microstructure lead to changes in meat quality. One of the causes of the myopathy development is animal stress. Pigs experience the strongest stress during pre-slaughter holding. The study of the postmortem meat structure depending on fasting time is a topical task. The objects of the research were samples of m. L. dorsi obtained after slaughter from pigs that differed in fasting time: 4 (group 1), 8 (group 2), 10 (group 3), 16 (group 4) and 18 (group 5) hours (N = 20, n = 4). Investigation of the microstructure and morphometric measurements were carried out on preparations stained with hematoxylin and eosin. Myopathic changes in muscle tissue were assessed using a semi-quantitative method developed earlier. All studied samples were characterized by the uniform condition of muscle tissue. Statistically significant differences between individual groups were observed regarding the number and area of giant fibers, sarcomere length, diameter of muscle fibers and proportion of muscle fibers, which diameter was lower or higher by 1/3 than the mean fiber diameter. An increase in the pre-slaughter holding time reduced the number and area of giant fibers (r = –0.8437 and –0.5796, respectively), as well as the diameter of “normal” fibers (r = –0.5337), which positively influenced pork quality. Groups 1, 2 and 3 were characterized by the presence of signs of moderate and pronounced myopathy. Only one carcass with pronounced myopathic signs was revealed in each of groups 4 and 5. In group 4, one carcass did not have signs of myopathy. Pre-slaughter holding during 4, 8 and 10 hours led to deterioration of pork quality. The recommended fasting time is 16 hours

DETECTION OF AUTOANTIBODIES RECOGNIZING CANCERRETINA ANTIGEN RECOVERIN IN BLOOD OF PATIENTS WITH NON-INVASIVE FOLLICULAR THYROID NEOPLASMS WITH PAPILLARY-LIKE NUCLEAR FEATURES (NIFTP)

Autoantibodies recognizing the cancer-retina autoantigen called recoverin (RCVRN-AutoAb) may serve as a highly specific biomarker of cancer-associated retinopathy. However, they may also be found in some cancer patients without clinical evidence of retinopathy. In the present study, dot-ELISA and Western blot assays were used to demonstrate the presence of circulating RCVRN-AutoAb in 4/7 (57%) of patients with recently recognized pathological entity, non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP); other thyroid tumors represented by follicular adenomas, and classical and follicular variants of papillary thyroid carcinomas, demonstrated low frequencies of RCVRN-AutoAb (0/15, 1/20 (5%) and 1/15 (7%), respectively), with no significant differences from healthy individuals (0/15). Our data implicate the circulating RCVRN-AutoAb as a potential biomarker of NIFTP capable of discrimination of this novel pathological entity from other thyroid tumors

mRNA accumulation in the Cajal bodies of the diplotene larch microsporocyte

In microsporocytes of the European larch, we demonstrated the presence of several mRNAs in spherical nuclear bodies. In the nuclei of microsporocytes, we observed up to 12 bodies, ranging from 0.5 to 6 μm in diameter, during the prophase of the first meiotic division. Our previous studies revealed the presence of polyadenylated RNA (poly(A) RNA) in these bodies, but did not confirm the presence of nascent transcripts or splicing factors of the SR family. The lack of these molecules precludes the bodies from being the sites of synthesis and early maturation of primary transcripts (Kołowerzo et al., Protoplasma 236:13–19, 2009). However, the bodies serve as sites for the accumulation of splicing machinery, including the Sm proteins and small nuclear RNAs. Characteristic ultrastructures and the molecular composition of the nuclear bodies, which contain poly(A) RNA, are indicative of Cajal bodies (CBs). Here, we demonstrated the presence of several housekeeping gene transcripts—α-tubulin, pectin methylesterase, peroxidase and catalase, ATPase, and inositol-3-phosphate synthase—in CBs. Additionally, we observed transcripts of the RNA polymerase II subunits RPB2 and RPB10 RNA pol II and the core spliceosome proteins mRNA SmD1, SmD2, and SmE. The co-localization of nascent transcripts and mRNAs indicates that mRNA accumulation/storage, particularly in CBs, occurs in the nucleus of microsporocytes

(Table 2) Chemistry of the organic matter at DSDP Leg 62 Holes

The wide distribution of sapropelic deposits in the sedimentary cover of the oceans, their Cretaceous age, and their possible oil- and gas-generating characteristics allow us to regard these deposits as a regular global stage in the history of oceanic sedimentation. So, Cretaceous sapropelic deposits are a unique object for study. Cretaceous sapropelic deposits of DSDP Sites 463, 465, and 466, as well as similar sediments of the Atlantic and Indian Oceans, are characterized by enrichment in organic matter, which sometimes reaches 33% (Cape Verde Basin, DSDP Sites 367 and 368). The objective of this study is the elucidation of genesis, paleogeographic environment of sedimentation, and oil-generating potential of Cretaceous sapropelic deposits at these sites. Attention is given to petrographic composition and distribution of the organic matter

Composition of organic matter from black shales drilled in the Cape Verde Basin in DSDP Hole 41-367

Results of geochemical studies of organic matter in black shales from the Cape Verde Basin are reported. Based on these results, in combination with data of petrographic analysis, conclusions are made about sapropelic nature of their organic matter and low degree of its coalification. It corresponds to the proto-catagenetic substage of sedimentary rocks. Black shales of the Cape Verde Basin are classified as potential oil source strata