Biology Commons^™

Reappraising The Evolutionary History Of The Largest Known Gecko, The Presumably Extinct Hoplodactylus Delcourti, Via High-Throughput Sequencing Of Archival Dna, Matthew P. Heinicke, Stuart V. Nielsen, Aaron M. Bauer, Ryan Kelly, Anthony J. Geneva, Juan D. Daza, Shannon E. Keating, Tony Gamble

Biological Sciences Faculty Research and Publications

Hoplodactylus delcourti is a presumably extinct species of diplodactylid gecko known only from a single specimen of unknown provenance. It is by far the largest known gekkotan, approximately 50% longer than the next largest-known species. It has been considered a member of the New Zealand endemic genus Hoplodactylus based on external morphological features including shared toe pad structure. We obtained DNA from a bone sample of the only known specimen to generate high-throughput sequence data suitable for phylogenetic analysis of its evolutionary history. Complementary sequence data were obtained from a broad sample of diplodactylid geckos. Our results indicate that the …

Excess Dietary Sugar Alters Colonocyte Metabolism And Impairs The Proliferative Response To Damage, Ansen H.P. Burr, Junyi Ji, Kadir Ozler, Heather L. Mentrup, Onur Eskiocak, Brian Yueh, Rachel Cumberland, Ashley V. Menk, Natalie Rittenhouse, Christopher Marshall, Pailin Chiaranunt, Xiaoyi Zhang, Lauren Mullinax, Abigail Overacre-Delgoffe, Vaughn S. Cooper, Amanda C. Poholek, Greg M. Delgoffe, Kevin P. Mollen, Semir Beyaz, Timothy W. Hand

Biological Sciences Faculty Research and Publications

Background & Aims

The colonic epithelium requires continuous renewal by crypt resident intestinal stem cells (ISCs) and transit-amplifying (TA) cells to maintain barrier integrity, especially after inflammatory damage. The diet of high-income countries contains increasing amounts of sugar, such as sucrose. ISCs and TA cells are sensitive to dietary metabolites, but whether excess sugar affects their function directly is unknown.

Methods

Here, we used a combination of 3-dimensional colonoids and a mouse model of colon damage/repair (dextran sodium sulfate colitis) to show the direct effect of sugar on the transcriptional, metabolic, and regenerative functions of crypt ISCs and TA cells. …

Lin-35 Is Necessary In Both The Soma And Germline For Preserving Fertility In Caenorhabditis Elegans Under Moderate Temperature Stress, Brian P. Mikeworth, Frances V. Compere, Lisa N. Petrella

Biological Sciences Faculty Research and Publications

Maintenance of germline function under stress conditions is crucial for species survival. The germ line in many species is especially sensitive to elevated temperature. We have investigated the role of the pocket protein LIN-35 in preserving fertility in Caenorhabditis elegans under moderate temperature stress. We show that lin-35 mutants display several temperature sensitive germline defects, and more severe reductions in brood size at elevated temperatures compared to wild type. This loss of fertility under temperature stress is primarily due to loss of zygotic, but not maternal, LIN-35. Additionally, we have found that expression of LIN-35 is necessary in both the …

Navigating Rice Seedling Cold Resilience: Qtl Mapping In Two Inbred Line Populations And The Search For Genes, Michael Schläppi, Avery R. Jessel, Aaron K. Jackson, Huy Phan, Melissa H. Jia, Jeremy D. Edwards, Georgia C. Eizenga

Biological Sciences Faculty Research and Publications

Due to global climate change resulting in extreme temperature fluctuations, it becomes increasingly necessary to explore the natural genetic variation in model crops such as rice to facilitate the breeding of climate-resilient cultivars. To uncover genomic regions in rice involved in managing cold stress tolerance responses and to identify associated cold tolerance genes, two inbred line populations developed from crosses between cold-tolerant and cold-sensitive parents were used for quantitative trait locus (QTL) mapping of two traits: degree of membrane damage after 1 week of cold exposure quantified as percent electrolyte leakage (EL) and percent low-temperature seedling survivability (LTSS) after 1 …

Identification Of A Cis-Sex Chromosome Transition In Banded Geckos (Coleonyx, Eublepharidae, Gekkota), Shannon E. Keating, Eli Greenbaum, Jerry D. Johnson, Tony Gamble

