A5029691634- Chromosomal and Genetic Variations
- CRISPR and Genetic Engineering
- Genetic diversity and population structure
- Genomics and Phylogenetic Studies
- Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
- Identification and Quantification in Food
- RNA and protein synthesis mechanisms
- Aquaculture disease management and microbiota
- Reproductive biology and impacts on aquatic species
- Circadian rhythm and melatonin
- Animal Genetics and Reproduction
- Sperm and Testicular Function
- Genomics and Chromatin Dynamics
- DNA Repair Mechanisms
- Insect Resistance and Genetics
- Physiological and biochemical adaptations
- MicroRNA in disease regulation
- Genetics, Aging, and Longevity in Model Organisms
- Epigenetics and DNA Methylation
- Skin Protection and Aging
- Fish Biology and Ecology Studies
- Date Palm Research Studies
- Light effects on plants
- Fish Ecology and Management Studies
- Evolution and Genetic Dynamics
Texas State University
2014-2024
Texas A&M University – Corpus Christi
2021-2023
Bioscience Research
2015-2017
Materials Research Group (United States)
2016
Division of Chemistry
2013
Florida State University
1981-2008
Brookhaven National Laboratory
1996-2006
South Texas Veterans Health Care System
2003
The University of Texas Health Science Center at San Antonio
1998-2003
The University of Texas at San Antonio
2003
Several attributes intuitively considered to be typical mammalian features, such as complex behavior, live birth and malignant disease cancer, also appeared several times independently in lower vertebrates. The genetic mechanisms underlying the evolution of these elaborate traits are poorly understood. platyfish, X. maculatus, offers a unique model better understand molecular biology traits. We report here sequencing platyfish genome. Integrating genome assembly with extensive maps...
The biological consequences of the Deepwater Horizon oil spill are unknown, especially for resident organisms. Here, we report results from a field study tracking effects contaminating across space and time in killifish during first 4 mo event. Remote sensing analytical chemistry identified exposures, which were linked to fish characterized by genome expression associated gill immunohistochemistry, despite very low concentrations hydrocarbons remaining water tissues. Divergence coincides...
Hybridization is increasingly being recognized as a widespread process, even between ecologically and behaviorally divergent animal species. Determining phylogenetic relationships in the presence of hybridization remains major challenge for evolutionary biologists, but advances sequencing technology techniques are beginning to address these challenges. Here we reconstruct among swordtails platyfishes (Xiphophorus: Poeciliidae), group species characterized by remarkable morphological...
The extreme rarity of asexual vertebrates in nature is generally explained by genomic decay due to absence meiotic recombination, thus leading extinction such lineages. We explore features a vertebrate genome, the Amazon molly, Poecilia formosa, and find few signs genetic degeneration but unique variability ongoing evolution. uncovered substantial clonal polymorphism and, as conserved feature from its interspecific hybrid origin, 10-fold higher heterozygosity than sexual parental species....
Five percent of live-born human offspring will have a genetic disorder. Of these, 20% are because germ-line de novo mutations. Several diseases, such as neurofibromatosis and Duchenne muscular dystrophy, associated with high percentage Until recently, direct analysis spontaneous mutation frequencies in mammalian germ cells has been prevented by technical limitations. We measured lacI transgene using enriched populations specific spermatogenic cell types. Similar to previously published...
Controversy continues both as to which wavelengths of sunlight cause melanoma and the mechanisms by these different act. Direct absorption UVB DNA is central in albino animal models, but melanin-pigmented models have shown major contributions longer than that are thought be mediated photosensitized oxidant production. The only model for action spectrum causation known a genetically melanoma-susceptible specific cross Xiphophorus fish. We used electron paramagnetic resonance quantitatively...
Abstract Background Males in some species of the genus Xiphophorus , small freshwater fishes from Meso-America, have an extended caudal fin, or sword – hence their common name “swordtails”. Longer swords are preferred by females both sworded and surprisingly also, non-sworded (platyfish) that belong to same genus. Swordtails been studied widely as models research on sexual selection. Specifically, pre-existing bias hypothesis was interpreted best explain observed presumed ancestral lineages...
