FACTORS AFFECTING EFFICIENCY OF FEEDER CATTLE HEDGING IN KENTUCKY

Livestock Production/Industries,

DNA double strand breaks but not interstrand crosslinks prevent progress through meiosis in fully grown mouse oocytes

There is some interest in how mammalian oocytes respond to different types of DNA damage because of the increasing expectation of fertility preservation in women undergoing chemotherapy. Double strand breaks (DSBs) induced by ionizing radiation and agents such as neocarzinostatin (NCS), and interstrand crosslinks (ICLs) induced by alkylating agents such as mitomycin C (MMC), are toxic DNA lesions that need to be repaired for cell survival. Here we examined the effects of NCS and MMC treatment on oocytes collected from antral follicles in mice, because potentially such oocytes are readily collected from ovaries and do not need to be in vitro grown to achieve meiotic competency. We found that oocytes were sensitive to NCS, such that this ionizing radiation mimetic blocked meiosis I and caused fragmented DNA. In contrast, MMC had no impact on the completion of either meiosis I or II, even at extremely high doses. However, oocytes treated with MMC did show ?-H2AX foci and following their in vitro maturation and parthenogenetic activation the development of the subsequent embryos was severely compromised. Addition of MMC to 1-cell embryos caused a similarly poor level of development, demonstrating oocytes have eventual sensitivity to this ICL-inducing agent but this does not occur during their meiotic division. In oocytes, the association of Fanconi Anemia protein, FANCD2, with sites of ICL lesions was not apparent until entry into the embryonic cell cycle. In conclusion, meiotic maturation of oocytes is sensitive to DSBs but not ICLs. The ability of oocytes to tolerate severe ICL damage and yet complete meiosis, means that this type of DNA lesion goes unrepaired in oocytes but impacts on subsequent embryo quality

The Src Homology 2 and Phosphotyrosine Binding Domains of the ShcC Adaptor Protein Function as Inhibitors of Mitogenic Signaling by the Epidermal Growth Factor Receptor

Upon ligand activation, the epidermal growth factor receptor (EGFR) becomes tyrosine-phosphorylated, thereby recruiting intracellular signaling proteins such as Shc. EGFR binding of Shc proteins results in their tyrosine phosphorylation and subsequent activation of the Ras and Erk pathways. Shc interaction with activated receptor tyrosine kinases is mediated by two distinct phosphotyrosine interaction domains, an NH2-terminal phosphotyrosine binding (PTB) domain and a COOH-terminal Src homology 2 (SH2) domain. The relative importance of these two domains for EGFR binding was examined by determining if expression of the isolated SH2 or PTB domain of ShcC would inhibit EGFR signaling. The SH2 domain potently inhibited numerous aspects of EGFR signaling including activation of Erk2 and the Elk-1 transcription factor as well as EGFR-dependent transformation. Furthermore, the SH2 domain inhibited focus formation by the Neu oncoprotein, another EGFR family member. Surprisingly, inhibition of the EGFR by the SH2 domain did not involve stable association with the receptor. In contrast, the PTB domain associated quite well with the receptor yet had little effect on EGFR signaling. Although the EGFR cytoplasmic tail contains consensus binding sites for the PTB and SH2 domains of ShcC, and both domains of ShcC interact with the receptor in vitro, the SH2 domain is more potent for inhibiting receptor function in vivo. However, inhibition is not due to stable association with the receptor, suggesting that the SH2 domain is binding to a heretofore unknown protein(s) necessary for proper EGFR function

Formal Synthesis of (+)-Sorangicin A

The formal synthesis of (+)-sorangicin A was completed by two independent routes. Both approaches feature a cross metathesis reaction to form the C29-C30 bond to arrive at the bicyclic ether/tetrahydropyran fragment. Formation of the C15-C16 olefin to unite the dihydropyran fragment with the rest of the molecule was achieved by either a cross metathesis reaction or a Julia-Kocienski olefination

