There is a strong positive relationship between nuclear genome size and cell size across the eukaryotic domain, but the cause and effect of this relationship is unclear. A positive coupling of cell size and DNA content has also been recorded for various bacteria, suggesting that, with some exceptions, this association might be universal throughout the tree of life. However, the link between cel...

It has long been known that genomes vary over a remarkable range of sizes in both plants (Bennett, Cox, and Leitch 1997) and animals (Gregory 2001). It also has become evident that across the broad phylogenetic sweep, genome size may be correlated with intron size (Deutsch and Long 1999; Vinogradov 1999; McLysaght et al. 2000), suggesting that some component of genome size evolution takes place...

Petrov, Lozovskaya, and Hartl (1996) demonstrated that unconstrained regions of the non-long terminal repeat retrotransposable element Helena lose DNA at an unusually high rate in species of the Drosophila virilis species group. More recent data also indicate a high rate of DNA loss of Helena in species of the Drosophila melanogaster species subgroup (Petrov and Hartl 1998). Based on these obse...

Three independent databases of eukaryotic genome size information have been launched or re-released in updated form since 2005: the Plant DNA C-values Database (www.kew.org/genomesize/homepage.html), the Animal Genome Size Database (www.genomesize.com) and the Fungal Genome Size Database (www.zbi.ee/fungal-genomesize/). In total, these databases provide freely accessible genome size data for >1...

The quotation above has led to the commonly held view that all bacteria will eventually become resistant to any antibiotic given enough time and exposure. However not all bacteria develop resistance to antibiotics at the same rate (and perhaps some species of bacteria may never develop resistance to certain antibiotics). And some bacteria that have been labeled “resistant” are not, in any clini...

In contrast to genome size variation in most bacterial taxa, the small genome size of Buchnera sp. was shown to be highly conserved across genetically diverse isolates (630 to 643 kb). This exceptional size conservation may reflect the inability of this obligate mutualist to acquire foreign DNA and reduced selection for genetic novelty within a static intracellular environment.