Bio Unit 3

Ligand

Signaling molecule

Receptor protein

what binds directly to the ligand

signal transduction

process of converting the ligand signal to a cellular response

endocrine

type of signaling that covers long distances and uses hormone

Paracrine signaling

typ of signaling that covers medium/short distances

GCPR

largest family of receptors that are typically targets of pharmeceuticals and contain 7 transmembrane domains

exchange factor

the changing of shape of gpcr as gdp switches with gtp

off state

GDP is bound to the gpcr

on state

GTP is bound to the gcpr

Development

a series of events in changing from a simple to a more complex form

cell division, differentiation and determination, pattern formation, morphogenesis

4 sub processes involved in development

differentiation

cells becoming more and more specialized in structure and function until a unique cell type is acheived

determination

potential fates of cells becoming more and more limited until the cell is committed to a specific identity

Stem cells

cells capable of continuous division that can give rise to differentiated cells (degree of determination varies)

Topoitonent

cell can give rise to any tissue in any organism

Pluripotent

cells can give rise to any cells in adult

Multipotent

cells can give rise to a limited number of cell types

unipotent

cells can only give rise to a single cell type

growth factors

signaling molecules that controll cell determination and diferentiation

Neural growth factor

discovered by ontelicini by feeding embryonic sensory ganglion tumor cell media

C-elegans

model organism for studying animal development.

Epidermal growth factor

growth factor secreted by anchor cells that activates egfr

EGFR

receptor tyrosine kinase that gets turned on by phosphorylation and binding of EGF.

Protein phosphorylation

kinases use ATP to phosphorylate a protein which decides if that signal will be on or off.

RTKS

receptors that form dimers upon ligand signaling and becomes active once it gets phosphorylated

induced pluripotent stem cells

created by treating differentiated cells with plasmids containing 4 genes related to master regulatory genes from a stem cell

zona pellucida

region of the egg that the sperm must travel through after passing follicle cell layer but before membrane fusion

phospholipase C zeta

enzyme in signaling pathways that cleaves lipids

PIP2

lipid that gets cleaved by a phospholipase and produces DAG and IP3

IP3

secondary messenger in signal transduction pathways that travels to the er and triggers the release of calcium

cortical granual release

triggered by the wave of calcium in an egg, this releases contents to prevent other sperm from fertilizing and triggers nuclear fusion

blastula

stage of development that is a ball of cells with a hole in the middle and is formed from cleavage

morphogenesis

generation of ordered form and structure

gastrulation

the process in which the blastula moves to fold inwards and generate 3 derm layers

ectoderm

derm layer that will form the skin and nervous system

mesoderm

derm layer that will form the muscles and cardiac system

endoderm

derm layer that will form gastrointestinal tract and endocrine system

Pattern formation

use of positional information to create body pattern by using changes in signaling and gene activity

Inducers

signals that promote dorsal or ventral patterning and formation of related structures

Organizer

tissue that contains inducer molecules

Spemann Mangold experiment

experiment that implanted dorsal organizational tissue to a ventral side leading to a conjoined twin forming

Bone morphogenic protein

ventral inducer molecule

Noggin

dorsal inducer molecule that acts by inhibiting the ventral inducer molecule

Homeotic mutations

mutations caused by Hox gene clusters that causes a body structure to be replaced by another (ex: legs for attenna)

Homeobox

gene clusters that encode transcription factors that regulate development (but often complement each other to prevent visible mutations)