Cell and Developmental Biology Commons^™

Save The Frogs, Mackenzie Johnson, Alison Bohlen, Andie Ellis, Ryan Pinto

Student Work

The species Xenopus laevis is native to sub saharan Africa, but ever since its discovery in effectiveness in pregnancy tests, the frog now lives invasively around the world. Today the Xenopus Laevis is used mostly in laboratories as a model organism for studying developmental biology (Willigan 2001). The commercialized herbicide Atrazine, has been found to interact with this model organism species in an odd way you might not have guessed (Sanders 2010). Atrazine is primarily absorbed in the gastrointestinal tract and has been shown to have neuroendocrine, reproductive, and developmental effects on experimental animals such as Xenopus laevis (ATSDR 2004). …

Just Cut It Out, Jack Barbosa, Ashley Curcio, Emiliana Martinez-Nobrega, Matthew Robledo

Student Work

Why should we care about trees? Social, Economic, and Environmental benefits.

What Uv Is What You Get, Jaylin Chlosta, Cassidy Mills, Mason Peckar, Nicholas Schaertl

Student Work

Vitamin D deficiency affects people differently and causes multiple health problems. Supplements may help when UV exposure is insufficient to generate Vitamin D in the body.

(Non)Parallel Developmental Mechanisms In Vertebrate Appendage Reduction And Loss, Samantha Swank, Thomas Sanger, Yoel E. Stuart

Biology: Faculty Publications and Other Works

Appendages have been reduced or lost hundreds of times during vertebrate evolution. This phenotypic convergence may be underlain by shared or different molecular mechanisms in distantly related vertebrate clades. To investigate, we reviewed the developmental and evolutionary literature of appendage reduction and loss in more than a dozen vertebrate genera from fish to mammals. We found that appendage reduction and loss was nearly always driven by modified gene expression as opposed to changes in coding sequences. Moreover, expression of the same genes was repeatedly modified across vertebrate taxa. However, the specific mechanisms by which expression was modified were rarely shared. …

Larval Chondrocranial And Internal Oral Morphology Of The Neotropical Treefrog Boana Crepitans (Wied-Neuwied, 1824; Amphibia, Anura, Hylidae), Marianna Isabella Rosa Rodrigues De Oliveira, Luiz Norberto Weber, Johnny Sousa Ferreira, Anna Evelin Coimbra Liborio, André Masahide Guimaraes Takazone, Rafael O. De Sá

Biology Faculty Publications

We describe the internal oral morphology and chondrocranial anatomy for Boana crepitans tadpoles, and compare them with available descriptions for other species in the subfamily Cophomantinae. Among species of the Boana faber group, the chondrocranial anatomy has been reported only for one species internal oral morphology and cranial anatomy are similar to other described species of Boana and Cophomantinae. B. crepitans lacks unique features in the oral cavity and chondrocranium that would distinguish it from other congeneric species. We identify six characters from the internal oral anatomy of tadpoles unique for Cophomantinae. In addition, Boana has infralabial papillae projections, buccal …

The Phoenix, Fernanda Perez-Alvarez

Montserrat Annual Writing Prize

This article uses a mythical creature, the phoenix, to examine and illustrate the biological principles for generation of an adult body plan from a single cell. Using the study of developmental biology, it explores the cellular and molecular biology that underpins the massive complexity of creating an adult body plan. It also explores the similarities and differences between different embryos, and how nature and evolution have shaped the biology of those embryos to create different body plans.

Larval Anatomy Of Monotypic Painted Ant Nest Frogs Lithodytes Lineatus Reveals Putative Homoplasies With The Leptodactylus Pentadactylus Group (Anura: Leptodactylidae), Filipe A.C Do Nascimento, Rafael O. De Sá, Paulo C. De A. Garcia

Biology Faculty Publications

The morphological diversity of anuran larvae made them an important source of information for evolutionary and systematic studies. For the monotypic frog genus Lithodytes, which has an interesting taxonomic history, including its past synonymizing with Adenomera and its placement as a subgenus of Leptodactylus, the information provided from its larvae can help to understand its systematics interrelationships and also provide insights about its evolutionary trajectories. Herein, we provide a detailed description of the larval morphology of Lithodytes lineatus, including novel data of internal morphology (buccopharyngeal cavity and skeleton), and discuss some morphological and evolutionary aspects in relation …

Evolutionary Bioethics Advanced By Ernest Everett Just: Implications For Biology, Ethics, And Theology, Theodore Walker

Perkins Faculty Research and Special Events

Ernest Everett Just (1883-1941) is an acknowledged “pioneer” in biology, being honored with a Black Heritage postage stamp in 1996. Here we discover that Just also made pioneering contributions to general evolutionary bioethics (distinct from special medical bioethics) by advancing a cell-biology-rooted theory of the origin and continuing evolution of ethical behavior influenced by the “law of environmental dependence.”

