ITS1 Markers Research Articles

Combination of morphological characters and ITS-sequence to characterize a new species of Macrocheles (Acari: Macrochelidae)

Macrocheles seraphim sp. nov. is described from French and Moroccan populations. This species was found phoretic on three species of dung beetles: Scarabaeus laticollis, Geotrupes mutator and G. spiniger. It was identified on the basis of morphological characters as belonging to the M. glaber group, but also has similarities with M. muscaedomesticae. Its systematic position as investigated by genetic analyses using the ITS-1 marker showed that this species was closely related to M. muscaedomesticae. Its relationship with glaber group species is discussed.

Morphological and genetic studies of waterlogged Prunus species from the Roman vicus Tasgetium (Eschenz, Switzerland)

Morphological and genetic studies were performed on waterlogged Prunus fruit stones from the Roman vicus Tasgetium (Eschenz, Switzerland). Some fruit stones could be identified to species level based on morphological and metric criteria. Other fruit stones found were not identifiable to species level. Of the latter, the morphological group Prunus insititia/ spinosa represents either native sloe, cultivated primitive plum (damson) or a hybrid of both. In one out of 10 individual fruit stones of this group Prunus specific chloroplast trnL- trnF and nuclear ITS1 markers were verifiably amplified. Sequences of trnL- trnF led to the identification of Prunus spinosa. The presence of authentic DNA was confirmed by phylogenetically meaningful sequences from the archaeobotanical group Prunus avium/ cerasus of the same sample using chloroplast rbcL and nuclear ITS1 DNA markers. The results demonstrate the utility of waterlogged plant remains for genetic analysis: as seeds of fruit trees are often preserved waterlogged in the archaeological record. Ancient DNA (aDNA) studies are a promising tool to answer archaeobotanical issues concerning early horticulture, which probably started in the Northern alpine region with the onset of Romanisation.

Genetic Variation of the Southern Corn Rootworm, (Coleoptera: Chrysomelidae)

Corn rootworms of the genus Diabrotica (Coleoptera: Chrysomelidae) are among the most important insect pest of crops in the United States. The southern corn rootworm, Diabrotica undecimpunctata howardi Barber is an economically important pest of corn, cucurbits and peanuts. Genetic analysis of southern corn rootworms, collected from South Dakota, Nebraska, and Arkansas was undertaken using DNA sequences of the nuclear ribosomal first internal transcribed spacer region (ITS1), and a portion of the mitochondrial DNA (mtDNA) cytochrome oxidase I and II genes. Among the 22 beetles subjected to DNA sequencing analysis, no polymorphic nucleotide sites were observed for the ITS1 marker and one variable nucleotide site was observed for the mtDNA marker. The lack of genetic distinction observed in southern corn rootworm populations suggests either high levels of dispersal or a recent geographical expansion from a relatively small base.