Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 12 of 12
Full-Text Articles in Life Sciences
Effects Of Microtubule Stabilizing And Recovery Agents On Vitrified Bovine Oocytes, Emily Dzekunskas
Effects Of Microtubule Stabilizing And Recovery Agents On Vitrified Bovine Oocytes, Emily Dzekunskas
LSU Master's Theses
Oocyte vitrification, while beneficial for research and species conservation, has limited success due to cryoinjury to the meiotic spindle. This study aimed to evaluate treatments to improve meiotic spindle recovery after vitrification by treating bovine oocytes with either a microtubule stabilizing agent, or a microtubule recovery agent. In the first two experiments, Taxol and epothilone B were used to treat bovine oocytes before vitrification. Both compounds have microtubule stabilizing properties and are known antimitotic compounds commonly used in cancer treatment. Oocytes were incubated with one of the microtubule stabilizing agents for 15 minutes before vitrification at one of three concentrations …
Sperm Decondensation And Male Pronuclear Formation In Bovine Intracytoplasmic Sperm Injection, Lauren Gatenby
Sperm Decondensation And Male Pronuclear Formation In Bovine Intracytoplasmic Sperm Injection, Lauren Gatenby
LSU Master's Theses
This study assessed the effects both DTT and progesterone have on bovine spermatozoa to induce decondensation or the acrosome reaction in order to facilitate male pronuclear formation after ICSI. Sperm prepared by swim-up in a 5 mM concentration of DTT displayed time dependent morphological changes resulting in decondensation over a 6-hour period. An estimated 90% of treated sperm displayed early changes in morphology after the second hour of incubation. Sperm displaying partial decondensation of the nucleus was estimated as 42% by the 3rd hour and increased to 62% by the 5th hour of incubation. Fully decondensed sperm or …
Regulation Of Oocyte Meiotic Resumption Using Camp Modulators In Bovine In Vitro Maturation, Sarah Farmer
Regulation Of Oocyte Meiotic Resumption Using Camp Modulators In Bovine In Vitro Maturation, Sarah Farmer
LSU Master's Theses
In vitro maturation (IVM) is a reproductive technique critical to in vitro embryo production (IVP) in commercial livestock industries, research, and human infertility treatment. Currently, IVP has low efficiency due to an inadequate IVM system in which premature meiotic resumption results in low oocyte viability. Meiotic arrest is regulated primarily by 3’,5’-cyclic adenosine monophosphate (cAMP), and the most successful methods of improving IVM utilize cAMP modulators to maintain high intra-oocyte cAMP, delaying the onset of maturation. This thesis includes experiments comparing standard bovine IVM to a novel extended IVM method similar to the procedure described by Albuz and colleagues (Albuz …
Comparison Of Epididymal And Ejaculated Sperm Collected From The Same Holstein Bulls, Michael A. Stout
Comparison Of Epididymal And Ejaculated Sperm Collected From The Same Holstein Bulls, Michael A. Stout
LSU Doctoral Dissertations
Salvaging of epididymal sperm from injured or deceased animals allows for the propagation of favorable traits from endangered or genetically superior males. Techniques developed in domestic species can also serve as the foundation for the collection, cryopreservation and utilization of epididymal sperm in exotic breeds. The need to preserve and utilize epididymal sperm, in the most efficient manner, is of the utmost importance. In a series of experiments, ejaculated and epididymal sperm from the same four mature, fertile, Holstein bulls were collected, cryopreserved, cultured and used for in vitro fertilization. In Experiment I, epididymal sperm was found to have higher …
A Novel Immunomodulatory Subunit Vaccine To Combat The Involvement Of Bovine Respiratory Coronavirus Infections In Shipping Fever, Genevieve Elizabeth Lum
A Novel Immunomodulatory Subunit Vaccine To Combat The Involvement Of Bovine Respiratory Coronavirus Infections In Shipping Fever, Genevieve Elizabeth Lum
LSU Doctoral Dissertations
