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The mechanisms underlying regeneration of the central nervous system (CNS) following lesions have been studied extensively in both vertebrate and invertebrate models. To shed light on regeneration, ascidians, a sister group of vertebrates and with remarkable ability to regenerate their brains, constitute an appropriate model system. Glial cells have been implicated in regeneration in vertebrates; however, their role in the adult ascidian CNS regeneration is unknown. A model of degeneration and regeneration using the neurotoxin 3-acetylpyridine (3AP) in the brain of the ascidian Styela plicata was used to identify astrocyte-like cells and investigate their role. We studied the CNS of control ascidians (injected with artificial sea water) and of ascidians whose CNS was regenerating (1 and 10 days after the injection with 3AP). Our results show that the mRNA of the ortholog of glutamine synthetase (GS), a glial-cell marker in vertebrates, is increased during the early stages of regeneration. Confirming the identity of GS, the protein was identified via immunostaining in a cell population during the same regeneration stage. Last, a single ortholog of GS (GSII) is present in ascidian and amphioxus genomes, while two types exist in fungi, some invertebrates, and vertebrates, suggesting that ascidians have lost the GSI type. Taken together, our findings revealed that a cell population expressing glial-cell markers may play a role in regeneration in adult ascidians. This is the first report of astrocyte-like cells in the adult ascidian CNS, and contributes to understanding of the evolution of glial cells among metazoans., (© 2024 Wiley Periodicals LLC.)

Enteric adenovirus (AdV), sapovirus (SaV), and human astrovirus (HAstV) are important pathogens involved in the gastroenteritis etiology. In this study, a total of 219 fecal samples and sera were collected from children hospitalized for acute gastroenteritis (AGE) in two large pediatric hospitals in Belém, from March 2012 to April 2015. The samples were analyzed by polymerase chain reaction (PCR) for AdV and HAstV (astrovirus) detection, and Nested-PCR and qPCR for SaV detection. AdV was detected in 50.2% (110/219) of the cases, with 42.7% (47/110) being sequenced and classified as: species F (63.9% - 30/47), A (4.2% - 2/47), B (6.4% - 3/47), C (17.1% - 8/47), D (4.2% - 2/47), and E (4.2% - 2/47). Of the 110 AdV-positive feces samples, 80 paired sera presented sufficient amounts and were also tested for this virus, of which 51 (63.7%) showed positive results and 26 (70.3%) pairs (feces plus sera) presented concordant results after sequencing being classified as: species F (21/26; 80.8%), A (1/26; 3.8%), B (1/26; 3.8%), and C (3/26; 11.5%). Overall, HAstV rate in the feces samples was 1.8% (4/219), including both HAstV-1a (2/4; 50%) and HAstV-2c (2/4; 50%). SaV was detected in 4.6% (10/219) of the fecal samples, out of which 50% (5/10) of the positive samples were characterized into the genogroups GI.1 (1), GI.2 (2), and GII.4 (2). These findings highlighted the important contributions of AdV, HAstV, and SaV in the enteric virus spectrum in our region and showed the high genetic diversity of AdV. In addition, it demonstrated for the first time in Brazil, the circulation of AdV in the serum of hospitalized children with AGE., (© 2018 Wiley Periodicals, Inc.)