Acceptance of the Clark P. Read Mentor Award: Students, Opportunity, Serendipity, and W.B. Yeats: \u3ci\u3eEducation Is Not the Filling of a Pail; It Is the Lighting of a Fire\u3c/i\u3e

Transcript of the speech given by Donald W. Duszynski, of the University of New Mexico, upon acceptance of the American Society of Parasitologists\u27 Clark P. Read Mentor Award, 2008

The roles of FGF and Wnt signaling during maxillary barbel regeneration in the Zebrafish (Danio rerio).

The zebrafish (Danio rerio) maxillary barbel is an integumentary sense organ that contains skin, glands, pigment cells, taste buds, nerve fibers, blood vessels and a putative lymphatic. Like other zebrafish organs, the maxillary barbel can regenerate most of its tissues after amputation. However, little is known about the molecular mechanisms that control this regeneration. Fibroblast growth factor (FGF) and wingless (Wnt) signaling are required for the control of zebrafish caudal fin regeneration; due to the similarities between the fin and the maxillary barbel, these regulatory networks may play a role in barbel regeneration as well. In this study, I explored the roles of FGF and Wnt signaling during barbel regeneration by detecting the expression of crucial genes in each pathway. These experiments revealed that many FGF and Wnt pathway members are expressed during early barbel regeneration. To test the necessity of these signaling pathways, I used a variety of in vivo molecular techniques to inhibit candidate genes in barbel regenerates. Results indicated that both pathways play important roles in barbel regrowth; however, some differences between barbel and fin regeneration were observed. Activating a dominant negative fibroblast growth factor receptor (dnfgfr1) reduced the length of barbel regenerates by 60% but completely prevented fin regeneration in the same fish. Interestingly, zebrafish homozygous recessive for a point mutation in fgf20a did not show any inhibition of barbel regeneration, although this ligand was essential for fin regeneration. When the canonical Wnt inhibitor drug IWR-1 was applied to wild type fish, barbel regenerate length decreased by nearly 50%, but was not completely prevented as in fin regenerates of the same fish. Finally, experiments transgenically overexpressing the Wnt antagonist notum1a (nom1a) dramatically inhibited regeneration in both barbels and tails, highlighting this molecule as a potential novel regulator of Wnt-dependent regeneration in zebrafish. These are the first results that describe the molecular mechanisms of zebrafish barbel regeneration. Understanding the similarities and differences between regenerating barbels and other organs could help uncover any molecular themes or, in contrast, any variations that control regeneration. Altogether, this project has established the zebrafish maxillary barbel as yet another accessible and productive model for vertebrate regeneration studies

Biodiversity of the Coccidia (Apicomplexa: Conoidasida) in Vertebrates: What We Know, What We Do Not Know, and What Needs to Be Done

Over the last two decades my colleagues and I have assembled the literature on a good percentage of most of the coccidians (Conoidasida) known, to date, to parasitise: Amphibia, four major lineages of Reptilia (Amphisbaenia, Chelonia, Crocodylia, Serpentes), and seven major orders in the Mammalia (Carnivora, Chiroptera, Lagomorpha, Insectivora, Marsupialia, Primates, Scandentia). These vertebrates, combined, comprise about 15,225 species; only about 899 (5.8%) of them have been surveyed for coccidia and 1,946 apicomplexan valid species names or other forms are recorded in the literature. Based on these compilations and other factors, I extrapolated that there yet may be an additional 31,381 new apicomplexans still to be discovered in just these 12 vertebrate groups. Extending the concept to all of the other extant vertebrates on Earth; i.e. lizards (6,300 spp.), rodents plus 12 minor orders of mammals (3,180 spp.), birds (10,000 spp.), and fishes (33,000 spp.) and, conservatively assuming only two unique apicomplexan species per each vertebrate host species, I extrapolate and extend my prediction that we may eventually find 135,000 new apicomplexans that still need discovery and to be described in and from those vertebrates that have not yet been examined for them! Even doubling that number is a significant underestimation in my opinion