Biological Sciences Faculty Research and Publications

Sex-determination systems are highly variable amongst vertebrate groups, and the prevalence of genomic data has greatly expanded our knowledge of how diverse some groups truly are. Gecko lizards are known to possess a variety of sex-determination systems, and each new study increases our knowledge of this diversity. Here, we used RADseq to identify male-specific markers in the banded gecko Coleonyx brevis, indicating this species has a XX/XY sex-determination system. Furthermore, we show that these sex-linked regions are not homologous to the XX/XY sex chromosomes of two related Coleonyx species, C. elegans and C. mitratus, suggesting that a cis- …

Experimental And Observational Evidence Of Negative Conspecific Density Dependence In Temperate Extomycorrhizal Trees, Fiona V. Jevon, Dayna De La Cruz, Joseph A. Lamanna, Ashley K. Lang, David A. Orwig, Sydne Record, Paige V. Kouba, Matthew P. Ayres, Jaclyn H. Matthes

Biological Sciences Faculty Research and Publications

Conspecific negative density dependence (CNDD) promotes tree species diversity by reducing recruitment near conspecific adults due to biotic feedbacks from herbivores, pathogens, or competitors. While this process is well-described in tropical forests, tests of temperate tree species range from strong positive to strong negative density dependence. To explain this, several studies have suggested that tree species traits may help predict the strength and direction of density dependence: for example, ectomycorrhizal-associated tree species typically exhibit either positive or weaker negative conspecific density dependence. More generally, the strength of density dependence may be predictably related to other species-specific ecological attributes such as …

Explore The Regulatory Roles Of Micrornas In Sperm Formation And Function Of C. Elegans, Lu Lu

Dissertations (1934 -)

Gene regulation mediated by microRNAs (miRNAs) at the post-transcriptional level is important for producing functional sperm in diverse species including C. elegans. However, the specific regulatory roles of miRNAs in this process are largely unknown. The central goal of my dissertation is to address this question. I proposed to study the function of miRNAs enriched in male gonads, which are approximately 95% germ cells and 5% somatic cells. I isolated adult gonads of males and hermaphrodites for small RNA sequencing and the analysis revealed a differential miRNA expression profile between hermaphrodite and male gonads. 29 male gonad-enriched miRNAs have the …

Ontogeny Of The Paraphalanges And Derived Phalanges Of Hemidactylus Turcicus (Squamata: Gekkonidae), Aaron H. Griffing, Tony Gamble, Aaron M. Bauer, Anthony P. Russell

Biological Sciences Faculty Research and Publications

Gekkotan lizards of the genus Hemidactylus exhibit derived digital morphologies. These include heavily reduced antepenultimate phalanges of digits III and IV of the manus and digits III–V of the pes, as well as enigmatic cartilaginous structures called paraphalanges. Despite this well-known morphological derivation, no studies have investigated the development of these structures. We aimed to determine if heterochrony underlies the derived antepenultimate phalanges of Hemidactylus. Furthermore, we aimed to determine if convergently evolved paraphalanges exhibit similar or divergent developmental patterns. Herein we describe embryonic skeletal development in the hands and feet of four gekkonid species, exhibiting a range of …

Thank You For Biting: Dispersal Of Beneficial Microbiota Through 'Antagonistic' Interactions, C.G.B. Grupstra, Nathan P. Lemoine, Chelsea N. Cook, Adrienne M.S. Correa

Biological Sciences Faculty Research and Publications

Multicellular organisms harbor populations of microbial symbionts; some of these symbionts can be dispersed through the feeding activities of consumers. Studies of consumer-mediated microbiota dispersal generally focus on pathogenic microorganisms; the dispersal of beneficial microorganisms has received less attention, especially in the context of 'antagonistic' trophic interactions (e.g., herbivory, parasitism, predation). Yet, this 'trophic transmission' of beneficial symbionts has significant implications for microbiota assembly and resource species (e.g., prey) health. For example, trophic transmission of microorganisms could assist with environmental acclimatization and help resource species to suppress other consumers or competitors. Here, we highlight model systems and approaches that have …

Somatostatin Regulates Circadian Clock Function And Photic Processing, Deborah A. M. Joye

Dissertations (1934 -)

Daily and seasonal rhythms are programmed by neural circuits that use daily timing and duration of light to anticipate predictable environmental changes (i.e., day length, temperature, food, predation). Daily and annual changes in light modulate human health to produce both positive and negative effects, but neural mechanisms underlying light-driven changes in the brain remain poorly understood. In mammals, light is processed and encoded by the brain’s central clock, the suprachiasmatic nucleus (SCN). The SCN also encodes day length (i.e., photoperiod) to regulate annual fluctuations in mammalian physiology, but it’s not clear precisely how the SCN network achieves this. One signal …

