Hara Yoshinobu, Katow Hideki
Laboratory of Developmental and Cell Biology, Graduate School of Life Sciences, Tohoku University, Asamushi, Aomori 039-3501, Japan.
Gene Expr Patterns. 2005 Apr;5(4):503-10. doi: 10.1016/j.modgep.2004.12.003.
Hedgehog (hh) is a multifunctional extracellular protein, and known as an essential signal molecule in morphogenetic movement in animal embryos. We have cloned, sequenced, and studied dynamic localization of Hphh, a hedgehog homologue of the sea urchin, Hemicentrotus pulcherrimus. The origin of Hphh transcribing cells was also verified during early embryogenesis. The amino acid sequence of Hphh shows high homology to Lvhh, an hh homologue cloned in the sea urchin, Lytechinus variegatus. Reverse transcriptase polymerase chain reaction showed that the transcription of Hphh occurred at and after 19 h post-fertilization (19 hpf) mesenchyme blastula stage until, at least, 69 hpf 4-arm pluteus stage. Whole mount in situ hybridization showed Hphh transcription sites in a few cells at the tip of archenteron in 30 hpf gastrulae. At around 45 hpf 2-arm pluteus stage, the number of Hphh transcribed cells was 8, and unequally split to two groups, 5 cells in left coelomic sac and 3 cells in right coelomic sac. A cell lineage tracing by staining the small micromeres with 5-Bromo-2-deoxyuridine showed that Hphh was transcribed exclusively in all the small micromere descendants and comprised the coelomic sacs in 69 hpf plutei.
刺猬因子（hh）是一种多功能细胞外蛋白，是动物胚胎形态发生运动中重要的信号分子。我们已经克隆、测序并研究了海胆（Hemicentrotus pulcherrimus）刺猬因子同源物Hphh的动态定位。同时也验证了Hphh转录细胞在早期胚胎发育过程中的起源。Hphh的氨基酸序列与在海胆（Lytechinus variegatus）中克隆的hh同源物Lvhh具有高度同源性。逆转录聚合酶链反应显示，Hphh的转录发生在受精后19小时（19 hpf）间充质囊胚期及之后，至少持续到69 hpf四腕幼虫期。整体原位杂交显示，在30 hpf原肠胚的原肠末端少数细胞中有Hphh转录位点。在大约45 hpf双腕幼虫期，转录Hphh的细胞有8个，不均匀地分为两组，左体腔囊中有5个细胞，右体腔囊中有3个细胞。用5-溴-2-脱氧尿苷对小分裂球进行染色的细胞谱系追踪显示，Hphh仅在所有小分裂球后代中表达，并在69 hpf幼虫中构成体腔囊。
