RESUMO
Cys2-His2 zinc finger genes (ZNFs) form the largest family of transcription factors in metazoans. ZNF evolution is highly dynamic and characterized by the rapid expansion and contraction of numerous subfamilies across the animal phylogeny. The forces and mechanisms underlying rapid ZNF evolution remain poorly understood, but there is growing evidence that, in tetrapods, the targeting and repression of lineage-specific transposable elements (TEs) plays a critical role in the evolution of the Krüppel-associated box ZNF (KZNF) subfamily. Currently, it is unknown whether this function and coevolutionary relationship is unique to KZNFs or is a broader feature of metazoan ZNFs. Here, we present evidence that genomic conflict with TEs has been a central driver of the diversification of ZNFs in animals. Sampling from 3221 genome assemblies, we show that the copy number of retroelements correlates with that of ZNFs across at least 750 million years of metazoan evolution. Using computational predictions, we show that ZNFs preferentially bind TEs in diverse animal species. We further investigate the largest ZNF subfamily found in cyprinid fish, which is characterized by a conserved sequence we dubbed the fish N-terminal zinc finger-associated (FiNZ) domain. Zebrafish possess approximately 700 FiNZ-ZNFs, many of which are evolving adaptively under positive selection. Like mammalian KZNFs, most zebrafish FiNZ-ZNFs are expressed at the onset of zygotic genome activation, and blocking their translation using morpholinos during early embryogenesis results in derepression of transcriptionally active TEs. Together, these data suggest that ZNF diversification has been intimately connected to TE expansion throughout animal evolution.
Assuntos
Elementos de DNA Transponíveis , Peixe-Zebra , Animais , Elementos de DNA Transponíveis/genética , Peixe-Zebra/genética , Dedos de Zinco/genética , Fatores de Transcrição/genética , Mamíferos/genética , Evolução MolecularRESUMO
La violeta de genciana es un colorante orgánico sintético, descrito por primera vez por Charles Lauth en 1861. Tiene propiedades antibacterianas, antifúngicas, antihelmínticas, antitripanosómicas, antiantiogénicas y antitumorales. Tiene diversos mecanismos de acción, entre los que principalmente se encuentra bloquear la actividad de las nicotinamida adenina dinucleótido fosfato oxidasas, evitando la generación de radicales superoxidativos y la posterior inflamación. En los últimos años se ha utilizado en marcadores para procedimientos en diferentes especialidades médicas, incluidos los de oftalmología. La tinta de violeta de genciana se describe por el fabricante como no tóxica, sin embargo existe evidencia clínica y experimental que sugiere que puede ser tóxica para el endotelio corneal y puede llegar a generar queratitis lamelar difusa posterior a LASIK y Femto-LASIK. Se describe el caso de una paciente de 23 años de edad, que presentó diversas patologías en la córnea después del uso de marcador quirúrgico durante procedimiento refractivo Femto-LASIK.
Gentian violet is a synthetic and organic dye. First described by Charles Lauth in 1861. It has antibacterial, antifungal, anthelmintic, antitrypanosomal, antiangiogenic, and antitumoral properties. It has various mechanisms of action, among which is mainly blocking the activity of nicotinamide adenine dinucleotide phosphate oxidases, preventing the generation of superoxidative radicals and subsequent inflammation. In recent years, it has been used as markers for procedures in different medical specialties, including ophthalmology. Gentian violet ink is described by the manufacturer as non-toxic, however, there is clinical and experimental evidence suggesting that it may be toxic to the corneal endothelium and may cause diffuse lamellar keratitis after LASIK and Femto-LASIK. The case about a 23-year-old female patient who presented various pathologies in the cornea after the use of a surgical marker during the Femto-LASIK refractive procedure is described.
Assuntos
Humanos , Feminino , AdultoRESUMO
Se reporta el caso de un adolescente de 11 años de edad que ingresa con un cuadro diarreico e hipoka-lemia severa (2.1 mEq/L) con alteraciones en el electrocardiograma. La hipokalemia fue persistente y se documentó alcalosis metabólica e hipomagnesemia con hipermagnesiuria e hipocalciuria. A la revisión de síntomas el paciente refiere calambres y deformidad de dedos que impiden la marcha desde los 6 años y avidez por la sal. La sospecha clínica correspondió al Síndrome de Gitelman, respondiendo al manejo con suplemento oral de potasio, dieta rica en potasio y diurético ahorrador de potasio. Se presenta este caso, su evolución y la revisión de la literatura por la importancia de un diagnóstico temprano por la presencia de parestesias, debilidad muscular y el alto riesgo de arritmias asociadas a la hipokalemia. Se revisa la literatura y la evolución del caso con el tratamiento médico.
We report the case of an eleven-year-old patient who presented with diarrhea and hypokalemia, potassium 2.1 mEq / L with electrocardiographic changes. Persistent hypokalemia metabolic alka-losis and hypomagnesemia with hypocalcemia and hypermagnesiuria were documented. The patient had a history since 6 years of age of cramps, along with deformity of the fingers that preclude him from walking; in addition he showed craving for salt. Due to the medical history and association of hypokalemia with hypomagnesemia, he was diagnosed with Gitelman Syndrome. Treatment was install with Oral potassium supplements, diet rich in potassium and potassium sparing diuretic. Medical improvement of the symptoms and of hypokalemia was reported. We present this case due to importance of the medical history of paresthesia and muscular weakness before he presented severe hypokalemia with high risk of arrhythmias. Revision of related literature and case evaluation with the medication management is done.