Workshops and Labs

Question 1

Familial Hypercholesterolaemia

Answer 1

• Symptoms: deposits of cholesterol in skin and tendons, premature atherosclerosis
• Gene: LDLR (low density lipoprotein receptor), involved in lipid metabolism, uptake of LDL-bound cholesterol
• AD

Question 2

Familial Haemochromatosis

Answer 2

• Symptoms: Skin colouration, fatigue, abdominal pain, heart abnormalities, liver disease etc.
• Gene: HFE (High iron), regulating iron uptake in intestinal and liver cells (MHC class I-type protein, TM)
• AR

Question 3

Bloom’s Syndrome

Answer 3

• Symptoms: Short, sun-sensitive, cancer-prone
• Gene: BLM, maintenance of chromosome stability, supressing inappropriate recombination
• AR

Question 4

Rett Syndrome

Answer 4

• Symptoms: Arrested development, regression of acquired skills, loss of speech, seizures
• Gene: MECP2 (Methyl CpG binding protein), modulates chromosome architecture, regulating gene activation and repression in neurones
• X-linked, D

Question 5

Lesch-Nyhan syndrome

Answer 5

• Symptoms: Severe motor handicap, learning disability, self-injurious behaviour (teeth removed)
• Gene: HRPT1 (Hypoxanthine guanine phosphoribosyl transferase), generation of purine nucleotides through purine salvage pathway
• X-linked, R

Question 6

Marfan syndrome

Answer 6

• Symptoms: Tall, weak connective tissue, joint laxity, scoliosis, aortic dilation, aneurysm
• Gene: FBN1 (Fibrillin 1 preprotein), main constituent of microfibrils in E-C matrix
• AD

Question 7

Ataxia Telangiectasia

Answer 7

• Symptoms: Uncoordinated movements, dilated blood vessels, weakened immune system, cancer-prone, radiation-sensitivity
• Gene: ATM, response to DSBs (cell cycle arrest, DNA break repair, apoptosis)
• AR

Question 8

Leber optic neuropathy

Answer 8

• Symptoms: Acute/subacute bilateral loss of vision
• Gene(s): MT-ND1,4,5, complex involved in ETC
• Maternal

Question 9

Key features of a plasmid cloning vector

Answer 9

• ori
• gene encoding selectable marker (e.g. ampicillin resistance, chloramphenicol R) allowing selection of transformants
• a means of detecting which transformants contain the recombinant plasmid (e.g. lacZa peptide; blue/white selection based on disrupting complementation of chr. lacA deletion mutation
• Convenient, unique restriction enzyme cleavage sites

Question 10

Procedure for eluting pure plasmid DNA

Answer 10

1. Harvesting of bacteria from liquid cultures
2. Alkaline lysis of bacteria
3. DNA adsorption of the membrane
4. Washing and elution of plasmid DNA

Question 11

Average extinction coefficient for dsDNA at 260nm wavelength

Answer 11

0.02 (micro g/ml)^-1 cm^-1

Question 12

Minimal vs complete medium

Answer 12

• Minimal: Contains only defined ingredient; sugar (C source) + slats (ammonium, nitrate, phosphate) + trace elements. Supports growth of wt bacteria w/ fully functional biosynthetic pathways
• Complete: aas, sugars, vitamins, essential metabolites. Supports growth of all bacteria regardless of status of biosynthetic pathways

Question 13

Interrupted mating experiment graph

Answer 13

• Y: No. of recombinant exconjugants colonies
• X: Time before mating interruption (mins)
• Smooth curve/line of best fit

Question 14

Homologous pairing process (RecA)

Answer 14

• RecA loaded onto ssDNA, forms presynaptic filament
• Helical nucleoprotein filament distors DNA, extending ~50%
• Promotes pairing w/ homologous DNA
• RecA protein catalyses exchange of strands between participating DNA molecules