A ROLE FOR CELLULAR IMMUNITY IN EARLY POSTPARTUM PERIOD

The functioning of the secretory organs is closely related to the activity of the immune system. As is well known, this participation is manifested in the fact that at certain stages of activity, the lymphoid cells migrating to the organ can be involved in the regulation of secretion. In addition, the products of the immune system and even its cellular elements can become components of a number of secrets. Colostrum and milk contain a large number of cells of a wide spectrum (up to 1/3 of the volume), of which the number of lymphocytes is up to 16% of leukocytes. Lymphocytes, in an immunologically active form, entering the newborn’s body with colostrum, activate the cellular immunity system. The transport of lymphokinin mediators plays a certain role in this process. Microphages, T- and B-lymphocytes, penetrating through the intercellular spaces into the lymphoid layer of the intestine, transmit immunoreceptors to the prolymphocytes of the newborn, "armed" with their activity to recognize genetically foreign ones. The lymphocytes contained in colostrum are the cells of the immune system that provide cellular and humoral immunity. They are mainly represented by T-cells, B-cells and killer cells. Milk T-cells produce a full spectrum of immune regulatory proteins such as interferon, tumor necrosis factor alpha. These cells are the cells of the immune memory. Newborns who received the first portion of colostrum no later than an hour after birth are characterized by an increased number of leukocytes, more pronounced phagocytosis, which indicates the stimulation of hemo- and lymphocytosis. When carrying out transmission and scanning electron microscopy in the epithelial layer of the intestine, cellular elements were found that got there from the intestinal lumen. Microsections show how cells of a lymphoid nature, pushing apart the structures of the epithelial layer, bypass natural barriers and, at the same time, retain their physiological usefulness. The possibility of penetration of immunocompetent cells of the mother’s colostrum into the bloodstream of the young is proved using the natural label of the female’s cells – sex chromatin. Naturally, sex chromatin-labeled cells were sought in male newborns. The detection of colostrum cells in the intestinal wall and bloodstream of the young is approximately 25% in the blood, 1% in the lymph, and about 70% in the intestine. There is no doubt that the leukocytes of colostrum are of exceptional importance in creating immunity in newborn animals.

Degenerated, Undifferentiated, Rearranged, Lost: High Variability of Sex Chromosomes in Geometridae (Lepidoptera) Identified by Sex Chromatin

Sex chromatin is a conspicuous body that occurs in polyploid nuclei of most lepidopteran females and consists of numerous copies of the W sex chromosome. It is also a cytogenetic tool used to rapidly assess the W chromosome presence in Lepidoptera. However, certain chromosomal features could disrupt the formation of sex chromatin and lead to the false conclusion that the W chromosome is absent in the respective species. Here we tested the sex chromatin presence in 50 species of Geometridae. In eight selected species with either missing, atypical, or normal sex chromatin patterns, we performed a detailed karyotype analysis by means of comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). The results showed a high diversity of W chromosomes and clarified the reasons for atypical sex chromatin, including the absence or poor differentiation of W, rearrangements leading to the neo-W emergence, possible association with the nucleolus, and the existence of multiple W chromosomes. In two species, we detected intraspecific variability in the sex chromatin status and sex chromosome constitution. We show that the sex chromatin is not a sufficient marker of the W chromosome presence, but it may be an excellent tool to pinpoint species with atypical sex chromosomes.

Meiotic sex chromosome cohesion and autosomal synapsis are supported by Esco2

In mitotic cells, establishment of sister chromatid cohesion requires acetylation of the cohesin subunit SMC3 (acSMC3) by ESCO1 and/or ESCO2. Meiotic cohesin plays additional but poorly understood roles in the formation of chromosome axial elements (AEs) and synaptonemal complexes. Here, we show that levels of ESCO2, acSMC3, and the pro-cohesion factor sororin increase on meiotic chromosomes as homologs synapse. These proteins are less abundant on the largely unsynapsed sex chromosomes, whose sister chromatid cohesion appears weaker throughout the meiotic prophase. Using three distinct conditional Esco2 knockout mouse strains, we demonstrate that ESCO2 is essential for male gametogenesis. Partial depletion of ESCO2 in prophase I spermatocytes delays chromosome synapsis and further weakens cohesion along sex chromosomes, which show extensive separation of AEs into single chromatids. Unsynapsed regions of autosomes are associated with the sex chromatin and also display split AEs. This study provides the first evidence for a specific role of ESCO2 in mammalian meiosis, identifies a particular ESCO2 dependence of sex chromosome cohesion and suggests support of autosomal synapsis by acSMC3-stabilized cohesion.

Absence of W Chromosome in Psychidae Moths and Implications for the Theory of Sex Chromosome Evolution in Lepidoptera

Moths and butterflies (Lepidoptera) are the largest group with heterogametic females. Although the ancestral sex chromosome system is probably Z0/ZZ, most lepidopteran species have the W chromosome. When and how the W chromosome arose remains elusive. Existing hypotheses place the W origin either at the common ancestor of Ditrysia and Tischeriidae, or prefer independent origins of W chromosomes in these two groups. Due to their phylogenetic position at the base of Ditrysia, bagworms (Psychidae) play an important role in investigating the W chromosome origin. Therefore, we examined the W chromosome status in three Psychidae species, namely Proutia betulina, Taleporia tubulosa, and Diplodoma laichartingella, using both classical and molecular cytogenetic methods such as sex chromatin assay, comparative genomic hybridization (CGH), and male vs. female genome size comparison by flow cytometry. In females of all three species, no sex chromatin was found, no female-specific chromosome regions were revealed by CGH, and a Z-chromosome univalent was observed in pachytene oocytes. In addition, the genome size of females was significantly smaller than males. Overall, our study provides strong evidence for the absence of the W chromosome in Psychidae, thus supporting the hypothesis of two independent W chromosome origins in Tischeriidae and in advanced Ditrysia.

X Chromatin inactivation in Menopause: A study on Hindu caste Bengalee population

Background: Menopause being a physiologic event and eventually the prime time to perform risk assessment of chronic diseases and initiate preventive health measures. Previous studies reported, later menopause is independently associated to increased risk of breast and endometrial cancer. The menopausal status is determined and influenced by intrinsic factors. Majority of the studies on menopause from Indian context, especially on Bengalee Hindu Caste population confined to socio demographic issues, attitudes, problems and quality of life. However, relatively little work is attempted to unravel the complex interplay of genetics and epigenetic mechanisms, the effect on menopause. In this background it seems to be an urgent need to understand menopause status objectively, to approach the interplay of genetics and epigenetic mechanisms of menopausal status by X chromatin inactivation.Aims and Objective: Best of the knowledge it is the first attempt to evaluate the prevalence of X chromatin inactivation in menopausal women among Bengalee Hindu Caste population.Materials and Methods: Sex chromatin inactivation was evaluated from 100 each pre and post menopausal women from the buccal smear of each individuals. After fixation and staining of altogether 20000 (twenty thousand) cells were scanned from the Bengalee Hindu Caste for a comparison of menopausal women and their menarcheal counterparts.Results: Result demonstrated significantly decreased (P<0.001) prevalence of X chromatin inactivation sites among the menopausal females in comparison to their menarcheal women counterpart.Conclusion: The present study vindicated possible association between the presence of sex hormone receptors and the prevalence of sex chromatin and also envisaged the role of X chromatin inactivation for early prognosis of menopause.Asian Journal of Medical Sciences Vol.9(3) 2018 41-45