We present frequencies of fetal chromosomal abnormalities in 4,907 prenatal cytogenetic examinations at Samsung Cheil Hospital from 1988 to 1997 for 10 yr duration. Prenatal karyotypes were undertaken in 3,913 amniotic fluid samples, 800 chorionic villi samples, and 194 percutaneous umbilical blood samples. The frequency of fetal abnormal karyotypes was 3.1% (150 cases). Numerical chromosome ab...

Norway rats (Rattus norvegicus) were introduced to the Falkland Islands and are detrimental to native passerines. Rat eradication programmes are being used to help protect the avifauna. This study assesses the effectiveness of eradication programmes while using this conservation practice as a natural experiment to explore the ecological resistance, resilience and homeostasis of bird communities...

A recent study by Zhang and colleagues published in the March 15, 2009, issue of Genes & Development (pp. 755-765) demonstrates that maize Ac/Ds transposons mediate translocations and other rearrangements through aberrant execution of the normal transposition process. Ac transposase uses one end from each of two neighboring elements in these events, which may happen more commonly than previousl...

BACKGROUND Genes that fuse to cause cancer have been studied to determine molecular bases for proliferation, to develop diagnostic tools, and as targets for drugs. To facilitate identification of additional, cancer fusion genes, following observation of a chromosomal translocation, we have characterized the genomic features of the fusion gene partners. Previous work indicated that cancer fusion...

We measure current blockade and time distributions for single-stranded DNA polymers during voltage-driven translocations through a single alpha-hemolysin pore. We use these data to determine the velocity of the polymers in the pore. Our measurements imply that, while polymers longer than the pore are translocated at a constant speed, the velocity of shorter polymers increases with decreasing le...

In mammals, most new mutations occur in males. But a study of the evolution of a human X to Y chromosomal translocation has revealed a sex bias much lower than previous estimates. Patterns of substitution suggest that differential methylation between male and female germ lines is a key determinant of the mutation rate.

Recurrent chromosomal translocations can drive oncogenesis, but how they form has remained elusive. Now, Chiarle et al. (2011) and Klein et al. (2011) characterize the genome-wide spectrum of translocations that form from a single double-stranded break, revealing that specific loci have an intrinsic predisposition for frequent chromosomal rearrangements.

The genetic ancestry of Polynesians can be traced to both Asia and Melanesia, which presumably reflects admixture occurring between incoming Austronesians and resident non-Austronesians in Melanesia before the subsequent occupation of the greater Pacific; however, the genetic impact of the Austronesian expansion to Melanesia remains largely unknown. We therefore studied the diversity of nonreco...

Escherichia coli FtsK is an essential cell division protein, which is thought to pump chromosomal DNA through the closing septum in an oriented manner by following DNA sequence polarity. Here, we perform single-molecule measurements of translocation by FtsK50C, a derivative that functions as a DNA translocase in vitro. FtsK50C translocation follows Michaelis-Menten kinetics, with a maximum spee...