Dra. Gamboa-Mendez, Maribet

Bacterial nanocellulose (BNC) is a sustainable, renewable, and eco-friendly nanomaterial, which has gained great attentions in both academic and industrial fields. Two bacterial nanocellulose-producing strains (CVV and CVN) were isolated from apple vinegar sources, presenting high 16S rRNA gene sequence similarities (96%–98%) with Komagataeibacter species. The biofilm was characterized by scanning electron microscopy (SEM), revealing the presence of rod-shaped bacteria intricately embedded in the polymeric matrix composed of nanofibers of bacterial nanocellulose. FTIR spectrum and XRD pattern additionally confirmed the characteristic chemical structure associated with this material. The yields and productivities achieved during 10 days of fermentation were compared with Komagataeibacter xylinus ATCC 53524, resulting in low levels of BNC production. However, a remarkable increase in the BNC yield was achieved for CVV (690% increase) and CVN (750% increase) strains at day 6 of the fermentation upon adding 22 mM citrate buffer into the medium. This effect is mainly attributed to the buffering capacity of the modified Yakamana medium, which allowed to maintain pH close to 4.0 until day 6, though in combination with additional factors including stimulation of the gluconeogenesis pathway and citrate assimilation as a carbon source. In addition, the productivities determined for both isolated strains (0.850 and 0.917 g L−1 d−1) compare favorably to previous works, supporting current efforts to improve fermentation performance in static cultures and the feasibility of scaling-up BNC production in these systems.

Stream ecosystems are spatially heterogeneous, with many different habitat patches distributed within a small area. The influence of this heterogeneity on the biodiversity of benthic insect communities is well documented; however, studies of the role of habitat heterogeneity in species coexistence and assembly remain limited. Here, we investigated how habitat heterogeneity influences spatial structure (beta biodiversity) and phylogenetic structure (evolutionary processes) of benthic stonefly (Plecoptera, Insecta) communities. We sampled 20 sites along two Alpine rivers, including seven habitats in four different reaches (headwaters, meandering, bar-braided floodplain, and lowland spring-fed). We identified 21 morphological species and delineated 52 DNA-species based on sequences from mitochondrial cox1 and nuclear ITS markers. Using DNA-species, we first analysed the patterns of variation in richness, diversity, and assemblage composition by quantifing the contribution of each reach and habitat to the overall DNA-species diversity using an additive partition analysis and distance-based redundancy analysis. Using gene-tree phylogenies, we assessed whether environmental filtering could lead to the co-occurrence of DNA-species using a two-step analysis to detect a phylogenetic signal. All four reaches significantly contributed to DNA-species richness, with the meandering reach having the highest contribution. Habitats had an effect on DNA-species diversity, where glide, riffle and, pool influenced the spatial structure of stonefly assemblage possibly due to the high habitat heterogeneity. Among the habitats, the pool showed significant phylogenetic clustering, suggesting high levels of evolutionary adaptation and strong habitat filtering. This assemblage structure may be caused by long-term stability of the habitat and the similar requirements for co-occurring species. Our study shows the importance of different habitats for the spatial and phylogenetic structure of stonefly assemblage and sheds light on the habitat-specific diversity that may help improve conservation practices.

A morphological and molecular study of 17 Cylindrotomidae species revealed that the two subspecies of Cylindrotoma distinctissima, the Nearctic C. americana Osten Sacken, 1865, stat. reval. and the Palearctic C. distinctissima (Meigen, 1818), represent separated lineages and consequently are raised to species level. Cylindrotoma japonica Alexander, 1919, syn. nov. and C. distinctissima alpestris Peus, 1952, syn. nov. are now known to be junior synonyms of C. distinctissima. Triogma kuwanai limbinervis Alexander, 1953, syn. nov. and T. nimbipennis Alexander, 1941, syn. nov. are now placed into synonymy under Triogma kuwanai (Alexander, 1913). The Japanese Cylindrotomidae are all redescribed and all available literature and distribution data are summarised. Supplementary descriptions and illustrations for male and female terminalia of Cylindrotoma nigriventris Loew, 1849, Diogma dmitrii Paramonov, 2005, Liogma nodicornis (Osten Sacken, 1865), Phalacrocera replicata (Linnaeus, 1758), P. tipulina Osten Sacken, 1865, and Triogma trisulcata (Schummel, 1829) are provided. The following new distribution records are outlined; Diogma caudata Takahashi, 1960 from Arkhangelsk Oblast, Russia; D. glabrata (Meigen, 1818) from Belarus, Latvia, and Altai Republic, Amur Oblast, Novgorod Oblast, Magadan Oblast, Samara Oblast, and Kuril Islands (Shikotan I and Paramushir I) in Russia; Liogma serraticornis Alexander, 1919 from Khabarovsk Krai, Russia; Phalacrocera replicata from Khabarovsk Krai, Russia; and the presence of Cylindrotoma nigriventris in Altai Republic, Russia is confirmed.

