With fewer than 7500 cheetahs remaining in the wild, ex situ cheetah populations serve as an insurance policy against extinction and a resource to study species' biology. This study aimed to identify the age of pubertal onset in ex situ female cheetahs using non-invasive faecal steroid hormone monitoring and body weights. Faecal samples from nine female cheetahs were collected two to three times weekly from 2 to 36months of age and body weights were recorded every 3months.
View Article and Find Full Text PDFThe North American cheetah population serves as a reservoir for the species, and acts as a research population to help understand the unique biology of the species. Little is known about the intrauterine physiology of the cheetah, including embryo differentiation, implantation, and the development of the placenta. After mating, cheetah females frequently experience (30-65% of matings) a non-pregnant luteal phase where progestogen metabolite levels match those found in pregnant females for the first ~55 days of gestation, but parturition does not occur.
View Article and Find Full Text PDFA recent large-scale welfare study in North America involving 106 Asian (Elephas maximus) and 131 African (Loxodonta africana) elephants at 64 accredited facilities identified links (i.e., risk factors) between zoo environmental factors and a number of welfare outcomes (stereotypic behavior, ovarian acyclicity, hyperprolactinemia, walking and recumbence, body condition, health status, serum cortisol).
View Article and Find Full Text PDFPituitary tumors are rare but are associated with significant symptoms that impact patients' quality of life (QOL). Surgery remains one of the most effective treatment options for long term disease control and symptom benefit, but symptom, and quality of life recovery in the subacute period has not been previously reported. This study aimed to better understand the impact of surgery on patients' symptom burden and QOL in the subacute post-surgical period.
View Article and Find Full Text PDFThe efficacy of several protocols for ovulation synchronization and timed artificial insemination (TAI) in goats was examined. In addition, the relationship between levels of pregnancy specific protein B (PSPB) during gestation assessed with a commercially available ELISA and the number of offspring at birth was determined. In Experiment 1, 70 does were randomized into four treatments: (1) breed by estrus [BBE], (2) 6-d treatment with a new [C6N], (3) once-used [C61], or (4) twice-used Controled Internal Drug Release (CIDR) device [C62)].
View Article and Find Full Text PDFCheetahs are one of the most heavily studied felid species, with numerous publications on health, disease, and reproductive physiology produced over the last 30 years. Despite this relatively long history of research, there is a paucity of crucial biological data, such as pubertal onset, which has direct and significant applications to improved management of ex situ cheetah populations. This study aimed to determine age of pubertal onset in ex situ male cheetahs using non-invasive fecal steroid hormone monitoring and body weights.
View Article and Find Full Text PDFBackground: Gastric duplication is a rare malformation mostly diagnosed during childhood. Symptoms in adults are atypical, rare, or may be completely absent. The diagnosis is suggested after a morphological and histological assessment.
View Article and Find Full Text PDFThe majority of pregnancy loss in cattle occurs between Days 8 and 16 of gestation, coincident with the initiation of conceptus elongation and the onset of maternal recognition of pregnancy. Differences in conceptus length on the same day of gestation may be related to an inherent lack of developmental competency or may simply be a consequence of asynchrony with the maternal environment. The objective of this work was to characterize differential patterns of mRNA expression between short and long bovine conceptuses recovered on Day 15 of gestation.
View Article and Find Full Text PDFThe hormone progesterone is essential for proper embryonic development. The objective of this study was to examine the relationship between recipient serum concentrations of progesterone, at the time of embryo transfer and at conceptus recovery, on conceptus development from in vivo- or in vitro-produced embryos. Embryos were produced in vivo by superovulation of Holstein cows (IVO; n = 17) or in vitro with either serum-containing (IVPS; n = 27) or serum-restricted medium (IVPSR; n = 34).
