limbs/digits/tail
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• pisiform and triangular carpal bones fused
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• malformed ulna and ulnar epiphysis
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skeleton
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• pisiform and triangular carpal bones fused
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• malformed ulna and ulnar epiphysis
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• one fewer rib than normal
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• transformation of the thirteenth thoracic (T13) vertebra to the first lumbar (L1) vertebra
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• addition of an eighth lumbar vertebra
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endocrine/exocrine glands
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• sexually mature mutant testes are smaller than wild-type
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• mutant testes exhibit incomplete descent into the scrotal sac, with variable expressivity
• in some mutants, testes are located intra-abdominally near the inferior pole of the kidneys
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reproductive system
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• in severe cases, many mutant male germ cells appear to undergo cell death by apoptosis
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• sexually mature mutant testes are smaller than wild-type
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• mutant testes exhibit incomplete descent into the scrotal sac, with variable expressivity
• in some mutants, testes are located intra-abdominally near the inferior pole of the kidneys
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• sexually mature male homozygotes display abnormal spermatogenesis with variable expressivity
• in severe cases, spermatogenesis fails to occur
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• although numerous spermatogonia are present, no mature sperm are found in the luminal lining of mutant seminiferous tubules
• also, no mature sperm are detected in mutant epididymides which only contain cell debris and fluid
• some mature sperm cell populations are present occasionally, consistent with variable expressivity
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• the mutant vas deferens is extensively coiled, esp. at the junction between the vas deferens and the cauda epididymis
• the lumen is patent but the luminal diameter is smaller than wild-type
• the epithelial lining appears more simple due to a reduced complexity of mucosal folding; a more stratified organization of the epithelial lining is observed
• the epithelial lining cells are more narrow and columnar than wild-type cells
• the nuclei are located more basally than wild-type nuclei
• the vas deferens malformation resembles a partial homeotic transformation to an epididymis
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• the mutant vas deferens is hypoplastic relative to wild-type
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• mutant uteri are unable to support embryonic development to term
• however, mutant ova develop properly post-fertilization when transplanted into oviducts of surrogate mothers, with all embryo transfers resulting in births of normal litters
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• multiple matings between mature male and female homozygotes fail to produce any offspring
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• female homozygotes mate normally with wild-type males but produce no progeny
• however, mutant ovaries appear histologically normal, and normal numbers of zygotes are retrieved from the oviducts upon detection of the vaginal plug
• also, development of embryos within the oviducts appears unaffected, and normal blastocysts are detected at E3.5
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• male homozygotes copulate with wild-type females and produce vaginal plugs at a normal frequency, but no pups are born
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cellular
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• although numerous spermatogonia are present, no mature sperm are found in the luminal lining of mutant seminiferous tubules
• also, no mature sperm are detected in mutant epididymides which only contain cell debris and fluid
• some mature sperm cell populations are present occasionally, consistent with variable expressivity
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• in severe cases, many mutant male germ cells appear to undergo cell death by apoptosis
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