New Young Star Candidates in BRC 27 and BRC 34

We used archival Spitzer Space Telescope mid-infrared data to search for young stellar objects (YSOs) in the immediate vicinity of two bright-rimmed clouds, BRC 27 (part of CMa R1) and BRC 34 (part of the IC 1396 complex). These regions both appear to be actively forming young stars, perhaps triggered by the proximate OB stars. In BRC 27, we find clear infrared excesses around 22 of the 26 YSOs or YSO candidates identified in the literature, and identify 16 new YSO candidates that appear to have IR excesses. In BRC 34, the one literature-identified YSO has an IR excess, and we suggest 13 new YSO candidates in this region, including a new Class I object. Considering the entire ensemble, both BRCs are likely of comparable ages, within the uncertainties of small number statistics and without spectroscopy to confirm or refute the YSO candidates. Similarly, no clear conclusions can yet be drawn about any possible age gradients that may be present across the BRCs.Comment: 54 pages, 19 figures, accepted by A

Cardiac-Specific Expression of the Tetracycline Transactivator Confers Increased Heart Function and Survival Following Ischemia Reperfusion Injury

Mice expressing the tetracycline transactivator (tTA) transcription factor driven by the rat α-myosin heavy chain promoter (α-MHC-tTA) are widely used to dissect the molecular mechanisms involved in cardiac development and disease. However, these α-MHC-tTA mice exhibit a gain-of-function phenotype consisting of robust protection against ischemia/reperfusion injury in both in vitro and in vivo models in the absence of associated cardiac hypertrophy or remodeling. Cardiac function, as assessed by echocardiography, did not differ between α-MHC-tTA and control animals, and there were no noticeable differences observed between the two groups in HW/TL ratio or LV end-diastolic and end-systolic dimensions. Protection against ischemia/reperfusion injury was assessed using isolated perfused hearts where α-MHC-tTA mice had robust protection against ischemia/reperfusion injury which was not blocked by pharmacological inhibition of PI3Ks with LY294002. Furthermore, α-MHC-tTA mice subjected to coronary artery ligation exhibited significantly reduced infarct size compared to control animals. Our findings reveal that α-MHC-tTA transgenic mice exhibit a gain-of-function phenotype consisting of robust protection against ischemia/reperfusion injury similar to cardiac pre- and post-conditioning effects. However, in contrast to classical pre- and post-conditioning, the α-MHC-tTA phenotype is not inhibited by the classic preconditioning inhibitor LY294002 suggesting involvement of a non-PI3K-AKT signaling pathway in this phenotype. Thus, further study of the α-MHC-tTA model may reveal novel molecular targets for therapeutic intervention during ischemic injury

Eosinophils Are Important for Protection, Immunoregulation and Pathology during Infection with Nematode Microfilariae

Eosinophil responses typify both allergic and parasitic helminth disease. In helminthic disease, the role of eosinophils can be both protective in immune responses and destructive in pathological responses. To investigate whether eosinophils are involved in both protection and pathology during filarial nematode infection, we explored the role of eosinophils and their granule proteins, eosinophil peroxidase (EPO) and major basic protein-1 (MBP-1), during infection with Brugia malayi microfilariae. Using eosinophil-deficient mice (PHIL), we further clarify the role of eosinophils in clearance of microfilariae during primary, but not challenge infection in vivo. Deletion of EPO or MBP-1 alone was insufficient to abrogate parasite clearance suggesting that either these molecules are redundant or eosinophils act indirectly in parasite clearance via augmentation of other protective responses. Absence of eosinophils increased mast cell recruitment, but not other cell types, into the broncho-alveolar lavage fluid during challenge infection. In addition absence of eosinophils or EPO alone, augmented parasite-induced IgE responses, as measured by ELISA, demonstrating that eosinophils are involved in regulation of IgE. Whole body plethysmography indicated that nematode-induced changes in airway physiology were reduced in challenge infection in the absence of eosinophils and also during primary infection in the absence of EPO alone. However lack of eosinophils or MBP-1 actually increased goblet cell mucus production. We did not find any major differences in cytokine responses in the absence of eosinophils, EPO or MBP-1. These results reveal that eosinophils actively participate in regulation of IgE and goblet cell mucus production via granule secretion during nematode-induced pathology and highlight their importance both as effector cells, as damage-inducing cells and as supervisory cells that shape both innate and adaptive immunity

Contact calls facilitate group contraction in free-ranging goats (Capra aegagrus hircus)

