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Biology subjects

Papa, F.

Publications and source records attributed to Papa, F..

3 recordsLinked to original sources

A modular model integrating metabolism, growth, and cell cycle predicts that fermentation is required to modulate cell size in yeast populations

For unicellular organisms, the reproduction rate and growth are crucial determinants of fitness and, therefore, essential functional manifestations of the organism genotype. Using the budding yeast Saccharomyces cerevisiae as a model organism, we integrated metabolism, which provides energy and building blocks for growth, with cell mass growth and cell cycle progression into a low-granularity, multiscale (from cell to population) computational model. This model predicted that cells with constitutive respiration do not modulate cell size according to the growth conditions. We experimentally validated the model predictions using mutants with defects in the upper part of glycolysis or glucose transport. Plugging in molecular details of cellular subsystems allowed us to refine predictions from the cellular to the molecular level. Our hybrid multiscale modeling approach provides a framework for structuring molecular knowledge and predicting cell phenotypes under various genetic and environmental conditions.

systems biology↗

Plasticenta: Microplastics in Human Placenta

Summary paragraphMicroplastics are particles smaller than five millimetres obtained from the degradation of plastic objects abandoned in the environment. Microplastics can move from the environment to living organisms and, in fact, they have been found in fishes and mammals. Six human placentas, prospectively collected from consenting women with uneventful pregnancies, were analyzed by Raman Microspectroscopy to evaluate the presence of microparticles. Detected microparticles were characterized in terms of morphology and chemical composition. 12 microparticles, ranging from 5 to 10 m in size, were found in 4 out of 6 placentas: 5 in the foetal side, 4 in the maternal side and 3 in the chorioamniotic membranes. All the analyzed microparticles were pigmented: three of them were identified as stained polypropylene, while for the other nine it was possible to identify only the pigments, which are all used for man-made coatings, paints and dyes. Here we show, for the first time, the presence of microparticles and microplastics in human placenta. This sheds new light on the impact of plastic on human health. Microparticles and microplastics in the placenta, together with the endocrine disruptors transported by them, could have long-term effects on human health.

ecology↗

Rapid evolution of female-biased genes among four species of Anopheles malaria mosquitoes

Understanding how phenotypic differences between males and females arise from the sex-biased expression of nearly identical genomes can often reveal important insights into the biology and evolution of a species. Among Anopheles mosquito species, these phenotypic differences include vectorial capacity, as it is only females that blood feed and thus transmit human malaria. Here, we use RNA-seq data from multiple tissues of four vectors spanning the Anopheles phylogeny to explore the genomic and evolutionary properties of sex-biased genes. We find that in these mosquitoes, in contrast to what has been found in many other organisms, female-biased genes are more rapidly evolving in sequence, expression, and genic turnover, than male-biased genes. Our results suggests that this atypical pattern may be due to the combination of sex-specific life history challenges encountered by females, such as blood feeding. Furthermore, female propensity to only mate once in nature in male swarms likely diminishes sexual selection of post-reproductive traits related to sperm competition among males. We also develop a comparative framework to systematically explore tissue- and sex-specific splicing, to document its conservation throughout the genus and identify a set of candidate genes for future functional analyses of sex-specific isoform usage. Finally, our data reveals that the deficit of male-biased genes on the X chromosomes in Anopheles is a conserved feature in this genus and can be directly attributed to chromosome-wide transcriptional regulation that demasculinizes the X in male reproductive tissues.

genomics↗