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  • 1
    ISSN: 1432-1254
    Keywords: Water buffalo ; Supplemental light ; Prolactin ; Progesterone ; LH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract Fifty non-pregnant Surti buffalo heifers aged between 17 and 42 months (n=24, 〈24 months;n=26, 〉24 months) were randomly assigned to groups subject to either natural daylight +4h supplemental light (n=25) or natural day light (n=25), to study changes in growth, serum prolactin (Prl), progesterone (P4) and luteinizing hormone (LH) to supplemental lighting. Ambient temperatures (T) and relative humidity (RH) generally were 〉27° C and 〈70% during the day-time, respectively. Light-supplemented heifers had 16.2 kg net body weight (BW) gain at 9 weeks compared to 20.8 kg for controls, but higher mean Prl after 6.5 weeks (P〈0.01), and higher P4 (0.41 vs 0.19 ng/ml;P〈0.06) than control heifers. Older heifers had 39.7% greater BW (P〈0.01), but a net 4.3% BW gain compared to a 10.1% gain for younger heifers at 10 weeks. Older, light-supplemented heifers had higher mean P4 (0.63 vs 0.19 ng/ml;P〈0.07) than the other groups. These weight and hormonal changes suggest that 4 h supplemental light can alter growth and endocrine function in buffaloes under similar planes of nutrition. While light supplementation did not have a positive effect on body wieght during the 10 week study, body weight and endocrine changes due to supplemental light may be important factors for initiation of reproductive cyclicity.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-7330
    Keywords: bovine ; buffalo rat liver cells ; embryo culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: The effectiveness of two culture media on the development of bovine embryos in a buffalo rat liver (BRL) coculture system was investigated. Methods: Bovine oocytes were matured and fertilized in vitro, then cocultured, 25 per well, for 7 days in 500 μl of modified M199 or modified Menuzo's B2 medium over a BRL cell monolayer at 39°C in an atmosphere of 5% CO 2 in air. Medium 199 was modified by the addition of 10% of (v/v) fetal bovine serum (FBS), 9 mg/ml bovine serum albumin, 2 mM glycine, 1 mM alanine, and 0.1 mM nonessential amino acids (NEAA). Menuzo's B2 medium was modified by the addition of 10% (v/v) FBS, 1 mM alanine, and 0.1 mM NEAA. Results: Modified Menuzo's B2 medium improved embryo development to the morula or blastocyst stage compared to modified M199 (121/353, 34.3%, versus 99/362, 27.3%, P〈0.05). Conclusions: These results suggest that Menuzo's B2 medium with modifications in a BRL coculture system can provide a significant benefit for culture of early bovine embryos over the traditional use of medium 199.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of assisted reproduction and genetics 9 (1992), S. 149-154 
    ISSN: 1573-7330
    Keywords: embryo culture ; incubation temperatures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Embryos from two strains of mice were used to assess the effect of incubation temperature on pronuclear and twocell development to the morula/blastocyst (M/B) stage. Embryos from B6D2F2 and B6SJLF1 strains were cultured in medium M16 at either 37 or 39°C until 120 hr post human chorionic gonadotropin (hCG) or 0, 24, or 48 hr at 37°C and the remaining time at 39°C. Overall M/B development for pronuclear embryos was 0.6, 0, 32.3, and 52.4% for 0—96, 24—72, 48—48, and 96—0 hr at 37 and 39°C, respectively. Only 0—96 and 24—72 hr at 37 and 39°C were not different (P 〉0.10). Overall M/B development for two-cell embryos was 48.1, 78.1, and 98.0% for 0—72, 24—48, and 72—0 hr at 37 and 39°C, respectively. Percentage development at each time was different (P 〈.01) for each category. Additionally, the number of nuclei for morulae and blastocysts tended to be higher for embryos initiating culture at the two-cell stage compared to pronuclear embryos. The first cell cycle was most dramatically affected by a 2°C increase in incubator temperature. More advanced embryos can tolerate slight increases in incubator temperature more readily than pronuclear embryos.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of assisted reproduction and genetics 9 (1992), S. 454-457 
    ISSN: 1573-7330
    Keywords: embryo culture ; density ; culture volume
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Methods Embryos were collected from immature C57BL6 female mice superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin and mated by CD1 males. Groups of 1, 5, 10, or 20 embryos were cultured in 5-, 10-, 20-, or 40-µl drops of CZB under silicon oil at 37.5°C in a humidified atmosphere of 5% CO 2 and 95% air.
    Abstract: Results Development score for embryos cultured in 10 µl was higher than that of embryos cultured in 20 or 40 µl. Embryos cultured in groups of 5, 10, or 20 had higher development scores than embryos cultured singly. The highest development score was obtained by the combination of 5 embryos per 10-µl drop. The percentage of live embryos in 20 or 40 µl was lower than that of embryos cultured in 10 µl. Additionally, the percentage of live embryos cultured singly was lower than that of embryos cultured in groups.