See especially “The Origin of Man’s Ethical Behavior (1941, unpublished book manuscript) by Ernest Everett Just and Hedwig Schnetzler Just, discovered in 2018 among the collected papers of E.E. Just at the Moorland-Spingarn Research Center at Howard University.

Accordingly, evolution is …

Hers And His: Silk Glands Used In Egg Sac Construction By Female Spiders Potentially Repurposed By A 'Modern' Male Spider, Mark A. Townley, Danilo Harms

Biological Sciences

Cylindrical silk gland (CY) spigots distinguish a large clade of modern spiders, the CY spigot clade, which includes all entelegyne spiders and their closest relatives. Following a widespread paradigm, CYs and their spigots are only known to occur in female spiders and they produce silk used in the construction of egg sacs. Here we report the occurrence of a CY spigot or CY nubbin on each posterior median spinneret (PMS) in males (5th stadium and later) of the spider Australomimetus maculosus. Late juvenile males had a CY spigot on each PMS, whereas adult males either had a CY spigot or, …

Martin Luther King Jr. And Ernest Everett Just - On Evolution Of Ethical Behavior, Theodore Walker

Perkins Faculty Research and Special Events

Rev. Martin Luther King Jr. prescribed an evolutionary advance in ethical behavior: the total “abolition of poverty” and the abolition of war throughout “the world house.” Cell biologist Ernest Everett Just advanced the idea that human ethical behavior evolved from cellular origins.

Also, astrobiologists Chandra Wickramasinghe and Sir Fred Hoyle advanced the idea of cosmic biology, including stellar evolution and cosmic evolution. From cells to humans to stars and cosmology, evolutionary natural science converges with natural theology.

Fgf-Signaling Is Compartmentalized Within The Mesenchyme And Controls Proliferation During Salamander Limb Development, Sruthi Purushothaman, Ahmed Elewa, Ashley W. Seifert

Biology Faculty Publications

Although decades of studies have produced a generalized model for tetrapod limb development, urodeles deviate from anurans and amniotes in at least two key respects: their limbs exhibit preaxial skeletal differentiation and do not develop an apical ectodermal ridge (AER). Here, we investigated how Sonic hedgehog (Shh) and Fibroblast growth factor (Fgf) signaling regulate limb development in the axolotl. We found that Shh-expressing cells contributed to the most posterior digit, and that inhibiting Shh-signaling inhibited Fgf8 expression, anteroposterior patterning, and distal cell proliferation. In addition to lack of a morphological AER, we found that salamander …

The ‘Law Of Environmental Dependence’ - Biology And Ethics In The Work Of Ernest Everett Just: + Found – Some 251 Mostly Typed Pages, Theodore Walker

Perkins Faculty Research and Special Events

Abstract-

“The Origin of Man’s Ethical Behavior” (circa October 1941) by Ernest Everett Just and Hedwig A. Schnetzler Just - is an unpublished book manuscript about the biological origins and evolution of ethical behavior, and about “the law of environmental dependence.” Missing since Just’s death in October 1941, it was found and identified in May 2018 among the collected papers of Ernest Everett Just preserved at the Howard University Moorland-Spingarn Research Center in Washington, DC. In addition to the 1996 US postage with the caption “Ernest E. Just, Biologist,” we now have reason to add two new postage stamps with …

Evolutionary Expansions And Neofunctionalization Of Ionotropic Glutamate Receptors In Cnidaria, Ellen G. Dow

FIU Electronic Theses and Dissertations

Reef ecosystems are composed of a variety of organisms, transient species of fish and invertebrates, microscopic bacteria and viruses, and structural organisms that build the living foundation, coral. Sessile cnidarians, corals and anemones, interpret dynamic environments of organisms and abiotic factors through a molecular interface. Recognition of foreign molecules occurs through innate immunity via receptors identifying conserved molecular patterns. Similarly, chemosensory receptors monitor the environment through specific ligands. Chemosensory receptors include ionotropic glutamate receptors (iGluRs), transmembrane ion channels involved in chemical sensing and neural signal transduction. Recently, an iGluR homolog was implicated in cnidarian immunological resistance to recurrent infections of …

The Effects Of Temperature On Maternal Investment Of Ovary Tissue In The Fish Species Danio Rerio, Noah R. Dillon, Alyce Demarais

