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On average, the genomes of Asteraceae display a high proportion of TEs (70%), representing an excellent system to study plant genome evolution ([11]). Keywords: Asteraceae; Database; Transposable elements annotation EN Asteraceae Database Transposable elements annotation 365 367 3 04/19/23 20230401 NES 230401 Transposable elements (TEs) are interspersed repetitive DNA sequences that can move independently within the genome through specific transposition mechanisms. Furthermore, given its size, detailed annotation, and user-friendly implementation, ASTER-REP will be a useful platform to study transposon variability, helping to unravel the genome structure and improving transposon annotation for other plant genomes. [Extracted from the article]

The complement receptor 2 (CR2, CD21) is part of a complex (CD21/CD19/CD81) acting as a co-receptor to the B cell receptor (BCR). Simultaneous triggering of the BCR and CD21 lowers the threshold for B cell activation. Although CD21 is important, B cells that express low amounts or lack surface CD21 (CD21-/low) are increased in conditions with chronic inflammation, e.g. autoimmune diseases. However, little is known about the CD21-/low B cell subset in peripheral blood from healthy donors. Here, we show that CD21-/low cells represent approximately 5% of B cells in peripheral blood from adults but are barely detectable in cord blood, after excluding transitional B cells. The CD21-/low subset can be divided into CD38-24+ and CD38-24low cells, where most of the CD38-24+ are CD27+immunoglobulin (Ig)M+IgD+ and the CD38-24low are switched CD27-. Expression levels of additional markers, e.g. CD95 and CD62L, are similar to those on classical memory B cells. In contrast to naive cells, the majority of CD21-/low cells lack expression of the ABCB1 transporter. Stimulation with a combination of BCR, Toll-like receptor (TLR)−7/8 and interleukin (IL)−2 induces proliferation and differentiation of the CD21-/low B cells comparable to CD21+CD27+ memory B cells. The response excluding BCR agonist is not on par with that of classical memory B cells, although clearly above that of naive B cells. This is ascribed to a weaker response by the CD38-24low subset, implying that some memory B cells require not only TLR but also BCR triggering. We conclude that the CD21-/low cells in healthy donors are memory B cells. [ABSTRACT FROM AUTHOR]

Seagrasses such as Posidonia oceanica (L.) Delile are marine phanerogams, widespread in various seas, where they form large prairies representing dynamic substrates exceeding the area of the sediment surface several times over and allowing settlement of epiphyte organisms. Studying mechanisms involved in water transport in marine plants, we isolated two aquaporin-encoding genes, PoPIP1;1 and PoTIP1;1, showing high similarity to plasma membrane- and tonoplast-intrinsic protein-encoding genes, respectively. PoPIP1;1 is unique in the genome of P. oceanica, while PoTIP1;1 belongs to an aquaporin subfamily of at least four members. PoPIP1;1 and PoTIP1;1 encode functional proteins, as indicated by expression experiments in Xenopus oocytes. Both genes are constitutively expressed in the leaves, with higher levels of transcripts in young than in differentiated leaf tissues. Variations of salt concentration in aquarium determined different PoPIP1;1 and PoTIP1;1 transcript accumulation, indicating the existence of adaptation mechanisms related to gene expression also in marine plants, i.e. adapted to very high salt concentrations. Hyposalinity induced lower levels of PIP1 transcripts, while hypersalinity determined more PIP1 transcripts than normal salinity. TIP1 transcripts increased in response to both hypo- and hypersalinity after 2 days of treatment and went back to control levels after 5 d. [ABSTRACT FROM PUBLISHER]