PMID(sorted ascending)
age-specific incidence of hereditary melanomas in the xiphophorus fish hybrids.the age-distribution in the late-onset form of melanomas in the xiphophorus fish hybrids was determined. the domesticated stock of the platyfish carrying the macromelanophore gene, sp, was hybridized with the green swordtail or albino swordtail to produce f1 hybrids. the hybrid fish developed pigmentary abnormalities, melanosis, at early ages. these fish matured sexually at about 6 to 8 months of age, although many of them were sterile. the senescence pattern of the hybrid fish was estimated on ...19817273296
cloning and comparative sequence analysis of tp53 in xiphophorus fish hybrid melanoma models.we have cloned and sequenced the p53-encoding cdna of green swordtail (x. helleri) and southern platyfish (x. maculatus). these two fish species are often used to produce hybrids that develop melanomas after genetic crossing. computer translation of derived cdna sequences revealed that p53 polypeptides from these two species are virtually identical, exhibiting only two conservative amino acid substitutions. tp53 mrna expression was detected in virtually all tissues tested. comparison of these fi ...19989661661
expression of pejerrey gonadotropin-releasing hormone in three orders of fish.molecular variants of gnrh were characterized by reverse-phase, high-performance liquid chromatography from brain extracts of fish in three different orders: synbranchiformes (swamp eel [synbranchus marmoratus]), cyprinidontiformes (platyfish [xiphophorus maculatus] and green swordtail [x. helleri]), and atheriniformes (patagonia pejerrey [odontesthes hatchery]). also, pituitary gland extracts from the pejerrey o. bonariensis (atheriniformes) were characterized. eluted fractions were tested in r ...200212444064
preliminary investigations of hydrogen peroxide treatment of selected ornamental fishes and efficacy against external bacteria and parasites in green swordtails.the objectives of these preliminary studies were to evaluate the use of hydrogen peroxide (h2o2) for the treatment of selected species of ornamental fishes and its efficacy in treating external bacteria and parasites. in the first part of the study, fish of five species (serpae tetra hyphessobrycon eques (also known as serpa tetra h. serpae), tiger barb puntius tetrazona, blue gourami trichogaster trichopterus, suckermouth catfish hypostomus plecostomus, and green swordtail xiphophorus hellerii) ...200718201053
a structural model of the extracellular domain of the oncogenic egfr variant xmrk.the epidermal growth factor receptor (egfr) variant xmrk of the mexican fish xiphophorus is one of the first oncogenes described. its overexpression in pigment cells of the skin occurs after certain repeated cross-breedings between the platyfish xiphophorus maculatus and the swordtail xiphophorus hellerii. xmrk overexpression results in melanoma with a high malignant potential. the xiphophorus melanoma model provides a valuable tool for the understanding of melanoma development in general. the x ...200618377216
record of urocleidoides vaginoclaustrum jogunoori, kritsky and venkatanarasaiah, 2004 (monogenea: dactylogyridae) from a freshwater fish in mexico.we describe herein the first occurrence of the monogenean urocleidoides vaginoclaustrum in the wild. this monogenean was originally described from an aquarium neotropical fish examined in india. worms were collected from the gills of xiphophorus hellerii, a species native to tropical mexico but introduced to the los berros spring in the state of durango, northern mexico. these specimens showed slight morphological differences in the sclerotized structures of the haptor with respect to the specim ...200818661283
[ichthyofauna of karstic wetlands under anthropic impact: the "petenes" of campeche, mexico]."petenes" are small springs and associated streams that drain into wetlands near the coast in karstic areas. we studied composition, distribution, and abundance of the ichthyofauna in los petenes region (northwest campeche). two petenes displaying different degrees and types of anthropic impact were selected, hampolol and el remate. hampolol has a smaller area but a longer derived stream; it is located within a protected area, but has been invaded by tilapia. el remate is a popular spa, with no ...200919637696
determination of sperm concentration for small-bodied biomedical model fishes by use of microspectrophotometry.the goal of this study was to establish an efficient method for determination of sperm concentration requiring only 1-2 microl of sample by use of microspectrophotometry. the objectives were (1) determination of wavelengths with absorbance profiles appropriate for analysis of sperm suspensions from zebrafish danio rerio, green swordtail xiphophorus helleri, and medaka oryzias latipes collected by crushing of dissected testis or by stripping of live males; (2) generation of standard curves and eq ...201020515322
an index of biotic integrity for shallow streams of the hondo river basin, yucatan index of biotic integrity (ibi) is proposed, based on the fish communities and populations in streams of the hondo river basin, mexico-belize. freshwater environments in this area are threatened by exotic fishes, eutrophication, and pesticide pollution, among other problems. this ibi should allow to identify the most vulnerable sites and eventually guide rehabilitation efforts. data on composition, structure, and function of fish communities were evaluated. twenty-three sites in the mexican p ...201021146199
characterization of telomeres and telomerase expression in xiphophorus.research investigating telomere lengths and telomerase expression in vertebrates has progressively become important due to the association of these two biological endpoints with cellular aging and cancer in humans. studies that rely upon the traditional use of laboratory mice have been faced with limitations largely due to inbred mice possessing large telomeres and ubiquitous expression of telomerase. recently, a number of small fish species have been shown to provide potentially informative mod ...201121619941
morphological and molecular description of eight new species of gyrodactylus von nordmann, 1832 (platyhelminthes: monogenea) from poeciliid fishes, collected in their natural distribution range in the gulf of mexico slope, mexico.eight new species of gyrodactylus are described from poecilia mexicana, poeciliopsis gracilis, pseudoxiphophorus bimaculatus [syn. = heterandria bimaculata], and xiphophorus hellerii collected in the nautla and la antigua river basins in veracruz, and in the tecolutla river basin in puebla, mexico. analyzing the morphology of the marginal hooks, gyrodactylus pseudobullatarudis n. sp. and gyrodactylus xtachuna n. sp. are both very similar to gyrodactylus bullatarudis; gyrodactylus takoke n. sp. r ...201526091759
two new species of urocleidoides mizelle et price, 1964 (monogenoidea) from the gill lamellae of profundulids and poeciliids from central america and southern mexico.during investigations of gill ectoparasites (platyhelminthes) parasitising freshwater fish from central america (guatemala, honduras, el salvador and panama) and southeastern mexico (guerrero, oaxaca and chiapas), the following dactylogyrid monogenoidean were found: urocleidoides simonae sp. n. from profundulus punctatus (günther) (type host), profundulus balsanus ahl, profundulus guatemalensis (günther), profundulus kreiseri matamoros, shaefer, hernández et chakrabarty, profundulus labialis (gü ...201526580223
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