Expression and function of an even-skipped homolog in the leech Helobdella robusta
Developmental biology published in Development (2002)
Abstract
We have identified homologs of the Drosophila pair-rule gene even-skipped in the glossiphoniid leeches Helobdella robusta and Theromyzon trizonare. In leech embryos, segments arise sequentially from five pairs of embryonic stem cells (teloblasts) that undergo iterated divisions to generate columns (bandlets) of segmental founder cells (primary blast cells), which in turn generate segmentally iterated sets of definitive progeny. In situ hybridization revealed that Hro-eve is expressed in the teloblasts and primary blast cells, and that these transcripts appear to be associated with mitotic chromatin. In more advanced embryos, Hro-eve is expressed in segmentally iterated sets of cells in the ventral nerve cord. Lineage analysis revealed that neurons expressing Hro-eve arise from the N teloblast. To assess the function of Hro-eve, we examined embryos in which selected blastomeres had been injected with antisense Hro-eve morpholino oligonucleotide (AS-Hro-eve MO), concentrating on the primary neurogenic (N teloblast) lineage. Injection of AS-Hro-eve MO perturbed the normal patterns of teloblast and blast cell divisions and disrupted gangliogenesis. These results suggest that Hro-eve is important in regulating early cell divisions through early segmentation, and that it also plays a role in neuronal differentiation.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Hro-eve, a Drosophila even-skipped homolog, regulates teloblast and blast-cell divisions and ventral nerve cord neuron differentiation in the leech Helobdella robusta — providing evolutionary insight into segmentation gene networks.
Por qué esto importa para la hirudoterapia
Este estudio identificó y caracterizó homólogos del gen pair-rule even-skipped de Drosophila (Hro-eve) en la sanguijuela glossiphónida Helobdella robusta, examinando su expresión en teloblastos, células blásticas primarias y neuronas del cordón nervioso ventral, y su función mediante experimentos de knockdown con morfolinos. El resumen describe cómo la inyección de morfolino antisentido contra Hro-eve alteró las divisiones de teloblastos y células blásticas e interrumpió la gangliogénesis, lo que sugiere funciones en la división celular temprana, la segmentación y la diferenciación neuronal. Se trata de un estudio de genética del desarrollo sin relevancia para la hirudoterapia, el secretoma de la sanguijuela ni ninguna aplicación terapéutica de sanguijuelas o compuestos derivados de ellas. La sanguijuela se emplea puramente como organismo modelo para el estudio del patrón corporal y la biología del desarrollo; el estudio no aborda anticoagulantes, componentes salivales ni ningún tema dentro del dominio de ASH.
Citación
Expression and function of an even-skipped homolog in the leech Helobdella robusta.
Song MH et al. · Development (Cambridge, England), 2002
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Añadido a la biblioteca ASH: May 26, 2026 · Última actualización del sitio: 18 de junio de 2026