Genetics

Genetics is published by the Genetics Society of America. The journal publishes empirical studies of organisms ranging from microbes to humans

Genetics

• Patterns of inheritance
  • sigle(mono)genic/mandelian inheritance
    • Co-segregation of mutant allele
    • Can be analyzed through mutant analysis
    • Deviation
      • Incomplete Penetrance
        • like those BRCA1/2 in the inherited breast cancer
          • 80% of them will have the disease
          • loss of heterozygosity
          • clinical heterogeneity
      • Expressibility
  • Polygenic inheritance
    • can reflects family degree of relatedness
      • the proportion of genome held in common, determines risk to any one relative
      • 1st: Siblings have on average 50% of their genome in common
      • 1st: Parent and child share 50% of genome in common
        • For sure
      • 2nd: Aunt has on average 25% in common with niece’s genome
      • 3rd: Cousins have on average 12.5% in common in their genomes
    • Heritability of a phenotype
      • define variances
      • define hereditability(H^2)
        • Broad sence
        • Narrow sence
  • Extracellular inheritance
    • mitochondrial DNA transmitted through the ova’s cytoplasm
• Traits/Characters
  • how many genes involved?
    • Mandelian character
      • A particular genotype at one locus is both necessary and sufficient for the character to be expressed
    • Non-Mandelian character
      • >1 locus, multifactorial, can be oligogenic and polygenic
    • • Consider the factor of enviroment
  • Is the trait quantitive?
    • Dichotomous characters
      • Susceptibility genes
    • Quantative/continous characters
      • Quantitative trait locus (QTL)
• Some notions in the Pedigree analysis