Summer Research

The impact of climate change is predicted to increase water temperatures by 2 °C on average globally within the next century. As ectotherms, fish metabolism is directly connected to ambient water temperature. With a shift in metabolism due to temperature change, physiological processes like maternal investment may be affected. This study is an ecological and developmental investigation of the impacts of shifting environmental temperature conditions on the reproductive traits of the fish species Danio rerio. This study investigated Danio rerio under different temperatures to measure maternal investment. Female Danio rerio were exposed to temperature treatments 20-30 °C. Ovary tissue …

Review Of The Family Rivulidae (Cyprinodontiformes, Aplocheiloidei) And A Molecular And Morphological Phylogeny Of The Annual Fish Genus Austrolebias Costa 1998, Marcelo Loureiro, Rafael O. De Sá, Sebastián W. Serra, Felipe Alonso, Luis Esteban Krause Lanés, Matheus Vieira Volcan, Pablo Calviño, Dalton Nielsen, Alejandro Duarte, Graciela Garcia

Biology Faculty Publications

The family Rivulidae is the fourth most diverse clade of Neotropical fishes. Together with some genera of the related African family Nothobranchiidae, many rivulids exhibit a characteristic annual life cycle, with diapausing eggs and delayed embryonic development, which allows them to survive in the challenging seasonal ponds that they inhabit. Rivulidae also includes two species known as the only the self-fertilizing vertebrates and some species with internal fertilization. The first goal of this article is to review the systematics of the family considering phylogenetic relationships and synapomorphies of subfamilial clades, thus unifying information that is dispersed throughout the literature. From …

First Record Of The Genus Leptodactylus (Anura: Leptodactylidae) In Cuba: Leptodactylus Fragilis, A Biological Invasion?, Tomás M. Rodríguez-Cabrera, L. Yusnaviel García-Padrón, Andrés R. Acosta Galvis, Rafael O. De Sá, Roberto Alonso Bosch

Biology Faculty Publications

The Neotropical genus Leptodactylus is currently represented by three species in the West Indies (Leptodactylus albilabris, Leptodactylus fallax and Leptodactylus validus). Based on morphological, acoustic and molecular evidence, we document the presence of a fourth species in the Caribbean region, Leptodactylus fragilis (Brocchi, 1877). The species was found at two localities in western Cuba, and molecular data suggest a northern South American origin, possibly Venezuela, for these populations. We discuss the potential invasive status of L. fragilis, based on its known distribution, relative abundance, behaviour and possible impacts on native species of Cuban amphibians.

Functional Studies Of The E. Coli Proc And A Putative Ortholog Mrub_1345, Maureen Azar, Dr. Lori Scott

Meiothermus ruber Genome Analysis Project

This project is part of the Meiothermus ruber genome analysis project, which uses the bioinformatics tools associated with the Guiding Education through Novel Investigation –Annotation Collaboration Toolkit (GENI-ACT) to predict gene function. We investigated the biological function of Escherichia coli and Meiothermus ruber proC genes using the complementation assay. In this research project, mutants of varying severity to the functional state of the protein were developed. The results showed that two or more amino acid deletions reduced or eliminated ProC function. Amino acid substitutions, on the other hand, were not severe enough to impact ProC function. Double and triple mutants …

Examination Of Orthologous Genes (Mrub_2518 And B3728, Mrub_2519 And B3727, Mrub_2520 And B3726, Mrub_2521 And B3725) Responsible For Abc Phosphate Transporters In Two Species M. Ruber And E. Coli, Margaret Meyer, Dr. Lori Scott

Meiothermus ruber Genome Analysis Project

In this project we investigated the biological function of the genes b3725, b3726, b3727, b3728 and Mrub_2518, Mrub_2519, Mrub_2520 and Mrub_2521 (KEGG map number 02010). We predict that these genes encode the components of a Phosphate ABC transporter: Orthologous genes Mrub_2518 (DNA coordinates 2565359..2566438) and b3728 encodes the periplasmic phosphate binding component; Orthologous genes Mrub_2519 (DNA coordinates 2566499..2567485) and b3727, and Mrub_2520 (DNA coordinates 2567496..2568326) and b3726 encode for the two transmembrane proteins; Orthologous genes Mrub_2521 (DNA coordinates 2568338..2569159) and b3725 encode for the ATP binding protein within the cytoplasm. Within the two species, M. ruber and E. coli, …

Comparative Study Of Spinning Field Development In Two Species Of Araneophagic Spiders (Araneae, Mimetidae, Australomimetus), Mark A. Townley, Danilo Harms

