transcription factors, signalling molecules, and other important molecules

Fz and Dsh

involved in establishing planar polarity, at N, Fz activates Dsh which actiates Fz, these are activated by Stmb in the S of another cell

IGFI and IGFII

the growth hormones that most cells actually respond to

growth hormone

only really affects post natal muscle growth directly, other tissues indirectly

Indian hedgehog

used to signal by mature cells, signals to the sheath of the bone which responds by making a peptide that diffuses back to the growth plate, signalling proliferation

FGFR3 and FGF

FGF binds to FGFR3 in bone to signal to calm bone growth in limbs. Activating mutation in FGFR3 causes receptor to be on in achondroplasia even if FGF is not present, causing truncated limbs

chalone

proposed quorum signalling molecule in spleen growth, only theoretical

Wnt4

expressed as a quorum sensing molecule in kidney mesenchyme, vital for aggregates to undergo the mesenchymal to epithelial transition and form extretory nephrons

neurotrophins

survival factors for neurones derived from the target, less neurotrophins mean higher neurone death after huge mitosis

TATA binding protein

binds to a TATA box, controls where DNA transcription starts but not which gene is transcribed

histone acetyl transferase

loosens histone interaction with DNA through acetylation, making the gene more accessible

FGF

a gactor that promotes myoblast proliferation (different from the FGF involved in achondroplasia)

MyoD

activates expression of the gene for muscle myosin II, myoblasts do not differentiate if MyoD is not present

Glabra1

affects the gene encoding a transcription factor for plant leaf trichomes

GATA1

a zinc finger transcription factor binds to GATA, its targets are alpha and beta globin, EPO receptor, haem biosynthesis enzymes and spectrin, it is not enough to activate transcription alone and only activates globin genes in erythroblasts

NF1 and CP1

are needed alongside GATA1 to activate the beta globin gene

MAP kinase

involved in signalling cascades, MAPKKK, MAPKK, MAPK, transcription factor

EGF (epidermal growth factor) and MYC

EGF is a growth factor that leads to the phosphorylation of MYC, this results in the stabilisation of MYC which drives the transcription of cyclin genes

EPO (erythropoietin)

secreted from the kidney, stimulates progenitor proliferation and RBC differentiation in bone marrow, phosphorylates GATA1, increasing its DNA binding affinity

SPCH, MUTE, and FAMA

transcription factors that represent sequential steps in guard cell differentiation, in mutants of each gene, guard cells are missing, and therefore stomata

growth factors (in muscle differentiation)

maintain proliferation, inhibit differentiation into muscle fibres

bHLH transcription factors (particularly MyoD and Myf5)

act as the master regulators in muscle differentiation, help commit cells to the muscle lineage

MyoD (additional info)

both pax3 and Myf5 must be present for MyoD expression, MyoD experiences positive autoregulation and its expression eventually becomes independent of Myf5 and pax3

miR-1

micro RNA responsible for the degradation of pax3 to allow later stages of muscle differentiation to proceed

Ngn3

required for the differentiation of all endocrine cells

Fgf3

secreted by the notochord, primordial gut cells that are close enough can respond to this, this allows pdx1 expression to be switched on

Cdx2

expression of this gives gut cells the competence to become pre-pancreatic cells but they will only do so if FGF2 signal is received

PU.1

required for myeloid fate choice and present with and mutually antagonistic to GATA1, preventing differentiation in erythroid myeloid progenitor cells

Pax6

specifies the eye primordium in animals, known as a master regulator, loss of one copy causes aniridia which results in many problems with the structure and function of the eye

CO

a plant protein which is sensitive to light and accumulates when days are long, helps to regulate flowering time

FT protein

hich CO protein levels promote synthesis of FT protein, FT levels are high when day is long FT protein moves through sap from leaf to shoot, flower forms at the shoot

EphB receptor

axons grow towards cells expressing this until direct cell to cell contact is made, the axon then steers away to avoid it

SRY (sex determining region Y chromosome)

a transcription factor only expressed in the Y chromosome, regulates gene expression leading to testes differentiation

SHH (role in zone of polarising activity)

morphogen responsible for the anterior posterior differences in limbs

Pax2 and Lim1

expressed very early on in kidney development, mutations in these genes cause kidneys to not develop at all

BMP2 (bone morphogenetic protein 2)

a secreted morphogen (likely from the lateral plate mesoderm that induces kidney tissue at medium levels) works in tandem with the paraxial mesoderm signal to induce Pax2/8 and Lim1

GDNF and ret

a factor active in the metanephric mesenchyme which is responsible for the branching of the ureteric bud, which contains ret receptors for GDNF, cells with higher ret exhibit stronger branching behaviour, GDNF also acts to inhibit collagen XVIII in the tip of the ureteric bud

Wnt9B

secreted from the ureteric bud in kidney formation is vital for the MET, also induces Wnt4 expression within MM which is the autocrine signal you are more familiar with

VEGF (vascular endothelial growth factor

a chemoattractant secreted by podocyte precursor cells that induces endothelial migration into the developing glomerulus

Lgr5

not a signal but crypt basal columnar cells and are the stem cells of the gut and express this

Wnt3

secreted by paneth cells in the gut, acts as a survival factor of sorts, keeping the gut stem cells active and in their niche

LIF

secreted signalling molecule which maintains embryonic stem cells

SHH (neural)

secreted by the notochord and floor plate, leads to the binding of PTCH1 which itself is then no longer able to repress SMO, which activates GLI, high SHH instructs ventral tissue

FGF8 and Wnt (neural)

FGF8 and medium Wnt instructs midbrain, FGF8 and high Wnt instructs hindbrain