The Ventral Hippocampus Dynamically Regulates Amygdala Encoding And Learned Fear, Matthew Richard Herbst

Dissertations (1934 -)

The nervous system has evolved a set of survival circuits optimized to respond to environmental threats. Adaptive threat responding requires learning to predict when and where a threat may occur based on available cues. Such learning depends on a distributed network of brain structures, but there is much we do not understand about how these brain areas interact to support fear memory. Addressing this gap is crucial for understanding anxiety- and fear-related disorders as dysfunction in fear learning networks is implicated in the development and persistence of pathological fear states. In my dissertation work, I used a rodent model of …

Investigations Into The Negative Impact Of Temperature Stress On Fertility In Wild Strains Of Caenorhabditis Elegans, Nicholas B. Sepulveda

Dissertations (1934 -)

Sexual reproduction and its coincident genetic recombination are powerful adaptive strategies. However, sexual reproduction has disadvantages. One ancient and conserved disadvantage is temperature sensitivity. In organisms diverse as plants, insects, nematode worms, and humans, as temperatures increase, fertility decreases. The goal of this dissertation is to examine the negative impact of elevated temperature stress on fertility in sexually reproducing organisms using wild strains of Caenorhabditis elegans. C. elegans presents a unique opportunity to study these effects broadly in two contexts, as worms may be either self-fertile hermaphrodites that produce both egg and sperm or males which produce only sperm. In …

Genome-Wide Identification Of The A20/An1 Zinc Finger Proteon Family Genes In Ipomoea Batatas And Its Two Relatives And Function Analysis Of Ibsap16 In Salinity Tolerance, Hao Xie, Qiangqiang Yang, Xiaoxiao Wang, Michael Schläppi, Hui Yan, Meng Kou, Wei Tang, Xin Wang, Yungang Zhang, Qiang Li, Shaojun Dai, Yaju Liu

Biological Sciences Faculty Research and Publications

Stress-associated protein (SAP) genes—encoding A20/AN1 zinc-finger domain-containing proteins—play pivotal roles in regulating stress responses, growth, and development in plants. They are considered suitable candidates to improve abiotic stress tolerance in plants. However, the SAP gene family in sweet potato (Ipomoea batatas) and its relatives is yet to be investigated. In this study, 20 SAPs in sweet potato, and 23 and 26 SAPs in its wild diploid relatives Ipomoea triloba and Ipomoea trifida were identified. The chromosome locations, gene structures, protein physiological properties, conserved domains, and phylogenetic relationships of these SAPs were analyzed systematically. Binding motif analysis of IbSAPs indicated that …

Caloric Restriction Prevents Obesity- And Intermittent Hypoxia-Induced Cardiac Remodeling In Leptin-Deficient Ob/Ob Mice, Aaron A. Jones, Sarah N. Framnes-Deboer, Arianne Shipp, Deanna M. Arble

Biological Sciences Faculty Research and Publications

Background:

Intermittent hypoxia (IH), a key characteristic of obstructive sleep apnea, is independently associated with cardiometabolic impairment. While endogenous leptin levels may provide cardioprotective effects against hypoxia, leptin resistance is common among obese individuals presenting with obstructive sleep apnea.

Methods:

Here, we assessed left ventricle (LV) function using M-mode echocardiography in lean wild-type, calorically-restricted ob/ob, and obese ob/ob mice before and after 6 days of IH to determine how obesity and intermittent hypoxia interact to affect cardiac function independent of leptin signaling.

Results:

Calorically-restricting ob/ob mice for 4 weeks prior to IH exposure prevented weight gain (−2.1 ± 1.4 …

Diversity Of Reptile Sex Chromosome Evolution Revealed By Cytogenetic And Linked-Read Sequencing, Ze-Xian Zhu, Kazumi Matsubara, Foyez Shams, Jason Dobry, Erik Wapstra, Tony Gamble, Stephen D. Sarre, Arthur Georges, Jennifer A. Marshall Graves, Qi Zhou, Tariq Ezaz

