Many animals, including zebrafish (Danio rerio), form social hierarchies as a result of competition for limited resources. Socially subordinate fish experience chronic activation of the hypothalamic-pituitary-interrenal (HPI) axis, leading to prolonged elevation of plasma cortisol, the glucocorticoid end-product of HPI axis activation. Elevated cortisol levels can reduce cellular proliferation and neurogenesis in the brain. Thus, the present study tested the hypothesis that social stress suppresses cellular proliferation in the brain of subordinate zebrafish via a cortisol-mediated mechanism. Cellular proliferation was assessed using the incorporation of 5-bromo-2'-deoxyuridine (BrdU), a thymidine analogue, as a marker. After 48 and 96 h of social interaction, significantly lower numbers of BrdU-positive cells were present in the forebrain of subordinate male zebrafish compared to dominant or control fish, suggesting a suppression of cellular proliferation in fish experiencing chronic social stress. Treatment of interacting male zebrafish with metyrapone, a cortisol synthesis inhibitor, attenuated the suppression of cellular proliferation in subordinate fish. Subordinate female zebrafish did not experience elevation of plasma cortisol or suppression of cellular proliferation in the forebrain. Collectively, these data provide evidence that cortisol plays a role in regulating cellular proliferation in the forebrain of male zebrafish during social interactions.

Pythons are a well-studied model of postprandial physiological plasticity. Consuming a meal has been shown by past work to evoke a suite of physiological changes in pythons and elicit one of the largest documented increases in post-feeding metabolic rates relative to resting values. However, little is known about how this plasticity manifests in the brains of ball pythons, Python regius. Previous work using the cell-birth marker 5-bromo-12’-deoxyuridine (BrdU) has shown that cell proliferation in the python brain increases six days following meal consumption. This study aimed to confirm these findings and build on them in the long term by tracking the survival and maturation of these newly created cells across a two-month period. We investigated whether these cells differentiated into neurons using double-immunofluorescence for BrdU and a reptile-specific neuronal marker (Fox3). We did not find significantly greater rates of cell proliferation in snakes six days after feeding, but we did observe more newly created cells in neurogenic regions in fed snakes two months after the meal. Feeding did not influence neurogenesis, but feeding does appear to have a neuroprotective effect. More newly created cells survived in fed snakes two months later, particularly in the olfactory bulbs and lateral cortex. These findings shed light on the extent of postprandial plasticity and regional differences in the creation of new neural cells in the brains of ball pythons.

No description available.

Através da meniscectomia no lado esquerdo, seguida ou não de enxerto, objetiva-se verificar as possíveis alterações nas superfícies articulares da ATM. Os animais formaram os grupos: GI (meniscectomia); GII (meniscectomia e enxerto); GIII (somente o acesso cirúrgico) que originaram subgrupos conforme o período pós-operatório (10 e 30 dias) e lado (direito e esquerdo). Nos animais GIII, GId, GIId, a Cm e a superfície articular da fossa mandibular (Fm) estavam organizadas em camadas com o predomínio de fibras colágenas do tipo I. Alterações morfológicas como erosão da Cm e Fm e amplos cistos subcondrais no osso subjacente foram verificadas nos animais GIe e GIIe. Em GIIe, a Cm apresentou um nível razoável de organização sob o enxerto. Fibras colágenas do tipo I constituíam as camadas articular e condroblástica nos animais GIe e GIIe e fibras do tipo III predominaram na camada pré-condroblástica. Amplos espaços vasculares eram evidentes na zona bilaminar dos animais GI e GII. / The morphological features of the temporomandibular joint (TMJ) of rats were studied after meniscectomy in the left side of the joint. The specimens were submitted or not to an interpositional auricular cartilage graft. The animals formed the following groups: GI (meniscectomy); GII (meniscectomy and graft); GIII (sham). The post-operative periods (10, 30 days) and the side allowed to form the subgroups. The articular surface of the TMJ exhibited organized layers (GIII, GId, GIId groups) where the type I collagen fibers arranged in regular nets prevailed. Morphological changes as erosion of the articular surface with large subchondral cysts in the subjacent bone were verified (GIe, GIIe). The condyle\'s surface of GII was regular and structurally preserved under the graft. The type I collagen fibers constituted the articular and chondroblastic layers in the GIe and GIIe animals where the type III collagen fibers were predominant in the prechondroblastic layer. Wide vascular spaces were evident in the bilaminar zone of the GI and GII animals.

