Cell lineage analysis of mirror-image morphs in Lymnaea stagnalis L.

• Grant number: 06/06896-2
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2008
• End date: April 30, 2010
• Field of knowledge: Biological Sciences - Morphology - Embryology
• Principal Investigator: Toshie Kawano
• Grantee: Toshie Kawano
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Cell lineages of two morphs of Lymnaea stagnalis will be analyzed to test whether the reversal of left-right polarity by itself alters later morphogenesis. In Lymnaea stagnalis, the dextral morph is the wild type, and the sinistral morph is a genetic mutant. It has been observed that the mortality of sinistrals is higher than that of dextrals, even though they share the same genomic background from the same parents. It indicates that sinistrals suffer anomalous development because of the polarity reversal, but not of genetic differences. Sinistral malformations are evident at the trochophore and veliger stages when observed by stereomicroscopy. The method of silver-nitrate staining will be used to follow the cell lineages. Our results will determine how the process of malformation starts at the early stages of development. The project will provide crucial implication on the process of developmental constraint against the reversal of left-right polarity, to answer a historical question: Why is the mirror-image morph so rare in animals? (AU)