The amount of copies in the complete genetic information obtained in human cells may have a decisive impact on the properties of these cells. The final results will help to explain why certain medications have strong unwanted side effects on sperm and eggs, and why certain organisms remain unaffected by environmental changes.
All cells within our bodies contain copies in the genetic information. However, different cells contain different numbers of the total genetic information. Normal human cells usually contain two copies on the genetic information, therefore two copies of the gene. Eggs and sperm, however, only contain some genes.
“Simultaneously, cellular matrix of the many plants and amphibians contain more copies of genetic information, along with the amount of copies could also vary during an organism’s development and between different stages of life,” explains Jonas Warringer, a researcher for the University of Gothenburg’s Department of Chemistry and Molecular Biology.
Researchers have often overlooked this variation in genetic information. However, Jonas Warringer and his colleagues have recently used ordinary baker’s yeast showing that the quantity of copies of genetic information features a decisive impact on the properties of cells.
Jonas and his colleagues collected yeast samples from around the world and created two variants of each one yeast culture – one with two copies on the genetic information, as well as the other with just one single copy. The study then examined the properties these yeast cells, like their ability to tolerate cancer medication and antibiotics. The study, that’s reported on within the journal PLOS One, implies that the quantity of copies of genetic information incorporates a decisive relation to the properties of cells.
“The cells with two copies of genetic information showed greater ability to tolerate some substances,” continues Jonas, “during other cases people with only one copy had a benefit. Surprisingly enough, these effects were even maintained in species separated by a few billions of generations of evolution, suggesting that they are actually of great importance naturally.”
The researchers’ discovery might be of considerable significance regarding know-how about what lies behind differences between organisms in nature.
“Vitamin c also helps to describe why certain medications have particularly strong negative effects on sperm and eggs whereas others tend not to, and why certain organisms are influenced by some environmental changes while others are unaffected,” he concludes.
The abstract of this article is given as below.
The number of chromosome sets contained within the nucleus of eukaryotic organisms is a fundamental yet evolutionarily poorly characterized genetic variable of life. Here, we mapped the impact of ploidy on the mitotic fitness of baker’s yeast and its never domesticated relativeSaccharomyces paradoxus across wide swaths of their natural genotypic and phenotypic space. Surprisingly, environment-specific influences of ploidy on reproduction were found to be the rule rather than the exception. These ploidy–environment interactions were well conserved across the 2 billion generations separating the two species, suggesting that they are the products of strong selection. Previous hypotheses of generalizable advantages of haploidy or diploidy in ecological contexts imposing nutrient restriction, toxin exposure, and elevated mutational loads were rejected in favor of more fine-grained models of the interplay between ecology and ploidy. On a molecular level, cell size and mating type locus composition had equal, but limited, explanatory power, each explaining 12.5%–17% of ploidy–environment interactions. The mechanism of the cell size–based superior reproductive efficiency of haploids during Li+ exposure was traced to the Li+ exporter ENA. Removal of the Ena transporters, forcing dependence on the Nha1 extrusion system, complet
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Reference: Zörgö E, Chwialkowska K, Gjuvsland AB, Garré E, Sunnerhagen P, et al. (2013) Ancient Evolutionary Trade-Offs between Yeast Ploidy States. PLoS Genet 9(3): e1003388. doi:10.1371/journal.pgen.1003388