Download The use of Pt-supported carbon nanotube papers, both single

EMBRYONIC EXPRESSION PATTERNS OF GENES THAT PLAY A ROLE IN
ENDOMESODERM CELL DIFFERENTIATION IN BRITTLE STARS. B.
Spiecker, H. Sweet, PhD*, Department of Biological Sciences, Rochester Institute of
Technology, [email protected], [email protected].
Isolation of endomesoderm-specific genes and characterization of their expression
patterns in brittle star embryos provides an element for comparison in evolution of
mesoderm development across the phylum, Echinodermata. Brittle stars have three germ
layers: mesoderm, endoderm, and ectoderm. Brachyury, GataE, GataC, GCM, and
Tbrain are part of a certain set of genes that regulate the differentiation of endomesoderm
cells into two separate germ layers, mesoderm and endoderm. Due to their common
ancestor, a comparison of gene expression between sea urchins and brittle stars will give
us details about how their expressions might have evolved, diverged, or were lost
throughout the years. Ophioplocus esmarki (Oe) and Ophiothrix spiculata (Os) are the
species of interest in this research and they undergo direct and indirect development,
respectively. Direct development indicates a specimen bypasses a feeding and swimming
larvae stage during its maturation. A comparison of gene expression between Oe and Os
will begin to give us clues how their expression patterns differ in relation to the different
types of development. These genes can be analyzed through collections of total RNAs at
varying developmental stages, reverse transcription to create complementary DNAs
(cDNA), degenerate PCR to isolate internal fragments of these genes of interest, and
rapid amplification of cDNA ends (RACE) using gene-specific primers to obtain the ends
of these cDNAs. As a result, GataC and GataE internal fragments were isolated for both
species and RACE-primers were designed. Thus far, the 5’ end of GataC was found for
Os. A future directive involves finding the remaining ends of these cDNAs, using the end
sequences to amplify full-length cDNAs of these genes, establishing a timeline of gene
expressions, and performing in-situ hybridization to discover where the genes are
expressed in the embryos.