Medically Assisted Conception An Agenda for Research (1989) / Chapter Skim
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Technologies for Assisted Conception/Embryo Transfer in Agricultural and Veterinary Practice
Technologies for Assisted Conception/Embryo Transfer in Agricultural and Veterinary Practice
Pages 96-116
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From page 96... ...
More than 60% of the 10 million United States dairy cows and nearly all West European dairy cattle are presently mated by artificial insemination (Betteridge, 1986~. The strength of this tool comes from the ability to statistically identify and select the very best bulls in the country in terms of genes for milk production and the ability to extend each ejaculate to produce more than 500 inseminations.
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From page 97... ...
A more uniform superovulation and increased frequency of high quality transferable bovine embryos has also been reported from the use of recombinant derived pure ESH material (Chappel et al., 1988~. Embryo Transfer More recently superovulation and embryo transfer have been used to multiply scarce exotic breeds of cattle and to accelerate genetic improvement by expanding the maximum number of offspring possible from genomic combinations of the best females and progeny tested sires.
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From page 98... ...
. Frozen cattle embryos are routinely thawed by a one-step method that allows nonsurgical embryo transfer directly from the straw, as with artificial insemination (Leibo, 1982; Renard et al., 1982; Chupin et al., 1984; Massip and van der Zwalmen, 1984~.
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From page 99... ...
Except for cases of chromatin translocations which often cause intersexuality, the presence of a Y chromosome antigen specifically identifies a male. Male specific antigens such as H-Y antigen are known to be highly conserved across species and present on cells of at least 70 species of vertebrates including mice, rats, cattle, dogs, goats, donkeys, horses, pigs and humans as well as on cells of the female, the heterogametic sex, of birds (Wachtel, 1984a)
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From page 100... ...
These studies in mice suggest that it should be possible to sex embryos of bovine and other species by use of an antibody to one or more male specific antigens. The accuracy of White et al.
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From page 101... ...
Table 1. Accuracy of immunological detection of embryonic H-Y antigen in various speciesa "b~so,~-.e ~ -.
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From page 102... ...
They are embryo bisection and nuclear transplantation. Embryo bisection is a procedure whereby an early embryo (2-cell through the blastocyst stage)
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From page 103... ...
These were born at Granada Genetics in 1987. A system for cloning of embryos useful to the livestock industry depends on the ability to produce offspring from donor embryos of large cell number and the ability to reclone as the clones develop to advanced cell number or to multiply donor ceils in culture.
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From page 104... ...
Figure 1 ^1~ — . _- ~ I,.' LN ~ it'' ~ DONOR EMBRYO I RECLONE CATTLE EMBRYO CLONING MODEL Transfer each donor cell to separate egg RECIPIENT EGG ~ ~ (~ |
From page 105... ...
In vitro production of embryos requires development of technology in three areas, oocyte development and maturation, in vitro fertilization and in vitro embryo development. Oocyte Maturation In domestic species oocytes recovered from follicles matured in viva either with or without superovulation can be fertilized and proceed through embryo development with good success (cattle: Leibfried-Rutledge et al., 1987; swine: Cheng et al., 1986~.
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From page 106... ...
In spite of these gaps in our . knowledge, supplementation of embryo cultures with frozen oviduct cell conditioned media has provided an in vitro method for development of bovine embryos which has resulted in an approximately normal pregnancy rate (50%)
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From page 107... ...
or human (Palmiter et al., 1983) growth hormone grew to nearly twice normal size greatly excited animal scientists with hopes of producing transgenic livestock.
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From page 108... ...
1986. In vitro fertilization of pig and sheep oocytes matured in vitro and in vivo.
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From page 109... ...
1988. Sex determination of bovine embryos using male-specific DNA probes.
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From page 110... ...
1988. Pregnancies after co-culture of cumulus cells with bovine embryos derived from in vitro fertilization of in vitro matured follicular oocytes.
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From page 111... ...
1987. Sexing bovine embryos using Y chromosome specific DNA probe.
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From page 112... ...
1987. Pregnancy established in cattle by transfer of embryos derived from in vitro fertilization of oocytes matured in vitro.
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From page 113... ...
1985. Commercial freezing of bovine embryos in glass ampules.
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From page 114... ...
1985. Pregnancies after in vitro fertilization of cow follicular oocytes, their incubation in rabbit oviduct and transfer to the cow uterus.
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From page 115... ...
1984. Immunofluorescent detection of a male specific factor on preimplantation bovine embryos.
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From page 116... ...
1988. Identification of embryonic sex by detection of male specific antigens.
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