Lack of Mitochondrial DNA Provides Metabolic Advantage in Yeast Osmoadaptation.

Alterations in mitochondrial function have been linked to a variety of cellular and organismal stress responses including apoptosis, aging, neurodegeneration and tumorigenesis. However, adaptation to mitochondrial dysfunction can occur through the activation of survival pathways, whose mechanisms are still poorly understood. The yeast Saccharomyces cerevisiae is an invaluable model organism for studying how mitochondrial dysfunction can affect stress response and adaptation processes. In this study, we analyzed and compared in the absence and in the presence of osmostress wild-type cells with two models of cells lacking mitochondrial DNA: ethidium bromide-treated cells (ρ0) and cells lacking the mitochondrial pyrimidine nucleotide transporter RIM2 (ΔRIM2). Our results revealed that the lack of mitochondrial DNA provides an advantage in the kinetics of stress response. Additionally, wild-type cells exhibited higher osmosensitivity in the presence of respiratory metabolism. Mitochondrial mutants showed increased glycerol levels, required in the short-term response of yeast osmoadaptation, and prolonged oxidative stress. The involvement of the mitochondrial retrograde signaling in osmoadaptation has been previously demonstrated. The expression of CIT2, encoding the peroxisomal isoform of citrate synthase and whose up-regulation is prototypical of RTG pathway activation, appeared to be increased in the mutants. Interestingly, selected TCA cycle genes, CIT1 and ACO1, whose expression depends on RTG signaling upon stress, showed a different regulation in ρ0 and ΔRIM2 cells. These data suggest that osmoadaptation can occur through different mechanisms in the presence of mitochondrial defects and will allow us to gain insight into the relationships among metabolism, mitochondria-mediated stress response, and cell adaptation.

Survey of Animal Neoplastic Cases Diagnosed in Nigerian Veterinary Teaching Hospitals, 2000-2017.

Incidence data from 17-year veterinary neoplasm surveillance and registration were reviewed. Most of the neoplastic cases diagnosed in Nigerian veterinary teaching hospitals (VTHs) were in the avian (49%) and canine species (44%). Fewer cases were recorded in the equine (3.2%), bovine (2.4%), ovine (1.5%), caprine (0.3%) and porcine (0.15%) species. Marek's disease was the most prevalently diagnosed neoplastic disease of domestic animals in Nigerian VTHs from 2000-2017. Also, the Nigerian local breed had a higher mean distribution than any other dog breed and this was statistically significant (p < 0.05). Nearly all of the neoplastic cases diagnosed, were found in females (60.4%) and so the mean distribution of sex was statistically significant (p < 0.05). The digestive system, with 296 (46.25%) cases, was the anatomic location where the majority of the neoplastic cases were found. However, the mean distribution of different neoplastic anatomic sites was not statistically significant (p > 0.05). In conclusion, little emphasis is given to the appropriate diagnosis and recording of neoplastic cases that are diagnosed. The study provides information regarding the prevalence and distribution of tumours in different animal species consulted in Nigeria veterinary teaching hospitals. To illustrate all of this, ArcGIS software was used. Veterinary clinicians, pathologists and epidemiologists from Nigeria may benefit from the results of this study by freely accessing some specific data regarding the breed, the age group or the gender of some animal species diagnosed with different tumours.

A Matlab-based application for quantification of yeast cell growth on solid media.

Quantitative assessment of growth and survival is a suitable technique in studying biochemical, genetic and physiological processes in the cells. The budding yeast Saccharomyces cerevisiae is one of the most widely used eukaryotic model organisms for studying cellular mechanisms and processes in evolutionarily distant species, including humans. Yeast growth can be evaluated on both liquid and solid media by measuring cell suspension turbidity and colony forming units, respectively. Several software tools utilizing different parameters have been proposed to quantify yeast growth on solid media. Here, we developed a Matlab-based application which provides a rapid and robust quantitative yeast growth analysis from spot plating assay. Spot plating assay is a typical procedure to evaluate yeast growth in low-throughput laboratory settings, including growth on different nutrient sources or treatment with specific stressors. The app has a one-step installation process, a self-explanatory interface and shorter analysis steps compared with previous established methods, providing a useful tool for both expert and non-expert yeast researchers.

