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Full-Text Articles in Life Sciences

The Role Of Hif1alpha And Hif2alpha In Muscle Development And Satellite Cell Function, Shiqi Yang Dec 2016

The Role Of Hif1alpha And Hif2alpha In Muscle Development And Satellite Cell Function, Shiqi Yang

Open Access Theses

Hypoxia inducible factors (HIFs) are central mediators of cellular responses to fluctuations of oxygen, an environmental regulator of stem cell activity. Muscle satellite cells are myogenic stem cells whose quiescence, activation, self-renewal and differentiation are influenced by microenvironment oxygen levels. However, the in vivo roles of HIFs in quiescent satellite cells and activated satellite cells (myoblasts) are poorly understood. Expression analyses indicate that HIF1α and HIF2α are preferentially expressed in pre- and post-differentiation myoblasts, respectively. Interestingly, double knockout of HIF1α and HIF2α (HIF1α/2α dKO) in embryonic myoblasts results in apparently normal muscle development and growth. However, HIF1α/2α dKO in postnatal …


Beryllium Nitrate Inhibits Fibroblast Migration To Disrupt Epimorphic Regeneration, Adam B. Cook, Ashley W. Seifert Oct 2016

Beryllium Nitrate Inhibits Fibroblast Migration To Disrupt Epimorphic Regeneration, Adam B. Cook, Ashley W. Seifert

Biology Faculty Publications

Epimorphic regeneration proceeds with or without formation of a blastema, as observed for the limb and skin, respectively. Inhibition of epimorphic regeneration provides a means to interrogate the cellular and molecular mechanisms that regulate it. In this study, we show that exposing amputated limbs to beryllium nitrate disrupts blastema formation and causes severe patterning defects in limb regeneration. In contrast, exposing full-thickness skin wounds to beryllium only causes a delay in skin regeneration. By transplanting full-thickness skin from ubiquitous GFP-expressing axolotls to wild-type hosts, we demonstrate that beryllium inhibits fibroblast migration during limb and skin regeneration in vivo. Moreover, …


Diversity Of Small Rna Expression During Zebrafish Caudal Fin Regeneration, Jefferson Adams May 2016

Diversity Of Small Rna Expression During Zebrafish Caudal Fin Regeneration, Jefferson Adams

Honors College

Over the years microRNA have been shown to play a role in the regulation of genes involved in regeneration of zebrafish (Danio rerio) tissues. However, recent research suggest that there may be other types of small RNA that play a regulatory role in these regenerative processes. For the most part these other small RNA (sRNA), such as transfer RNA (tRNA) derived fragments, ribosomal RNA (rRNA) derived fragments, and small nucleolar RNA, are disregarded. Here I analyzed the expression pattern of these sRNA during the regeneration of the zebrafish caudal fin. High-throughput sequencing was used to characterize the expression of small …


Comparative Analysis Of Ear-Hole Closure Identifies Epimorphic Regeneration As A Discrete Trait In Mammals, Thomas R. Gawriluk, Jennifer Simkin, Katherine L. Thompson, Shishir K. Biswas, Zak Clare-Salzler, John M. Kimani, Stephen G. Kiama, Jeramiah James Smith, Vanessa O. Ezenwa, Ashley W. Seifert Apr 2016

Comparative Analysis Of Ear-Hole Closure Identifies Epimorphic Regeneration As A Discrete Trait In Mammals, Thomas R. Gawriluk, Jennifer Simkin, Katherine L. Thompson, Shishir K. Biswas, Zak Clare-Salzler, John M. Kimani, Stephen G. Kiama, Jeramiah James Smith, Vanessa O. Ezenwa, Ashley W. Seifert

Biology Faculty Publications

Why mammals have poor regenerative ability has remained a long-standing question in biology. In regenerating vertebrates, injury can induce a process known as epimorphic regeneration to replace damaged structures. Using a 4-mm ear punch assay across multiple mammalian species, here we show that several Acomys spp. (spiny mice) and Oryctolagus cuniculus completely regenerate tissue, whereas other rodents including MRL/MpJ ‘healer’ mice heal similar injuries by scarring. We demonstrate ear-hole closure is independent of ear size, and closure rate can be modelled with a cubic function. Cellular and genetic analyses reveal that injury induces blastema formation in Acomys cahirinus. …


Analogous Cellular Contribution And Healing Mechanisms Following Digit Amputation And Phalangeal Fracture In Mice, Lindsay A. Dawson, Jennifer Simkin, Michelle Sauque, Maegan Pela, Teresa Palkowski, Ken Muneoka Feb 2016

Analogous Cellular Contribution And Healing Mechanisms Following Digit Amputation And Phalangeal Fracture In Mice, Lindsay A. Dawson, Jennifer Simkin, Michelle Sauque, Maegan Pela, Teresa Palkowski, Ken Muneoka

Biology Faculty Publications

Regeneration of amputated structures is severely limited in humans and mice, with complete regeneration restricted to the distal portion of the terminal phalanx (P3). Here, we investigate the dynamic tissue repair response of the second phalangeal element (P2) post amputation in the adult mouse, and show that the repair response of the amputated bone is similar to the proximal P2 bone fragment in fracture healing. The regeneration-incompetent P2 amputation response is characterized by periosteal endochondral ossification resulting in the deposition of new trabecular bone, corresponding to a significant increase in bone volume; however, this response is not associated with bone …


