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Polyunsaturated fatty acids and oocyte maturation and early embryo development in the cowMarei, Waleed Fawzy Abdel-Aziz January 2010 (has links)
No description available.
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Expression of extracellular matrix proteins during blastulation in bovine embryos and factors affecting bovine endodermal cell outgrowth In VitroCoreyAyne, Singleton 27 November 2002 (has links)
During early embryonic development, endodermal cells leave the
inner cell mass (ICM) and migrate over an extracellular matrix (ECM),
located on the blastocoelic side of the trophectoderm, to form a continuous
layer of extraembryonic endoderm. Cell migration events depend on a
family of cell surface proteins known as integrins that bind specific ECM
proteins. In an effort to understand the mechanisms involved in bovine
endodermal cell migration, two experiments were conducted. In the first
experiment, expression of the ECM proteins fibronectin, laminin and
vitronectin was evaluated by immunofluorescent staining in in vivo and in
vitro developing embryos during Day 6-10 and Day 7-10, respectively (Day
0=onset of estrus). Fibronectin was detected in all stages of in vivo and in
vitro embryos, however no difference (P>0.10) was observed due to day or
developmental stage. Laminin staining was moderately expressed in all
stages of in vivo embryos, with an increase (P<0.05) in Day 10 in vivo
embryos. Laminin staining in Day 9 in vitro embryos was less intense
(P<0.05) than Day 7 and 8 in vitro embryos. Higher (P<0.05) expression of
laminin was observed in Day l0 in vivo embryos as compared to Day 10 in
vitro. Vitronectin staining was expressed throughout all stages of
development. Day 6 in vivo embryos exhibited more intense (P<0.05)
staining compared to Day 8 in vivo embryos. Day 10 in vivo embryos
expressed more (P<0.05) vitronectin than Day 10 in vitro embryos. In the
second experiment, the effects of ECM-type and inhibitors of integrin
binding on bovine endodermal cell outgrowth from the ICM were evaluated.
Day 7 embryos were nonsurgically collected and cultured for 96 h on either
fibronectin-layered microdrops containing 0 (control), 0.5 or 1.0 mg/ml RGD
and/or EILDV peptides or vitronectin-layered microdrops containing 0, 0.5
or 1.0 mg/ml RGD peptides. At 24-h intervals, ICM were photographed and
the numbers of cells leaving the ICM were counted. Areas of cellular
outgrowth were calculated from the photomicrographs. Compared to the
control, addition of 0.5 or 1.0 mg/ml RGD, EILDV or RGD and EILDV did
not (P>0.10) reduce the areas of cellular outgrowth from the ICM on
matrices of fibronectin. Numbers of cells in outgrowths were greater
(P<0.05) in control ICM compared to 0.5 mg/ml RGD, but this effect was
eliminated (P>0.10) when the inhibitor concentration was increased to 1.0
mg/ml. Addition of 0.5 or 1.0 mg/ml RGD did not reduce (P>0.10) the area
of cellular outgrowth from the ICM on vitronectin and had no effect (P>0.10)
on numbers of cells in the outgrowths. Detection of fibronectin, laminin and
vitronectin by immunofluorescence suggests these proteins are present in
the developing bovine embryo to support endodermal cell migration and
stabilization in extraembryonic endoderm formation. Because cell migration
over fibronectin and vitronectin was not inhibited by the RGD and EILDV
peptides, endodermal cells must use either an integrin that recognizes
alternative binding sites in fibronectin and vitronectin or an alternative cell
adhesion system. / Graduation date: 2003
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Expression of the Ets family of transcription factors in early bovine and ovine embryo developmentCollins, Jonna Erin 10 June 2002 (has links)
Maternally-derived transcripts and proteins support early bovine and ovine
embryo development until the 8- to 16-cell stage, at which time embryonic
transcripts become essential for continued development. One purported
mechanism for the switch from maternal to zygotic control of development
(maternal to zygotic genome activation; MZGA) is the appearance of transcription
factors that activate specific genes in the embryonic genome. Members of the E26
transformation specific (Ets) family are unique transcription factors involved in
development, differentiation, and protease regulation. This study was undertaken
to evaluate expression and function of the Ets transcription factors, Ets-1, Ets-2,
and Elf-1, in early bovine and ovine embryos from the one-cell stage to Day 15 of
pregnancy (Day 0 onset of estrus).