Molecular, Cellular & Biomedical Sciences

External studies of spider spinning fields allow us to make inferences about internal silk gland biology, including what happens to silk glands when the spider molts. Such studies often focus on adults, but juveniles can provide additional insight on spinning apparatus development and character polarity. Here we document and describe spinning fields at all stadia in two species of pirate spider (Mimetidae: Australomimetus spinosus, A. djuka). Pirate spiders nest within the ecribellate orb-building spiders (Araneoidea), but are vagrant, araneophagic members that do not build prey-capture webs. Correspondingly, they lack aggregate and flagelliform silk glands (AG, FL), specialized for forming prey-capture …

Butyl Benzyl Phthalate (Bbp) Induces Caudal Defects During Embryonic Development, Nicole M. Roy, Ewelina Zambrzycka, Jenna Santangelo

Biology Faculty Publications

Butyl benzyl phthalate (BBP) is commonly added during the manufacturing of plastics to increase flexibility and elasticity. However, BBP leaches off of plastic and environment presence has been detected in soil, groundwater and sediment potentially effecting organisms in the environment. Given the widespread uses of BBP in household, consumer goods and the presence of BBP in the environment, studies on developmental toxicity are needed. Here, we use a zebrafish model to investigate the early developmental toxicity of BBP. We treated gastrula staged embryos with increasing concentrations of BBP and noted concentration-dependent defects in caudal tail development, but the effect was …

There’S More Than One Way To Climb A Tree: Limb Length And Microhabitat Use In Lizards With Toe Pads, Travis J. Hagey, Scott Hart, Matthew Vickers, Luke J. Harmon, Lin Schwarzkopf

Biology

Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar …

Current Status Of American Bullfrog, Lithobates Catesbeianus, Invasion In Uruguay And Exploration Of Chytrid Infection, Gabriel Laufer, Noelia Gobel, Claudio Borteiro, Alvaro Soutullo, Claudio Martinez-Debat, Rafael O. De Sá

Biology Faculty Publications

The American bullfrog Lithobates catesbeianus is an invasive species that can strongly affect native amphibian communities through competition, predation, or introduction of diseases. This frog has invaded multiple areas in South America, for which niche models predict suitable environments across much of the continent. This paper reveals the state of the invasion of this species in Uruguay and its possible relationship with the chytrid pathogenic fungus, Batrachochytrium dendrobatidis. Surveys at invaded sites were conducted from 2007 to 2015, identified two populations undergoing recent range expansion (one of them exponential), two populations that failed to establish, and a new record …

Chondrocranium And Internal Oral Morphology Of The Tadpole Of Corythomantis Greeningi (Anura: Hylidae), Marianna Isabella Rosa Rodrigues De Oliveira, Luiz Norberto Weber, Rafael O. De Sá, Johnny Sousa Ferreira, Anna Evelin Coimbra Libório, André Masahide Guimarães Takazone

Biology Faculty Publications

Corythomantis greeningi is a casque-headed frog that occurs in xeric and sub-humid regions of northeastern Brazil. Individuals are often found on rocks on banks of temporary streams or in ponds upon “lajedos”. Suctorial tadpoles are often found clasping to the rocks in the streams so as not to be dragged by the current; therefore, they have modified external and internal morphology. Here, we describe the internal oral anatomy and the chondrocranium of the tadpole of C. greeningi and compare it to the available descriptions of Lophyohylinae and other suctorial tadpoles. The internal oral morphology in C. greeningi resembles pond-dwelling casque-headed …

Assessment Of The Calling Detection Probability Throughout The Day Of Two Invasive Populations Of Bullfrog (Lithobates Catesbeianus) In Uruguay, Gabriel Laufer, Noelia Gobel, Alvaro Soutullo, Claudio Martinez-Debat, Rafael O. De Sá

Biology Faculty Publications

Bullfrog invasion is a major conservation concern in South America, so there is an urgent need to detect and monitor its many invasion foci. Amphibian sampling methods commonly use calling display, specifically the nuptial calls of males. With the aim of obtaining the better day period to sample and monitor Lithobates catesbeianus presence, we recorded its calls at three ponds in two invaded localities in Uruguay (Aceguá, Cerro Largo, and San Carlos, Maldonado) during the reproductive season. Then, we studied the records, obtaining a subsample of calling intensity at the first 5 minutes for each hour. We detected that vocalization …

Mating Patterns And Post-Mating Isolation In Three Cryptic Species Of The Engystomops Petersi Species Complex, Paula A. Trillo, Andrea E. Narvaez, Santiago R. Ron, Kim L. Hoke

