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Glycans are expressed as conjugates of glycoproteins, glycolipids, and proteoglycans. The huge diversity of glycans on glycoconjugates contributes to many biological processes, from glycan-based molecular recognition to developmental events, such as regeneration in the nervous system. Echinoderms, which have a close phylogenetic relationship with chordates, are an important group of marine invertebrates for body regeneration. Although many major roles of glycans on glycoconjugates are known, their role in the glycosylation profile of the nervous system in sea urchins is poorly understood. In this study, we aimed to determine the terminal glycan profile by lectin blotting and to quantify sialic acids by the capillary liquid chromatography electrospray ionization tandem mass spectrometry system in the nervous tissue of the sea urchin Paracentrotus lividus. We determined the N -acetyl-D-glucosamine, mannose, and sialic acids (mainly α2,3 linked) by lectin blotting and five types of sialic acids (N -glycolylneuraminic acid, N -acetylneuraminic acid, 9- O -acetyl- N -alycolylneuraminic acid, 5- N -acetyl-9- O -acetyl- N -acetylneuraminic acid, and di- O -acetylated- N -alycolylneuraminic acid) by capillary liquid chromatography electrospray ionization tandem mass spectrometry. This potential first description of the terminal glycan profile in the nervous system of the sea urchin is expected to help us understand its role in nervous system development and regeneration. [ABSTRACT FROM AUTHOR]

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The flow mechanism that is realized in 3-D depending on the fabric’s porosity structure determines the fabric’s permeability performance. During the flow movement that happens both in the in-plane and through-plane directions, not only the inter-yarn pore properties but inter-fiber pore properties play a significant role as well. The aim of this study is to offer a new method to identify intra-yarn porosity, which has mostly been neglected during the theoretical studies. In this method, initially the cross-sectional images of the cotton yarn in the fabric were achieved, and then the intra-yarn porosity was predicted via image processing and analysis steps. Besides, intra-yarn porosity was calculated theoretically depending on fiber and yarn parameters. The results that were obtained through the image analysis method and theoretical approaches were compared with the experimental data achieved by using Stereo Investigator. As a result, it was observed that the image analysis method was giving fast, objective, successful and expected results while predicting the intra-yarn porosity. [ABSTRACT FROM PUBLISHER]

Fine structure of synaptonemal complexes (SCs) was investigated in primary, spermatocytes of Galleria mellonella testes. In longitudinal sections, the SCs were discriminated as linear or curved rods in the prophase nuclei of the first meiotic division. These rods were attached to the inner surface of the nuclear envelope by their one end. Two electron dense axial or lateral elements were clearly distinguished in fine structure of the SCs. A central element was formed by parallel bands with a lesser electron density than the lateral elements. The diameters of the central and the lateral elements were 37 nm and 48.7 nm, respectively. The central element is embedded within the electron lucent central region. Fine transverse filaments crossing the central region between the lateral and central elements were seen. The width of this area was measured 40.4 nm. Taken together, total diameter of the SCs in the testes of G. mellonella reaches to 218 nm. [ABSTRACT FROM AUTHOR]

Transcription is a fundamental process involving the interaction of RNA polymerase II and related transcription factors. TFIIB is a transcription factor that plays a significant role in the formation and stability of the preinitiation complex in a precise orientation, as well as in the control of initiation and pre-elongation steps. At the initiation step, TFIIB interacts with three structures: the end of the TATA-binding protein, a GC-rich DNA sequence followed by the TATA box, and the C-terminal domain of RNA polymerase II. It is known that RNA polymerase II is a glycoprotein and contains O-GlcNAc sugar at the C-terminal domain during the initiation stage of transcription. However, it is unclear whether the transcription factors interacting with RNA polymerase II are glycoproteins or not. The study aims to determine the glycosylation (N- and/or O-linked glycosylations) of TFIIB by using bioinformatics in one invertebrate and seven vertebrate species and experimental methods in the sea urchin Paracentrotus lividus oocyte. Both bioinformatics and experimental analysis have shown that TFIIB is a glycoprotein. In addition, PNGase-F enzyme treatment, lectin blotting, and colloidal-gold conjugated lectin labeling results revealed that TFIIB contains O-linked GalNAc, mannose, GlcNAc, and α-2,3-linked sialic acid. Based on our results, we suggest that glycosylation modification may be involved in the transcription mechanism of the TFIIB protein.

Reelin is an extracellular matrix glycoprotein that plays a key role in cortical development, maturation, synaptic plasticity, and memory formation in the adult mammalian brain. Glycosylation is a significant post- and co-translational modification of proteins. Although glycosylation contributes to the characteristic of proteins from their production to molecular interactions, the knowledge about the glycosylation pattern of reelin is very limited. In this study, we aimed to predict the potential glycosylation pattern of the 5 th -6 th repeat of central reelin fragment that responsible for their signaling, by using in silico methods. We found that the predicted glycosylation pattern of the 5 th -6 th repeat of human reelin was highly conserved between vertebrate species. However, this conservation was not observed in analyzed invertebrates. For the first time, we described the sites of glycosylation at a three-dimensional protein structure in human reelin. Because the sites were very closed to EGF-like repeats and receptor binding sites, they could contribute the interaction with a partner of reelin in addition to the effect of thermostability to protein. Many of the residues related glycosylation were also conserved in analyzed species. These findings may guide biochemical, genetic, and glycobiology base on further experiments about reelin glycosylation. The understanding of reelin glycosylation might change the point of view of treatment for many pathological conditions in neurodegenerative diseases such as Alzheimer's disease. Communicated by Ramaswamy H. Sarma.