110 research outputs found

    MATING SYSTEM EVOLUTION, PLANT-POLLINATOR INTERACTIONS, AND FLORAL ULTRAVIOLET PATTERNING IN MIMULUS GUTTATUS

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    The evolution and maintenance of plant mating systems has been a topic of great interest throughout the history of evolutionary biology. Despite a large body of literature describing mating system variation, critical knowledge is lacking regarding the mechanisms involved in mating system transitions, including the rate and magnitude of trait changes. I combine experimental evolution, pollinator behavioral studies, and classic phytomorphology to examine the mating system transition from outcrossing to self-fertilizing (selfing) in flowering plants. Using the wildflower Mimulus guttatus (yellow monkeyflower) as a model, I investigate which traits facilitate outcrossing via mutualistic relationships with pollinators and which traits evolve in response to pollination disruption. In Chapters 1 and 2, I demonstrate that rapid evolution of adaptive floral and genetic traits can occur in populations that lose pollinators and that trait evolution occurs sequentially. In Chapter 3, I find strong pollinator preference for specific floral traits, evidence that pollinator selection maintains attractive traits in wild populations. However, pollinators displayed limited ability to distinguish between subtle population variants and thus are unlikely drivers of ethological speciation. In Chapter 4, I document within and among population variation in a cryptic floral trait, ultraviolet (UV) patterning. UV patterning is a visual stimulant for pollinators, but I found it in a selfing Mimulus species, suggesting that UV patterning in flowers functions beyond pollinator attraction. My research has direct implications for forecasting plant adaptation as anthropogenic environmental disturbance increasingly decouples plant-pollinator relationships. Rapid adaptation is an option for some self-compatible, pollinator-reliant plants; however, a transition to selfing results in decreased genetic diversity which may expose populations to extinction with further environmental disturbances

    Collection and freezing of equine epididymal spermatozoa

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    The epididymis and vas deferens store an important number of fertile spermatozoa called the extragonadal sperm reserves. These stored spermatozoa can be collected in an ultimate attempt to preserve viable spermatozoa of a critically ill or dying stallion. Epididymides are collected via routine castration. After cooled transport of the testicles and epididymides, spermatozoa are collected either by retrograde flushing or by the float-up method. Retrograde flushing usually results in a much higher sperm yield and is considered the method of choice. Epididymal spermatozoa can be frozen using standard freezing protocols

    Rapid Evolution caused by pollinator loss in mimulus guttatus

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    This is the peer reviewed version of the following article: Bodbyl Roels, S. A., & Kelly, J. K. (2011). RAPID EVOLUTION CAUSED BY POLLINATOR LOSS IN MIMULUS GUTTATUS. Evolution; International Journal of Organic Evolution, 65(9), 2541–2552. http://doi.org/10.1111/j.1558-5646.2011.01326.x, which has been published in final form at http://doi.org/10.1111/j.1558-5646.2011.01326.x. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Anthropogenic perturbations including habitat loss and emerging disease are changing pollinator communities and generating novel selection pressures on plant populations. Disruption of plant–pollinator relationships is predicted to cause plant mating system evolution, although this process has not been directly observed. This study demonstrates the immediate evolutionary effects of pollinator loss within experimental populations of a predominately outcrossing wildflower. Initially equivalent populations evolved for five generations within two pollination treatments: abundant bumblebee pollinators versus no pollinators. The populations without pollinators suffered greatly reduced fitness in early generations but rebounded as they evolved an improved ability to self-fertilize. All populations diverged in floral, developmental, and life-history traits, but only a subset of characters showed clear association with pollination treatment. Pronounced treatment effects were noted for anther–stigma separation and autogamous seed set. Dramatic allele frequency changes at two chromosomal polymorphisms occurred in the no pollinator populations, explaining a large fraction of divergence in pollen viability. The pattern of phenotypic and genetic changes in this experiment favors a sequential model for the evolution of the multitrait “selfing syndrome” observed throughout angiosperms

    Comparative analysis of remotely-sensed data products via ecological niche modeling of avian influenza case occurrences in Middle Eastern poultry.

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    Ecological niche modeling integrates known sites of occurrence of species or phenomena with data on environmental variation across landscapes to infer environmental spaces potentially inhabited (i.e., the ecological niche) to generate predictive maps of potential distributions in geographic space. Key inputs to this process include raster data layers characterizing spatial variation in environmental parameters, such as vegetation indices from remotely sensed satellite imagery. The extent to which ecological niche models reflect real-world distributions depends on a number of factors, but an obvious concern is the quality and content of the environmental data layers

    Maternal recognition of pregnancy in the horse : are MicroRNAs the secret messengers?