Many social animal species produce vocalizations believed to facilitate group contraction when one or more group members have become distant. However, the mechanisms underlying this function remain unclear for many species. We examined this question with data on a semi-free ranging group of 16 adult domesticated goats (Capra aegagrus hircus) inhabiting Tsaobis Nature Park, Namibia. All goats wore dataloggers consisting of a GPS and audio recorder for 5–6 h per day for 10 days, providing continuous data on their geolocations and vocal communication. We found that callers were farther from the group centroid than expected by chance and that call production was associated with the cessation of group expansion and subsequent group contraction. We did not find strong evidence for antiphonal call exchange between distant and core group members. Rather, we found that (i) call production by distant group members is associated with a significant reduction of group movement away from the caller, and (ii) call production by core group members is associated with greater, though not significantly greater, group movement toward the caller. These findings suggest that calls may be used by distant, and potentially core, group members to facilitate the contraction of group spread. Results from our study clarify the mechanisms through which social animals can regulate collective movement behavior and the specific role that vocalizations play in this process

Generation of Stable Pluripotent Stem Cells From NOD Mouse Tail-Tip Fibroblasts

OBJECTIVE: The NOD mouse strain has been widely used to investigate the pathology and genetic susceptibility for type 1 diabetes. Induced pluripotent stem cells (iPSCs) derived from this unique mouse strain would enable new strategies for investigating type 1 diabetes pathogenesis and potential therapeutic targets. The objective of this study was to determine whether somatic fibroblasts from NOD mice could be reprogrammed to become iPSCs, providing an alternative source of stem cells for the production of genetically modified NOD cells and mice. RESEARCH DESIGN AND METHODS: Adult tail-tip fibroblasts from male NOD mice were reprogrammed by retroviral transduction of the coding sequences of three transcription factors, OCT4, SOX2, and KLF4, in combination with a histone deacetylase inhibitor, valproic acid. RESULTS: Eighteen NOD iPSC lines were generated, and three of these cell lines were further characterized. All three cell lines exhibited silencing of the three reprogramming transgenes and reactivation of endogenous pluripotent markers (OCT4, SOX2, NANOG, REX1, and SSEA1). These NOD iPSCs readily differentiated in vitro to form embryoid bodies and in vivo by teratoma formation in immunodeficient mice. Moreover, NOD iPSCs were successfully transfected with a reporter transgene and were capable of contributing to the inner cell mass of C57BL/6 blastocysts, leading to the generation of a chimeric mouse. CONCLUSIONS: Adult tail-tip fibroblasts from NOD mice can be reprogrammed, without constitutive ectopic expression of transcription factors, to produce iPSCs that exhibit classic mouse embryonic stem cell (ESC) features. These NOD iPSCs can be maintained and propagated under normal ESC culture conditions to produce genetically altered cell lines, differentiated cells, and chimeric mice

Ornamental plants: a summary of research, 1990

Physical facilities and capital requirements for establishing a three-acre perennial container nursery in Ohio -1989 / Reed D. Taylor, Elton M. Smith, George P. Pealer -- Production costs of operating a three-acre perennial container nursery in Ohio - 1989 / Reed D. Taylor, Elton M. Smith, George P. Pealer -- Comparative costs of producing alternative plants in a three-acre perennial container nursery in Ohio – 1989 / Reed D. Taylor, Elton M. Smith, George P. Pealer -- Marketing and sales strategies practiced by Ohio nurseries / Reed D. Taylor, Elton M. Smith, W. Timothy Rhodus -- Evaluation of flowering crabapple susceptibility to apple scab in Ohio - 1989 / Elton M. Smith and Sharon A. Treaster -- Fertilizing trees in the landscape: an 18-year evaluation / Elton M. Smith and Sharon A. Treaster -- The influence of irrigation water temperature upon leaf abscision in Ficus benjamina and Dracaena marginata / Julia A. O’Bryan and John C. Peterson -- A two-year tolerance study of narcissus cultivars to selected pre-emergence herbicides / Elton M. Smith and Sharon A. Treaster -- Tolerance of clematis and wisteria to Ronstar and Devrinol / Elton M. Smith and Sharon A. Treaster -- Increasing efficiency of slow-release herbicide tablets / Elton M. Smith and Sharon A. Treaster -- Developing biorational pesticides for the landscape industry / David G. Nielsen -- Interactions between subdue and slow-release fertilizers at high temperatures / Y. Inbar, H. A. J. Hoitink, M. E. Watson, K. D. Cochran, E. M. Smith -- Evaluation of powdery mildew severity on deciduous azaleas at the Secrest Arboretum - 1989 / Kenneth D. Cochran and C. Wayne Ellett -- Winter damage, regrowth and vigor of old garden roses / Gary A. Anderso