The Dynamics of Histone Modifications during Mammalian Zygotic Genome Activation.

Mammalian fertilization initiates the reprogramming of oocytes and sperm, forming a totipotent zygote. During this intricate process, the zygotic genome undergoes a maternal-to-zygotic transition (MZT) and subsequent zygotic genome activation (ZGA), marking the initiation of transcriptional control and gene expression post-fertilization. Histone modifications are pivotal in shaping cellular identity and gene expression in many mammals. Recent advances in chromatin analysis have enabled detailed explorations of histone modifications during ZGA. This review delves into conserved and unique regulatory strategies, providing essential insights into the dynamic changes in histone modifications and their variants during ZGA in mammals. The objective is to explore recent advancements in leading mechanisms related to histone modifications governing this embryonic development phase in depth. These considerations will be useful for informing future therapeutic approaches that target epigenetic regulation in diverse biological contexts. It will also contribute to the extensive areas of evolutionary and developmental biology and possibly lay the foundation for future research and discussion on this seminal topic.

Neutropenia congénita. Presentación de un caso / https://revhematologia.sld.cu/index.php/hih/article/view/1695/1412

Introducción: Las inmunodeficiencias primarias son enfermedades de origen genético causadas por alteraciones cuantitativas o funcionales del sistema inmune. La incidencia de las neutropenias es de 3,4 casos por millón de personas por año Son enfermedadess heterogéneas en cuanto a la etiología, la fisiopatología, la clínica y la respuesta al tratamiento. Muchos casos presentan manifestaciones graves y mal pronóstico aún con diagnóstico y tratamiento oportunos. Objetivo: Presentar a la comunidad científico-médica un caso de neutropenia congénita con evolución desfavorable. Presentación de caso: Lactante femenina de siete meses con antecedentes de múltiples ingresos por infecciones respiratorias altas y bajas complicadas, asociadas a cuadros diarreicos, infecciones de piel y partes blandas (abscesos en región glútea y pabellones auriculares). Valorada por las especialidades de Inmunología y Hematología, las que diagnosticaron una neutropenia congénita (infecciones por Estafilococo aureus, Pseudomona sp y Cándida albicans). Recuento absoluto de neutrófilos en varias ocasiones con valores en 108 mm3; ausencia de elementos del gránulo en sistema granulopoyético en medulograma y estudios inmunológicos (ausencia de área tímica e IgA en 0,14 g/L). Se inició tratamiento con antimicrobianos de amplio espectro, inmunomoduladores (Hebertrans, Leukocin, Prednisona) y concentrado de granulocitos de donación paterna con escasa respuesta al tratamiento. Evolucionó desfavorablemente y falleció por shock séptico. El informe de necropsia confirmó el diagnóstico. Conclusiones: La neutropenia congénita se sospecha en pacientes con antecedentes de infecciones recurrentes con evolución tórpida y valores disminuidos de neutrófilos, es de gran importancia establecer un diagnóstico de certeza y conducta terapéutica temprana que favorezcan la disminución de la morbilidad y mortalidad(AU)

Introduction: Primary immunodeficiencies are diseases of genetic origin caused by quantitative and/or functional alterations of the immune system. The incidence of neutropenia is 3.4 cases per million people per year; it is a heterogeneous entity in terms of etiology, pathophysiology, clinic and response to treatment. It presents with severe manifestations and poor prognosis even with timely diagnosis and treatment. Objective: To present to scientific and medical community a case of Congenital Neutropenia with unfavorable evolution. Case presentation: Seven-month-old female infant with a history of multiple admissions for complicated upper and lower respiratory tract infections, associated with diarrhea and skin and soft tissue infections (abscesses in the gluteal region and ear pinnae). He was evaluated by Immunology and Hematology and Congenital Neutropenia was diagnosed (Staphylococcus aureus, Pseudomonas sp and Candida albicans infections), absolute neutrophil count on several occasions with values in 108 mm3, absence of granule elements in granulopoietic system in medullogram and studies immunological (absence of thymic area and IgA at 0.14 g/L). Treatment was started with broad-spectrum antimicrobials, immunomodulators (Hebertrans, Leukocin, Prednisone) and paternally donated granulocyte concentrate with little response to treatment. He evolved unfavorably and died of septic shock. The autopsy report confirmed the diagnosis. Conclusions: Congenital Neutropenia is suspected in patients with a history of recurrent infections with torpid evolution and neuthopenia, it is of great importance to establish an accurate diagnosis and early therapeutic behavior that favor the reduction of morbidity and mortality(AU)