Abstract Background The release of oil resulting from the blowout Deepwater Horizon (DH) drilling platform was one largest in history discharging more than 189 million gallons and subject to widespread application dispersants. This event impacted a wide range ecological habitats with complex mix pollutants whose biological impact is still not yet fully understood. To better understand effects on vertebrate genome, we studied gene expression salt marsh minnow Fundulus grandis , which local...
The genetic basis of spontaneous melanoma formation in spotted dorsal ( Sd ) Xiphophorus platyfish–swordtail hybrids has been studied for decades, and is adequately explained by a two-gene inheritance model involving sex-linked oncogene, Xmrk , an autosomal tumor suppressor, DIFF . oncogene encodes receptor tyrosine kinase related to EGFR ; the nature suppressor gene unknown. We analyzed UV-B-induced closely related, side hybrids, which carry different pigment pattern locus, Sp UV-irradiated...
The sperm whale, made famous by Moby Dick, is one of the most fascinating all ocean-dwelling species given their unique life history, novel physiological adaptations to hunting squid at extreme ocean depths, and position as earliest branching toothed whales (Odontoceti). We assembled whale (Physeter macrocephalus) genome resequenced individuals from multiple basins identify new candidate genes for adaptation an aquatic environment infer demographic history. Genes crucial skin integrity...
Abstract Interspecies hybrids between distinct species of the genus Xiphophorus are often used in varied research investigations to identify genomic regions associated with inheritance complex traits. There 24 described and a greater number pedigreed strains; thus, potential interspecies hybrid cross combinations is quite large. Previously, select experimental crosses have been shown exhibit differing characteristics parental among fishes derived from crossing them, such as widely...
Xiphophorus models are important for melanoma, sex determination and differentiation, ovoviviparity evolution. To gain a global view of the molecular mechanism(s) whereby gene expression may influence sexual dimorphism in to develop database future studies, we performed large-scale transcriptome study.The 454-FLX massively parallel DNA sequencing platform was employed obtain 742,771 721,543 reads from 2 normalized cDNA libraries generated whole adult female male X. maculatus Jp 163 A,...
The remarkable diversity of sex determination mechanisms known in fish may be fuelled by exceptionally high rates chromosome turnovers or transitions. However, the evolutionary causes and genomic underlying this variation instability are yet to understood. Here we report on an over 30-year experiment which tested consequences hybridisation selection between two Xiphophorus species with different systems. We find that introgression imposing for pigmentation phenotypes results retention...
Significance The Bateson–Dobzhansky–Muller (BDM) model describes negative epistatic interactions that occur between genes with a different evolutionary history to account for hybrid incompatibility and is central theory explaining genetic mechanisms underlying speciation. Since the early 1900 s when BDM was forwarded examples of have been described in only few nonvertebrate cases. This study reports vertebrate system, clearly defined interacting loci, supports model. In addition, this also...
Abstract Hybridization has been recognized as an important driving force for evolution, however studies of the genetic consequence and its cause are still lagging behind in vertebrates due to lack appropriate experimental systems. Fish central American genus Xiphophorus were proposed have evolved with multiple ancient ongoing hybridization events, served a valuable research model evolutionary biology biomedical on human disease more than century. Here, we provide complete genome resource...
The Xiphophorus hybrid melanoma model represents one of the earliest reported cases genetically regulated tumor susceptibility. Melanoma formation in hybrids may be explained by inheritance two genes: a sex-linked oncogene, Xmrk, and putative suppressor locus, termed DIFF, located Linkage Group V (LG V). Several genetic mapping procedures were used to produce new LG map with 20 loci. All markers, particularly recently cloned CDKN2 gene family member, called CDKN2X, tested for associations...
The combined observations of elevated DNA repair gene expression, high uracil-DNA glycosylase-initiated base excision repair, and a low spontaneous mutant frequency for lacI transgene in spermatogenic cells from young mice suggest that activity is cell types. Notably, the greater obtained old mice, suggesting germ line may decline with age. A paternal age effect recognized human population as well. To determine if male changes age, was measured mixed (i.e., all types adult testis) nuclear...
Germ cells perform a unique and critical biological function: they propagate the DNA that will be used to direct development of next generation. Genetic integrity germ cell is essential for producing healthy reproductively fit offspring, yet damaged by endogenous exogenous agents. Nucleotide excision repair (NER) an important mechanism coping with variety lesions. Little known about NER activity in spermatogenic cells. We expected would more efficient at than somatic cells, this efficiency...