Nuclear factor of activated T cells (NFAT) is a transcription factor essential for immunological and other biological responses. To develop analyzing system for NFAT activity in vitro and in vivo, we generated reporter mouse lines introduced with NFAT-driven enhanced green fluorescent protein (EGFP) expressing gene construct. Six tandem repeats of −286 to −265 of the human IL2 gene to which NFAT binds in association with its cotranscription factor, activator protein (AP)-1, was conjunct with thymidine kinase minimum promoter and following EGFP coding sequence. Upon introduction of the resulting reporter cassette into C57BL/6 fertilized eggs, the transgenic mice were obtained. Among 7 transgene-positive mice in 110 mice bone, 2 mice showed the designated reporter mouse character. Thus, the EGFP fluorescence of CD4+ and CD8+ T cells in these mice was enhanced by stimulation through CD3 and CD28. Each of phorbol 12-myristate 13-acetate (PMA) and ionomycin (IOM) stimulation weakly but their combined stimulation strongly enhanced EGFP expression. The stimulation-induced EGFP upregulation was also observed following T cell subset differentiation in a different manner. The EGFP induction by PMA + IOM stimulation was more potent than that by CD3/CD28 stimulation in helper T (Th)1, Th2, Th9, and regulatory T cells, while both stimulation conditions displayed the equivalent EGFP induction in Th17 cells. Our NFAT reporter mouse lines are useful for analyzing stimulation-induced transcriptional activation mediated by NFAT in cooperation with AP-1 in T cells.

The mechanisms of immunity linked to biological evolution are crucial for understanding animal morphogenesis, organogenesis, and biodiversity. The nuclear factor of activated T cells (NFAT) family consists of five members (NFATc1–c4, 5) with different functions in the immune system. However, the evolutionary dynamics of NFATs in vertebrates has not been explored. Herein, we investigated the origin and mechanisms underlying the diversification of NFATs by comparing the gene, transcript and protein sequences, and chromosome information. We defined an ancestral origin of NFATs during the bilaterian development, dated approximately 650 million years ago, where NFAT5 and NFATc1–c4 were derived independently. The conserved parallel evolution of NFATs in multiple species was probably attributed to their innate nature. Conversely, frequent gene duplications and chromosomal rearrangements in the recently evolved taxa have suggested their roles in the adaptive immune evolution. A significant correlation was observed between the chromosome rearrangements with gene duplications and the structural fixation changes in vertebrate NFATs, suggesting their role in NFAT diversification. Remarkably, a conserved gene structure around NFAT genes with vertebrate evolutionary-related breaking points indicated the inheritance of NFATs with their neighboring genes as a unit. The close relationship between NFAT diversification and vertebrate immune evolution was suggested.

The larva of the Balkan microendemic Isoperla vevcianensis Ikonomov, 1980 (Plecoptera: Perlodidae: Isoperlinae) is described on the basis of larvae associated with adults by means of cox1 sequences similarities. Eggs and everted penis of the male are described for the first time. The larva possessed blunt paraprocts which were previously sharp among Palaearctic larvae of this huge Holarctic and Oriental genus. The commonly pointed paraproct remains as the only distinguishing generic character for the morphologically diverse larvae of Palaearctic Isoperla, but should not be considered as an exclusive character state for the genus. Morphological characters are illustrated in comparison with the sympatric larvae of the Isoperla tripartita species complex.