The X and Y sex chromosomes represent one of the key cellular differences between male and female. Here, we introduce the unique, silent nature of the inactive X in female cells (and its exceptions) and summarise recent insights to the molecular processes taking place on the X chromosome. We...
In placental mammals, the sex chromosomes are heterogametic (XY) for males and homogametic (XX) for females. The Y chromosome contains a very limited number of genes including the SRY gene that provides instructions for the development of male gonads. The X chromosome, on the other hand, ...
(redirected fromChromosomes, human, x) Thesaurus Medical Encyclopedia X chromosome orX-chro·mo·some(ĕks′krō′mə-sōm′) n. The sex chromosome associated with female characteristics in mammals, occurring paired in the female and single in the male. ...
, although rather irritating in its many little inaccuracies and convoluted logic (for example, the role of X inactivation is seen as protecting the female against the toxicity of her two X chromosomes, rather than as a secondary effect of the necessity to boost production in the poor male)....
His explanation of the female default pathway and the chain reaction leading to maleness is quite nice. After whizzing through reproduction in sea worms, honeybees, flies, and moles, and even ZW chromosomes in birds, he relates the saga of the “sad divorce of X and Y” and the ...
Small regions of sequence homology located at the tips of mammalian X and Y chromosomes where recombination still occurs during male meiosis. Cellular mosaicism The chimeric state of female tissues that results from random X chromosome inactivation, meaning that normal mammalian females have two genetica...
male. Thus, all offspring (son or daughter) inherit an X chromosome from their mother. However, from their father, the son inherits a Y chromosome and the daughter an X chromosome. Thus, it became easy to distinguish phenotypes caused by genes on the X chromosomes from those caused by ...
Dutch researchers have found the first evidence that a process of inactivating the X chromosome during embryo development and implantation, which was known to occur in mice but unknown in humans, does, in fact, take place in human female embryos prior to
campbelli females and P. sungorus males. In hybrid spermatocytes, a high frequency of asynapsis of X and Y chromosomes during the pachytene-like stage and dissociation of these chromosomes during metaphase I (MI) was observed. No autosomal univalency was observed during pachytene-like and MI ...
摘要: Males with two X-chromosomes ejaculate more often than males with a single X-chromosome. Male mice with two X-chromosomes are faster to attain ejaculations than males with one X-chromosome. In both sexes, an additional X-chromosome facilitates display of mounting and thrusting....