ISSN:
1573-9368
Keywords:
β-casein gene promoter
;
early development
;
milk‐mZP3
;
mZP3 gene
;
transgenic mice
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Mouse egg zona pellucida glycoprotein mZP3 (∼83 kDa Mr) serves as a species‐specific sperm receptor and acrosome reaction‐inducer during fertilization in mice. These biological activities are dependent on certain mZP3 serine/threonine‐ (O‐) linked oligosaccharides present at the combining‐site for sperm. In an attempt to produce large amounts of biologically active mZP3, we generated several transgenic mouse lines carrying the full‐length mZP3 gene fused to the β‐casein gene promoter and transcription termination sequence. We found that different transgenic mouse lines have different amounts of recombinant mZP3 (∼63 kDa Mr) in milk of lactating females, from ∼0.3 to 3.5 μg/μl of milk. In all cases, purified milk-mZP3 is active as a sperm receptor and acrosome reaction-inducer in vitro. Unexpectedly, we also found that development of litters from these transgenic mice is related to the amount of mZP3 in the mother's milk. In the most extreme case, litters from the highest expressers fail to live beyond about day-7 post partum unless placed immediately after birth with surrogate wild-type mothers. Litters from lower expressers initially display a complex phenotype that includes effects on hair and body growth, but some of the mice survive and, in time, are restored to a wild-type phenotype. These results demonstrate that relatively large amounts of biologically active mZP3 can be produced in transgenic mouse milk for structural and other studies, but that the presence of mZP3 in milk has dramatic developmental effects on litters, ranging from retarded hair and body growth to death of newborn pups.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008996612032
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