Inactivation of HAP4 Accelerates RTG-Dependent Osmoadaptation in Saccharomyces cerevisiae.

Mitochondrial RTG (an acronym for ReTroGrade) signaling plays a cytoprotective role under various intracellular or environmental stresses. We have previously shown its contribution to osmoadaptation and capacity to sustain mitochondrial respiration in yeast. Here, we studied the interplay between RTG2, the main positive regulator of the RTG pathway, and HAP4, encoding the catalytic subunit of the Hap2-5 complex required for the expression of many mitochondrial proteins that function in the tricarboxylic acid (TCA) cycle and electron transport, upon osmotic stress. Cell growth features, mitochondrial respiratory competence, retrograde signaling activation, and TCA cycle gene expression were comparatively evaluated in wild type and mutant cells in the presence and in the absence of salt stress. We showed that the inactivation of HAP4 improved the kinetics of osmoadaptation by eliciting both the activation of retrograde signaling and the upregulation of three TCA cycle genes: citrate synthase 1 (CIT1), aconitase 1 (ACO1), and isocitrate dehydrogenase 1 (IDH1). Interestingly, their increased expression was mostly dependent on RTG2. Impaired respiratory competence in the HAP4 mutant does not affect its faster adaptive response to stress. These findings indicate that the involvement of the RTG pathway in osmostress is fostered in a cellular context of constitutively reduced respiratory capacity. Moreover, it is evident that the RTG pathway mediates peroxisomes-mitochondria communication by modulating the metabolic function of mitochondria in osmoadaptation.

Biological and technical challenges for implementation of yeast-based biosensors.

Biosensors are low-cost and low-maintenance alternatives to conventional analytical techniques for biomedical, industrial and environmental applications. Biosensors based on whole microorganisms can be genetically engineered to attain high sensitivity and specificity for the detection of selected analytes. While bacteria-based biosensors have been extensively reported, there is a recent interest in yeast-based biosensors, combining the microbial with the eukaryotic advantages, including possession of specific receptors, stability and high robustness. Here, we describe recently reported yeast-based biosensors highlighting their biological and technical features together with their status of development, that is, laboratory or prototype. Notably, most yeast-based biosensors are still in the early developmental stage, with only a few prototypes tested for real applications. Open challenges, including systematic use of advanced molecular and biotechnological tools, bioprospecting, and implementation of yeast-based biosensors in electrochemical setup, are discussed to find possible solutions for overcoming bottlenecks and promote real-world application of yeast-based biosensors.

Important Mycoses of Wildlife: Emphasis on Etiology, Epidemiology, Diagnosis, and Pathology-A Review: PART 1.

In the past few years, there has been a spurred tripling in the figures of fungal diseases leading to one of the most alarming rates of extinction ever reported in wild species. Some of these fungal diseases are capable of virulent infections and are now considered emerging diseases due to the extremely high number of cases diagnosed with fungal infections in the last few decades. Most of these mycotic diseases in wildlife are zoonotic, and with the emergence and re-emergence of viral and bacterial zoonotic diseases originating from wildlife, which are causing devastating effects on the human population, it is important to pay attention to these wildlife-borne mycotic diseases with zoonotic capabilities. Several diagnostic techniques such as fungal isolation, gross pathology, histopathology, histochemistry, cytology, immunohistochemistry, radiography, CT, and molecular methods such as PCR or ELISA have been invaluable in the diagnosis of wildlife mycoses. The most important data used in the diagnosis of these wildlife mycoses with a zoonotic potential have been re-emphasized. This will have implications for forestalling future epidemics of these potential zoonotic mycotic diseases originating from wildlife. In conclusion, this review will highlight the etiology, epidemiology, diagnosis, pathogenesis, pathogenicity, pathology, and hematological/serum biochemical findings of five important mycoses found in wild animals.

