# name
Inhibitory Smads and Bone Morphogenetic Protein (BMP) modulate anterior photoreceptor cell number during planarian eye regeneration

# metadata.dc.description.abstract[].value
Planarians represent an excellent model to study the processes of body axis and organ re-specification during regeneration. Previous studies have revealed a conserved role for the bone morphogenetic protein (BMP) pathway and its intracellular mediators Smad1/5/8 and Smad4 in planarian dorsoventral (DV) axis re-establishment. In an attempt to gain further insight into the role of this signalling pathway in planarians, we have isolated and functionally characte-rized the inhibitory Smads (I-Smads) in Schmidtea mediterranea. Two I-Smad homologues have been identified: Smed-smad6/7-1 and Smed-smad6/7-2. Expression of smad6/7-1 was detected in the parenchyma, while smad6/7-2 was found to be ex-pressed in the central nervous system and the eyes. Neither single smad6/7-1 and smad6/7-2 nor double smad6/7-1,-2 silencing gave rise to any apparent disruption of the DV axis. However, both regenerating and intact smad6/7-2 (RNAi) planarians showed defects in eye morphogenesis and displayed small, rounded eyes that lacked the ante-rior subpopulation of photoreceptor cells. The number of pigment cells was also reduced in these animals at later stages of regeneration. In contrast, after low doses of Smed-bmp(RNAi), planarians regenerated larger eyes in which the anterior subpopulation of photoreceptor cells was expanded. Our results suggest that Smed-smad6/7-2 and Smed-bmp control the re-specification and maintenance of anterior photoreceptor cell number in S. medi-terranea.

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International Journal of Developmental Biology, 2012, vol. 56, p. 155-163

# metadata.dc.rights[].value
(c) University of the Basque Country Press, 2012

# metadata.dc.source[].value
Articles publicats en revistes (Genètica, Microbiologia i Estadística)

# metadata.dc.title[].value
Inhibitory Smads and Bone Morphogenetic Protein (BMP) modulate anterior photoreceptor cell number during planarian eye regeneration