Presentation Type

Poster Presentation

Abstract/Artist Statement

Multicellular organisms are a dynamic system, maintaining structure through interactions between individual cells, and the environment around cells known as the extracellular matrix (ECM). Communication between cells and the ECM is important in every aspect of development and organ function. Numerous studies have demonstrated disruptions in cell - ECM signaling can lead to diseases such as cancer, and cardiovascular disease. In addition, specific interactions between neurons of the brain and the ECM are critical for wiring of the developing nervous system, learning and memory, and neural regeneration following injury.

The CCN (Cyr61, CTGF, NOV) members are an important family of regulatory ECM proteins that are secreted by cells, and function by cell-cell signaling. CCN proteins contain four well-characterized, conserved modules that enable a single CCN family member to interact with numerous other ECM proteins. CCN proteins have been described as the water cooler of the ECM, bringing various workers to the area at different times to regulate cell behavior, and aid in providing cell homeostasis. In vertebrates, there are 6 CCN family members. In the fruit fly, Drosophila melanogaster, there is one identified CCN protein (Drosophila CCN (dCCN)) which is highly expressed in neurons. Octopamine, a neuromodulator of courtship and aggression behaviors, is required for male behavior. Previously, rodent models have been challenging to use. Due to the simplicity of the Drosophila nervous system and single CCN protein, we are able to examine the requirement of dCCN in neuron function, octopamine neurons, and male behavior.

To test the hypotheses that dCCN is required for neuron function, in octopamine neurons, and male behavior, progeny will be generated that have reduced dCCN in dCCN-expressing neurons and control progeny. Both control and experimental dCCN-expressing neurons will express a green fluorescence protein (GFP) reporter to visualize the neurons. Dissected brains and use of the confocal microscope will provide images and allow quantification of dCCN-expressing neurons in control and mutant brains. Progeny will be generted that have reduced dCCN in octopamine neurons as well as control progeny. Experimental progeny will be placed in behavioral assays to examine male aggression and data will be used as readout of neuron function. Progeny lacking dCCN in octopamine neurons will express a nuclear tag to allow visualization of dCCN expressing cells. An anti-tdc2 antibody will mark octopamine neurons. Brains and ventral nerve cords will be obtained and fluorescent images will be acquired using a confocal microscope.

It is predicted that neurons without dCCN will survive but exhibit abnormal neuron function. It is also predicted that a lack of dCCN in octopamine neurons will display abnormal neuron function and altered aggression. This result would demonstrate that the ECM of the nervous system is a key player in neuron development and neuron signaling, and provide functional data useful in all organisms.

This work is significant and important because experiments will reveal insight into how CCN proteins govern neuronal growth, development, interactions with neurotransmitters, function, and behavioral circuitry. Results will also contribute to the understanding of neuron and ECM interactions in general.

Mentor Name

Dr. Sarah Certel

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Apr 20th, 5:00 PM Apr 20th, 6:30 PM

Regulation of neuron growth and development by the matricellular protein dCCN

UC South Ballroom

Multicellular organisms are a dynamic system, maintaining structure through interactions between individual cells, and the environment around cells known as the extracellular matrix (ECM). Communication between cells and the ECM is important in every aspect of development and organ function. Numerous studies have demonstrated disruptions in cell - ECM signaling can lead to diseases such as cancer, and cardiovascular disease. In addition, specific interactions between neurons of the brain and the ECM are critical for wiring of the developing nervous system, learning and memory, and neural regeneration following injury.

The CCN (Cyr61, CTGF, NOV) members are an important family of regulatory ECM proteins that are secreted by cells, and function by cell-cell signaling. CCN proteins contain four well-characterized, conserved modules that enable a single CCN family member to interact with numerous other ECM proteins. CCN proteins have been described as the water cooler of the ECM, bringing various workers to the area at different times to regulate cell behavior, and aid in providing cell homeostasis. In vertebrates, there are 6 CCN family members. In the fruit fly, Drosophila melanogaster, there is one identified CCN protein (Drosophila CCN (dCCN)) which is highly expressed in neurons. Octopamine, a neuromodulator of courtship and aggression behaviors, is required for male behavior. Previously, rodent models have been challenging to use. Due to the simplicity of the Drosophila nervous system and single CCN protein, we are able to examine the requirement of dCCN in neuron function, octopamine neurons, and male behavior.

To test the hypotheses that dCCN is required for neuron function, in octopamine neurons, and male behavior, progeny will be generated that have reduced dCCN in dCCN-expressing neurons and control progeny. Both control and experimental dCCN-expressing neurons will express a green fluorescence protein (GFP) reporter to visualize the neurons. Dissected brains and use of the confocal microscope will provide images and allow quantification of dCCN-expressing neurons in control and mutant brains. Progeny will be generted that have reduced dCCN in octopamine neurons as well as control progeny. Experimental progeny will be placed in behavioral assays to examine male aggression and data will be used as readout of neuron function. Progeny lacking dCCN in octopamine neurons will express a nuclear tag to allow visualization of dCCN expressing cells. An anti-tdc2 antibody will mark octopamine neurons. Brains and ventral nerve cords will be obtained and fluorescent images will be acquired using a confocal microscope.

It is predicted that neurons without dCCN will survive but exhibit abnormal neuron function. It is also predicted that a lack of dCCN in octopamine neurons will display abnormal neuron function and altered aggression. This result would demonstrate that the ECM of the nervous system is a key player in neuron development and neuron signaling, and provide functional data useful in all organisms.

This work is significant and important because experiments will reveal insight into how CCN proteins govern neuronal growth, development, interactions with neurotransmitters, function, and behavioral circuitry. Results will also contribute to the understanding of neuron and ECM interactions in general.