View Article and Find Full Text PDFObjective: 1) further define the time course required for transcription initiation in bovine cumulus-oocyte-complexes (COC); 2) determine the pattern of expression for Nr4A1 and Egr1 mRNAs in bovine COC; and, 3) reduce Nr4A1 mRNA expression using small interfering RNAs (siRNA) to determine the effect on breakdown of the germinal vesicle (GVBD).
Methods: A series of experiments were performed to define the time required for transcription initiation during FSH-induced maturation in bovine COCs, determine the pattern of expression for candidate mRNAs during GVBD, and use RNAi to determine their potential role in GVBD by examining whether candidate-specific siRNA can reduce mRNA expression in bovine COCs and affect the occurrence of GVBD.
Results: Transcription required for GVBD in bovine COC occurred as early as 30 min after culture initiation.
The insulin-like growth factor type 2 receptor (IGF2R) regulates fetal growth by removing IGF2 from circulation. In mice, expression of the Igf2r gene is only imprinted after implantation and is associated with expression of the antisense non-coding (nc)RNA, Airn. The objectives of this study were, first, to determine if bovine AIRN was expressed during developmentally important stages of gestation, and second, to determine if expression of bAIRN was affected by method of embryo production.
View Article and Find Full Text PDFMastitis or other infectious diseases have been related to reduced fertility in cattle. Inflammatory cytokines such as tumor necrosis factor α (TNFα) are released in response to infection and may have negative effects on embryo development. In the current study the effect of exposure to TNFα on the development of in vitro fertilized bovine embryos was examined.
View Article and Find Full Text PDFRationale: Previous studies indicate that the rewarding effect of D-1 dopamine receptor stimulation in nucleus accumbens (NAc) shell is greater in food-restricted (FR) than in ad libitum fed (AL) rats. The D-1 receptor is positively coupled to adenylyl cyclase and activates protein kinase A (PKA).
Objectives: The purpose of this study was to determine whether PKA is involved in the rewarding effect of D-1 receptor stimulation and, if so, whether it is involved in the enhanced response of FR rats.
The objective of this study was to determine if laboratory modules of an undergraduate animal anatomy course offered in distance education (DistEd) format were as effective as face-to-face (F2F) format in helping students learn. Students (n = 159) completed an anatomy pretest as well as a presurvey to assess prior DistEd experience. Alternating each week, laboratory topics were presented either as F2F or as virtual DistEd laboratories.
View Article and Find Full Text PDFThe objective of this study was to determine the effects of in vitro embryo production on physical development and levels of expression of mRNAs for insulin-like growth factor (IGF) ligands (IGF1, IGF2), their receptors (IGF1R, IGF2R), and IGF binding protein-2 (IGFBP2) in bovine fetuses during early gestation. In vivo embryos were recovered from superovulated Holstein cows. For production of embryos in vitro, Holstein oocytes were matured, fertilized, and subsequently cultured in M199 with 10% serum to 168 hpi.
View Article and Find Full Text PDFThe objective of this study was to determine the effect of season on sperm quality variables, expression of the fertility-related protein SP22 and selected mRNA transcripts in fresh and cryopreserved stallion sperm. Four stallions were collected in each of the four seasons: summer, fall, winter and spring. Ejaculates were divided and then evaluated for motility, morphology, SP22 staining and expression of selected mRNAs as either fresh semen samples or cryopreserved samples.
View Article and Find Full Text PDFDevelopment of the post-hatching conceptus in ruminants involves a period of morphological expansion that is driven by complex interactions between the conceptus and its intrauterine environment. As a result of these interactions, endometrial physiology is altered, leading to establishment of the pregnancy and continued development of the placenta. Disruption of normal fetal and placental development can occur when embryos are exposed to manipulations in vitro or when inappropriate endocrine sequencing occurs in vivo during the pre- and peri-implantation periods.
