| Abstract: |
Alterations to the mammalian genome that occur during the development of germ cells, in particular during meiosis, can be introduced into the population upon fertilization. These alterations can occur through homologous recombination, genome rearrangement, or mutagenesis. Such events usually occur infrequently for any particular sequence. Because of the difficulty in analyzing a large number of offspring in a mammalian cross, we have developed a marker to detect these events in sperm, since a large number of these meiotic progeny are produced during male gametogenesis. We have expressed the Escherichia coli lacZ gene during spermatogenesis in transgenic mice and quantitated the levels of β-galactosidase activity in single sperm with the fluorescence-activated cell sorter and a fluorogenic substrate, 5- dodecanoylaminofluorescein di-β-D-galactopyranoside. Detection of rare positives was demonstrated in mixed sperm populations with as few as 0.01% positive sperm. Although the distribution of β-galactosidase activity in caudal epididymal sperm populations is bimodal, it appears that β- galactosidase, like other proteins that have been expressed postmeiotically, is distributed between transgene-positive and transgene-negative sperm. |
| Keywords: |
nonhuman; flow cytometry; animal cell; mouse; animal; meiosis; mammalia; mice; gene expression; enzyme activity; transgenic mouse; animalia; mus musculus; mice, transgenic; gene rearrangement; genetic recombination; escherichia coli; progeny; homozygote; beta galactosidase; cell marker; mutagenesis; enzyme localization; spermatozoa; beta-galactosidase; sperm; spermatogenesis; gametogenesis; restriction mapping; fluorescence activated cell sorter; fertilization; blotting, southern; male; female; priority journal; article; support, non-u.s. gov't; support, u.s. gov't, p.h.s.; genes, structural, bacterial
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