Inducing Osmotic Stress Leads To Better Genetic Transformation Efficiency In Cotton (Gossypium Hirsutum L.), Surendra Barpete, Allah Bakhsh, Emi̇ne Anayol, Sancar Fati̇h Özcan, Muhammet Cağri Oğuz, Ömer Cem Karakoç, Sebahatti̇n Özcan Jan 2016

Inducing Osmotic Stress Leads To Better Genetic Transformation Efficiency In Cotton (Gossypium Hirsutum L.), Surendra Barpete, Allah Bakhsh, Emi̇ne Anayol, Sancar Fati̇h Özcan, Muhammet Cağri Oğuz, Ömer Cem Karakoç, Sebahatti̇n Özcan

Turkish Journal of Biology

The present study investigated the effect of different salts on cotton shoot regeneration and transformation efficiency. Two-day-old germinating embryos of a local cotton cultivar (SG-125) were pretreated with 50 mM each of NaCl, CaCl2, and KCl for 60 min. The embryo explants were transformed by cocultivation with Agrobacterium tumefaciens strain LBA 4404 harboring a binary plasmid pTF101.1 that carried the insecticidal gene (cry1Ac) under control of wound-inducible promoter (AoPR1) and bilanafos acetyl reductase (bar) gene for plant selection. The salt-pretreated embryos showed maximum response on regeneration MS medium containing 0.50 mg/L 6-benzylaminopurine (BAP) and 0.10 mg/L indole-3-butyric acid (IBA), also …


Cellular And Molecular Basis Of Cardiac Regeneration, Justin Judd, Wanling Xuan, Guo N. Huang Jan 2016

Cellular And Molecular Basis Of Cardiac Regeneration, Justin Judd, Wanling Xuan, Guo N. Huang

Turkish Journal of Biology

Heart disease is one of the largest causes of death in humans throughout the developed world. Despite its critical role in maintaining physiologic homeostasis, the adult mammalian heart does not exhibit a significant capacity for regeneration. By contrast, several lower vertebrates exhibit a remarkable ability to regenerate the aging myocardium in response to severe injury. Additionally, recent evidence has shed light on a transient regenerative window in postnatal mammals. In this review, we discuss key findings that help to unravel the differences in cardiac regeneration across phylogeny and ontogeny. Furthermore, we highlight recent significant progress in the pursuit of adult …


A Matter Of Regeneration And Repair: Caspases As The Key Molecules, Şehnaz Bolkent, Füsün Öztay, Selda Oktayoğlu, Serap Sancar Baş, Ayşe Karatuğ Jan 2016

A Matter Of Regeneration And Repair: Caspases As The Key Molecules, Şehnaz Bolkent, Füsün Öztay, Selda Oktayoğlu, Serap Sancar Baş, Ayşe Karatuğ

Turkish Journal of Biology

Researchers have been focused on understanding the pathogenesis of human diseases. They have been working to find the roles of caspases in the balance between apoptosis, autophagy, pyroptosis, and necroptosis, and also in the regeneration of damaged tissue. At this point, besides their death-inducing roles, new findings indicate the role of caspases in proliferation for maintaining the viability of cells in response to signals from apoptotic cells. Recently, determining cell fate has also been identified among other functions of caspases. Findings indicate that caspases direct cellular pathways to cell differentiation by suppressing stem cell self-renewal. The common opinion about the …


Triterpenoid Saponin-Rich Fraction Of Centella Asiatica Decreases Il-1ss Andnf-?B, And Augments Tissue Regeneration And Excision Wound Repair, Amena Mahmood, Ambrish Tiwari, Kazi̇m Şahi̇n, Ömer Küçük, Shakir Ali Jan 2016

Triterpenoid Saponin-Rich Fraction Of Centella Asiatica Decreases Il-1ss Andnf-?B, And Augments Tissue Regeneration And Excision Wound Repair, Amena Mahmood, Ambrish Tiwari, Kazi̇m Şahi̇n, Ömer Küçük, Shakir Ali

Turkish Journal of Biology

Wound healing is an orderly process driven by numerous cellular mediators that aim to accelerate it. In skin conditions such as leprosy and psoriasis, Centella asiatica, which contains high amounts of triterpenoid saponins (TSs), has been reported to have beneficial effects. This study examined the effects of TS fraction of the herb on tissue regeneration and excision wound repair in rat skin. Briefly, TS fraction was prepared from C. Asiatica and applied on the wound area for 7 consecutive days. The IL-1β, NF-κB, and other biochemical parameters were then estimated, followed by examination of inflammatory cell infiltration, epithelialization, angiogenesis, and …


Investigation Of Exoribonuclease-1 Function In Regulation Of Stem Cells During Planarian Regeneration, Steven Gobinsing Sayson Jan 2016

Investigation Of Exoribonuclease-1 Function In Regulation Of Stem Cells During Planarian Regeneration, Steven Gobinsing Sayson

Browse all Theses and Dissertations

Precise regulation of gene expression is crucial for the maintenance of pluripotency and proper differentiation of stem cells. Due to their exceptional capacity for stem cell-driven regeneration, planarians are ideal models to dissect mechanisms regulating gene expression that secure stem cell function in vivo. While mechanisms of transcriptional regulation of gene expression in stem cells have been extensively investigated, less is known about regulation at the post-transcriptional level. Exoribonuclease-1 (XRN-1) is a conserved enzyme in eukaryotes that catalyzes 5' to 3' exonucleolytic degradation of RNA. XRN-1 is known to be required for proper regeneration of Dugesia japonica. Here, I …