Expression patterns of the top five genes encoding TSR domain proteins in <i>Hydra oligactis</i>.

<p>(A) A schematic drawing of a longitudinal cross section of an adult hydra. (B-F) Expression patterns of the top five genes encoding TSR domain proteins in <i>Hydra oligactis</i> by whole mount <i>in situ</i> hybridization. All the genes are expressed in the head region. The accession numbers of the genes were shown on the lower left in each panel.</p

Domain structures of <i>Hydra magnipapillata</i> TSR domain proteins.

<p>The domain structures of TSR domain proteins identified in the present study. TSR domains are indicated by red ovals. The accession numbers are from the NCBI nucleotide database.</p

Thrombospondin Type-1 Repeat Domain-Containing Proteins Are Strongly Expressed in the Head Region of <i>Hydra</i>

<div><p>The head region of <i>Hydra</i>, the hypostome, is a key body part for developmental control and the nervous system. We herein examined genes specifically expressed in the head region of <i>Hydra oligactis</i> using suppression subtractive hybridization (SSH) cloning. A total of 1414 subtracted clones were sequenced and found to be derived from at least 540 different genes by BLASTN analyses. Approximately 25% of the subtracted clones had sequences encoding thrombospondin type-1 repeat (TSR) domains, and were derived from 17 genes. We identified 11 TSR domain-containing genes among the top 36 genes that were the most frequently detected in our SSH library. Whole-mount <i>in situ</i> hybridization analyses confirmed that at least 13 out of 17 TSR domain-containing genes were expressed in the hypostome of <i>Hydra oligactis</i>. The prominent expression of TSR domain-containing genes suggests that these genes play significant roles in the hypostome of <i>Hydra oligactis</i>.</p></div

Expression patterns of the genes encoding TSR domain proteins of the A-C groups in the head region of <i>Hydra oligactis</i>.

<p>Among the 10 genes of the A-C groups, six (A- D, G and I) are strongly expressed in the endodermal cells and two (H and J) in the ectodermal cells of the hypostome. The transcripts of XM_002167490 (E) and XM_00215776 (F) were only detected in the tentacles, and not in the hypostome. XM_002160899 (H) was detected in the ectodermal cells of both the hypostome and tentacles. Accession numbers were labeled on the lower left of each panel. The domain structures of the genes were shown on the top of photo panels for each group.</p

Results of a BLAST homology search of cDNA clones isolated from the SSH library of <i>Hydra oligactis</i>.

<p>Results of a BLAST homology search of cDNA clones isolated from the SSH library of <i>Hydra oligactis</i>.</p

Expression patterns of the genes encoding TSR domain proteins of the D and E groups in the head region of <i>Hydra oligactis</i>.

<p>Among the 6 genes of the D and E groups, five (A, B, D-F) are strongly expressed in the endodermal cells of the head region. The transcript of XM_002154766 (C) was only detected in the tentacles, and not in the hypostome. Accession numbers were labeled on the lower left of each panel. The domain structures of the genes were shown on the top of the photo panels for each group.</p