Meeting Abstract
91.2 Thursday, Jan. 7 Evolutionarily conserved expression of genes involved in the differentiation of anterior neural tissues within the larva of the articulate brachiopod, Terebratalia transversa. SANTAGATA, S.**; RESH, C.; HEJNOL, A.; PASSAMANECK, Y.; MARTINDALE, M.Q.; Long Island University, C.W. Post Campus; Long Island University, C.W. Post Campus; Kewalo Marine Laboratory, University of Hawaii; Kewalo Marine Laboratory, University of Hawaii; Kewalo Marine Laboratory, University of Hawaii scott_santagata@hotmail.com
Evolutionarily conserved transcription factors are involved in the anterior-posterior patterning of the nervous system among divergent bilaterian phyla. Specifically, several genes such as fez, otp, and NK2.1 are expressed in cells within the anterior and medial regions of the nervous system. We isolated and characterized the expression patterns of these genes and others found in neuronal cells within the embryos and larvae of the articulate brachiopod, Terebratalia transversa. Both fez and otp exhibit broad expression within the developing apical ganglion during the late stages of gastrulation. Fez maintains broad expression within the apical ganglion through late larval stages, however otp becomes restricted to a small subset of medially positioned neuronal cells in the apical ganglion and the mantle lobe at late larval stages. Similar to otp, NK2.1 is expressed more broadly within anterior neuronal tissues during the latter stages of gastrulation and becomes restricted to a medial group of neuronal cells within the apical ganglion by the late larval stage. These results, coupled with immunohistochemical data on the distribution of neurotransmitters, support bilaterian-wide developmental conservation of anterior neurosecretory structures. Although some aspects of these expression patterns are shared among all bilaterians and influenced by functional constraints, the majority of our data are more consistent with expression patterns found among trochozoan larval forms than those of deuterostomes.
