Phenotypes Associated with This Genotype

Genotype
MGI:3051575

• Allelic Composition: Efnb2^tm1Henk/Efnb2^tm1Henk
• Genetic Background: either: 129 or (involves: 129 * C57BL/6) or (involves: 129 * CD-1)

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

mortality/aging

neonatal lethality, complete penetrance ( J:91491 , J:91492 )

• surprisingly, the remaning 50% of homozygotes survive embryonic development and are live born, but die within 24 hrs after birth from cardiac abnormalities (J:91492)

embryonic lethality between implantation and placentation, incomplete penetrance ( J:91492 )

• ~50% of homozygotes exhibit peri-implantation lethality, possibly due to placentation defects

digestive/alimentary system

anal atresia ( J:91491 )

• the anal pit does not form a connection with the rectum

persistent cloaca ( J:91491 )

• the rectum is connected to the neck of the bladder in males or the vagina and neck of the bladder in females forming a single tube

renal/urinary system

persistent cloaca ( J:91491 )

• the rectum is connected to the neck of the bladder in males or the vagina and neck of the bladder in females forming a single tube

abnormal urethra morphology ( J:91491 )

• the external urethra is untubularized

hypospadia ( J:91491 )

♂ • males have severe hypospadia

reproductive system

persistent cloaca ( J:91491 )

• the rectum is connected to the neck of the bladder in males or the vagina and neck of the bladder in females forming a single tube

splayed clitoris ( J:91491 )

♀ • females display a splayed clitoris

cardiovascular system

cardiovascular system phenotype ( J:91492 )

N • at E9 until birth, homozygotes are grossly normal and exhibit none of the early vascular defects observed in Efnb2^tm1.1Henk homozygotes

abnormal heart valve morphology ( J:91492 )

• homozygotes exhibit an overall normal chamber formation and vascular connections but show thickened cardiac valves

thick mitral valve cusps ( J:91492 )

• at E18 and P0, homozygotes exhibit slightly hyperplastic mitral valve leaflets with ~30% more mesenchymal cells relative to wild-type mice

• in contrast, tricuspid valves show no significant changes in leaflet size

enlarged aortic valve ( J:91492 )

• at E18 and P0, all homozygotes display significantly enlarged aortic valves

aortic valve hyperplasia ( J:91492 )

• at E18 and P0, all homozygotes display hyperplastic (thickened) aortic valves, with nearly twice as many mesenchymal cells relative to wild-type mice

thick aortic valve ( J:91492 )

• at E18 and P0

enlarged pulmonary valve ( J:91492 )

• at E18 and P0, all homozygotes display significantly enlarged pulmonary valves

pulmonary valve hyperplasia ( J:91492 )

• at E18 and P0, all homozygotes display hyperplastic (thickened) pulmonary valves, with nearly twice as many mesenchymal cells relative to wild-type mice

thick pulmonary valve ( J:91492 )

• at E18 and P0

nervous system

abnormal axon guidance ( J:91492 )

• at E16, all homozygotes display defective pathfinding of axons that form a major forebrain commissure, the posterior tract of the anterior commissure

abnormal anterior commissure pars posterior morphology ( J:91492 )

• at E16, formation of the posterior tract of the anterior commissure, a major forebrain commissure that connects the two temporal lobes of the cortex, is severely impaired

embryo

abnormal septation of the cloaca ( J:91491 )

• at E11 a complete lack of septation of the cloaca is seen

• at E13 endoderm is not partitioned into the hindgut by epithelial cells

cellular

abnormal axon guidance ( J:91492 )

• at E16, all homozygotes display defective pathfinding of axons that form a major forebrain commissure, the posterior tract of the anterior commissure