Important Mycosis of Wildlife: Emphasis on Etiology, Epidemiology, Diagnosis, and Pathology-A Review: PART 2.

Wild animals are an important component of the ecosystem, and play a major role in it. However, in recent years, there has been an astronomical increase in the incidence of wildlife mycotic diseases leading to wildlife extermination. It is important to note that most of these mycotic diseases are zoonotic, and since there is a lot of attention given to zoonosis of a bacterial or viral origin in recent times, it is important to look into the mycotic diseases which may have zoonotic potential. Previously, the authors expatiated on some major wildlife mycotic diseases. In this review, we shed light on the etiology, epidemiology, diagnosis, pathogenesis, pathogenicity, macroscopic and microscopic pathology, and hematological and serum biochemical findings of dermatophytosis, coccidioidomycosis, blastomycosis, and sporotrichosis, which are very important mycoses of wildlife.

Ameliorative effects of L-glutamine on haematological parameters in heat-stressed Red Sokoto goats.

The aim of the study was to evaluate haematological responses in Red Sokoto goats (RSGs) administered with L-glutamine during the hot-dry season. Experimental animals included 28 clinically healthy RSGs divided into treated group (n = 14); each administered L-glutamine at 0.2 g/kg body weight, dissolved in 10 mL distilled water, and control group (n = 14); each administered 10 mL distilled water, per os once daily for 21 days. The ambient temperature and relative humidity recorded daily for 4 weeks were used to calculate the temperature-humidity index. Three millilitres of blood sample was collected from each goat by jugular venipuncture for haematology, while rectal temperature (RT), heart rate (HR) and respiratory rate (RR) were also measured once weekly at weeks 0 (before), 1, 2, 3 (during) and 4 (after L-glutamine administration). The haematological, RT, HR and RR data obtained weekly were analysed using repeated-measures one-way ANOVA, followed by Tukey's post-hoc test to evaluate differences between periods, and between treated and control groups. The PCV, haemoglobin concentration and RBC count were higher (P < 0.05) in the treated group compared to the control group during the period of L-glutamine administration. These differences were sustained till week 4. Beginning from week 1 of the study, the total leucocyte count in treated group (10.10 ± 0.25 × 103/µL) was higher (P < 0.05) than the count in control group (7.23 ± 0.41 × 103/µL), this trend was also maintained throughout the study. The neutrophil:lymphocyte ratio during weeks 3 and 4 of the experiment was lower (P < 0.05) in the treated compared to the control group. RT was lower (P < 0.05) in treated group than the control group. In conclusion, L-glutamine administration ameliorated the adverse effects of heat stress on the haematological parameters in RSGs during the hot-dry season.

Osteocyte viability and bone density in cadmium chloride-induced osteoporosis ameliorated with Pilostigma thonningii stem bark-extracted D-3-O-methy-chiroinositol.

BACKGROUND: This study examined the ameliorative effect of D-3-O-methyl-chiroinositol, isolated from the stem bark of Piliostigma thonningii, on cadmium chloride-induced osteoporosis in male Wistar rats. METHODS: Thirty-six rats were assigned to three treatment groups (n = 12). Group A (2 mL distilled water), group B: (2.5 mg/kg b.w. CdCl2) and group C: (2.5 mg/kg b.w. CdCl2 and D-3-O-methyl-chiroinositol 2 mg/kg b.w.). Bone ash, calcium, phosphate, magnesium, and zinc content, as well as bone histological changes were determined at the end of months 1, 2, and 3. RESULTS: There were significant differences (P ≤ 0.05) in the weight of the cervical, tibia, and femoral bones in all groups. The serum concentration of CdCl2 was significantly different across the three groups with time. There was significant variation (P < 0.005) in the mean bone ash across groups. The concentration of OH-proline was significantly different (P < 0.0001) across groups. There were significant differences (P < 0.0001) in bone calcium, magnesium, zinc, and phosphorus concentrations. Histology revealed high levels of bone mineralisation in the CdCl2-treated group, indicative of osteoporosis with hypertrophied osteocytes, while the femur of Wistar rats treated with D-3-O-methyl-chiroinositol showed bone trabeculae and viable osteocytes. CONCLUSION: The study concluded that D-3-O-methyl-chiroinositol extract from Piliostigma thionningii stem bark ameliorated cadmium chloride-induced osteoporosis in male Wistar rats.