Reassignment of Some \u3ci\u3eCaryospora\u3c/i\u3e Species (Apicomplexa: Eimeriidae) to \u3ci\u3eEumonospora\u3c/i\u3e (Apicomplexa: Sarcocystidae) and a Summary

This review was crafted to clear up some of the current confusion regarding the correct taxonomic placement of those apicomplexan coccidians that produce unique monosporocystic octosporozoic (1 sporocyst with 8 sporozoites) oocysts during the sexual phase of their life history in vertebrate hosts. Currently, such oocysts have been placed in 1 of 4 genera, Avispora, Caryospora, Karyospora, or Eumonospora, 2 of which are no longer accepted or useful (Avispora and Karyospora). My review suggests that to present (2023) there are 62 valid Caryospora and 26 valid Eumonospora species. Caryospora species are recorded from a bird (1), lizards (4), snakes (56), and a turtle (1), and Eumonospora species are recorded from birds (25) and a mammal (1). In addition to the morphotypes with (more-or-less) valid binomials in both genera, there are an additional 24 Caryospora-like forms mentioned in the literature that do not yet have sufficient structural or genetic information to have merited a binomial and, therefore, must be designated as species inquirendae; these include 5 in birds, 2 in lizards, 1 in a mammal, and 16 in snakes. Similarly, 4 Eumonospora morphotypes in birds and 1 in a mammal also must be designated species inquirendae. Vertebrate hosts reported to have been infected with 1 or more species of these 2 genera include: birds: 14 families, 23 genera, 40 species; lizards: 3 families, 3 genera, 4 species; mammals: 2 families, 2 genera, 2 species; snakes: 10 families, 54 genera, 83 species; and turtles: 1 family, 1 genus, 1 species. Finally, such infections occur worldwide and have been documented in vertebrates in 43 countries on 6 of 7 continents on Earth (except Antarctica)

Concepts in Animal Parasitology, Chapter 09: The Coccidia Proper: Important Apicomplexa Other than Haemoprotozoa

Chapter 9 in Concepts in Animal Parasitology on the Coccidia Ppoper, important Apicomplexa other than Haemoprotozoa by Donald W. Duszynski. 2024. S. L. Gardner and S. A. Gardner, editors. Zea Books, Lincoln, Nebraska, United States. doi: 10.32873/unl.dc.ciap00

Synthesis and Characterization of Gd-Doped InP/ZnS Quantum Dots for Use in Multimodal Imaging Probes

Quantum dots (QDs), which are intensely fluorescent nanocrystals ranging 2-10 nanometers in diameter, have shown promise in fluorescence imaging. However, in vivo applications of QDs are limited due to the opaque surrounding of tissue and bones. In this study, InP/ZnS QDs were doped with a paramagnetic atom in an attempt to render them MRI-active. We have further bioconjugated these nanoprobes to develop highly specific MRI-active probes that can be used for detection of neurodegenerative diseases. These bioconjugated nanoprobes detect a mutated form of alpha-synuclein that forms oligomers that are a hallmark of Parkinson’s disease andother alpha-synucleinopathies. Here, we have optimized the doping of QDs with MRI-active metals (e.g. Gadolinium) and characterized the MRI activity. The resulting nanocrystals werefurther studied to assess the success of the paramagnetic atom’s incorporation into the crystallattice and its performance as a probe for alpha-synucleinopathies such as Parkinson’s disease

Taxonomy of North American fish Eimeriidae

Taxonomic descriptions, line drawings, and references are given for the 30 named and 5 unnamed species of North American fish Eimeriidae. In addition, a key was developed based on available morphologic data to distinguish between similar species. Taxa are divided into two genera: Eimeria (27 species) which are tetr&sporocystic with dizoic, nonbivalved sporocysts, and Goussia (3 species) which are tetrasporocystic with dizoic, bivalved sporocysts that lack Stleda bodies and have sporocyst walls composed of two longitudinal valves. (PDF file contains 24 pages.