A Genome-Wide Survey on Basic Helix-Loop-Helix Transcription Factors in Giant Panda

Qin Yao,Debao Zhang,Yong Wang,Vladimir N. Uversky,Chunwang Dang,Keping Chen

doi:10.1371/journal.pone.0026878

Abstract

The giant panda (Ailuropoda melanoleuca) is a critically endangered mammalian species. Studies on functions of regulatory proteins involved in developmental processes would facilitate understanding of specific behavior in giant panda. The basic helix-loop-helix (bHLH) proteins play essential roles in a wide range of developmental processes in higher organisms. bHLH family members have been identified in over 20 organisms, including fruit fly, zebrafish, mouse and human. Our present study identified 107 bHLH family members being encoded in giant panda genome. Phylogenetic analyses revealed that they belong to 44 bHLH families with 46, 25, 15, 4, 11 and 3 members in group A, B, C, D, E and F, respectively, while the remaining 3 members were assigned into “orphan”. Compared to mouse, the giant panda does not encode seven bHLH proteins namely Beta3a, Mesp2, Sclerax, S-Myc, Hes5 (or Hes6), EBF4 and Orphan 1. These results provide useful background information for future studies on structure and function of bHLH proteins in the regulation of giant panda development.

Highlights

The basic helix-loop-helix proteins form a large superfamily of transcription factors that play crucial roles in a wide range of developmental processes including neurogenesis, myogenesis, hematopoiesis, sex determination and gut development
Giant Panda basic helix-loop-helix (bHLH) Family Members The tblastn searches, sequence alignment, and examination of the 19 conserved amino acid sites revealed that there were 107 bHLH genes encoded in giant panda genome
Each identified giant panda bHLH (GpbHLH) gene was named according to nomenclature used by mouse bHLH sequences

Summary

Introduction

The basic helix-loop-helix (bHLH) proteins form a large superfamily of transcription factors that play crucial roles in a wide range of developmental processes including neurogenesis, myogenesis, hematopoiesis, sex determination and gut development. As bHLH proteins present great importance in the regulation of organismal development, in this study, we have made exhaustive effort to obtain the complete list of bHLH family members encoded in the genome of giant panda. Each giant panda bHLH motif sequence was used to conduct in-group phylogenetic analyses [9] with mouse bHLH motif sequences.

Results

Conclusion