Skip to content
Login Register

#knockout mice

2 public questions tagged with this topic.

Limb Development -lll

What happens when all six alleles of Hox11 paralogues are knocked out in mice?

Hox11 paralogues Hoxa11, Hoxc11 and Hoxd11 redundantly pattern the zeugopod intermediate segment. Individual or double knockouts display mild radius ulna or tibia fibula shortening, reflecting dosage compensation and functional overlap. Progressive allele loss reveals quantitative dependence, and eliminating all six alleles results in complete loss of zeugopod elements while stylopod humerus femur dependent on Hox9 and autopod dependent on Hox12-13 remains largely intact. This demonstrates regional specificity, redundancy, and dosage sensitivity, explaining why full Hox11 null phenotype is defined by dramatic zeugopod agenesis.

Ref: Wellik and Capecchi, Science 2003, Hox11 paralogous group specifies zeugopod region formation.

View Details
Gene Tar getting

What is the correct sequence for generating knockout mice?

Generation of knockout mice by ES cell method follows ordered protocol. Homology arms plus positive-negative selection markers are cloned into targeting vector containing floxed or null allele. Vector electroporated into cultured embryonic stem cells where homologous recombination occurs. G418 and ganciclovir selection enriches correctly targeted clones confirmed by Southern blot analysis. Targeted ES cells microinjected into blastocysts implanted into pseudopregnant foster mothers produce chimeric offspring. Chimeras bred for germline transmission yield heterozygous knockout founders, later intercrossed to homozygous knockout lines.

Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.

View Details