Biological Sciences Faculty Research and Publications

Reptile sex determination is attracting much attention because the great diversity of sex-determination and dosage compensation mechanisms permits us to approach fundamental questions about mechanisms of sex chromosome turnover. Recent studies have made significant progress in better understanding diversity and conservation of reptile sex chromosomes, with however no reptile master sex determination genes identified. Here we describe an integrated genomics and cytogenetics pipeline, combining probes generated from the microdissected sex chromosomes with transcriptome and genome sequencing to explore the sex chromosome diversity in non-model Australian reptiles. We tested our pipeline on a turtle, two species of geckos, and a monitor …

Conformational Selection Governs Carrier Domain Positioning In Staphylococcus Aureus Pyruvate Carboxylase, Joshua H. Hakala, Amanda J. Laseke, Anya Lei Koza, Martin St. Maurice

Biological Sciences Faculty Research and Publications

Biotin-dependent enzymes employ a carrier domain to efficiently transport reaction intermediates between distant active sites. The translocation of this carrier domain is critical to the interpretation of kinetic and structural studies, but there have been few direct attempts to investigate the dynamic interplay between ligand binding and carrier domain positioning in biotin-dependent enzymes. Pyruvate carboxylase (PC) catalyzes the MgATP-dependent carboxylation of pyruvate where the biotinylated carrier domain must translocate ∼70 Å from the biotin carboxylase domain to the carboxyltransferase domain. Many prior studies have assumed that carrier domain movement is governed by ligand-induced conformational changes, but the mechanism underlying this …

Recycled Concrete Aggregates Are An Economic Form Of Urban Riparian Erosion Management With Limited Impacts On Freshwater Chemistry And Microbial Diversity, Rachelle E. Beattie, Bixia Su, Rebecca Thill, Krassimira R. Hristova

Biological Sciences Faculty Research and Publications

Urban streams are at high risk of riparian erosion which impacts adjacent infrastructure stability. Methods to prevent stream erosion have been proposed including using recycled concrete (RC) materials to help stabilize the streambed; however, little is known about the environmental and biological impacts of using RC in urban streams. RC, new concrete (NC), and river rock controls were evaluated for their impact on water chemistry, water quality, and microbial community composition over 6.5 months in controlled laboratory mesocosms. Concentrations of 19 metals, nutrients, and pH of mesocosms containing RC were not significantly different from the river rock mesocosm throughout the …

Evolution Of Sex Chromosomes In Geckos (Reptilia: Gekkota), Shannon Elizabeth Keating

Dissertations (1934 -)

Sex chromosomes control sex determination in many plants and animals, playing a vital role in a species’ evolution. Current models of sex chromosome evolution have been formulated by studying clades with stable, morphologically distinct (heteromorphic) sex chromosomes, such as mammals and birds. However, many taxa have morphologically indistinguishable (homomorphic) sex chromosomes, including many fish, amphibians, and reptiles. The knowledge gained from these understudied systems may provide new insights into the overarching paradigms of sex chromosome evolution. Thus, the historical focus on stable, heteromorphic sex chromosomes and failure to consider homomorphic sex chromosomes or systems with frequent turnovers may mean the …

Embryology Of The Gekkota: Insights Into The Evolution An Development Of Morphological Diversity, Aaron Harp Griffing

Dissertations (1934 -)

Understanding the patterns and processes which result in morphological diversity is a central goal of evolutionary developmental biology or evo-devo. This diversity encompasses morphologies which have evolved numerous, independent times within a clade (evolutionary convergence) and others which have evolved only once within a clade (i.e. evolutionary novelty). Though many of these diverse morphologies exhibit functional capabilities and are intertwined with the ecology and diversification of the evolutionary lineage in question, their origins are largely unknown. Robust phylogenic analysis, genomic information, and detailed developmental data are critical lines of evidence to explain the evolutionary and ontogenetic origins of morphological novelty …

Modulation Of Mitochondrial Protein Synthesis In Yeast – Role Of The Mrp7 (Bl27) Protein, Jessica Anderson

Dissertations (1934 -)

Oxidative phosphorylation (OXPHOS) is responsible for the generation of most of the cellular energy (ATP) within the cell. OXPHOS enzymes are mosaic in origin, as protein subunits are encoded by both nuclear and mitochondrial genomes. Mitochondrial ribosomes have been shown to respond to the availability and import of nuclearly encoded OXPHOS components, and thus the current dogma states that mitochondrial translation is synchronized to the import of these nuclear encoded proteins, as well as the availability of chaperones to co-assemble them within the inner mitochondrial membrane. We demonstrate here that the yeast Mrp7 (bL27) protein is involved in the coordination …

