Role Of Homeobox Geness

Using these three articles (or more), you should tell the story of the discovery and developmental function (including the relevant signaling pathway) -

Hilde Mangold looked beyond the genetic makeup of embryos to find a small patch of tissue that was able to direct other cells to form an entire body plan. This is called the organizer. According to Shubin, “... many scientists consider Mangold’s work to be the single most important experiment in the history of embryology.” However, in the 20th century, scientists decided to try to understand why embryos of different species look the same and figure out more information, even beyond the organizer. Neil shares that scientists discovered a sequence of DNA within a few specific genes. The book shares more information on this sequence, stating, “ This little sequence is called a homeobox. The eight genes that contain the homeobox are called Hox genes.” Eventually scientists realized that the Hox genes are present in every animal with a body. Shubin tells of how hox genes establish proportions of our bodies too. They are responsible for the different regions of our head, chest, and lower back. Hox genes are involved with the development of different organs, limbs, genitalia, and guts. Shubin states that changes in our hox genes bring about changes in the way our bodies are put together. The similarities that are revealed between the basic body structures of different animals and creatures show how immensely diverse evolution

Sean Carroll’s book Endless Forms Most Beautiful, attempts to explain the variety of animal forms, structures and functions by comparing them to rules that he had found. Such rules include: major “rules” for generating animal forms, species-specific encoding information, evolutionary diversity and large-scale trends in evolution. It begins by assessing the similarities between ancient and modern organisms. It notes that the structure of certain parts like vertebrates and limbs are similar in proportion and can be varied in shape and repetition. It cites animals parts like butterfly wings to show repetition of scales, snakes to show repeating vertebrae and compared a salamander to a dinosaur to express how each follow the same modular body plan.

There are two important type of genes responsible for the development or cancer namely tumor suppressor because their normal function is

Opitz syndrome is a disease characterized by a defect along the ventral midline of the human body. Some of these abnormalities include a cleft lip, heart defects, wide-spaced eyes (hypertelerism), laryngeal cleft, agenesis of the corpus callosum, and hypospadias. An important irregularity in patients is the effect disrupted proteins have on the corpus colloseum. The corpus colloseum is a neuronal component that separates the two halves of the brain. This protein is imperative because it controls MID-1 or the midline. The MID-1 protein also forms homodimers, which associate with microtubules in the cytoplasm, especially during fetal development. Therefore, MID-1 is involved in formation of multiprotein structures, acting as anchor points to

regulators of the competence pathway the first that will be discussed is ComX. ComX binds to

Yin Yang 1 in HCC: YY1 is a transcription factor with complex biological functions, including apoptosis, tumorigenesis, development and differentiationYY1 is a member of the Polycomb Group protein family, a group of homeobox gene receptors that play critical roles in hematopoiesis and cell cycle control [26, 27]. The human YY1 gene is located on the telomere region of human chromosome 14 at the segment q32.2. It consists of five highly conserved exons encoding a protein of 14 amino acids in length, and an estimated molecular weight of 44 kDa. The YY1 protein contains four C2H2-type zinc-finger motifs with two specific domains that characterize its function as an activator or repressor. YY1 is a phosphoprotein with a half-life of 3.5 hours.

Tumour suppressor genes: In health this family of genes usually act as a counter balance for oncogenesis. It is thought that they may be responsible for repairing gene damage in cells, or are growth inhibitor genes. In Hodgkin’s disease, there are often evidences of mutation in tumour suppressor genes as well as other genes.

The most recent discovery to provide evidence that genetics is a contributing factor to the development of FAS is the discovery of the exact locus that controls the alcohol sensitivity of the L1 protein. L1 is an essential part of the neural development of foetuses. It is located on the outside of cells and is important to the joining of cells as well as axon control and movement of cells. Phosphorylation, controlled by the enzyme ERK2, occurred inside the L1

The Pitx2 protein is a bicoid-related homeodomain transcription factor involved in left-right asymmetric cardiogenesis as well as development of eye and craniofacial regions (Hjalt et al., 2000). Most interestingly, experimental murine models utilizing targeted loss of Pitx2 function resulted in severe cardiovascular defects including transposition of the great arteries,

Type II syndactyly or synpolydactyly(SPD) is a semi dominant inherited limb malformation that involves a fusion of digits. It is caused by mutations in HOXD13 on chromosome 2 due to polyalanine repeat expansions. Polyalanine repeats in SPD are mitotically and meiotically stable, causing polymorphisms to be rare, unlike other nucleotide repeat expansions such as Friedreich’s ataxia. HOXD13 is a member of the HOX family, a family of transcription factors that are proteins which contain homeodomain that are important for controlling cell fate along the limb axes and body. HOXD13 is a part of the HOXD gene cluster and crucial for limb development, particularly during the early and late stages of limb development. The stage occurs during the creation of the limb buds at week 4, during this stage the limbs have AP polarity through the expression of sonic hedgehog(shh) signaling from the zone of polarizing

PDXL1 is pancreatic and duodenal homeobox gene 1. The function is to regulating pancreatic development, regulates insulin gene expression and, and cell function. PDXL1 is involved in cell specific expressions in several genes.

The cell memory machinery is involved in maintaining cell type specific gene expression patterns rather than its establishment. Cellular memory is provided by two counteracting groups of chromatin proteins termed Trithorax group (TrxG) and Polycomb group (PcG) [2]. Proteins of the Polycomb group (PcG) and of the trithorax group (trxG) are involved in the regulation of key developmental genes, such as homeotic genes. PcG proteins maintain silent states of gene expression, while the trxG of genes counteracts silencing with a chromatin opening function. In Drosophila, PcG and trxG complexes are recruited to specific DNA elements named as PcG and trxG response elements (PREs and TREs, respectively). Once recruited, these complexes seem to be able to establish silent or open chromatin states that can be inherited through multiple cell divisions even after decay of the primary silencing or activating signal

Mutations in MSX1 gene cause a verity of diseases. Mutations hit different sites on msx1 that resulted in different phenotypes. It has been identified some mutations’ locations such as in frame mutations, including 18 missense mutations and truncating mutations, including 5 nonsense mutations, 5 indel mutations, 1 splice variant, 1 nonstop variant, and 1 entire gene deletion. Farther, some of these mutations disturb the homeodomain and some don’t but located in N terminus protein. The indel mutations and the missense mutations severely disturb the DNA binding domain (4). These mutations in homeodomain are associated with tooth agenesis with or without orofacial clefting. The outside homeodomain mutations are associated with nonsyndromic

During the course of the past thirty years, the study of model organisms has become more significant in the study of embryological development. A model organism is a species that is easy to cultivate and monitor in a laboratory environment and is used to represent broad groups of organisms. Examples of successful and important model organisms include the Ascidia, Zebrafish, and Medeka species. Through intense researching of these organisms, scientists have been able to gain valuable insight into the developmental processes of many complex vertebrates, including humans.