Através da meniscectomia no lado esquerdo, seguida ou não de enxerto, objetiva-se verificar as possíveis alterações nas superfícies articulares da ATM. Os animais formaram os grupos: GI (meniscectomia); GII (meniscectomia e enxerto); GIII (somente o acesso cirúrgico) que originaram subgrupos conforme o período pós-operatório (10 e 30 dias) e lado (direito e esquerdo). Nos animais GIII, GId, GIId, a Cm e a superfície articular da fossa mandibular (Fm) estavam organizadas em camadas com o predomínio de fibras colágenas do tipo I. Alterações morfológicas como erosão da Cm e Fm e amplos cistos subcondrais no osso subjacente foram verificadas nos animais GIe e GIIe. Em GIIe, a Cm apresentou um nível razoável de organização sob o enxerto. Fibras colágenas do tipo I constituíam as camadas articular e condroblástica nos animais GIe e GIIe e fibras do tipo III predominaram na camada pré-condroblástica. Amplos espaços vasculares eram evidentes na zona bilaminar dos animais GI e GII. / The morphological features of the temporomandibular joint (TMJ) of rats were studied after meniscectomy in the left side of the joint. The specimens were submitted or not to an interpositional auricular cartilage graft. The animals formed the following groups: GI (meniscectomy); GII (meniscectomy and graft); GIII (sham). The post-operative periods (10, 30 days) and the side allowed to form the subgroups. The articular surface of the TMJ exhibited organized layers (GIII, GId, GIId groups) where the type I collagen fibers arranged in regular nets prevailed. Morphological changes as erosion of the articular surface with large subchondral cysts in the subjacent bone were verified (GIe, GIIe). The condyle\'s surface of GII was regular and structurally preserved under the graft. The type I collagen fibers constituted the articular and chondroblastic layers in the GIe and GIIe animals where the type III collagen fibers were predominant in the prechondroblastic layer. Wide vascular spaces were evident in the bilaminar zone of the GI and GII animals.

Made available in DSpace on 2015-03-26T13:47:12Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1681295 bytes, checksum: 41cbc7f4bb36b7a1d7c8d9f98b41a88f (MD5) Previous issue date: 2011-02-28 / The coati (Nasua nasua) belonging the order Carnivora and the family Procyonidae, does not configure the List of species in Brazilian fauna threatened of extinction from the Ministry of the Environment. On the contrary, its unstoppable population growth near urban areas has been causing economic, environmental and sanitary problems. The detailed study about reproductive characteristics of this species proves to be an important tool in reproductive biotechnologies application concerning to conservation as well as to its population control. The objectives on this work were to describe the stages of the seminiferous epithelium combining the techniques of tubular morphology method and acrossomic system method, besides determining the total duration of seminiferous epithelium cycle (SEC) with the incorporation of bromodeoxyuridine (BrdU). In this experiment six captive adult male animals were used. All six animals were used in the description of the stages, but only two were used in the measurement of SEC duration. The total duration of the seminiferous epithelium cycle in this species was calculated in 8,13 days and, as long as it takes approximately 4,5 cycles so that the whole spermatogenic process is complete, about 36,58 days are spent in the production of spermatozoa from a spermatogonia. / O quati (Nasua nasua) pertencente a ordem Carnívora e a família Procyonidae, não configura a Lista das Espécies da Fauna Brasileira Ameaçada de Extinção do Ministério do Meio Ambiente (MMA). Pelo contrário, seu desenfreado crescimento populacional próximo à áreas urbanas, vem causando transtornos de ordem econômica, ambiental e sanitária. O estudo detalhado acerca das características reprodutivas desta espécie é uma potencial ferramenta na aplicação de biotécnicas reprodutivas voltadas a programas tanto de conservação quanto para seu controle populacional em locais onde atuam sinantropicamente. Os objetivos deste estudo foram descrever os estádios do ciclo do epitélio seminífero associando as primícias do método da morfologia tubular com o método do sistema acrossômico, além de calcular a duração total do ciclo do epitélio seminífero (CES) com incorporação da bromodeoxiuridina (BrdU). Foram utilizados seis animais machos adultos provenientes de cativeiro. Todos os animais foram utilizados na descrição dos estádios, mas somente dois destes para o cálculo da duração do CES. A duração total do ciclo do epitélio seminífero foi calculada em 8,13 dias e com aproximadamente 4,5 ciclos do epitélio seminífero são necessários para que todo o processo espermatogênico seja completado, cerca de 36,58 dias são despendidos na produção de espermatozóides a partir de uma espermatogônia.