Implications Of The Actin Cytoskeleton On The Multi-Step Process Of [ Psi+] Prion Formation, Jane E. Dorweiler, Douglas R. Lyke, Nathan P. Lemoine, Sam Guereca, Hannah E. Buchholz, Emily R. Legan, Claire M. Radtke, Anita L. Manogaran

Biological Sciences Faculty Research and Publications

Yeast prions are self-perpetuating misfolded proteins that are infectious. In yeast, [PSI⁺] is the prion form of the Sup35 protein. While the study of [PSI⁺] has revealed important cellular mechanisms that contribute to prion propagation, the underlying cellular factors that influence prion formation are not well understood. Prion formation has been described as a multi-step process involving both the initial nucleation and growth of aggregates, followed by the subsequent transmission of prion particles to daughter cells. Prior evidence suggests that actin plays a role in this multi-step process, but actin’s precise role is unclear. Here, we …

Vegetative Phenologies Of Lianas And Trees In Two Neotropical Forests With Contrasting Rainfall Regimes, Jose A. Medina-Vega, S. Joseph Wright, Frans Bongers, Stefan A. Schnitzer, Frank J. Sterck

Biological Sciences Faculty Research and Publications

• Among tropical forests, lianas are predicted to have a growth advantage over trees during seasonal drought, with substantial implications for tree and forest dynamics. We tested the hypotheses that lianas maintain higher water status than trees during seasonal drought and that lianas maximize leaf cover to match high, dry-season light conditions, while trees are more limited by moisture availability during the dry season.
• We monitored the seasonal dynamics of predawn and midday leaf water potentials and leaf phenology for branches of 16 liana and 16 tree species in the canopies of two lowland tropical forests with contrasting rainfall regimes in …

Plant Growth-Promoting Activity Of Bacteria Isolated From Asian Rice (Oryza Sativa L.) Depends On Rice Genotype, Nasim Maghboli Balasjin, James Maki, Michael Schläppi, Christopher Marshall

Biological Sciences Faculty Research and Publications

Asian rice is one of the most important crops because it is a staple food for almost half of the world’s population. To have production of rice keep pace with a growing world population, it is anticipated that the use of fertilizers will also need to increase, which may cause environmental damage through runoff impacts. An alternative strategy to increase crop yield is the use of plant growth-promoting bacteria. Thousands of microbial species can exist in association with plant roots and shoots, and some are critical to the plant’s survival. We isolated 140 bacteria from two distantly related rice accessions …

Immunosuppression Broadens Evolutionary Pathways To Drug Resistance And Treatment Failure During Acinetobacter Baumannii Pneumonia In Mice, Wenwen Ho, Lindsay M. Busch, Juan Hernandez-Bird, Efrat Hamami, Christopher Marshall, Edward Geisinger, Vaughn S. Cooper, Tim Van Opijnen, Jason W. Rosch, Ralph R. Isberg

Biological Sciences Faculty Research and Publications

Acinetobacter baumannii is increasingly refractory to antibiotic treatment in healthcare settings. As is true of most human pathogens, the genetic path to antimicrobial resistance (AMR) and the role that the immune system plays in modulating AMR during disease are poorly understood. Here we reproduced several routes to fluoroquinolone resistance, performing evolution experiments using sequential lung infections in mice that are replete with or depleted of neutrophils, providing two key insights into the evolution of drug resistance. First, neutropenic hosts acted as reservoirs for the accumulation of drug resistance during drug treatment. Selection for variants with altered drug sensitivity profiles arose …

Lianas Decelerate Tropical Forest Thinning During Succession, Jose A. Medina-Vega, Geertje M. F. Van Der Heijden, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

The well-established pattern of forest thinning during succession predicts an increase in mean tree biomass with decreasing tree density. The forest thinning pattern is commonly assumed to be driven solely by tree-tree competition. The presence of non-tree competitors could alter thinning trajectories, thus altering the rate of forest succession and carbon uptake. We used a large-scale liana removal experiment over 7 years in a 60- to 70-year-old Panamanian forest to test the hypothesis that lianas reduce the rate of forest thinning during succession. We found that lianas slowed forest thinning by reducing tree growth, not by altering tree recruitment or …