View Article and Find Full Text PDFUnderstanding mechanisms responsible for meiotic resumption in mammalian oocytes is critical for the identification of strategies to enhance developmental competence of in vitro-matured oocytes. Improvement of in vitro oocyte maturation systems is dependent on a better understanding of mechanisms that regulate oocyte maturation both in vivo and in vitro as well as on the identification of methods to manipulate the meiotic progression of oocytes matured in vitro in a physiological manner. The purpose of this review is two-fold: first, to examine the mechanisms that underlie the acquisition of oocyte developmental competence and regulation of oocyte maturation in vivo and in vitro; second, to present data examining the role of transcription in mediating the ability of EGF and FSH to induce oocyte maturation in vitro.
View Article and Find Full Text PDFIn cultured cumulus oocyte complexes (COC), FSH induces gene transcription required for germinal vesicle breakdown (GVBD). Experiments were performed to determine the critical period when gene transcription is required for GVBD and to identify candidate mRNAs involved. Experiment I: murine COC were cultured 4 h in the presence of FSH with 5,6-dichloro-1-beta-d-ribofuranosylbenzimidazole (DRB) added at different intervals after the start of culture.
View Article and Find Full Text PDFThe objectives of this study were, first, to evaluate the effectiveness of 2 culture media, Menezo's B2 (B2) and Tissue Culture Medium-199 (M-199), for the production of bovine blastocysts in a commercial embryo transfer program; and, second, to characterize the stage of development, quality grade and cell number of blastocysts produced in each medium. One-cell bovine embryos were produced using in vitro maturation and fertilization procedures. After fertilization, the embryos were co-cultured on Buffalo rat liver (BRL) cell monolayers in either B2 or M-199+1% BSA (M-199) medium.
View Article and Find Full Text PDFIn vitro systems for oocyte maturation, fertilization and embryo culture [in vitro production (IVP)] have the potential for more wide-spread use in creative breeding programs for dairy and beef cattle. However, one negative consequence of both IVP and somatic cell nuclear transfer (SCNT) in cattle and other species is that embryos, fetuses, placentas, and offspring can differ significantly in morphology and developmental competence compared with those from embryos produced in vivo. Fetuses and placentas derived from IVP and SCNT embryos may fall within the normal range of development, may have obvious abnormalities such as increased fetal and placental weights, or may have subtle abnormalities such as aberrant development of fetal skeletal muscle, placental blood vessels, and altered metabolism.
View Article and Find Full Text PDFApproximately 100 species become extinct a day. Despite increasing interest in using cloning to rescue endangered species, successful interspecies nuclear transfer has not been previously described, and only a few reports of in vitro embryo formation exist. Here we show that interspecies nuclear transfer can be used to clone an endangered species with normal karyotypic and phenotypic development through implantation and the late stages of fetal growth.
View Article and Find Full Text PDFThe objective of this study was to determine the effects of undefined and semidefined culture systems for in vitro embryo production on angiogenesis and morphometry of bovine placentas during early gestation. Blastocysts produced in vivo were recovered from superovulated Holstein cows and served as controls. Blastocysts produced in vitro were exposed to either serum-supplemented medium with cumulus cell coculture (in vitro-produced with serum; IVPS) or modified synthetic oviductal fluid medium without serum or coculture (mSOF).
View Article and Find Full Text PDFThe establishment of in vitro fertilization and culture systems for mammalian embryos has facilitated the application of embryo technologies in research, industry, and clinical settings. Furthermore, the advent of cloning by nuclear transfer has significantly enhanced the potential for genetic modification of livestock. Based on studies in cattle, sheep, and mice, it has become apparent that embryos produced using these systems can differ in morphology and developmental potential compared with embryos produced in vivo.
View Article and Find Full Text PDFThe objective of this study was to determine the effects of in vitro embryo production on angiogenesis and morphometry of the bovine placenta during late gestation. Blastocysts produced in vivo were recovered from superovulated Holstein cows. Blastocysts produced in vitro were obtained after culture of in vitro-matured and -fertilized Holstein oocytes.
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