Betaine and ascorbic acid modulate indoor behavior and some performance indicators of broiler chickens in response to hot-dry season.

Heat stress causes lipid peroxidation in poultry, necessitating antioxidant administration. The experiment evaluated the modulating effects of betaine and ascorbic acid (AA) on indoor behavior and some performance parameters of broiler chickens during the hot-dry season. Experimental groups were: Group I (control) was daily given sterile water; Group II, betaine at 250 mg/kg; Group III, AA (50 mg/kg), and Group IV, betaine (250 mg/kg) + AA (50 mg/kg), orally for 42 days. The natural occurring dry-bulb temperature (28.0-37.0 °C), relative humidity (69.0-93.0%), and temperature-humidity index (27.9-36.1 °C) were predominantly outside the thermo-neutral zone for broiler chickens, indicating heat stress conditions. Scan test, used to assess the percentage of birds sitting/lying, panting, feeding, drinking and spreading wings, was performed at 06:00 h, 13:00 h and 18:00 h on each of days 35 and 42. Feed intakes (FD), water consumption (WC), body weight, average daily weight gain (ADG) and feed-to-gain ratio (FGR) were obtained. Betaine+AA reduced (P < 0.05) percentage of birds panting; AA decreased (P < 0.05) percentage of birds spreading wing, compared with control. Finisher phase: betaine and/or AA, decreased FGR, increased ADG (P < 0.05); betaine reduced (P < 0.01) FD compared with control. Grower phase: betaine, either alone or with AA, lowered FGR and FD (P < 0.01); AA reduced (P < 0.01) FD, compared with control. Starter phase: betaine and/or AA decreased WC (P < 0.05); AA lowered FGR, compared with controls. Betaine administration decreased (P < 0.05) FD at 4 week-old, but its administration, either alone or with AA, reduced WC at 1 week-old, compared with control. Overall, betaine and/or AA group lowered FGR compared with controls. In conclusion, administration of betaine and/or AA to broiler chickens modulated indoor behavior, some performance indicators and water consumption during the hot-dry season.

Effects of L-glutamine on rectal temperature and some markers of oxidative stress in Red Sokoto goats during the hot-dry season.

The experiment investigated the ameliorative effects of L-glutamine administration on rectal temperature (RT), erythrocyte osmotic fragility (EOF), serum antioxidant enzyme activities and malondialdehyde (MDA) concentration in Red Sokoto goats during the hot-dry season. Twenty eight healthy Red Sokoto goats, comprising 14 experimental (administered 0.2 g/kg of L-glutamine dissolved in 10 mL of distilled water, once daily for 21 days) and 14 control (administered equivalent of distilled water) goats served as subjects. Rectal temperature (measured at 6:00, 13:00 and 18:00 h) and blood samples (taken at 8:00 h) were obtained from all subjects weekly, before, during and after L-glutamine administration. Data obtained were compared using one-way repeated-measures ANOVA, followed by Tukey's post-hoc test. The dry-bulb temperature, relative humidity and temperature-humidity index for the study period ranged between 24.0 and 37.5 °C, 26.0 and 84.0% and 73.0 and 86.3, respectively. L-glutamine administration decreased (P < 0.05) RT, EOF and MDA and increased superoxide dismutase (SOD) activity in experimental group, compared to controls during weeks 1, 2 and 3. Glutathione peroxidase (GPx) and catalase activities were higher (P < 0.05) in the experimental group than in the controls only during week 1 of L-glutamine administration. In conclusion, L-glutamine administration mitigated increases in RT, EOF and serum MDA concentration and enhanced serum SOD, GPx and catalase activities and may be beneficial in heat-stressed goats during the hot-dry season.