Molecular Genetics 4

Writers

Add a functional group to genes

Readers

Binds to modification to specialize

Erasers

Remove functional group

DNA Methylation

Gene is suppressed

Histone Methylation

Usually suppresses gene expression but in some cases can activate expression

Histone Acytelation

Activates gene expression

DNA Acytelation

Does not exist

lncRNA

Accommodates smaller RNA stopping it from suppressing genes

Somatic

Mutation is not passed on

Gametic

Mutation is passed on

Blastula

Single layer of cells

Gastula

Three layers of cells, exoderm mesoderm and endoderm

Blastocyte Stage

When the zygote attaches to the uterine wall

Maternal to Zygotic Transition

The embryo goes from using the mothers mRNA to using its own

Oncogens

Mutated or abnormally expressed proto-oncogens that lead to uncontrolled cell growth

Proto-Oncogens

Unmutated, helps to regulate cell division

Carcinogens

Cancer causers

Benine Tumor

Stays in one area

Malignant Tumor

Invades surounding tissue, associated with cancer

EMT-MET

Change in protein meant to centralize where the cell resides

Apoptosis

Programed cell death, no inflammation

Necroptosis

Cell death wherein it explodes

Pyroptosis

Cell death that is systematic(spreads throughout the body) highly inflammatory

Autophagy

Self eating cell destruction, will not always end in death but if to much of the cell is infected/eaten apoptosis will begin

Genetic

Heritable gene alteration that is irriversable and not influenced by the environment

Epigenetic

Sometimes heritable gene modification influenced by the environment, reversible

Developmental Genetics

How genetics influenced the development of cells, tissues and organs

Ectoderm

Outermost layer, nervous system and skin

Mesoderm

Middle layer, muscles, skeleton, kidney and reproductive system

Endoderm

Innermost layer, endocrine glands, lungs, digestive tract and liver

Zygotic Genome Activation

Zygote begins translating its own mRNA

Mammal ZGA

Happens in two stages

Drosophillia ZGA

during mid blastula transition

Zebrafish ZGA

Happens at 512 cell stage

miR family

Targets maternal mRNA for degrasion, 430- zebrafish, 427-xenopus, 309-drosophila

PABPC

Protein for mRNA circulation and translation, low in early development higher in mature cells

Cell Proliferation

increase number of cyclin and CDKs

Cell Fate

Assign identity to cell, Sox2, Pax6, NeroG

Patterning

Organization, SHH, Wnt, BMP, Hot

Migration

Positioning cells, reeling interlines and chenokies

Cell death

tissue sculpting, caspase and BCL2

Morphogenesis

Organ shaping, cytoskeleton and cell adhesia

EMT/MET

mobility and epithelialization, snail twist and E-eadherin

Induction

Talk between cells, FGF, BMP, SHH

Axis Formation

Body plane setup nodal, Hox,

Organ Maturation

Functional specialization, tissue specific

Morphogenes

Secreted to travel down a concentration gradient signaling to turn genes on/off based on concentration threshold

SHH

Specialize motor nerves

BMP

neural crest induction, ectoderm patterning

FGF

Limb development, mesoderm induction

Nodal

Determines organ sidedness

ZPA

Secretes different amount of SHH to activate transcription factors

XIST lncRNA

Preform X-inactivation to insure dosage compensation in females

G1/S Checkpoint

Checks for DNA damage before transcription

G2/M Checkpoint

Ensures full and correct replication before mitosis

Spindal Assembly Checkpoint

Ensures properly aligned chromosomes before separation

DNA Aduct Formation

Carcinogens bind to DNA covalently causing replication errors

Viral Oncogenesis

Viral genes integrate and disrupt host genome of produce oncogenic proteins

TP53

guard genome, activate cell cycle rest, repair of apoptosis

RB1

Inhibits E2F blocking G1 to S transition

CDKN2A

inhibits CDK4/6 to maintain RM activation

ATM/ATR

Sense damage and signal for checkpoint

BRCA1/2

Involved in homologues recombination repair

Barr Body

The inactive X chromosome in females

Down Syndrome

Trisomy on chromosome 21

Edwards Syndrome

Trisomy on chromosome 18

Patau Syndrome

Trisomy on chromosome 13

Uninheritable Down Syndrome

Trisomy is due to failed segregation during meiosis

Inherited Down Syndrome

Translocated of one chromosome 21 occurs, if they both end up in the same egg trisomy will occur

Turner Syndrome

Only one X chromosome

Mosaic Turner Syndrome

Some cells have just X and the rest have XX

Klinfelter Syndrome

XXY

Tripple X Syndrome

XXX

Cri-du-chat

Deletes the short arm (p) of chromosome 5

Wolf-Hirschorn Syndrome

Delete short arm (p)of chromosome 4

Williams Syndrome

7q micro deletion, about 28 genes on the long arm

DiGeorge Syndrome

Deletion of 22q11.2

Cherot Marie Tooth

17p11.2 duplication

Ring Chromosome 14

End to end joining of chromosome

Burkilt Lymphomia

Translocation 8 → 14, causes overactive B cells

CML

Translocation 9→ 22

Single Nucleotide Polymorphism

Mutation of a single base pair causes change in the genome

Sickle Cell Anemia

GAG→GTG meaning Glu→Val, causing red blood cells to change shape

LoF

Loss of function due to a mutation

GoF

Hyperactivity due to mutation

Dominent-Negative

Mutation interferes with the function of a wild-type

ASO

Binds to sense RNA in order to inhibit expression, type of nucleic acid therapy

Aptamers

Fold into a 3D structure in order to emulate DNA/protein interaction binds to 40s ribosome in order to tag molecule

mRNA Therapies

Directly put into the body which takes care of synthesis and removes the need to destabilize RNA

Viral Vector

Encapsulates plasma in non-viral vector deactivating the virus

Insertional Mutagenosis

Viral DNA inserts itself near the proto-oncogene changing enhancing expression creating a oncogene

Loss of Regulatory Control

Promotors or enhancers cause unregulated expression creating a oncogene

Ferroptosis

An abundance of iron causes stress and then cell death