{"Procedure":"<ol>\t<li>\t\t<strong>Set up timed mating with heterozygous animals. Aim to dissect and collect &gt;=28 alive embryos, otherwise lethal and subviable calls cannot be made. If more than three homozygous pups are produced before 28 pups are genotyped, a viable call can be made. </strong></li>\t<li>\t\t<strong>Collect tissue for genotyping and (OPTIONAL) score Gross Morphology and/or process for Histopathology and or Imaging.</strong></li>\t<li>\t\t<strong>Genotype all embryos and </strong>\t\t<ol style=\"list-style-type:lower-alpha;\">\t\t\t<li>\t\t\t\t<strong>Strains that produce NO existing homozygous embryos will be considered LETHAL (</strong><strong>complete embryonic lethality</strong><strong> [MP:TBC]). </strong></li>\t\t\t<li>\t\t\t\t<strong>Strains that produce NO live (absence of heartbeat) homozygous embryos will be considered LETHAL (</strong><strong>complete embryonic lethality</strong><strong> [MP:TBC]). </strong></li>\t\t\t<li>\t\t\t\t<strong>Strains that produce live homozygous embryos but with an obvious defect will be left to the discretion of the center with the decision and reason recorded in the parameters. </strong></li>\t\t\t<li>\t\t\t\t<strong>X-linked strains that produce NO live hemizygous male embryos from female carriers will be considered LETHAL (</strong><strong>complete embryonic lethality</strong><strong> [MP:TBC]). </strong></li>\t\t</ol>\t</li>\t<li>\t\t<strong>Flag strains that produce less than normal numbers of homozygous/hemizygous male progeny</strong>\t\t<ol style=\"list-style-type:lower-alpha;\">\t\t\t<li>\t\t\t\t<strong>Strains that produce &lt;50% expected homozygous progeny will be annotated as </strong><strong>partial embryonic lethality</strong><strong> [MP:TBC]. </strong></li>\t\t\t<li>\t\t\t\t<strong>X-linked strains that produce &lt;50% expected male hemizygous progeny from female carriers will be considered </strong><strong>partial embryonic lethality</strong><strong> [MP:TBC].</strong></li>\t\t</ol>\t</li></ol>","Purpose":"<p>\n\tTo assess the viability, sub-viability, and lethality of homozygous embryos at E14.5 or E15.5</p>\n","Experimental Design":"<ul>\t<li>\t\tSet up timed matings with heterozygous mice</li>\t<li>\t\tDay 0 is defined as the midpoint of the prior dark cycle following the identification of a copulation plug.</li>\t<li>\t\tCollect embryos at E14.5 or E15.5</li>\t<li>\t\tCollect tissue and genotype embryos.</li></ul>","Notes":"<h3>Recording data for X-linked lines</h3>\r\n<p>As the procedure does not allow recording of hemizygous males specifically, hemizygous males should be recorded as homozygotes in this procedure.</p>\r\n<p>&nbsp;</p>\r\n<h3>Data QC</h3>\r\n<p>All genotypes should be collected using validated assays.</p>\r\n<p>Y chromosome assay required for X-linked lethal strains.</p>\r\n<p>&nbsp;</p>\r\n<h3>Data Analysis, annotation and display (+statistics)</h3>\r\n<p>&nbsp;</p>\r\n<p>Total Embryos: All, WT, Het, Hom<br />&nbsp;&nbsp;&nbsp; &bull;Alive, dead, and defect (all genotyped)<br />Total Dead: All, WT, Het, Hom<br /><br />Total Defect (Alive or Dead):&nbsp; All, WT, Het, Hom<br />&nbsp;&nbsp;&nbsp; &bull;Abnormal and dead embryos<br />Litter size: all genotyped embryos<br />&nbsp;&nbsp;&nbsp; &bull;ignore partials and reabsorptions.</p>"}