gen mini 1b

• -inactivation of X chromosome
• -only seen with >1 X chromosome (NO MALES)
• - can happen at 2-10,000 cell stage, so females can be mosaics of both X chromosomes, depending when it was deactivated, ex X-linked anhidrotic dysplasia

an ordered display of all chromosomes from one cell

meta- roughly the middle

submeta- uneven, shorter p arms than q arms

acro- centromere basically at top, all that is above the centromere are satellites (rDNA)

21

• later replication
• fewer active genes
• more condensed
• higher A-T bp
• stain with quinacrine and light with R-banding

13,18,21, X and Y

X

13, 14, 15, 21, 22

• chromosome with 2 identical arms
• can be partial monosomy or partial trisomy

if a chromosome loses both telomeres (or double strand break on both ends) the ends will fuse and cause a circular chromosome

• can cause a chromosome with 2 (or 0) centromeres (0 is lost)
• if have 2 centromeres, can still function as a single chromosome

if thyroid levels are normalized early, symptoms can be helped

on chromosome 21, is thought to be involved in early senility of Downs syndrome pts due to over expression

• SRY on the Y chromosome
• if absent default p/w is female development

• SOX9 and AR
• -mutations will lead to expressionof female phenotype

most are 46XX with an SRY translocation

fusing of 2 fetilized eggs to make a single organism

• - over production of androgens, due to blocked syn of corticosteroids
• -cause adrenogenital syndrome- female with virilized (man-like) characteristics
• -HYPO-Na and HYPER-K often seen
• - tx with cortisol (for feedback inhibition of ACTH from pituitary) and surgical reconstruction (later in life)

can cause very high levels of deoxycorticosterone, which causes opposite Na and K problem

• 46, XY, externally and psychosocially female
• X-linked rec, androgen receptor defect
• "Male Intersex A"
• - no uterus,fallopian duct or wolfian structures and undescended testes

• 46, XY
• wolfian structures present, testes often undescended, hppospadia sometimes
• - no conversion of testosterone (less active) to dihydroxytestosterone (more active)
• -many raised as females until puberty

GF signal nucleus to turn on cyclin D, which binds Cdk4 and Cdk6 to activate them, which PO4 Rb causing it to release E2F

• cyclin E- Cdk2,
• cyclin E is upregulated by E2F after release from Rb-PO4

cyclin A- Cdk 2

• cyclin B- Cdk1- MPF
• cyclin A- Cdk1- progression thru G2

controls G1/S restriction by binding Cdk4/6 and preventing cycle progression

binds E2F preventing S phase progression, when PO4 by Cdk4/6/cyclin D, it will release E2F, which then upregulates cyclin E allowing progression to S phase

• MPF= Cdk1/cyclin B
• will move cell cycle into mitosis phase
• *activity related to [cyclin A] and [cyclin B]*

• phosphatase that removes inhibitory PO4 from Cdk1, to allow progression into M phase
• -if DNA is damaged Cdc25 is inactivated, arresting the cell cycle

will PO4 Cdk/cyclin inactiving them. Cdc25 has opposite affect

• removes cohesion allowing sister chromatids to be pulled apart (anaphase)
• _must be dePO4 by Cdc20 to be activated

• a ubiquitin ligase
• -Cdc20 dePO4 to activate it
• -ubiquitinates cyclin B

• -restriction endonucleases
• -cloning capability (amplification)
• - probes (for ID)

• same sequence when read 5'-3' or 3'-5' on both strands
• -target of restiction endonucleases
• - methylation will protect pallindromes from RE

• -5' promoter
• - Shine-Dalgarno is correct place in 5' UTR (so start codon places in the P-site
• -termination sequence placed after the gene

• allele specific probes
• -can be used to target specific alleles of a gene, which can be used to determine if a patient has a mutant gene and whether they are homo or heterozygoud for it.

% of those with the allele that will show the phenotype

influence traits of one sex or traits influenced by sex hormones

difference in age of onset or severity for a seemingly identical genotype

• different alleles at the same locus produce different diseases
• -can be different alleles that cause the same nonfunctional gene in different ways

-mutation of one gene having >1 effect or >1 physiological system effected

• - anchorage
• -contact inhibition
• - mitogen cofactor dep't