allele

Examples of allele in the following topics:

• Complementation

  • When this occurs, each strain's haploid supplies a wild-type allele to "complement" the mutated allele of the other strain's haploid, causing the offspring to have heterozygous mutations in all related genes.
  • It answers the question: "Does a wild-type copy of gene X rescue the function of the mutant allele that is believed to define gene X?".
  • If there is an allele with an observable phenotype whose function can be provided by a wild type genotype (i.e., the allele is recessive), one can ask whether the function that was lost because of the recessive allele can be provided by another mutant genotype.
  • If not, the two alleles must be defective in the same gene.

• MHC Polymorphism and Antigen Binding

  • This means that the alleles inherited from both progenitors are expressed in an equivalent way.
  • That means that one heterozygous individual can inherit 6 or 8 Class-II alleles, three or four from each progenitor.
  • The set of alleles that is present in each chromosome is called MHC haplotype.
  • In humans, each HLA allele is named with a number.
  • The polymorphic regions in each allele are located in the region for peptide contact, which is going to be displayed to the lymphocyte.

• Exceptions to Koch's Postulates

  • Noninfection may be due to such factors as general health and proper immune functioning; acquired immunity from previous exposure or vaccination; or genetic immunity, as with the resistance to malaria conferred by possessing at least one sickle cell allele.

• Selective and Differential Media

  • Normally, the presence of a specific gene or an allele of a gene confers upon the cell the ability to grow in the selective medium.

• Bovine Spongiform Encephalopathy

  • TSEs can arise in animals that carry an allele which causes previously normal protein molecules to contort by themselves from an alpha helix arrangement to a beta sheet, which is the disease-causing shape for the particular protein.