Developmental Biology Commons^™

Using A Novel Multiplexing Method To Track Cell Populations And Cytodifferentiation During Development Of The Submandibular Salivary Gland, Charles Thomas Manhardt

Legacy Theses & Dissertations (2009 - 2024)

The development of submandibular salivary glands is complex and requires coordination of specific signaling events. Submandibular salivary glands originate as an epithelial invagination into the adjacent mesenchyme that leads to a single stalk and end bud; this end bud will go through a clefting process. Numerous rounds of clefting will lead to a fully developed salivary gland by this process, which is known as branching morphogenesis. As the gland undergoes morphogenesis, specific cues leading to differentiation of multiple cell types and even epithelial sub classes are required. By the later stages of development the glands are fully innervated, have an …

Developmental Evolution Of The Visual System In The Cave-Adapted Small Carrion Beetle Ptomaphagus Hirtus, Jasmina Kulacic

Wayne State University Theses

Extensive research has been done to date on Drosophila and Tribolium eye development; however, not much is known about the molecular basis of development of extremely reduced and modified eyes in cave insects. Ptomaphagus hirtus represents an emerging model system for studying the changes at the molecular level that occurred during the evolutionary adaptation of the eye to the cave environment. Therefore, I have started exploring the morphology and organization of the reduced P. hirtus eyelet, using immunohistochemistry, laser scanning microscopy, and ultrastructural imaging approaches. My findings demonstrate that the adult eyelet lacks ommatidial subdivision and has a thick, clear …

What Are The Possible Causes For Autism Spectrum Disorder?, Rochel Preiserowicz

The Science Journal of the Lander College of Arts and Sciences

Ever since the mid 1980’s when Autism Spectrum Disorder (ASD) started to become increasingly prevalent, researchers have been trying to find a possible cause for it. Autism Spectrum Disorder is a developmental disorder that manifests itself in children who are between 18-30 months old. People with autism have reduced social skills, and they have a difficult time communicating verbally and non-verbally. Autism is diagnosed through a questionnaire and other instruments that allow psychologists, psychiatrists, speech therapists, neurologists and many other doctors to determine if a child has a form of ASD. There are many theories about what causes autism. It …

Development Of Neuroendocrine Components Of The Thyroid Axis In The Direct-Developing Frog Eleutherodactylus Coqui: Formation Of The Median Eminence And Onset Of Pituitary Tsh Production., David H. Jennings, Bryce Evans, James Hanken

SIUE Faculty Research, Scholarship, and Creative Activity

Direct-developing frogs lack, wholly or in part, a wide range of larval features found in metamorphosing species and form adult-specific features precociously, during embryogenesis. Most information on thyroid regulation of direct development relies on hormone manipulations; the ontogeny of many thyroid axis components has not been fully described. This analysis examines differentiation of the median eminence of the hypothalamus and production of thyroid-stimulating hormone (TSH) by the pituitary of the direct-developing frog Eleutherodactylus coqui. The median eminence is established two-thirds of the way through embryogenesis. Cells immunoreactive to human TSHb antibodies are first detected during embryogenesis and quantitative changes in …

The Influence Of Extracellular-Regulated Kinases (Erks) On Granulosa Cell Fate In The Bovine Follicle, Nicolette M. Schwab

Honors Theses and Capstones

Each year, infertility in cows costs the dairy industry over $400 million. This project is focused on the onset of follicular atresia in cows; the process by which the egg-bearing follicles die prematurely and can lead to infertility. The cellular mechanisms that influence programmed cell death, or apoptosis, of bovine granulosa cells (bGCs) within follicles are being investigated. In general, the extra-cellular regulated kinases (ERKs) are intracellular signaling proteins believed to influence the proliferation, survival, and differentiation of cells. In the context of follicular atresia, however, the relationship between the onset of apoptosis of bGCs and the effects of ERKs …

Developing A Gene Editing System To Study Haplodiploidy In The Jewel Wasp, Nasonia Vitripennis, Emily A. Muller