    Notes: Background One-cell mouse embryos were used to determine the effects of drop size and number of embryos per drop for optimum development in vitro.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1573-9368
    Keywords: DNA integration ; transgenics ; micromanipulation ; PCR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of DNA microinjection at various times afterin vitro insemination on DNA detection and survival rates of bovine embryos was investigated. Oocytes were inseminated 24 h after maturation with frozen/thawed semen prepared with a Percoll separation procedure. At 11, 15 and 19 h after insemination, embryos were centrifuged to visualize pronuclei and microinjected with a murine whey acidic protein-human protein C genomic DNA construct. After culture for 7 days on Buffalo Rat Liver cells, embryos were assessed for stage of development and assayed for the presence of the transgene by polymerase chain reaction. Of zygotes in the 11h after insemination treatment, 16% (25/152) of non-injected and 7% (11/161) of injected embryos developed to the morula or blastocyst stage. Comparable development of non-injected and injected embryos treated at 15h after insemination was 15% (23/158) and 4% (6/159) and treated at 19 h after insemination was 14% (23/162) and 1% (1/165), respectively. Development of injected embryos was greater (p〈0.05) when injection was performed at 11 h after insemination compared to 19 h after insemination. Development of non-injected embryos was greater (p〈0.01) than that of injected embryos. There was no difference in transgene detection frequency in embryos of all developmental states between treatments (53% at 11; 50% at 15; 48% at 19h after insemination). Injected embryos testing positive for the presence of the transgene exhibited increased development over negative embryos (p〈0.01). Greater development efficiencies can be obtained in microinjected bovine embryos when injection is performed early in pronuclear formation.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1573-9368
    Keywords: transgenic mice ; embryos ; PCR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The polymerase chain reaction (PCR) technique was used to detect a whey acidic protein (WAP) gene and transgene presence in mouse ova cultured to various stages of development after pronuclear microinjection at the one-cell stage. The PCR technique detected an endogenous 442 bp WAP DNA sequence in 78% of one-cell, 88% of two-cell and 94% of four-cell ova, and in 95% of morulae and 97% of blastocysts. The heterologous WAP-human protein C transgene was detected in 88% of one-cell, 88% of two-cell and 44% of four-cell ova, and in 40% of morulae and 29% of blastocysts. For comparison, the integration frequency for transgenic mouse production using the same DNA construct was 22%. After five days ofin vitro culture, embryos that were either developmentally arrested or fragmented were tested for the presence of the transgene. The injected construct was detected in 83% of arrested one-cell, 85% of arrested two-cell, and 85% of fragmented ova. In culture, only 28% of zygotes microinjected with DNA developed to the blastocyst stage compared to 74% of noninjected zygotes, while 63% of zygotes developed to the blastocyst stage after injection of buffer alone. Pronuclear injection of the transgene at concentrations of 1.5, 15 and 50 μg ml−1 resulted in 28, 11 and 9% development to blastocysts and 29, 86 and 88% transgene detection, respectively. Transgene detection was 85, 96 and 97% in degenerate embryos at the respective doses of DNA. These data show that pronuclear microinjection of the transgene is detrimental to subsequent embryonic development. Also, unintegrated copies of the transgene probably exist at least until the blastocyst stage, and thereafter are degraded to the extent that they can no longer be detected by PCR.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1573-9368
    Keywords: Gene transfer ; gestational losses ; non-manipulated mice embryos
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Litter size of DNA microinjected zygotes is lower than for non-manipulated zygotes. The rate of embryonic and fetal survival in early, mid and late gestation was determined to assess whether DNA integration was responsible for embryonic losses. Also, the effect of including non-microinjected embryos with injected embryos on pregnancy rate and transgenic pup production was determined. In Experiment 1, one-cell embryos from immature CD-1 mice were microinjected with a whey acidic protein promoter-human protein C gene construct. One hour after microinjection embryos were transferred to pseudopregnant recipients (45 transfers of 30 embryos each). Fifteen recipients were sacrificed on day 4, 12 and 18 of gestation and the embryos/fetuses analysed for the transgene. The percentage of embryos or fetuses that were positive for the transgene was not significantly different at any day. However, the number of viable embryos at day 4 was significantly greater than fetuses on days 12 or 18. In addition, a high degree of mosaicism was observed in day 18 fetuses and placentae recovered. In Experiment 2, one-cell embryos from CD-1 mice were microinjected and co-transferred with non-manipulated embryos (C57BL/6). Pregnancy rate and the total number of pups born were improved by addition of non-injected embryos. However, the number of transgenic mice produced was similar whether non-injected embryos were included or not. There were 32.2% (15/46) transgenic pups when 0 non-injected embryos were transferred compared with 15.1% (13/86) transgenic pups when 4 or 8 non-injected embryos were added to the transfers. In summary, a high degree of embryonic and fetal mortality occurs among microinjected embryos. Furthermore, since the percentage of transgenesis did not change throughout pregnancy, DNA integration does not appear to account for all of the embryonic losses. other factor(s) related to the microinjection procedure may be involved in the embryonic and fetal failure of microinjected embryos. Addition of non-injected embryos, although it increased pregnancy rate and the number of pups born from microinjected embryos, actually decreased the number of transgenic pups obtained per pregnancy.
    Type of Medium: Electronic Resource
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