Expression analysis of Rab11 during zebrafish embryonic development.

Background: Rab proteins are GTPases responsible for intracellular vesicular trafficking regulation. Rab11 proteins, members of the Rab GTPase family, are known to regulate vesicular recycling during embryonic development. In zebrafish, there are 3 rab11 paralogues, known as rab11a, rab11ba and rab11bb, sharing high identity with each other. However, the expression analysis of rab11 is so far lacking.

Results: Here, by phylogeny analysis, we found the three rab11 genes are highly conserved especially for their GTPase domains. We examined the expression patterns of rab11a, rab11ba and rab11bb using RT-PCR and in situ hybridization. We found that all the three genes were highly enriched in the central nervous system, but in different areas of the brain. Apart from brain, rab11a was also expressed in caudal vein, pronephric duct, proctodeum, pharyngeal arches and digestive duct, rab11ba was detected to express in muscle, and rab11bb was expressed in kidney, fin and spinal cord. Different from rab11a and rab11ba, which both have maternal expressions in embryos, rab11bb only expresses during 24hpf to 96hpf.

Conclusions: Our results suggest that rab11 genes play important but distinct roles in the development of the nervous system in zebrafish. The findings could provide new evidences for better understanding the functions of rab11 in the development of zebrafish embryos.