Bovine respiratory coronavirus (BRCoV) is a group 2a coronavirus expressing both hemagglutinin-esterase and spike (S) envelope glycoproteins. The S glycoprotein is a primary coronavirus virulence factor responsible for both receptor specificity and membrane fusion-mediated entry into host cells. In addition, the S glycoprotein serves as a major antigen targeted by both the cellular and humoral immune responses and, as such, is an important target for antibody-facilitated virus neutralization. The objective of this research was the design of a safe and effective vaccine against BRCoV using a “prime-boost” vaccination approach. This method utilized an initial DNA vaccine encoding either the soluble …
Effects Of Cryopreservation And Constituents Of Semen Extenders On Mitochondrial Function Of Bull Spermatozoa, Abdulhakeem Hashim Eljarah
Effects Of Cryopreservation And Constituents Of Semen Extenders On Mitochondrial Function Of Bull Spermatozoa, Abdulhakeem Hashim Eljarah
LSU Doctoral Dissertations
This study investigated the effects of semen extender constituents and cryopreservation on bovine spermatozoal mitochondrial function. Three yearling Holstein bulls were used. Two ejaculates per bull were collected and pooled on a weekly basis for five weeks and extended in four treatments: 1) sodium citrate egg yolk extender with antibiotics (lincomycin, spectinomycin, gentamicin and tylosin); 2) ¡°1¡± with glycerol; 3) ¡°2¡± without antibiotics; and 4) ¡°1¡± without antibiotics. Each was divided into portions for analyses before freezing and after cryopreservation. The pre-freeze and thawed semen were transferred to a 37¡ãC water bath, the same assays were performed. In experiment 1, …
In Utero And In Vitro Sex Ratio Of Bovine Embryos And Calves Originating From The Left And Right Ovaries, Darin Alan Hylan
In Utero And In Vitro Sex Ratio Of Bovine Embryos And Calves Originating From The Left And Right Ovaries, Darin Alan Hylan
LSU Doctoral Dissertations
An asymmetric distribution of the sexes within the left and right uterine horns has been described in multiple polytocous, laboratory species. A series of experiments were conducted to evaluate the sex ratio (% male) of calves gestated in the left and right uterine horns, as well as the sex ratio of embryos originating from the left and right ovaries of cattle. In Experiment 1, the sex ratio of calves and fetuses gestated in the left and right uterine horns was investigated. The sex ratio of calves and fetuses gestated in the right uterine horn was significantly higher compared with the …
Effect Of Culture Conditions On Gene Expression In Manipulated Bovine Embryos, Megan Nicole Purpera
Effect Of Culture Conditions On Gene Expression In Manipulated Bovine Embryos, Megan Nicole Purpera
LSU Master's Theses
Numerous studies have reported aberrant gene expression levels attributed to suboptimal in vitro culture conditions presented to embryos. Since the culture environment is a common aspect of both in vitro production (IVP) and nuclear transfer (NT), research focusing on the in vitro culture system will have the potential to improve both techniques. This study investigated the effects of different culture systems and protein sources on the developmental competence of IVP embryos measured by cleavage and blastocyst rates, cell number, and relative abundance of oct-4, nanog, connexin 43, and GLUT-1 transcripts when compared to in vivo embryos. Experiment 1 compared IVP …
Cryopreservation And Intracytoplasmic Sperm Injection With Bovine Epididymal Spermatozoa, Carlos Andres Guerrero
Cryopreservation And Intracytoplasmic Sperm Injection With Bovine Epididymal Spermatozoa, Carlos Andres Guerrero
LSU Doctoral Dissertations
Recently, interest in the preservation of epididymal sperm as a potential source of valuable genes for genome resource banks has escalated. The development of a successful protocol to recover and cryopreserve sperm harvested from the epididymides would salvage germplasm from genetically valuable males that are injured and can no longer mate or have unexpectedly died and can be used as a model for the preservation of male gametes from endangered species. In a series of experiments, epididymal sperm was successfully harvested, cryopreserved and used for intracytoplasmic sperm injection. In Experiment I, ethylene glycol was found to cause significantly (P<0.05) less osmotic damage to bovine sperm during a one step addition and/or removal at 4°C as compared with glycerol in all concentrations evaluated. Furthermore, prolonged exposure (5 days at 4°C) of ethylene glycol was found to be less toxic than glycerol to sperm. In Experiment II, it was demonstrated that glycerol was more effective than ethylene glycol in providing protection against freezing injury during the cryopreservation process in the concentrations evaluated. In Experiment III, it was demonstrated that epididymal sperm retrieval using seminal plasma is beneficial to enhance sperm overall and progressive motility characteristics and to protect it from morphological abnormalities derived from the freezing process. In Experiment IV, a one step dilution process for removal of glycerol from cryopreserved epididymal sperm was found to significantly affect plasma membrane integrity and mitochondrial function of sperm previously exposed to seminal plasma. However, seminal plasma exposure did not have any significant detrimental effect on acrosome integrity. Furthermore, it was demonstrated that the longevity and survivability in vitro during a 4-hour incubation period at 37°C of post-thaw epididymal sperm exposed to seminal plasma prior to cryopreservation was not compromised when compared with the control extended sperm. In Experiment V, we have demonstrated that fertilization, blastocyst and fetal development could be achieved with cryopreserved bovine epididymal sperm by intracytoplasmic sperm injection (ICSI). To our knowledge, this is the first report in the United States and second in the world to use bovine epididymal sperm for ICSI. We achieved far markedly improved blastocyst rates over those results recently reported in the first study originating in Japan.
Reconstruction Of Nuclear Transfer Embryos In Goats And Cattle [Electronic Resource], Allison Morris Landry
Reconstruction Of Nuclear Transfer Embryos In Goats And Cattle [Electronic Resource], Allison Morris Landry
LSU Doctoral Dissertations
The low survival rates of nuclear transfer fetuses and neonates in goats and cattle have been linked to placental abnormalities. A series of studies was designed to investigate the possibility of supplementing nuclear transfer embryos with electrofused embryos to generate placental tissue in goats and cattle. The initial study was designed to determine if the breeding season of goats could be extended with hCG treatment. Progesterone concentrations in treated does increased but pregnancy rates were unaffected. In the second study, goat embryos were electrofused and combined with nuclear transfer embryos at the 8-cell stage to produce the first offspring as …
Cryopreservation Of Bovine And Caprine Oocytes By Vitrification, Sabrina Marie Luster
Cryopreservation Of Bovine And Caprine Oocytes By Vitrification, Sabrina Marie Luster
LSU Master's Theses
Cryopreservation of animal oocytes will permit germplasm of valuable or unique females to be preserved for extended times. The objective of this research was to derive a procedure to cryopreserve bovine oocytes by vitrification to be used as recipients for somatic cell nuclear transfer (SCNT). Caprine oocytes vitrified by the same procedure were assayed by cytological examination of microtubules. In the first two of three experiments, bovine oocytes matured in vitro were vitrified in a mixture of ethylene glycol (EG), dimethylsulfoxide (Me2SO) and trehalose, and then subjected to in vitro fertilization (IVF) or SCNT. For vitrification, oocytes were first exposed …
The Effect Of Holding Bovine Oocytes In Follicular Fluid On Subsequent Fertilization And Embryonic Development, Angela Marie Klumpp
The Effect Of Holding Bovine Oocytes In Follicular Fluid On Subsequent Fertilization And Embryonic Development, Angela Marie Klumpp
LSU Master's Theses
The objective of Experiment 1 was to determine the effect of bovine follicular fluid (bFF) on nuclear maturation. Treatment A (Control) oocytes were stained with Hoechst-33342 immediately after aspiration from follicles, whereas, oocytes in Treatment B were held in bFF for 12 hours at 38¢ªC and then stained to determine nuclear status. No significant difference was detected between treatment groups. Results indicate that bFF inhibits resumption of meiosis. The objective of Experiment 2 was to determine the effect of bFF on embryonic development. Oocytes in Treatment A (Control) were placed into in vitro maturation (IVM) for 22 hours followed by …