Biology Faculty Publications

Determining the extent of reproductive isolation in cryptic species with dynamic geographic ranges can yield important insights into the processes that generate and maintain genetic divergence in the absence of severe geographic barriers. We studied mating patterns, propensity to hybridize in nature and subsequent fertilization rates, as well as survival and development of hybrid F₁ offspring for three nominal species of the Engystomops petersi species complex in Yasuní National Park, Ecuador. We found at least two species in four out of six locations sampled, and 14.3% of the wild pairs genotyped were mixed-species (heterospecific) crosses. We also found reduced …

Bioethics In The Work Of Ernest Everett Just: + Missing - Some 400 Pages, Theodore Walker

Perkins Faculty Research and Special Events

Biology + ethics = bioethics. Here we see that Howard University biologist Ernest Everett Just (born 1883, died 1941) connected biology to ethics.

According to Just, various forms of specific biology (including especially cell biology) plus “general biology” are necessary for explaining adequately the origin of ethical behaviors. Social ethical behaviors, especially mutual aid and cooperative interactions with others and the environment, are essential to evolutionary advances among living creatures, ranging from humans to cells. Accordingly, theory of ethics (moral theory) should have roots in biology.

Also, Just wrote an unpublished book-length manuscript—“some 400 typed pages” (Just 1940)—on seeking the …

The Effects Of Artemisia Derived Natural Products On Adipogenesis, Steven Abood

FIU Electronic Theses and Dissertations

For the first time in human history, more people worldwide suffer from obesity than are undernourished. Numerous health complications are associated with obesity including cardiovascular disease, Type 2 Diabetes, cancers of reproductive tissues, stroke, depression, anxiety disorders, and Alzheimer’s disease. A deeper understanding of the anti-adipogenic effects and mechanism of action of sesquiterpene lactones may have pharmacological import in the continuing search for therapeutic modalities to ameliorate the effects of this global obesity epidemic.

Dehydroleucodine (DhL), 11,13-dihydro-dehydroleucodine (DH-DhL), and dehydroparashin-B (DhP), sesquiterpene lactones extracted from or derived from compounds extracted from Artemisia douglasiana, were investigated for their anti-adipogenic effects …

Sex Ratio And Gamete Size Across Eastern North America In Dictyostelium Discoideum, A Social Amoeba With Three Sexes, Tracy Edwards Douglas, Joan E. Strassmann, David C. Queller

Biology Faculty Publications & Presentations

Theory indicates that numbers of mating types should tend towards infinity or remain at two. The social amoeba, Dictyostelium discoideum, however, has three mating types. It is therefore a mystery how this species has broken the threshold of two mating types, but has not increased towards a much higher number. Frequency-dependent selection on rare types in combination with isogamy, a form of reproduction involving gametes similar in size, could explain the evolution of multiple mating types in this system. Other factors, such as drift, may be preventing the evolution of more than three. We first looked for evidence of …

Molecular Evolution And Functional Divergence Of Trace Amine–Associated Receptors, Seong-Il Eyun, Hideaki Moriyama, Federico G. Hoffmann, Etsuko N. Moriyama

School of Biological Sciences: Faculty Publications

Trace amine-associated receptors (TAARs) are a member of the G-protein-coupled receptor superfamily and are known to be expressed in olfactory sensory neurons. A limited number of molecular evolutionary studies have been done for TAARs so far. To elucidate how lineage-specific evolution contributed to their functional divergence, we examined 30 metazoan genomes. In total, 493 TAAR gene candidates (including 84 pseudogenes) were identified from 26 vertebrate genomes. TAARs were not identified from non-vertebrate genomes. An ancestral-type TAAR-like gene appeared to have emerged in lamprey.We found four therian-specific TAAR subfamilies (one eutherian-specific and three metatherian- specific) in addition to previously known nine …

High Genetic Diversity But Low Population Structure In The Frog Pseudopaludicola Falcipes (Hensel, 1867) (Amphibia, Anura) From The Pampas Of South America, José A. Langone, Arley Camargo, Rafael O. De Sá

Biology Faculty Publications

Relative to South America’s ecoregions, the temperate grasslands of the Pampas have been poorly studied from a phylogeographic perspective. Based on an intermediate biogeographic setting between subtropical forest (Atlantic Forest) and arid ecosystems (Chaco and Patagonia), Pampean species are expected to show unstable demographic histories due to the Quaternary climatic oscillations. Herein, we investigate the phylogenetic relatedness and phylogeographic history of Pseudopaludicola falcipes, a small and common frog that is widely distributed across the Pampean grasslands. First, we use molecular data to assess if P. falcipes represents a single or multiple, separately evolving cryptic lineages. Because P. falcipes is …