In the first experiment, bovine embryos from the one- to 16-cell stages were
derived by in vitro maturation, fertilization, and culture. Days 6, 8, 10, 12, and 14
embryos were collected nonsurgically from estrous synchronized and
superovulated cows. RNA was extracted at the appropriate time interval and
reverse transcribed. The resultant cDNA was amplified by PCR using primers
designed for Ets-1, Elf-1, and Ets-2. Ets-1 transcripts were present in both primary
and matured oocytes, cleavage stage embryos, and Days 10, 12, and 14 embryos, as
well as in the positive control, bovine ovary. Elf-1 transcripts were detected in the
matured oocyte, cleavage stage embryos, and Days 6, 10, and 14 embryos. Ets-2
transcripts were not observed in the embryonic stages investigated or the bovine
ovary.
Ovine embryos were surgically collected from synchronized and
superovulated ewes and similarly analyzed for Ets-1 and Elf-1 expression using the
same RNA extraction and RT-PCR technique. Embryos expressed both transcripts
at Days 13 and 15, but did not show expression at any of the earlier stages
evaluated.
The second experiment was designed to determine if inhibition of ETS-1
translation would interfere with development and plasminogen activator (PA)
production in bovine embryos. Plasminogen activator production was evaluated in
Days 5 and 6 embryos nonsurgically collected from superovulated cows and
cultured in 1, 2.5, 5, or 10 ��M concentrations of sense or antisense Ets-1
oligonucleotides. In preliminary experiments, 1 ��M antisense was ineffective in
suppressing PA production, and 10 ��M oligonucleotides were detrimental to
development. Day 5 embryos treated with 2.5 ��M oligonucleotides inhibited
developmental effect and total PA production was (P<0.05) lower in antisense treatments when compared to either control or sense treatments. No difference
(P>0.10) in PA production was observed between Day 6 embryos treated with 2.5
or 5 ��M sense and antisense oligonucleotides. A significant time effect on PA
production was observed in both Day 5 and Day 6 embryos cultured in either 2.5 or
5 ��M concentrations of oligonucleotides.
Based on these results, it is unlikely that Elf-1 and Ets-2 are involved in
MZGA because the former is constituitively expressed throughout development,
and the latter was not observed. There is some uncertainty regarding the
expression of Ets-1 during MZGA. This factor may be expressed after MZGA for
controlling PA production and other proteases involved in extracellular matrix
turnover and early germ layer formation. / Graduation date: 2003
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Evaluation of extracellular matrices and proteinase interactions in bovine and porcine endodermal cell migration in vitroSchilperoort-Haun, Kelly Rae 28 March 1997 (has links)
Graduation date: 1997
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Factors affecting zona pellucida solubility and hatching in bovine embryos in vitroCoates, Arwyn Alexandra 07 January 1993 (has links)
Graduation date: 1993
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The effects of hormones and inducers of intracellular messengers on bovine embryo development in vitro : plasminogen activator production and changes in embryonic sizeAl-Hozab, Adel Abdulla 27 April 1990 (has links)
The effects of several hormones and inducers of intracellular
messengers on plasminogen activator (PA) production and changes in
embryonic size by cultured bovine embryos were evaluated. Day 8 embryos
were cultured in Ham's F-12 with 1.5 mg/ml bovine serum albumin (BSA)
containing different levels of progesterone (P), estradiol -17fl (E₂),
dexamethasone (Dex), retinoic acid (RA), dibutyryl cyclic AMP (dbcAMP),
or phorbol myristate acetate (PMA) for 5 days under paraffin oil in a
humidified atmosphere of 5% CO₂ in air at 37°C. The concentrations of
PA in the conditioned media were determined by a caseinolytic assay.
Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and
zymography were used to determine the molecular weight of PA in the
medium and in the embryo homogenate. Changes in embryonic size were
determined by measuring overall embryo diameter (OD) at 24-h intervals.
None of the hormones and agents tested herein had a significant effect
on PA production. Dimethyl sulfoxide (DMSO) which was used to dissolve
PMA significantly inhibited PA production during the first 72 h of
culture. Time of culture, however, exerted a significant effect on PA
production by cultured embryos. The production of this protease was low
during the first 48 h, increased during 72 and 96 h, and either remained
high or slightly decreased toward the end of the culture period.
Furthermore, the peak production of PA was attained 48 h after hatching.