Scripps Senior Theses

Hymenopteran insects, which include all ants, bees and wasps, reproduce through a poorly understood form of reproduction known as haplodiploidy. A promising experimental system for understanding this developmental process is the jewel wasp, Nasonia vitripennis. A critical aspect of using Nasonia as a model is establishing an effective means for editing specific genes of interest so that their functions can be studied through genetic means. For my thesis research, I performed a pilot study of the gene editing method known as CRISPR in Nasonia. I targeted the single heterochromatin protein 1 (HP1) gene present in the Nasonia genome …

Unraveling The Genetic Mechanisms Involved In The Evolution And Development Of The Thoracic Appendages In Insects, Victor Medved

Wayne State University Dissertations

Insects display the greatest amount of structural and functional variation among animal groups, particularly in regard to their appendage morphology. These differences can range from the diverse pigmentation patterns between fore- and hindwings to changes in the size and shape of legs. The greatly enlarged jumping hind leg in crickets and grasshoppers is one of the best known illustrations of such diversity, representing a unique feature for the entire order of these insects (Orthoptera). Previous work from our lab has shown that the homeotic gene Ultrabithorax (Ubx) plays a key role in the enlargement of hind legs not only in …

Systematics Of The African River Frog Genus Amietia (Anura: Pyxicephalidae) From Eastern Democratic Republic Of The Congo, Thornton Robert Larson

Open Access Theses & Dissertations

The African river frog genus Amietia is found near rivers and other lentic water sources throughout central, eastern and southern Africa. Because the genus includes multiple morphologically conservative species, taxonomic studies of river frogs have been limited. We sampled 49 individuals of Amietia from multiple localities in and near the Albertine Rift (AR) of Burundi, Democratic Republic of the Congo and Uganda. We utilized single-gene (16S) and concatenated (12S, 16S, cytochrome b and RAG1) gene-tree analyses and coalescent species-tree analyses to construct phylogenetic trees. Two divergence dating approaches were used in BEAST, including secondary calibration points with 12S, 16S and …

Phylogeny And Systematics Of Panaspis And Afroablepharus Skinks (Squamata: Scincidae) In The Savannas Of Sub-Saharan Africa, Maria Fernanda Medina

Open Access Theses & Dissertations

African snake-eyed skinks are relatively small lizards of the genera Panaspis and Afroablepharus. The allocation of these genera was frequently rearranged in the 20th century based on morphology, ecology and biogeography. Members of these genera occur primarily in savanna habitats throughout sub-Saharan Africa and include species that have highly conserved morphology, which poses a challenge for taxonomic studies. We sequenced two mitochondrial (16S and cyt b) and two nuclear genes (PDC and RAG1) from 91 Panaspis and Afroablepharus samples from various localities in eastern, central and southern Africa. Concatenated gene-tree and divergence dating analyses were conducted to infer phylogenies and …

Beryllium Nitrate Supports Fibroblast Migration As An Essential Component Of Skin And Limb Regeneration In Axolotls, Adam Boyd Cook

Theses and Dissertations--Biology

Tissue regeneration in salamanders is a robust process that is not easily interrupted or altered. Therefore, inhibiting regeneration provides a means to interrogate the underlying cellular and molecular mechanisms regulating this complex event. Here we show that application of a relatively low concentration of beryllium nitrate solution (100mM) causes a delay in skin regeneration and severely alters normal limb regeneration. We provide evidence showing a beryllium-induced reduction in dermal fibroblast migration in vivo and in vitro. We link this phenomenon to delayed regeneration of the skin and abnormal blastema formation resulting in limb patterning defects during regeneration. Though our …

Role Of Sox11 During Vertebrate Ocular Morphogenesis And Retinal Neurogenesis, Lakshmi Shashidharan Pillai

Theses and Dissertations--Biology

Microphthalmia, anophthalmia, and coloboma (MAC) are distinct abnormalities demonstrating a continuum of developmental eye defects that contribute to 15-20% of blindness and severe vision deficiencies in children worldwide. The genetic etiology of MAC is large, complex and encompasses the whole developmental biology of the eye. Understanding how the eye develops will aid in identifying genes and developmental pathways involved in MAC. Although investigation of the genetic architecture of congenital anomalies is growing exponentially, much work remains to be accomplished to understand the complex, genetically heterogeneous congenital anomalies, which significantly impact childhood vision.