Immunosuppression Broadens Evolutionary Pathways To Treatment Failure During Acinetobacter Baumannii Pneumonia, Wenwen Huo, Lindsay M. Busch, Juan Hernandez-Bird, Efrat Hamami, Christopher Marshall, Edward Geisinger, Vaughn S. Cooper, Tim Van Opijnen, Jason W. Rosch, Ralph R. Isberg

Biological Sciences Faculty Research and Publications

Acinetobacter baumannii is increasingly refractory to antibiotic treatment in healthcare settings. As is true of most human pathogens, the genetic path to antimicrobial resistance (AMR) and the role that the immune system plays in modulating AMR during disease are poorly understood. Here we reproduced several routes to fluoroquinolone resistance, performing evolution experiments using sequential lung infections in mice that are replete or depleted of neutrophils, providing two key insights into the evolution of drug resistance. First, neutropenic hosts acted as reservoirs for the accumulation of drug resistance during drug treatment. Selection for variants with altered drug sensitivity profiles arose readily …

B-Vitamins Influence The Consumption Of Macronutrients In Honey Bees, Walaa Ahmed Elsayeh, Chelsea N. Cook, Geraldine A. Wright

Biological Sciences Faculty Research and Publications

Insects require dietary sources of B-vitamins, but relatively little is known about whether they regulate B-vitamin intake in the same way they regulate other nutrients. Honey bees meet their B-vitamin requirements mainly from the pollen they collect. Employing the geometric framework for nutrition, we found that honey bees actively regulate their vitamin intake following Bertrand’s rule. We fed bees with a diet of essential amino acids (EAAs) and carbohydrate (C) to identify how the addition of B-vitamins affected the regulation of these macronutrients. In our experiments, honey bees preferred vitamins in concentrations comparable to those found in honey bee food …

Tree Species Diversity Increases With Conspecific Negative Density Dependence Across An Elevation Gradient, Joseph A. Lamanna, F. Andrew Jones, Davod M. Bell, Robert J. Pabst, David C. Shaw

Biological Sciences Faculty Research and Publications

Elevational and latitudinal gradients in species diversity may be mediated by biotic interactions that cause density-dependent effects of conspecifics on survival or growth to differ from effects of heterospecifics (i.e. conspecific density dependence), but limited evidence exists to support this. We tested the hypothesis that conspecific density dependence varies with elevation using over 40 years of data on tree survival and growth from 23 old-growth temperate forest stands across a 1,000-m elevation gradient. We found that conspecific-density-dependent effects on survival of small-to-intermediate-sized focal trees were negative in lower elevation, higher diversity forest stands typically characterised by warmer temperatures and greater …

Evolved Resistance To A Novel Cationic Peptide Antibiotic Requires High Mutation Supply, Alfonso Santos-Lopez, Melissa J. Fritz, Jeffrey B. Lombardo, Ansen H.P. Burr, Victoria A. Heinrich, Christopher Marshall, Vaughn S. Cooper

Biological Sciences Faculty Research and Publications

Background and Objectives

A key strategy for resolving the antibiotic resistance crisis is the development of new drugs with antimicrobial properties. The engineered cationic antimicrobial peptide WLBU2 (also known as PLG0206) is a promising broad-spectrum antimicrobial compound that has completed Phase I clinical studies. It has activity against Gram-negative and Gram-positive bacteria including infections associated with biofilm. No definitive mechanisms of resistance to WLBU2 have been identified.

Methodology

Here, we used experimental evolution under different levels of mutation supply and whole genome sequencing (WGS) to detect the genetic pathways and probable mechanisms of resistance to this peptide. We propagated populations …

Chromosome-Level Genome Assembly Reveals Dynamic Sex Chromosomes In Neotropical Leaf-Litter Geckos (Sphaerodactylidae: Sphaerodactylus), Brendan J. Pinto, Shannon E. Keating, Stuart V. Nielsen, Daniel P. Scantlebury, Juan D. Daza, Tony Gamble

Biological Sciences Faculty Research and Publications

Sex determination is a critical element of successful vertebrate development, suggesting that sex chromosome systems might be evolutionarily stable across lineages. For example, mammals and birds have maintained conserved sex chromosome systems over long evolutionary time periods. Other vertebrates, in contrast, have undergone frequent sex chromosome transitions, which is even more amazing considering we still know comparatively little across large swaths of their respective phylogenies. One reptile group in particular, the gecko lizards (infraorder Gekkota), shows an exceptional lability with regard to sex chromosome transitions and may possess the majority of transitions within squamates (lizards and snakes). However, detailed genomic …