(07) Infection Flashcards
What three things is genetic variation in a population due to?
allelic variation, gene expression, gene interactions
Dont really know if he expects us to learn this… but should look at it a little
What Do We Mean By Resistance?
Animals are said to be resistant if after entry into the body the pathogen (or parasite)…..
- Fails to establish an infection (give 3 terms)
- Established infection but fails to complete development (give 1 term)
- Establishes infection but is elimitated by host
- non-susceptible, innate, non-specific (taken care of by innate)
- susceptible
- acquired resistance
(Major Histocompatibility Complex)
- large cluster of genes that controls activity of many immune cells
1. Primary functions (2 of them)?
2. Is this the strongest associated between genetic variation and disease resistance?
- bind and present antigenic peptides; recognition by t cells
- yes (ex resistance against Marek’s disease in poultry and mastitis in cattle)
(Nramp1)
- Stands for?
- gene identified in what animal?
- expressed in what?
- encodes what?
- recruited to phagosome and decreases what?
- natural resistance-associated macrophage protein 1
- mice
- macrophages
- metal cation transporter (Fe2+)
- intracellular microbial replication
(Nramp1 cont)
- Mice strains had variable susceptibility to what?
- Amino acid change at position 169 to what?
- does what?
- homologs identified in what?
- associated with resistance to what?
- attenuated mycobacterium bovis BCG
- glycine to aspartic acid (G to D(susceptible))
- impairs protein folding (causes degradation)
- humans, cattle, sheep, etc
- mycobacterium, salmonella, brucella, leishmania
(Brucellosis)
- Caused by what bacteria?
- Disease to what animals?
- Detect animals by appearance?
- What are the candidate genes controlling natural resistance to brucellosis in bovines?
- Brucella abortus
- ruminants
- no
- Nramp1; Differential expression of anti-LPS IgG2a allotypes
- Is Host Resistance to many diseases polygenic? example?
- yes, 250 genes affect HIV exposure outcome (lots of variation in response - not a simple yes or no)
These are some approaches to Controlling and Preventing Disease:
- Medication, Isolation, Vaccination, Eradication, Sanitation
- What is it called when disease control measures allow unfit animals into breeding population, and prevent natural selection for disease resistance?
- yep
- antagonistic effect
What are the Negative Aspects of Selective Breeding? (there are 2 of them)
- Increased frequency of “recessive lethal” alleles (increased incidence of genetic diseases)
- Loss of genetic variation (increased disease susceptibility)
Why is population genetics important?
- Provides a more comprehensitve understanding of the biology
- Selection for resistance or another trait
didn’t forget - just read them
Why is it hard to implement improvement programs (when considering resistance)?
- status may be polygenic, environmental factors, difficult to establish and costly, resistance alleles may not even exist in given population
read this… but know it pretty well
What are the two routes to identify host genetic factors?
- Candidate Gene Studies (case control, gene knock-out)
- Genome-wide association studies (GWAS)
(Clinical Clues to Genetic Component)
Two WAys
- Variation observed in pattern of disease (name them… there are 4)
- Variation related to what else?
- severity, parasites/pathogen load, time to recovery, differential mortality
- age, sex, nutrition, or reproductive condition
(Use of Experimental Populations)
just read this