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    The signal for maternal recognition of pregnancy (MRP) has still not been identified in the horse. High-throughput molecular biology at the embryo-maternal interface has substantially contributed to the knowledge on pathways affected during MRP, but an integrated study in which proteomics, transcriptomics and miRNA expression can be linked directly is currently lacking. The aim of this study was to provide such analysis. Endometrial biopsies, uterine fluid, embryonic tissues, and yolk sac fluid were collected 13 days after ovulation during pregnant and control cycles from the same mares. Micro-RNA-Sequencing was performed on all collected samples, mRNA-Sequencing on the same tissue samples and mass spectrometry was conducted previously on the same fluid samples. Differential expression of miRNA, mRNA and proteins showed high conformity with literature and confirmed involvement in pregnancy establishment, embryo quality, steroid synthesis and prostaglandin regulation, but the link between differential miRNAs and their targets was limited and did not indicate the identity of an unequivocal signal for MRP in the horse. Differential expression at the embryo-maternal interface was prominent, highlighting a potential role of miRNAs in embryo-maternal communication during early pregnancy in the horse. These data provide a strong basis for future targeted studies

    Detection and Plant Monitoring Programs: Lessons from an Intensive Survey of Asclepias meadii with Five Observers

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    A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author’s publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Monitoring programs, where numbers of individuals are followed through time, are central to conservation. Although incomplete detection is expected with wildlife surveys, this topic is rarely considered with plants. However, if plants are missed in surveys, raw count data can lead to biased estimates of population abundance and vital rates. To illustrate, we had five independent observers survey patches of the rare plant Asclepias meadii at two prairie sites. We analyzed data with two mark-recapture approaches. Using the program CAPTURE, the estimated number of patches equaled the detected number for a burned site, but exceeded detected numbers by 28% for an unburned site. Analyses of detected patches using Huggins models revealed important effects of observer, patch state (flowering/nonflowering), and patch size (number of stems) on probabilities of detection. Although some results were expected (i.e. greater detection of flowering than nonflowering patches), the importance of our approach is the ability to quantify the magnitude of detection problems. We also evaluated the degree to which increased observer numbers improved detection: smaller groups (3–4 observers) generally found 90 – 99% of the patches found by all five people, but pairs of observers or single observers had high error and detection depended on which individuals were involved. We conclude that an intensive study at the start of a long-term monitoring study provides essential information about probabilities of detection and what factors cause plants to be missed. This information can guide development of monitoring programs

    Proteins involved in embryo-maternal interaction around the signalling of maternal recognition of pregnancy in the horse

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    During maternal recognition of pregnancy (MRP), a conceptus-derived signal leads to the persistence of the corpus luteum and the maintenance of gestation. In the horse, the nature of this signal remains to be elucidated. Several studies have focused on the changes in gene expression during MRP, but little information exists at the protein level. The aim of this study was to identify the proteins at the embryo-maternal interface around signalling of MRP in the horse (day 13) by means of mass spectrometry. A distinct influence of pregnancy was established, with 119 proteins differentially expressed in the uterine fluid of pregnant mares compared to cyclic mares and with upregulation of several inhibitors of the prostaglandin synthesis during pregnancy. By creating an overview of the proteins at the embryo-maternal interface in the horse, this study provides a solid foundation for further targeted studies of proteins potentially involved in embryo-maternal interactions, MRP and pregnancy loss in the horse

    Intraoperative ventilator settings and their association with postoperative pulmonary complications in neurosurgical patients : post-hoc analysis of LAS VEGAS study

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    Background Limited information is available regarding intraoperative ventilator settings and the incidence of postoperative pulmonary complications (PPCs) in patients undergoing neurosurgical procedures. The aim of this post-hoc analysis of the 'Multicentre Local ASsessment of VEntilatory management during General Anaesthesia for Surgery' (LAS VEGAS) study was to examine the ventilator settings of patients undergoing neurosurgical procedures, and to explore the association between perioperative variables and the development of PPCs in neurosurgical patients. Methods Post-hoc analysis of LAS VEGAS study, restricted to patients undergoing neurosurgery. Patients were stratified into groups based on the type of surgery (brain and spine), the occurrence of PPCs and the assess respiratory risk in surgical patients in Catalonia (ARISCAT) score risk for PPCs. Results Seven hundred eighty-four patients were included in the analysis; 408 patients (52%) underwent spine surgery and 376 patients (48%) brain surgery. Median tidal volume (V-T) was 8 ml [Interquartile Range, IQR = 7.3-9] per predicted body weight; median positive end-expiratory pressure (PEEP) was 5 [3 to 5] cmH(2)0. Planned recruitment manoeuvres were used in the 6.9% of patients. No differences in ventilator settings were found among the sub-groups. PPCs occurred in 81 patients (10.3%). Duration of anaesthesia (odds ratio, 1.295 [95% confidence interval 1.067 to 1.572]; p = 0.009) and higher age for the brain group (odds ratio, 0.000 [0.000 to 0.189]; p = 0.031), but not intraoperative ventilator settings were independently associated with development of PPCs. Conclusions Neurosurgical patients are ventilated with low V-T and low PEEP, while recruitment manoeuvres are seldom applied. Intraoperative ventilator settings are not associated with PPCs
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