Today, many research studies and clinical assessments are based on DNA and RNA analyses of limited sample sizes, including rare tissues, liquid biopsies, fine-needle aspirates and single cells.
Comparative genomics based on DNA-array analyses, first conducted by Salama et al. on 15 Caucasian isolates [ 23], led to the elucidation of the H. pylori core genome comprising the pool of ubiquitous H. pylori genes and strain-specific genes (non-ubiquitous).
Based on DNA hybridization and FISH analyses, Wang et al. [ 54] suggested that the Ns genome of Leymus species may be originated from Psa. juncea and Psa.
Based on DNA sequence and protein database analyses, one can infer that these proteins play a role in mRNA stability and/or in processes requiring interactions with RNA [26].
Most sequence-based rice genome analyses are based on DNA polymorphisms, single nucleotide polymorphisms (SNPs) and insertion-deletions (InDels).
Phylogeographic studies and migration analyses based on DNA data suggested that the center of origin of M. graminicola was the Middle East and that the pathogen was dispersed throughout the world during the spread of wheat cultivation [23], [24], [25].
Analyses based on DNA composition have identified 20 Leptospira species with seven pathogenic species, which are L. interrogans, L. borgpetersenii, L. santarosai, L. noguchi, L. weilii, L. kirschneri and L. alexanderi comprising the main agents of leptospirosis [1], [2], [6].
Phylogenetic analyses based on DNA sequences suggest that Gryllus species in eastern North America may be divided into four clades characterized by different life history traits, and that G. rubens forms a separate clade with G. fultoni and G. pennsylvanicus [51], [52], [53].
Thus further analyses based on DNA sequences could reveal up to eight haplotypes, differing by SNPs and indels that include the ones found in this study.
Genetic and phylogenetic analyses based on DNA information usually are effective in clarifying details about the biological entity of a "species".
