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Latest Chromosome Stories

2011-11-01 20:35:00

An international team of scientists, including biologists from the University of North Carolina at Chapel Hill, may have pinpointed for the first time the mechanism responsible for cell polyploidy, a state in which cells contain more than 2 paired sets of chromosomes. When it comes to human chromosomes and the genes they carry, our tissue cells prefer matched pairs. Bundled within the nucleus of our cells are 46 chromosomes, one set of 23 inherited from each of our parents. Thus, we are...

2011-10-31 10:40:01

Vocabulary of epigenetics expanding In 2009, the DNA alphabet expanded. Scientists discovered that an extra letter or "sixth nucleotide" was surprisingly abundant in DNA from stem cells and brain cells. Now, researchers at Emory University School of Medicine have mapped the patterns formed by that letter in the brains of mice, observing how its pattern of distribution in the genome changes during development and aging. Those patterns, stable or dynamic depending on the gene, suggest...

2011-10-28 12:11:35

Parasite genomes speak of evolution by changes in gene, region and chromosome number, not by mutation in genes Two remarkable discoveries were today revealed by researchers into genome analysis of Leishmania parasites. These results uncovered a surprising level of variation at the genome structure level. First, they found that the DNA sequence of individual strains of each species populations is almost completely identical. It appears that only a small number of genes may cause...

2011-10-18 13:19:30

Geneticists at Emory University School of Medicine have demonstrated a method that enables the routine amplification of all the genes on the X chromosome. The technology allows the rapid and highly accurate sequencing and identification of novel genetic variants affecting X chromosome genes. The method, developed in cooperation with RainDance Technologies, is described in the Oct. 2011 issue of Genomics. Senior author Michael Zwick, PhD, assistant professor of human genetics at Emory...

2011-10-10 09:09:47

In order for cells of different types to maintain their identities even after repeated rounds of cell division, each cell must "remember" which genes were active before division and pass along that memory to its daughter cells. Cells deal with this challenge by deploying a "bookmarking" process. In the same way a sticky note marks the last-read page in a book, certain molecules tag the active genes in a cell so that, after it divides, the same genes are reactivated right away in the new...

2011-10-07 12:20:24

New findings of researchers from the University of Modena and Reggio Emilia (Mauro Mandrioli, Valentina Monti and Gian Carlo Manicardi) show that in aphids the two X chromosomes have a different inheritance. The study was published in Comparative Cytogenetics. Aphids are insects with a sex determination model based on the presence of two X chromosomes (XX) in females and a single X chromosome (XO) in males. Previous studies suggested that X chromosome loss during male determination was...

2011-10-06 13:08:46

In children with genomic disorders, often a gamete — egg or sperm — has gone disastrously awry with either a duplication or deletion of genetic material that results in physical and neurological problems for the subsequent child. Previous studies have identified a procedure called nonallelic homologous recombination, which occurs during meiosis or sexual cell division, as the event that most commonly occurs and results in this mistake in DNA. Researchers from Baylor College...

2011-10-05 12:25:09

When cells divide normally, DNA gets copied perfectly and distributed among the daughter cells with an even hand. Occasionally though, DNA breaks during division and is rearranged, resulting in duplications or deletions of important parts of the blueprint. Now researchers at Baylor College of Medicine who study families with such genomic disorders have found a shared, yet unusual, architecture resulting from this jumble that is associated with very severe forms of disease. They also...

2011-10-04 10:16:18

Chromosomal abnormalities linked to intellectual disability can be traced back to the father, particularly those who are older when the child is conceived, finds research published online in the Journal of Medical Genetics. Chromosomal abnormalities are caused by copy number variations, or CNVs. These are structural variations resulting in missing, repeated, inverted or misplaced DNA sequences in cells. They can be inherited or arise anew, and are a common cause of disease. However,...


Word of the Day
out-herod
  • In the phrase to out-herod Herod, to be more violent than Herod (as represented in the old mystery plays); hence, to exceed in any excess of evil.
Herod refers to 'Herod the Great,' a Roman client king and 'a madman who murdered his own family and a great many rabbis.' According to the OED, the term is 'chiefly with allusion to Shakespeare's use' in Hamlet.
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