17 research outputs found
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2D versus 3D human induced pluripotent stem cell-derived cultures for neurodegenerative disease modelling
Neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD) and amyotrophic lateral sclerosis (ALS), affect millions of people every year and so far, there are no therapeutic cures available. Even though animal and histological models have been of great aid in understanding disease mechanisms and identifying possible therapeutic strategies, in order to find disease-modifying solutions there is still a critical need for systems that can provide more predictive and physiologically relevant results. One possible avenue is the development of patient-derived models, e.g. by reprogramming patient somatic cells into human induced pluripotent stem cells (hiPSCs), which can then be differentiated into any cell type for modelling. These systems contain key genetic information from the donors, and therefore have enormous potential as tools in the investigation of pathological mechanisms underlying disease phenotype, and progression, as well as in drug testing platforms. hiPSCs have been widely cultured in 2D systems, but in order to mimic human brain complexity, 3D models have been proposed as a more advanced alternative. This review will focus on the use of patient-derived hiPSCs to model AD, PD, HD and ALS. In brief, we will cover the available stem cells, types of 2D and 3D culture systems, existing models for neurodegenerative diseases, obstacles to model these diseases in vitro, and current perspectives in the field
Ultraviolet reflectance influences female preference for colourful males in the European serin
Avian plumage colouration is one of the most impressive
displays in nature and is frequently used as sexual
signal. There is now considerable evidence that females consistently
prefer males with the most elaborated colour displays.
Bird colour vision expands into the ultraviolet (UV) range,
which prompted several studies to test the importance of UV
in mate choice, revealing that females are affected by the UV
light component. These studies were mostly performed on
structural plumage, whereas carotenoid-based plumage was
rarely considered, although it also has a typical reflection peak
in the UV. Our study tested the female choice over male yellow
colouration, and whether it is influenced by UVremoval, in the
European serin (Serinus serinus ), a sexually dichromatic
cardueline finch, with males showing a conspicuous
carotenoid-based yellow plumage. We shows that females preferred
yellower males and that male attractiveness was lost
when the UV colouration was blocked, with either of the UVblocking
techniques used. The results of our study indicate that
the UV component of carotenoid colouration is important in the
female mate assessment in serins and highlights the importance
of considering colour perception in avian mate choice.This research was supported by the project PTDC/BIA-BEC/
105325/2008 to PGM from the Fundação para a Ciência e a Tecnologia