The molecular weight of PA in the conditioned medium and embryo tissues
suggested that the bovine embryo at this developmental stage produced an
urokinase-type PA. With the exception of dbcAMP and PMA, the hormones
tested in this study did not affect embryonic size. While dbcAMP
decreased OD later in culture, PMA enhanced OD throughout culture. The
mechanism by which dbcAMP and PMA modulated embryonic size is not clear.
These results suggest that cultured bovine embryos produce urokinasetype
PA in a time dependent manner and the production of this enzyme is
independent of exogenous hormonal regulation. / Graduation date: 1990
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The in vitro produced cow embryo : factors affecting development and metabolismSteeves, Tracey Elizabeth, 1968- January 2000 (has links)
Abstract not available
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Partial characterization of gelatinases produced by preimplantation porcine, ovine and bovine embryosChamberlin, RaeAnne 08 August 1995 (has links)
Graduation date: 1996
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The Effects of Injectable Trace Mineral Supplements in Donor Cows at the Initiation of a Superovulation Protocol on Embryo Outcomes and Pregnancy Rates in Recipient FemalesSilva, Felipe January 2018 (has links)
Concentrations of trace minerals within the body are known to impact reproductive processes. Thus, the current study analyzed the effects of using an injectable trace mineral supplement containing selenium, zinc, copper, and manganese during a superovulation protocol on embryo outcomes in donor beef cows and further effects on pregnancy rate in recipient females. We hypothesized that an injectable trace mineral (TM) supplement provided to cows fed to meet known nutrient requirements would increase TM status and influence superovulation, embryo characteristics, and enhance pregnancy rates. Our findings indicate that the injectable TM increased concentration of Se within the liver. However, superovulatory response, embryo production, quality grade, and developmental stage were not influenced by TM status. In addition, embryo treatment did not influence pregnancy rate, gestation length, or calf body weight.
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Bovine embryo microinjection, culture, microsurgery, and DNA analysis by the polymerase chain reaction techniqueSparks, Amy Elizabeth Thuemmel 06 June 2008 (has links)
The first experiment was conducted to determine the optimum in vitro culture system for one-cell bovine embryos. Subsequent experiments compared bisection and biopsy for acquisition of cellular material from bovine morulae for DNA amplification by the polymerase chain reaction technique (PCR), and evaluated the use of DNA microinjection, in vitro culture, morula bisection, and PCR for production and selection of transgenic bovine preimplantation embryos. In vivo fertilized one-cell bovine embryos were cultured in TCM-199 (n=46), co-cultured with bovine oviductal epithelial cells (OEC; n=38), or in explanted immature mouse oviducts (n=54). Of the embryos that cleaved once, 52.6, and 30.4 and 0.0% developed to morulae/blastocysts after culture in OEC, TCM-199, and explanted mouse oviducts. Mean cell number for embryos cultured in OEC (24.5) was higher than for embryos cultured in TCM-199 (12.8) or in explanted mouse oviducts (5.9; P<.05).
Bovine morulae were subjected to bisection (n=44; 20 to 30 cells) or biopsy (n=50; 8 to 12 cells) to assess embryo development in vitro and compare the efficiency of PCR amplification of an endogenous 18S rRNA. Mean development scores (l1=degenerate, 2=morula, 3=blastocyst) and mean cell number after microsurgery and 48 h of culture did not differ between treatments (P>.05; 2.4 ± .1 and 41.8 ± 2.5 versus 2.3 ± .1 and 48.8 ± 2.9, respectively). Frequency of the 18S rRNA amplifications was similar (P>.05) for demi-morulae (78%; 32/41) and biopsies (81%; 39/48).
In the third experiment, in vivo fertilized one- (n=155), two- (n=57) and four-cell (n=62) bovine embryos were collected for pronuclear and nuclear DNA microinjection. Approximately 70% of the embryos were injected with DNA and 30% served as controls. Injection did not affect (P>.05) mean development scores after 144 h of cultured in TCM-199 with OEC. Sixty-five (34%) of the DNA injected embryos developed to morulae and were bisected. Injected DNA was amplified by PCR in 29% (19/65) of the demi-morulae. Frequency of DNA detection was more frequent (P<.01) in morulae injected at the 1-cell stage (50%: 16/32) than at the 2-cell (10%; 1/10) or 4-cell (9%: 2/23) stage. Production and selection of transgenic bovine morulae was most successful when one-cell bovine embryos were microinjected. / Ph. D.
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