Mitochondrial unfolded protein response gene Clpp is required to maintain ovarian follicular reserve during aging,for oocyte competence,and development of pre‐implantation embryos

Caseinolytic peptidase P mediates degradation of unfolded mitochondrial proteins and activates mitochondrial unfolded protein response (mtUPR) to maintain protein homeostasis. Clpp^?/? female mice generate a lower number of mature oocytes and two‐cell embryos, and no blastocysts. Clpp^?/? oocytes have smaller mitochondria, with lower aspect ratio (length/width), and decreased expression of genes that promote fusion. A 4‐fold increase in atretic follicles at 3 months, and reduced number of primordial follicles at 6–12 months are observed in Clpp^?/? ovaries. This is associated with upregulation of p‐S6, p‐S6K, p‐4EBP1 and p‐AKT473, p‐mTOR2481 consistent with mTORC1 and mTORC2 activation, respectively, and Clpp^?/? oocyte competence is partially rescued by mTOR inhibitor rapamycin. Our findings demonstrate that CLPP is required for oocyte and embryo development and oocyte mitochondrial function and dynamics. Absence of CLPP results in mTOR pathway activation, and accelerated depletion of ovarian follicular reserve.     

Bergmann's and Rensch's rules and the spur‐thighed tortoise (Testudo graeca)

Body size is an ecologically important variable in animals. The geographical size variation of most snakes and some lizards counters Bergmann's rule in that, among related taxa, the larger ones live at warmer latitudes. However, exceptions notwithstanding, and despite being ectothermic, turtles as a group tend to obey Bergmann's rule. We examined this idea in Testudo graeca, ranging from Morocco to Romania and to Iran with disputed systematics, both at the global scale (using literature) and within the focal area of Israel (using museum specimens). Both globally and locally, carapace length correlated with latitude, in accordance with Bergmann's rule. The scant data on reproduction fully support the hypothesis that Bergmann's rule enables larger clutches where the climate would limit repeated clutches. The sexual size dimorphism (SSD) was approached using two methodologies: (1) ‘conventional’, using globally literature data and locally museum samples and (2) ‘innovated’, using photographs of copulating tortoises from Israel and Turkey. By each methodology, SSD emerged as being male biased in the larger‐bodied populations and female biased in the smaller‐bodied populations, obeying Rensch's rule. Some observations support the hypothesis that the evolution of large males serves intermale combating. Finally, Rensch's rule was found to apply separately within Anatolia and within the Levant, possibly indicating that these populations are separate.     

Effects of Continuous and Intermittent Magnetic Fields on Oxidative Parameters In vivo

Continuous and intermittent 50 Hz, 1.5 mT magnetic field with the exposure period of 4 h/day for 4 days was used to investigate its possible effect on adult guinea pigs. Tissues and plasma specimens were assessed by biochemical parameters. Malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO) levels and myeloperoxidase activity (MPO) were examined in plasma, liver and brain tissues. All parameters were determined by spectrophotometer. While intermittent magnetic field was effective on plasma lipid peroxidation, continuous magnetic field was found to be effective on plasma MPO activity and NO levels. Augmentation of lipid peroxidation was also observed in liver tissue both intermittent and continuous magnetic field exposures. These results indicate that both the intermittent and continuous magnetic field exposures affect various tissues in a distinct manner because of having different tissue antioxidant status and responses.     

Lethal and sublethal effects of preimaginal treatments with two pyrethroids on the life history of the egg parasitoid <Emphasis Type="Italic">Telenomus busseolae</Emphasis>

The egg parasitoid Telenomus busseolae Gahan (Hymenoptera: Scelionidae) is one of the most important natural enemies of the Mediterranean corn stem borer, Sesamia nonagrioides Lefebvre (Lepidoptera: Noctuidae). The effects of lethal and sublethal concentrations of two commonly used pyrethroids, deltamethrin and cyfluthrin, on emergence, fecundity, longevity, and offspring sex ratio of T. busseolae exposed during different preimaginal stages were studied. The insecticide, the tested concentrations of the insecticide (field-recommended concentration and three dilutions with twofold concentration decreases), and the stage of parasitoid preimaginal development (first and second larval stages and pupae) all significantly influenced the percentage of emergence. Life history parameters of parasitoids exposed to the highest and lowest tested concentrations of the two insecticides (3.0 and 0.375 ml l⁻¹ for cyfluthrin and 0.5 and 0.0625 ml l⁻¹ for deltamethrin) at eight days post-oviposition (pupal stage) were calculated. The intrinsic rate of increase, the total progeny produced, and the net reproductive rate of the parasitoid were all adversely affected by the field-recommended concentrations of at least one insecticide. However, the longevity, the length of the oviposition period, and the offspring sex ratio were unaltered by the two insecticides. The effects of sublethal concentrations of the insecticides, applied at preimaginal stages, on the responses of T. busseolae females to host abdominal scales, were studied in open-arena bioassays. Cyfluthrin altered both the residence time and linear speed of the parasitoid in the host scale-containing areas, whereas deltamethrin had no effect. Our results indicate that, in addition to lethal effects, sublethal effects should also be considered when evaluating insecticide consequences on non-targets.     

Erythropoietin prevents the increase in blood-brain barrier permeability during pentylentetrazol induced seizures

Recombinant human erythropoietin (r-Hu EPO) has been shown to exert neuroprotection in ischemic, excitotoxicity, trauma, convulsions and neurodegenerative disorders. Blood-brain barrier (BBB) leakage plays a role in the pathogenesis of many pathological states of the brain including neurodegenerative disorders. This study aimed to investigate the effects of r-Hu EPO on BBB integrity in pentylentetrazol (PTZ) induced seizures in rats. Seizures were observed and evaluated regard to latency and intensity for an hour. Macroscopical and spectrophotometrical measurement of Evans Blue (EB) leakage were observed for BBB integrity. r-Hu EPO was given intraperitoneally 24 h prior to seizure induction. Total seizure duration of 720+/-50 s after single PTZ administration (80 mg/kg i.p.) was declined to 190+/-40 s in r-Hu EPO pretreatment. A typical BBB breakdown pattern (i.e. staining in cerebellum, cerebral cortex, midbrain, hippocampus, thalamus and corpus striatum) was observed in rat brains with PTZ induced seizures; whereas, EPO pretreatment confined BBB leakage to cerebellum and cortical areas, and lessened the intensity of tonic-clonic seizures observed in PTZ seizures. The protective effect of r-Hu EPO on BBB permeability in seizures is a new and original finding. The protective action of r-Hu EPO in seizures and some of CNS pathologies warrant further investigations.