Trabajo plegable biomol

“REWIRING STEM CELLS: NEW TECHNIQUE MAY REVOLUTIONIZE UNDERSTANDING OF HOW GENES

FUNCTION”AND

“IMPORTANT DISCOVERY FOR DIAGNOSIS OF GENETIC DISEASES”.

María Angélica Díaz UribeMedicine student

III Semester

Molecular Biology

INTRODUCTION

news report on genetic studies about effective method to identify the working of genes in cell differentiation and possible causes of genetic syndromes attributed to the three-dimensional organization of chromatin.

“REWIRING STEM CELLS:

NEW TECHNIQUE MAY

REVOLUTIONIZE

UNDERSTANDING OF HOW

GENES FUNCTION”

“REWIRING STEM CELLS: NEW TECHNIQUE MAY REVOLUTIONIZE

UNDERSTANDING OF HOW GENES FUNCTION”

Cell type in an organism expresses a subset of all the genes that constitute the genome of that species. Each cell type is defined by its particular pattern of regulated gene expression. Cell differentiation is thus a transition of a cell from one cell type to another and it involves a switch from one pattern of gene expression to another. Cellular differentiation during development can be understood as the result of a gene regulatory network.



Haploid cells show all of the same characteristics as stem cells with two sets of chromosomes, and retain the same full developmental potential. This cells facilitates that the process is a bit faster.

The searches used unfertilised mouse eggs to generate embryonic stem cells with a single set of chromosomes, known as haploid stem cells.



The researchers used transposons -- "jumping genes"- to make mutations in nearly all genes. The effect of a mutation can be seen immediately in haploid cells because there is no second gene copy.

A transposable element (TE, transposon or retrotransposon) is a DNA sequence that can change its position within the genome, sometimes creating or reversing mutations and altering the cell's genome size. Transposition often results in duplication of the TE

Identify key players regulating exit from self-renewal in ESCs using a forward genetic screen in haploid ESCs.



They used haploid ESCs to develop a forward genetics screen for pluripotency regulators.

A cohort of candidate genes that promote collapse of self-renewal was validated.

The conserved zinc finger protein Zfp706 promotes differentiation.

Pum1 mediates posttranscriptional destabilization of the pluripotency network.

METHODS

Circuits self-renewal of embryonic stem cells (ESCs) haploid is a useful and fast tool for determining the operational work of the gene, this discovery opens the door for intervention in the development process and makes possible the understanding of a large number heart disease, liver problems and cancer.

PERSONAL OBSERVATION




The substance distributed in the nucleus of a cell that condenses to form chromosomes during cell division. The basic repeating structural (and functional) unit of chromatin is the nucleosome, which contains nine histone proteins and about 166 base pairs of DNA


activity of genes

controlling embryonic

development

The three-dimensional organization

of the chromatin.

Hox genes encode transcription factors with crucial roles during development. These genes are grouped in four different clusters names HoxA, B, C, and D. Mutations in genes of the HoxAand D clusters have been found in several human syndromes, affecting in some cases limb development.



Enhancer

In genetics, an enhancer is a short region of DNA that can be bound with proteins (namely, the trans-acting factors, much like a set of transcription factors) to enhance transcription levels of genes (hence the name) in a gene cluster. While enhancers are usually cis-acting, an enhancer does not need to be particularly close to the genes it acts on, and sometimes need not be located on the same chromosome


Model illustrating how genome topology underlies the tissue-specific regulation of HoxA genes.The HoxA cluster is partitioned between two TADs (light blue), physically segregating3′HoxA from 5′HoxA genes in a mostly cell-type independent manner. In contrast, the sub-TAD interaction pattern is drastically different in the limb (A) compared to the head (B).


PERSONAL OBSERVATION

The study reveals that extensive three-

dimensional chromatin interactions control

the expression of HoxA genes in

developing limbs by forming distinct

topological domains containing limb

enhancers, which interact with each other

and with the topological domains

containing their target genes.

MEDICAL UTILITY

MEDICAL UTILITY

Achieve a better understanding of

cell differentiation process is

essential for the future of genetic

research and therefore, for medical

progress in search of fighting

diseases current.

studies on the structure and

organization of chromatin are the

beginning to identify the source of

many genetic diseases and

manipulate the genes involved to

prevent.

BIBLIOGRAPHY

Rewiring stem cells: New technique may revolutionize understanding of how genes function, Science Daily; 2014 [cited 2014 january 9]. Available at: http://www.sciencedaily.com/releases/2014/01/140109132309.htm

Important discovery for diagnosis of genetic diseases. Science Daily; 2014 [january 16]. Available at: http://www.sciencedaily.com/releases/2014/01/140116113512.htm

Leeb M, Dietmann S, Paramor M, Niwa H, Smith A.(2014). Genetic Exploration of the Exit from Self-Renewal Using Haploid Embryonic Stem Cells. Cell Stem Cell [online]. Availabe at: http://www.sciencedirect.com/science/article/pii/S1934590913005572 Soizik Berlivet, Denis Paquette, Annie Dumouchel,David Langlais, Josée Dostie, & Marie Kmita. (2014).Clustering of Tissue-Specific Sub-TADs Accompanies the Regulation of HoxAGenes in Developing Limbs. PloS Genetics [online] Available at:http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1004018

THANKS

Education

Trabajo plegable biomol