All Phenotypes Lgr4<Gt(pGT0TMpfs)1Wcs> MGI Mouse

postnatal lethality, incomplete penetrance ( J:105945 )

• on a predominantly CD-1 background, homozygotes are viable and most of them reach adulthood; however, the health of some deteriorates during milk feeding leading to early death

epididymal cyst ( J:105945 )

• as early as P3, homozygotes fail to elongate the epididymal duct, which evolves into a cystic structure observed at P9 and P23

decreased body size ( J:105945 )

• at P7, homozygotes are 28% and 25% smaller than wild-type and heterozygous littermates

decreased body weight ( J:105945 )

• at P14-P49, homozygotes display a weight deficit and reach a body weight plateau earlier than wild-type or heterozygous mice

• a proportionate reduction in organ weight is observed for all major organs, except for testis/epididymis

abnormal testis morphology ( J:105945 )

abnormal rete testis morphology ( J:105945 )

• after the onset of puberty, all homozygotes display a bilateral edema in the rete area of the testis, sometimes associated with the presence of red cells

rete testis obstruction ( J:105945 )

• in adults, the rete testis continues to dilate and fills with large amounts of spermatozoids and liquid

• however, the vas deferens, seminal glands and prostate appear normal

abnormal seminiferous tubule epithelium morphology ( J:105945 )

• after the onset of puberty, all homozygotes show luminal enlargement of the seminiferous tubules and thinning of the germinal epithelium (atrophy)

abnormal testis physiology ( J:105945 )

• in efferent ducts, immune cells infiltrate the epithelium and reach the lumen, blocking the transit of sperm and testicular fluid

• the hypoplasia and low convolution of mutant efferent ducts result in a reduction of the epithelial area involved in liquid reabsorption

• these phenotypes result in tissue swelling upstream the blockade due to liquid and sperm accumulation

abnormal efferent ductules of testis morphology ( J:105945 )

• at P3, the number of proliferating (BrdU-labeled) cells is significantly reduced in the epithelium of mutant efferent ducts

• at the onset of puberty (~3 weeks), all homozygotes exhibit severely hypoplastic and less convoluted efferent ducts relative to wild-type mice

• at the proximal region (close to the testis), mutant ducts are dilated, their lumina are filled with sperm cells, and immune cell granulomas infiltrate the lumina and surrounding mesenchyme tissue, blocking the transit of sperm and testicular fluid

• at ~3 weeks, the duct diameter is severely reduced

• in adult homozygotes, certain epithelial characteristics of the ducts, such as cell height and pseudo-stratification, display a strong variation at the proximal region relative to wild-type

• notably, the distal region shows normal epithelial height with no differences in ciliated cells and pseudo-stratification

abnormal epididymis morphology ( J:105945 )

• although normal at birth, as early as P3, the typically thin and highly convoluted duct is replaced by a large dilated and much less convoluted cystic tube surrounded by a thick condensation of mesenchymal cells

• in most homozygotes, the epididymis is devoid of sperm cells

epididymal cyst ( J:105945 )

• as early as P3, homozygotes fail to elongate the epididymal duct, which evolves into a cystic structure observed at P9 and P23

small caput epididymis ( J:105945 )

• in homozygotes, a thinner, underdeveloped structure replaces the typically inflated caput epididymis seen in wild-type mice

• the average height of the epithelium in the caput region is reduced by 60% relative to wild-type

• at P3, the number of proliferating (BrdU-labeled) cells is significantly reduced in the epithelium of the caput epididymis

abnormal epididymis epithelium morphology ( J:105945 )

• in adult homozygotes, the cell shape pattern is perturbed and the epithelial cell height is nearly constant throughout the caput and corpus regions

• two layers of nuclei are observed in most caput and corpus regions and epithelial buds are shown to project from the epididymal ducts

epididymis hypoplasia ( J:105945 )

• all adult homozygotes display a severely hypoplastic epididymis

male infertility ( J:105945 )

decreased epididymal cell proliferation ( J:105945 )

• at P3, the number of proliferating (BrdU-labeled) cells is significantly reduced in the epithelium and, to a lesser extent, in the mesenchymal compartment of the caput epididymis