need help with the homeodomain protein (PAX) - normalpressurehydroc

[ArchivalUser]

what do we neeed to know about this.
is it that homeodomain protein is added by pax gene and what is the abnromality is it in the conea of the eye.

[ArchivalUser]

Homeodomain proteins are major factors in controlling this embryonic gene expression.

I think the abnormality ur thinking of is Klein-Waardenburg Syndrome-, which affects a multitude of systems which PAX-3 gene is expressed. Dystopia canthorum (eye abnormality with lat. displacement of the inner corner of the eye), Pigment abnormalities, Deafness, Limb abnormalities are seen in this syndrome.

Hope this helps.

[ArchivalUser]

thanks.

[ArchivalUser]

HOX genes:
A homeobox is a DNA sequence found within genes that are involved in the regulation of development (morphogenesis) of animals, fungi and plants. Genes that have a homeobox are called homeobox genes and form the homeobox gene family. Homeobox genes encode transcription factors which typically switch on cascades of other genes, for instance all the ones needed to make a leg. The homeodomain binds DNA in a specific manner.

A particular subgroup of homeobox genes are the Hox genes, which are found in a special gene cluster, the Hox cluster (also called Hox complex). Hox genes function in patterning the body axis. Thus, by providing the identity of particular body regions, Hox genes determine where limbs and other body segments will grow in a developing fetus or larva.
Mutations in any one of these genes can lead to the growth of extra, typically non-functional body parts in invertebrates, for example antennapedia complex in Drosophila, which results in a leg growing from the head in place of an antenna and is due to a defect in a single gene. Mutations to homeobox genes can produce easily visible phenotypic changes.

HOX-D 13 : is associated with synpolydactyly (fusion of fingers or toes)
HOX-11 : T-cell ALL
In the absence of HOX10 function, no lumbar vertebrae are formed. Instead, ribs project
from all posterior vertebrae, extending caudally from the last thoracic vertebrae to
beyond the sacral region.
In the absence of HOX11 function, sacral vertebrae are not formed and instead these
vertebrae assume a lumbar identity.
Pbx-1: Pre-Bcell ALL
HOX A-9 : AML
Gbx and Nkx 3.1: Prostrate CA
HOX 11- Tcell ALL
PBX 1 - Pre B ALL
HOX A9- ALL
HOX 13 - is also hand foot genital syndrome
HOX B2- facial nerve (remember pharyngeal arch 2)
HOX A1- inner ear malformations
HOX A2- pharyngeal arch 2 transforms to arch 1 with duplication of malleus n incus
HOX10 or HOX11 paralogous group are disrupted provide evidence that these HOX
genes are involved in global patterning of the axial and appendicular skeleton.
In the absence of HOX10 function, no lumbar vertebrae are formed. Instead, ribs project
from all posterior vertebrae, extending caudally from the last thoracic vertebrae to
beyond the sacral region.
In the absence of HOX11 function, sacral vertebrae are not formed.

[ArchivalUser]

WOW> thanks so much lucidinterval. your always there for the answer.

thank u