Polyglutamine toxicity in yeast uncovers phenotypic variations between different fluorescent protein fusions

The palette of fluorescent proteins (FPs) available for live‐cell imaging contains proteins that strongly differ in their biophysical properties. FPs cannot be assumed to be equivalent and in certain cases could significantly perturb the behavior of fluorescent reporters. We employed Saccharomyces cerevisiae to comprehensively study the impact of FPs on the toxicity of polyglutamine (polyQ) expansion proteins associated with Huntington's disease. The toxicity of polyQ fusion constructs is highly dependent on the sequences flanking the polyQ repeats. Thus, they represent a powerful tool to study the impact of fluorescent fusion partners. We observed significant differences on polyQ aggregation and toxicity between commonly used FPs. We generated a novel series of vectors with latest yeast‐optimized FPs for investigation of Htt toxicity, including a newly optimized blue FP for expression in yeast. Our study highlights the importance of carefully choosing the optimal FPs when designing tagging strategies.      

Effects of Limb Length,Body Mass,Gender, Gravidity,and Elevation on Escape Speed in the Lizard Psammodromus algirus

Most animals rely on their escape speed to flee from predators. Here, we test several hypotheses on the evolution of escape speed in the lizard Psammodromus algirus. We test that: (1) Longer limbs should improve speed sprint. (2) Heavier lizards should be impaired regarding their sprint speed ability, suggesting a trade-off between fat storage and escape capability. (3) Males should achieve faster speeds due to their higher exposure to predators. (4) Gravid females, with increased body mass, should perform lower speed than non-gravid females. And (5) there are inter-population differences in sprint speed across an elevational gradient. We measured lizards sprint speed in a lineal raceway in the laboratory, filming races in standardized conditions and then calculating their maximal speed. We found that hind limb length greatly determined maximal sprint speed, lizards with longer limbs being faster. In parallel, higher body masses reduced maximal speed, which points to a trade-off between fat storage and escaping capability. Sexual differences also arose, as males were faster than females, as a consequence of males having longer limbs. Regarding females, gravidity did not impair maximal sprint speed, suggesting adaptations which compensate for the increased body mass. Finally, we found no elevational trend in both limbs length and sprint speed. In any case, this study suggests that selection on escape capacity may cast morphological evolution, and affect other life-history traits, such as fat storage and reproduction.     

Receptor specificity and functional comparison of recombinant sea bass (Dicentrarchus labrax) gonadotropins (FSH and LH) produced in different host systems

Different yields, biopotency, and in vivo pharmacokinetics are obtained for recombinant sea bass gonadoltropins depending on the production system and DNA construct, but they show specific activation of their corresponding receptors. Gonadotropins (GTHs) are glycoprotein hormones that play a major role in the regulation of gonadal functions. Recently, we succeeded in isolating the native sea bass Fsh from sea bass pituitaries, but to ensure the availability of bioactive GTHs and no cross-contamination with other related glycoproteins, recombinant sea bass GTHs were produced using two expression systems-insect and mammalian cells-and different constructs that yielded tethered or noncovalently bound dimers. Their production levels, binding specificity to their homologous cognate receptors, and bioactivity were investigated and compared. Both expression systems were successful in the generation of bioactive recombinant GTHs, but insect Sf9 cells yielded higher amounts of recombinant proteins than mammalian Chinese Hamster Ovary (CHO) stable clones. All recombinant GTHs activated their cognate receptors without cross-ligand binding and were able to stimulate sea bass gonadal steroidogenesis in vitro, although with different biopotencies. To assess their use for in vivo applications, their half-life in sea bass plasma was evaluated. Sf9-GTHs had a lower in vivo stability compared with CHO-GTHs due to their rapid clearance from the blood circulation. Cell-dependent glycosylation could be contributing to the final in vivo stability and biopotency of these recombinant glycoproteins. In conclusion, both insect and mammalian expression systems produced bioactive sea bass recombinant gonadotropins, although with particular features useful for different proposes (e.g., antibody production or in vivo studies, respectively).     

Symptoms of Lewy body dementia and clinical course compared with Alzheimer's disease

Lewy body dementia (LBD) is a neurodegenerative disease with well-defined symptoms and established clinical criteria, characterized by the presence of cortical and subcortical dementia, accompanied by some characteristic features such as Parkinsonism, visual hallucinations and fluctuations in alertness and attention, as well as hypersensitivity to neuroleptics. Compared with Alzheimer's disease, LBD seems to have a more rapid clinical course and greater mortality. The differences with Alzheimer's disease may be more apparent in the initial stages of the disease but tend to disappear with disease progression. Because of the greater presence of neuropsychiatric symptoms and the higher degree of dependency in LBD, there is greater caregiver overload and probably greater resource use.     

Medida de la capacidad funcional y la calidad de vida relacionada con la salud de un grupo de personas mayores que llevan a cabo un programa de caminatas: estudio piloto

Introduction

This pre-experimental study analyses the Functional Capacity (FC), Body Mass Index (BMI), Health Related Quality of Life (HRQoL) and Health Capital Stock (HCS) of elderly people participating in a Walking program in Granollers (Barcelona).

Material and methods

One hundred and seventy-three participants were invited to participate. One hundred and one of them were users of the Municipal Program for Elderly People, and 72 received information by the communication media. One hundred and thirty-one (76.3%) of the participants completed the Program.The intervention consisted of a 6-month program, supervised by a specialist instructor once a week and controlled daily by a pedometer.The 6-minute walk test (6MWT) was analysed for the FC, and the EuroQoL for the HRQoL. The preferences derived from the EuroQoL scores and the Life Expectancy were used to calculate the FC. The monetary data were obtained using a fixed value.

Results

An increase in the average number of steps was observed after the program, especially in men. The results also showed a decrease in the BMI. The participants showed a improvement in overall health perception at the end of the program. The HCS scores confirmed the improvement in the HRQoL in men.

Conclusions

The Program was positive for increasing the number of steps and improving physical condition and health. The usefulness of the pedometer as a motivational tool of physical exercise is discussed.     

Modulation of cell-cycle dynamics is required to regulate the number of cerebellar GABAergic interneurons and their rhythm of maturation

The progenitors of cerebellar GABAergic interneurons proliferate up to postnatal development in the prospective white matter, where they give rise to different neuronal subtypes, in defined quantities and according to precise spatiotemporal sequences. To investigate the mechanisms that regulate the specification of distinct interneuron phenotypes, we examined mice lacking the G1 phase-active cyclin D2. It has been reported that these mice show severe reduction of stellate cells, the last generated interneuron subtype. We found that loss of cyclin D2 actually impairs the whole process of interneuron genesis. In the mutant cerebella, progenitors of the prospective white matter show reduced proliferation rates and enhanced tendency to leave the cycle, whereas young postmitotic interneurons undergo severe delay of their maturation and migration. As a consequence, the progenitor pool is precociously exhausted and the number of interneurons is significantly reduced, although molecular layer interneurons are more affected than those of granular layer or deep nuclei. The characteristic inside-out sequence of interneuron placement in the cortical layers is also reversed, so that later born cells occupy deeper positions than earlier generated ones. Transplantation experiments show that the abnormalities of cyclin D2(-/-) interneurons are largely caused by cell-autonomous mechanisms. Therefore, cyclin D2 is not required for the specification of particular interneuron subtypes. Loss of this protein, however, disrupts regulatory mechanisms of cell cycle dynamics that are required to determine the numbers of interneurons of different types and impairs their rhythm of maturation and integration in the cerebellar circuitry.