title: Mendel: a simple excel workbook to compare the observed and expected distributions of genotypes/phenotypes in transgenic and knockout mouse crosses involving up to three unlinked loci by means of a χ2 test.
abstract: The analysis of transgenic and knockout mice always involves the establishment of matings with individuals carrying different loci, segregating independently, whose presence is expected among the progeny, according to a Mendelian distribution. The appearance of distorted inheritance ratios suggests the existence of unexpected lethal or sub-lethal phenotypes associated with some genotypes. These situations are common in a number of cases, including: testing transgenic founder mice for germ-line transmission of their transgenes; setting up heterozygous crosses to obtain homozygous individuals, both for transgenic and knockout mice; establishing matings between floxed mouse lines and suitable cre transgenic mouse lines, etc. The Pearson's χ(2) test can be used to assess the significance of the observed frequencies of genotypes/phenotypes in relation to the expected values, in order to determine whether the observed cases fit the expected distribution. Here, I describe a simple Excel workbook to compare the observed and expected distributions of genotypes/phenotypes in transgenic and knockout mouse crosses involving up to three unlinked loci by means of a χ(2) test. The file is freely available for download from my laboratory's web page at: http://www.cnb.csic.es/~montoliu/Mendel.xls .
authors.affiliation: Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología (CNB-CSIC), Campus de, Cantoblanco Darwin 3, 28049 Madrid, Spain. montoliu@cnb.csic.es
authors.forename: Lluís
authors.initials: L
authors.lastname: Montoliu
mesh_terms: D000483:Alleles; D000818:Animals; D001947:Breeding; D016009:Chi-Square Distribution; D019295:Computational Biology / Q000379:methods*; D003433:Crosses, Genetic; D005787:Gene Frequency; D056426:Genetic Loci; D005838:Genotype; D040582:Inheritance Patterns; D020407:Internet; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D010641:Phenotype; D012984:Software