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Full-Text Articles in Developmental Biology

Effects Of Calcium Availability On The Reproductive Output Of Insectivorous Bats, Christina M. Booher Aug 2007

Effects Of Calcium Availability On The Reproductive Output Of Insectivorous Bats, Christina M. Booher

All-Inclusive List of Electronic Theses and Dissertations

Reproduction is a period of high calcium demand in vertebrates, and calcium deficiency can limit reproductive output in mammals. Insects are a poor calcium source, suggesting that insectivorous species are more likely to be calcium deficient. Pregnant big brown bats (Eptesicus fuscus) consume 10 times less calcium than they are estimated to require. To accommodate calcium demand during pregnancy, many mammals mobilize more calcium from the skeleton, and extensive bone loss has been observed in some bats during pregnancy. A conflict may arise between the female and developing embryo over allocation of limited calcium supplies, which could limit reproductive output …


Physiological Notch Signaling Promotes Gliogenesis In The Developing Peripheral And Central Nervous Systems, Merritt Taylor, Kelly Yeager, Sean J. Morrison Jul 2007

Physiological Notch Signaling Promotes Gliogenesis In The Developing Peripheral And Central Nervous Systems, Merritt Taylor, Kelly Yeager, Sean J. Morrison

Peer Reviewed Articles

Constitutive activation of the Notch pathway can promote gliogenesis by peripheral (PNS) and central (CNS) nervous system progenitors. This raises the question of whether physiological Notch signaling regulates gliogenesis in vivo. To test this, we conditionally deleted Rbpsuh (Rbpj) from mouse PNS or CNS progenitors using Wnt1-Cre or Nestin-Cre. Rbpsuh encodes a DNAbinding protein (RBP/J) that is required for canonical signaling by all Notch receptors. In most regions of the developing PNS and spinal cord, Rbpsuh deletion caused only mild defects in neurogenesis, but severe defects in gliogenesis. These resulted from defects in glial specification or differentiation, …


Stoichiometric Controls Of Mercury Dilution By Growth, Roxanne Karimi, Celia Y. Chen, Paul C. Pickhardt, Nicholas S. Fisher, Carol L. Folt May 2007

Stoichiometric Controls Of Mercury Dilution By Growth, Roxanne Karimi, Celia Y. Chen, Paul C. Pickhardt, Nicholas S. Fisher, Carol L. Folt

Dartmouth Scholarship

Rapid growth could significantly reduce methylmercury (MeHg) concentrations in aquatic organisms by causing a greater than proportional gain in biomass relative to MeHg (somatic growth dilution). We hypothesized that rapid growth from the consumption of high-quality algae, defined by algal nutrient stoichiometry, reduces MeHg concentrations in zooplankton, a major source of MeHg for lake fish. Using a MeHg radiotracer, we measured changes in MeHg concentrations, growth and ingestion rates in juvenile Daphnia pulex fed either high (C:P = 139) or low-quality (C:P = 1317) algae (Ankistrodesmus falcatus) for 5 d. We estimated Daphnia steady-state MeHg concentrations, using a …


The Zebrafish As A Model Of Ventricular And Arterial Pole Malformations, Adrian Colin Grimes Jan 2007

The Zebrafish As A Model Of Ventricular And Arterial Pole Malformations, Adrian Colin Grimes

MUSC Theses and Dissertations

The zebrafish is becoming an almost ubiquitously accepted model for the study of comparative developmental biology, its utility coming to rival that of the fruitfly, frog, chick and mouse. Unfortunately, however, it is widely held belief that the zebrafish cardiac outflow tract makes it unusual as a model of comparative cardiogenesis and this is based, in part, on the report that bulbus arteriosus undergoes a developmental myocardium-to-smooth muscle phenotypic transition. This would imply that the zebrafish may be poorly suited to the study of human cardiac outflow abnormalities. While the use of chamber-specific molecular markers has allowed extensive characterization of …


The Effect Of Homocysteine On Neural Crest Cells, N-Cadherin, And Its Binding Partners, Kacie Rae Callaway Jan 2007

The Effect Of Homocysteine On Neural Crest Cells, N-Cadherin, And Its Binding Partners, Kacie Rae Callaway

Honors Program Theses

At elevated levels the amino acid homocysteine has been linked to defects such as spina bifida and improper septation of the outflow tract of the heart. Neural crest cells (NCCs) originate from the neural tube (which forms from fusion of neural folds and will become the spinal cord), disassociate from their neighbors, and migrate throughout the body to form many essential structures. N-cadherin, a cell adhesion protein expressed on the surface of neural tube cells of the early embryo, plays a major role in cell shape change, long-range migration, and communication. α-catenin is a member of the cadherin adhesion complex …