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La simetría izquierda-derecha de los embriones de pez cebra requiere cierta tensión superficial
Sundar R Naganathan1, Marko Popović2,3,4, Andrew C Oates5
1Institute of Bioengineering, École polytechnique fédérale de Lausanne, Lausanne, Switzerland. sundar.naganathan@epfl.ch.
Nature
|April 28, 2022
Resumen
Las longitudes de somites embrionarios se forman inicialmente con errores, lo que lleva a la asimetría. Sin embargo, la tensión superficial del tejido remodela activamente los somites después de la formación, asegurando una segmentación corporal precisa y simétrica en el pez cebra.
Área de la Ciencia:
- Biología del desarrollo
- La biofísica
- La embriogénesis
Sus antecedentes:
- El desarrollo embrionario de los vertebrados implica una segmentación periódica en somitas bilaterales.
- Tradicionalmente se cree que la longitud, posición y simetría anteroposterior de las somitas están determinadas molecularmente antes de la morfogénesis.
Objetivo del estudio:
- Para investigar la precisión de las longitudes y posiciones anteroposteriores iniciales de las somitas en embriones de pez cebra.
- Identificar los mecanismos responsables de corregir las asimetrías iniciales y garantizar una cierta simetría morfológica.
Principales métodos:
- Experimentos in vivo que observan el desarrollo embrionario del pez cebra.
- Culturas explantadas de un solo somito in vitro.
- Modelado mecánico para analizar los efectos de la tensión superficial de los tejidos.
- Perturbación de las moléculas de tensión superficial (integrina, fibronectina) y componentes del reloj de segmentación.
Principales resultados:
- Las longitudes y posiciones anteroposteriores iniciales son imprecisas, causando asimetría izquierda-derecha.
- Las somitas ajustan sus longitudes anteroposterior dentro de una hora después de la formación, mejorando la simetría morfológica.
- Los ajustes de longitud se producen a través de cambios de forma (anteroposterior compensado por mediolateral) sin alteración de volumen.
- La tensión superficial de la somita, mediada por la integrina y la fibronectina, impulsa los ajustes de longitud.
- El reloj de segmentación no está involucrado en este proceso de ajuste de longitud posterior a la formación.
Conclusiones:
- La tensión superficial del tejido es un mecanismo crucial para corregir las inexactitudes iniciales de la longitud del somite y garantizar la simetría embrionaria.
- Este proceso impulsado por la tensión superficial representa un mecanismo distinto del reloj de segmentación para lograr longitudes de segmentos morfológicos precisos.
- Los hallazgos sugieren la tensión superficial del tejido como principio general para el ajuste de la forma y la precisión en el desarrollo de los tejidos embrionarios.
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