Ionizing radiation (IR) triggers many signaling pathways stemming from DNA damage, and, independently, from extra-nuclear events. To generate radio-mimetic DNA double-strand breaks (DSBs) without and minimizing the effects on extra-nuclear radiation targets, human (p53+) glioma and carcinoma cells containing bromodeoxyuridine (BrdU)- substituted DNA were treated with Hoechst 33258 followed by long wave-length UV (UV-A) (BrdU photolysis). BrdU photolysis resulted in well-controlled, dose-dependent generation of DSBs equivalent to 0.2 - 20 Gy of IR, as detected by pulse-field gel electrophoresis, accompanied by dose-dependent H2AX phosphorylation at ser-139 and ATM phosphorylation at ser-1981, indicating ATM activation. Furthermore, BrdU photolysis increased phosphorylation of Chk2 (at thr-68) and p53 (at ser-15). p53 phosphorylation was reduced by the ATM inhibitor caffeine, and H2AX phosphorylation was greatly reduced in AT cells, confirming that phosphorylation was primarily ATM-dependent. We also examined the effects of BrdU photolysis on the major cellular signaling ERK pathways. Interestingly, low-dose (≤ 2 Gy-equivalents) BrdU photolysis stimulated ERK1/2 phosphorylation whereas higher doses (≥ 5 Gy eq.) resulted in Em1/2 dephosphorylation. ERK1/2 phosphorylation was ATM-dependent, whereas dephosphorylation was ATM-independent and DSBs dose-dependent. Thus ERK1/2 appear to be both positively and negatively regulated by ATM depending on the severity of the insult to DNA. In summary, few DSBs trigger ATM-dependent ERK1/2 pro-survival signals whereas more DSBs result in ERK1/2 dephosphorylation consistent with a switch from pro-survival to anti-survival signaling that might affect DSBs repair.

The relationship between biodiversity and ecosystem functioning (BEF) is a central issue in soil and microbial ecology. To date, most belowground BEF studies focus on the diversity of microbes analyzed by barcoding on total DNA, which targets both active and inactive microbes. This approach creates a bias as it mixes the part of the microbiome currently steering processes that provide actual ecosystem functions with the part not directly involved. Using experimental extensive grasslands under current and future climate, we used the bromodeoxyuridine (BrdU) immunocapture technique combined with pair-end Illumina sequencing to characterize both total and active microbiomes (including both bacteria and fungi) in the rhizosphere of Trifolium pratense. Rhizosphere function was assessed by measuring the activity of three microbial extracellular enzymes (β-glucosidase, N-acetyl-glucosaminidase, and acid phosphatase), which play central roles in the C, N, and P acquisition. We showed that the richness of overall and specific functional groups of active microbes in rhizosphere soil significantly correlated with the measured enzyme activities, while total microbial richness did not. Active microbes of the rhizosphere represented 42.8 and 32.1% of the total bacterial and fungal taxa, respectively, and were taxonomically and functionally diverse. Nitrogen fixing bacteria were highly active in this system with 71% of the total operational taxonomic units (OTUs) assigned to this group detected as active. We found the total and active microbiomes to display different responses to variations in soil physicochemical factors in the grassland, but with some degree of resistance to a manipulation mimicking future climate. Our findings provide critical insights into the role of active microbes in defining soil ecosystem functions in a grassland ecosystem. We demonstrate that the relationship between biodiversity-ecosystem functioning in soil may be stronger than previously thought.

No description available.

No description available.