Two microbial species are especially common in the core community of microbes inside the human bed bug, Cimex lectularius, according to a PLOS One study. The University of Cincinnati's Regina Baucom and company used 16S ribosomal RNA sequencing to characterize collections of intra-bed bug microbes, using 31 bed bug samples collected at eight urban sites across Ohio. The analysis turned up a range of microbial species, researchers say. But the core microbiome in the blood-sucking pests was made up of mainly two microbes: the obligate endosymbiont Wolbachia and an unnamed gamma-proteobacterium that resembles an endosymbiotic species previously found in the leafhopper.
An international team led by investigators in Germany explores the relationship between genetic variation on the Y chromosome, geography, and language groups in native South Americans. As they reported in PLOS Genetics, the researchers looked at SNP and short tandem repeat patterns on the Y chromosomes of 1,011 men from 50 tribal populations in 81 South American locales. Though they did not see genetic variant profiles with clear ties to tribal geography or language groups on the continent, investigators did find a new Y chromosome haplotype that seems to have been introduced to the area within the past 6,000 years.
In PLOS Neglected Tropical Diseases, researchers from Italy and Slovakia report on a phylogeographical analysis of the parasitic roundworms Ascaris lumbricoides and A. suum species. Using a PCR-restriction fragment length polymorphism method, the team assessed nuclear gene profiles in 143 Ascaris worms from pigs and another eight from human hosts. Together with mitochondrial gene sequence data on the same samples, the PCR-RFLP profiles allowed the team to assess phylogeny and phylogeography of the worms, which came from Italy, Slovakia, Hungary, Syria, Romania, and Pakistan. "Results obtained suggest that A. suum and A. lumbricoides may be variants of the same species," study authors say, "with the lack of fixed genetic differences and considerable phylogeographic admixture confirming an extremely close evolutionary relationship among these nematodes."