Gastrulation occurs by a variety of morphogenetic movements, often correlated with diverse expression of the T-box transcription factor Brachyury (Bra). Bra may be expressed in ectoderm, mesoderm, or endoderm, but its role in cell fate specification or regulation of gastrulation movements has not been studied in the development of crustaceans. Penaeid shrimp (Decapoda: Dendrobranchiata: Penaeidae) develop by complete cleavage and gastrulation by invagination to a free-swimming nauplius larva. Penaeid gastrulation diverges from other decapods and from insects, occurring early at a low cell number with the formation of a radial invagination. Toward a better understanding of gastrulation movements in penaeid shrimp, bra was identified from newly available penaeid shrimp genomes and transcriptomes of Litopenaeus vannamei, Marsupenaeus japonicus, and Penaeus monodon. Additional bra homologs were obtained from the outgroups Sicyonia ingentis (Decapoda: Dendrobranchiata: Sicyoniidae) and the caridean shrimp Caridina multidentata (Decapoda: Pleocymata). The genes encoded penaeid shrimp Bra proteins of 551–552 amino acids, containing the highly conserved T-box DNA-binding region. The N-terminal Smad1-binding domain, conserved in most animals, was absent in shrimp Bra. The R1 repressor domain was the best conserved of the C-terminal regulatory domains, which were widely divergent compared to other species. The penaeid shrimp bra gene consisted of six exons, with splice sites conserved with other phyla across the animal kingdom. Real-time qPCR and FPKM analysis showed that shrimp bra mRNA was strongly expressed during gastrulation. These findings begin to address the evolution of gastrulation in shrimp at the molecular level.

中文翻译：

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对虾对虾腕足动物：胃排卵过程中的序列分析和表达。

胃蠕动通过多种形态发生运动发生，通常与T盒转录因子Brachyury（Bra）的多种表达相关。胸罩可能在外胚层，中胚层或内胚层中表达，但在甲壳类动物的发育中尚未研究其在细胞命运规范或胃泌乳运动调节中的作用。对虾（十足目：Dendrobranchiata：对虾科）通过完全分裂和内胚化，通过向自由游动的无节幼体幼虫内插来发育。对虾的胃化与其他十足动物和昆虫不同，它们以低细胞数早期发生，并形成放射状内陷。为了更好地了解对虾对虾的胃排泄运动，从新近获得的对虾对虾的基因组和转录组中鉴定出胸罩。凡纳滨对虾，Mar鱼和斑节对虾。另外的胸罩同源物是从以下群体中获得的：西洋对虾（十足目：Dendrobranchiata：Sicyoniidae）和and虾对虾（Carideina multidentata）（十足目：Pleocymata）。这些基因编码了551-552个氨基酸的对虾虾Bra蛋白，其中包含高度保守的T-box DNA结合区。在大多数动物中保守的N末端Smad1结合域在虾Bra中不存在。R1阻遏物结构域是C端调节结构域中最保守的，与其他物种相比，其差异很大。虾皮文胸该基因由六个外显子组成，其剪接位点与整个动物界的其他门均保守。实时定量PCR和FPKM分析表明，在排卵过程中虾胸罩mRNA强烈表达。这些发现开始在分子水平上解决虾的胃化演变。