However, Ren explains, "There has been a problem with this scenario." Except for the
sex chromosomes, everyone has two copies of each chromosome.
Chromosomal breaks and/or gaps affecting autosomes and
sex chromosomes were seen in 5 of a total of 14 cases.
Female iPS cells contain two copies of the X-chromosome, which is one of two
sex chromosomes. While males carry one X and one Y-chromosome, females' two X-chromosomes could result in a potentially toxic double dose of genes-except for a unique evolutionary mechanism whereby one of the two X's is silenced in a process known as "X-inactivation."
Sex chromosomes were of primary interest:, as they are most susceptible to disomy; however, 1818 disomy was also evaluated as a second-ary outcome.
Among this year's topics are the genomic enzymology of antibiotic resistance, the evolution of
sex chromosomes in insects, principles and mechanisms of protein homeostasis and the phenotype manifestation of genetic diversity, the challenge to understanding the genetics of arbuscular mycorrhiza, genome analysis in the domestic dog, and circadian control of global gene expression patterns.
In this issue, Bidau and Martf (2010) examine the history of orthopteran cytogenetics from McClung's classic paper (1899) to the current day, highlighting Michael White's contributions to the field in such diverse subjects as
sex chromosomes, anomalous meiotic systems and population and evolutionary cytogenetics.
Chromosomes can be one of two types:
sex chromosomes or autosomes.
After an overview of the role of
sex chromosomes in evolution and human diseases, research chapters cover topics such as the role of extrachromosomal elements in human leukemia cells, and alternative splicing transcripts affected by junction tandem repeats in the human genome.
(6) Interestingly, Stella Welsh was discovered to have ambiguous genitalia and abnormal
sex chromosomes during an autopsy after she was a victim of a shooting incident in 1980, (6) highlighting that sex verification during sporting events would not only identify those cheating but also athletes with a rare intersex condition.
destructor from the USA populations was karyotyped (Stuart and Hatchett 1988) and the authors found that female somatic cells have two pairs of autosomes and two pairs of
sex chromosomes (2n = 8), while male somatic cells have two pairs of autosomes and two monosomic
sex chromosomes (2n - 2 = 6).
Sexually reproducing organisms have two major types of chromosomes; that is,
sex chromosomes and autosomes.
