Identification of Bombyx atonal and functional comparison with the Drosophila atonal proneural factor in the developing fly eye

作者：Yu, Linlin; Zhou, Qingxiang; Zhang, Chuanxi; Pignoni, Francesca^*

来源：GENESIS, 2012, 50(5): 393-403.

DOI：10.1002/dvg.20816

• proneural factor
• bHLH
• neurogenesis

The proneural genes are fundamental regulators of neuronal development in all metazoans. A critical role of the fly proneural factor Atonal (AtoDm) is to induce photoreceptor neuron formation in Drosophila, whereas its murine homolog, Atonal7Mm (aka Ath5) is essential for the development of the ganglion cells of the vertebrate eye. Here, we identify the Bombyx mori ato homolog (atoBm). In a pattern strikingly reminiscent of atoDm, the atoBm mRNA is expressed as a stripe in the silkworm eye disc. Its DNA-binding and protein-protein interaction domain is highly homologous to the AtoDm bHLH. Targeted expression of AtoBm in the endogenous atoDm pattern rescues the eyeless phenotype of the fly ato1 mutant and its ectopic expression induces similar gain-of-function phenotypes as AtoDm. Rescue experiments with chimeric proteins show that the non-bHLH portion of AtoBm (N-region) can effectively substitute for the corresponding region of the fly transcription factor, even though no apparent conservation can be found at the amino acid level. On the contrary, the highly similar bHLH domain of AtoBm cannot similarly substitute for the corresponding region of AtoDm. Thus, the bHLHBm domain requires the AtoBm N-region to function effectively, whereas the bHLHDm domain can operate well with either N-region. These findings suggest a role for the non-bHLH portion of Ato proteins in modulating the function of the bHLH domain in eye neurogenesis and implicate specific aa residues of the bHLH in this process. genesis 50:393403, 2012.

• 出版日期2012-5
• 单位浙江大学