Phosphatidylserine (PS) expression on the cell membrane surface initiates multiple physiological processes, notably hemostasis, apoptosis, and immune regulation. Platelet activation via membrane flip-flop exposes PS on the outer leaflet. A cascade of inactive blood serine proteases is then activated by PS binding in the presence of Ca2+ ions, ultimately leading to clot formation. During coagulation, potent anticoagulant proteins, such as protein C and its cofactor protein S, are also activated. A deficiency in either of these factors increases the risk of thrombosis. Beta-2-glycoprotein I (β2GPI), a serine protease inhibitor, also binds to PS. Autoantibodies targeting PS, cardiolipin (CL), and β2GPI serve as markers for antiphospholipid syndrome. In efferocytosis and immune regulation, PS receptors play a crucial role. The structure and function of TIM (T-cell immunoglobulin and mucin domain) and TAM (Tyro3, Axl, and MerTK) receptors are well defined. Unlike TIM receptors, TAM receptors do not bind to PS directly; instead, their ligands Gas6 and protein S act as bridges by binding to PS. Phagocytes bearing these receptors clear apoptotic cells, support embryonic development, maintain homeostasis, and regulate immune responses to malignancies and infections. Notably, all lymphocyte subtypes exhibit some affinity for PS, with naive B lymphocytes showing the highest levels. Although several candidate molecules have been proposed as membrane receptors for PS, only a few are well characterized. This review aims to describe how under normal physiological conditions or in certain diseases, PS exposure on the cell membrane surface, through specific cell receptors or circulating proteins, induces a cascade of biological reactions.
In embryogenesis, Sox2, which is a pivotal transcription factor, plays an important role in regulating the development and maintenance of stem-cell populations. Many aspects of tissue differentiation are regulated by Sox2 during the developmental process. This study investigates the distribution of Sox2 in the developing tongue of the chick embryo at embryonic days 10, 15, and 19. Using immunohistochemistry and ELISA techniques, Sox2 was found to be strongly expressed in the epithelium of the developing tongue in all experimental stages. The expression of Sox2 was also observed in the cartilage tissues of the tongue at embryonic days 10 and 15, and in the lingual gland at embryonic day 19. Based on the results of this study, it could be speculated that Sox2 might play a role in regulating epithelial cell proliferation and tissue patterning. These findings highlight the importance of Sox2’s active role in tissue morphogenesis and stem cell regulation in the development of the chick tongue, which contribute to a better understanding of Sox2’s dynamic role during the developmental process.
The Permanent Preservation Area (PPA) of Morro da Glória, Brazil, is crucial for conserving biodiversity. Nevertheless, its location near an urban area makes it vulnerable to invasion by non-native species. This study reports, for the first time, an ecological interaction involving multiple species within this PPA, including the invasive ant Tetramorium bicarinatum, the whitefly Aleurothrixus floccosus, the non-native fungus Penicillium coffeae, and two host plants: the exotic Citrus sinensis and the native Eugenia uniflora. This interaction has not previously been documented in the literature or zoological catalogs. For monitoring, study areas were marked and observed three times daily throughout the spring and summer. The fungus was identified using molecular biology techniques, whereas the insects and plants were identified using taxonomic keys. Observations indicated that the fungus rapidly colonized whitefly nymphs and leaf surfaces, leading to increased defoliation through indirect stress on the plants. Citrus sinensis served as a pest reservoir, leading to the spillover of pests to native plants. The ant effectively exploited two food sources: honeydew and fungal biomass. This tri-trophic relationship highlights the potential risks posed by interactions of multiple non-native species within protected areas, reinforcing the necessity to monitor these PPAs.
Embelia ribes, a member of the subfamily Myrsinoideae within the family Primulaceae, is a widely distributed medicinally important plant and the primary source of embelin. Despite its wide distribution across South and Southeast Asia, and its medicinal importance, the genomics of E. ribes and the genus Embelia remain unexplored. In this study, the complete plastome sequence of E. ribes was determined and compared with those of 14 other plastomes from the families Primulaceae and Ebenaceae. The plastome of E. ribes spans 1,57,186 bp, and exhibits a quadripartite structure with a large single-copy region (86,681 bp), a small single-copy region (SSC; 18,248 bp), and a pair of inverted repeat (IR) regions (26,093 bp). The plastome comprises 134 genes, including 89 protein-coding genes, 8 rRNA genes, and 37 tRNA genes, of which 19 are duplicated in the IR region. The comparative plastome analysis revealed a conserved structure and gene content across the family, with minor IR boundary shifts. Six hypervariable regions and 61 simple sequence repeats were identified and can be used as potential tools for species identification and population genetic studies. Phylogenomics supports a close relationship of Embelia with Aegiceras and Myrsine. The study provides the complete plastome data of E. ribes, contributing to species delineation, evolutionary relationship studies, population genetics, and conservation.
