genetics

[Ummehani]

Hi all,

Kindly help me out with this question.

 

Turners syndrome in females occurs due to the absence of one X-chromosome. And we know that in every woman, there is only one active X-chromosome, due to the lyonization process in which one X-chromosome is inactivated. Then why don't all women have turners syndrome, if either ways one X-chromosome does not function (is absent of inactive)?

[jp255]

X-inactivation does not cause gene silencing for all genes along the inactive X in a normal 46 XX female. There are a group of genes which can escape x inactivation silencing. So this can probably lead to haploinsufficiency effects that can cause some of the Turner syndrome symptoms and physiological features.

 

There are also imprinted genes on the X chromosome, and this can also contribute to some of the Turner syndrome defects. In case you don't know much about imprinting, this means that some of the Turner syndrome defects and symptoms can be caused by gene silencing of various genes which is dependent on whether the inherited X is inherited from the mother or father. A normal female will usuall have 50% of cells expressing a paternal X and the other 50% expressing maternal X, however in Turner Syndrome there will be either 100% paternal or maternal X. The defects and symptoms can vary depending on parental origin of the X in someone with Turner syndrome, such as increased risk of coronary artery disease when the inherited X comes from the mother.

 

It pretty much comes down to expression differences caused by X inactivation escape and genomic imprinting.

 

 

 

[krash661]

something interesting.

 

Adhesive Differences Enable Separation of Stem Cells to Advance Potential Therapies

 

http://www.labmanager.com/?articles.view/a...tial-Therapies/

 

interesting also,

a webinar, the registration for the webinar is on the link.

 

http://www.genengnews.com/webinars/glycobiology-analysis-solutions-using-hpae-pad/200/#utm_medium=facebook&utm_medium=social&utm_campaign=april

 

Broadcast Date: Thursday, April 18, 2013

Time: 8:00 am PDT, 11:00 am EDT, 16:00 BST

 

Glycobiology Analysis Solutions Using HPAE-PAD

 

 

" Post-translational modification of proteins with oligosaccharides to form glycoproteins is a common biological motif. These glycoprotein oligosaccharides are involved in a wide range of biological and physiological processes including recognition and regulatory functions, cellular communication, gene expression, cellular immunity, growth, and development. Aberrant glycosylation of proteins is connected to cancer progression, invasion, and metastasis. With many biological functions, glycosylation is one of the most important post-translational modifications of eukaryotic cell proteins. "

[krash661]

this is interesting,

 

Two Proteins Found to Block Cancer Metastasis

 

http://genengnews.com/gen-news-highlights/two-proteins-found-to-block-cancer-metastasis/81248307/