ANALIZE MEDICALE DE LABORATOR
Aici gasiti analizele medicale grupate pe categorii precum si detalii generale si specifice pentru categoriile respective.
Selectati o categorie din lista de mai jos:

Dictionar de medicamente online

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Dictionar medical online

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Puteti trimite articole cu tema medicala la
adresa de email

Solutie antistress!
Construieste poduri :)
Joc, Construieste podul, Cargo Bridge

Prinde pisica neagra :)
Prinde pisica neagra- Chat Noir - Flash game

Dictyostelium Cells Shown To Lay 'Breadcrumb Trail' As First Step In Multicellular Formation

When starved of their food source and then presented with a chemoattractant signal like cAMP, individual Dictyostelium cells acquire a polarized morphology and aggregate to form a migrating stream. This is the first step in a developmental program that culminates in the formation of a multicellular organism. Kriebel et al. show how this streaming response is coordinated at a single-cell level in the December 1, 2008 issue of the Journal of Cell Biology.

Besides acquiring a polarized morphology and beginning to chemotax, Dictyostelium cells respond to cAMP signals by making their own cAMP, thereby recruiting yet more cells to join the parade. The team previously discovered that ACA - the enzyme that makes cAMP - is highly enriched at the back of migrating cells. They thus proposed that the attractant is released mainly from the rear of cells, which prompts fellow cells to align and generate head-to-tail streaming structures. Kriebel et al. now show that ACA is packaged into intracellular vesicles that cluster at the rear of cells in a process that is dependent on actin and microtubule networks. They also show that de novo protein synthesis is required to maintain the asymmetrical distribution of the ACA vesicles.

Interestingly, the ACA-containing vesicles themselves, not just their contents, are deposited behind the Dictyostelium cells like a breadcrumb trail as the cells crawl along. As cAMP is a small and diffusible molecule, perhaps the vesicles serve to package the chemoattractant so that it doesn't immediately diffuse away, says author Carole Parent.

Notes:

ABOUT THE JOURNAL OF CELL BIOLOGY

 Founded in 1955, The Journal of Cell Biology/ (JCB) is published by the Rockefeller University Press. All editorial decisions on manuscripts submitted are made by active scientists. JCB content is posted to PubMed Central, where it is available to the public for free six months after publication. Authors retain copyright of their published works and third parties may reuse the content for non-commercial purposes under a creative commons license. For more information, please visit http://www.jcb.org.

Kriebel, P.W., et al. 2008. J. Cell Biol. doi:10.1083/jcb.200808105.

Source:
 Rita Sullivan
Rockefeller University Press





Dictyostelium celule arãtat de a stabili 'breadcrumb Trail ", ca prim pas în formarea multicelulare - Dictyostelium Cells Shown To Lay 'Breadcrumb Trail' As First Step In Multicellular Formation - articole medicale engleza - startsanatate