Category: Uncategorized

GENE REGULATION. "Promoters are central to the regulation of gene expression. Changes in gene regulation are thought to underlie much of the adaptive diversification between species and phenotypic variation within populations." https://lnkd.in/d6USApZ View in LinkedIn

MASKING EFFECT. "Genetic buffering mechanisms modify this relationship by concealing the effects of genetic and environmental variation on phenotype. Genetic buffering allows the build-up and storage of genetic variation in phenotypically normal populations." https://lnkd.in/duMqB2A View in LinkedIn

NEUTRAL VARIATION. "There appear to be many ways that phenotypes are buffered from perturbation by genotypic and environmental variation (2 ± 4) and, in fact, selectively neutral genetic variation is widespread." https://lnkd.in/duMqB2A View in LinkedIn

ALTERNATION OF GENERATIONS. "In 1851, Hofmeister recognized that plants alternate be- tween two distinct phases, yet it was not until 1894 that Strasburger proposed that this ‘‘alternation of generations’’ represented an alternation between haploid and diploid phases. Such an alternation of generations is a necessary consequence of sexual reproduction, since a haploid phase must follow meiosis and a diploid phase must follow gamete fusion, but the lengths of these two phases vary widely among organisms." An important article. https://lnkd.in/d_wyEN8 View in LinkedIn

HAPLOID-DIPLOID DIVIDE. "Sexual eukaryotic organisms are characterized by an alternation between haploid and diploid phases. In vascular plants and animals, somatic growth and development occur primarily in the diploid phase, with the haploid phase reduced to the gametic cells. In many other eukaryotes, however, growth and development occur in both phases, with substantial variability among organisms in the length of each phase of the life cycle." https://lnkd.in/d_wyEN8 View in LinkedIn

DIPLOID WINDOW. "Widespread and abundant variation is maintained in a selectively neutral form within the genetic architectures of eukaryotes, particularly those with an extended diploid phase of the life cycle." https://lnkd.in/duMqB2A View in LinkedIn

"PROMOTOR TURNOVER has occurred at the majority (>56%) of protein-coding genes since humans and mice diverged. Tissue-restricted promoters are the most evolutionarily volatile where retrotransposition is an important, but not the sole source of innovation." http://genome.cshlp.org/content/early/2015/07/30/gr.190546.115 View in LinkedIn

SO ENDS this meditation on the connection between genes and traits, and how our collective scientific perspective on the subject has drastically modified based in new data. We have transitioned from a simplistic view of the relationship of genotype to phenotype to one that appreciates the profound contextual interconnectedness of natural systems. Next weekend we consider why alternation of generations occurs, where gene numbers keep halving and doubling in life cycles. View in LinkedIn

ABUNDANT EXAMPLES. "In the last 15 years, more than 1,000 examples of DNA sequence changes have been linked to naturally occurring non-deleterious phenotypic differences between individuals or species in Eukaryotes." https://lnkd.in/d3vzXnd View in LinkedIn

VERTEBRATE HOMOGENEITY. "Vertebrates have almost identical numbers of genes—slightly less than 30,000—with remarkable similarity across diverse species. Mice and humans, for example, have many genes for which sequences are 90% identical, yielding protein products that are almost indistinguishable." https://lnkd.in/eNHFjJ8 View in LinkedIn