With an interest in elucidating the mechanisms that …

Dual Functions For Insulinoma-Associated 1 In Retinal Development, Marie A. Forbes-Osborne

Theses and Dissertations--Biology

Proper visual system function requires tightly controlled proliferation of a pool of relatively homogeneous retinal progenitor cells, followed by the stepwise specification and differentiation of multiple distinct cell types. These retinal cells, both neuronal and glial, must be generated in the correct numbers, and the correct laminar location to permit the formation of synaptic connections between individual cell types. After synapses are made, constant signaling is required as part of normal retinal function, and to maintain cellular identity and connectivity. These processes rely on both extrinsic and intrinsic signaling, with regulation of gene expression by cascades of transcription factors having …

Myosinx Is Required For Craniofacial Development In Danio Rerio, Cole Yancey

College of Graduate Studies: Theses & Dissertations

Craniofacial development is the process of laying early cartilage and bone patterns in the anterior region of the embryo, which ultimately results in shaping the structure of the face and head of an organism. Craniofacial abnormalities in humans, such as cleft lip and palate, are among the most common of all birth defects. Therefore, investigating the molecular mechanisms involved in craniofacial development will help us understand both evolutionary processes and genetic diseases. Craniofacial cartilage and bone structures are almost entirely derived from neural crest cells. Neural crest are a pluripotent migratory stream of cells that originate from the early developing …

Presence And Localization Of Pro-And Mature Forms Of Biglycan And Decorin In Human Costal Cartilage Derived From Chest Wall Deformities, Anthony Asmar, A. Werner, R. E. Kelly Jr., A. Fecteau, Michael W. Stacey

Bioelectrics Publications

Costal cartilage is a type of hyaline cartilage that forms rod-like structures that connect the ribs to the sternum. The most common chest wall deformities, pectus excavatum and pectus carinatum involved efective costal cartilage resulting in sternal displacement. Costal cartilage is not widely studied leaving little insight into possible factors involved in the pathogenesis of these pectus deformities. This study focused on the presence and distribution of two important regulators of collagen fibrillogenesis and organization, biglycan and decorin. Immunohistochemical analysis of transverse cross sections of normal and deformed costal cartilage revealed that biglycan and decorin mainly localized in the territorial …

Myosin 10 Is Required For Spinal Motor Axon Growth And Guidance In Zebrafish Embryos, Crystal Ivey

College of Graduate Studies: Theses & Dissertations

Neurodevelopmental disorders are disabilities caused by malfunctioning mechanisms within the developing nervous tissue. These abnormalities often result in conditions such as autism spectrum disorders, Attention Deficient Hyperactivity Disorder (ADHD), motor dysfunctions, learning disabilities and mental retardation. Recent surveys indicate that there will be a 12% increase of children in the United States alone who are affected by neurodevelopmental disorders. Thus, it is important to understand both the normal and abnormal mechanisms of neural development. Neural development involves specification of new neurons and formation of neural circuits that connect the nervous system to every organ of the developing embryo. Neural circuits …

Cell Cycle Regulation Of Retinal Progenitors; A Role For The Nance-Horan Syndrome Protein In Retinogenesis, Paul J. Vorster

Theses and Dissertations

The Nance-Horan syndrome gene (NHS) plays a role in lens, eye and brain development. To date, the function of NHS remains unclear. Recent evidence showed that p53 isoform, Δ113p53, inhibits abnormal cell growth during organogenesis. We show that NHS is expressed in the retinas of Danio rerio and Xenopus tropicalis during key stages of retinogenesis, and that knockdown of the gene resulted in a small eye phenotype in both species. Initially, knockdown of nhsb in zebrafish had no visible defects at 24hpf. But examination of the retina at 48hpf, we see a marked difference in size compared to control embryos. …