Genome-wide Identification And Sequence Analysis Of Four Avian BHLH Transcription Factors

The basic helix-loop-helix(bHLH)gene family is a family of transcription factors ubiquitous in plants and animals.The bHLH sequence consists of basic domain and helix-loop-helix domain.Basic regions bind to specific hexonucleotide DNA,and helix-loop-helix domains act as dimers with other bHLH proteins.With the completion of a large number of animal and plant genome sequencing data,many research groups at home and abroad have carried out in-depth research on the bHLH gene family.Animal bHLH transcription factors are divided into 6 major classes(A-F)and 45 subclasses.At present,little is known about the identification of avian bHLH.As a bird species with high homology with domestic chickens,the study on the whole genome of Turkey is of great reference value in the analysis of human related diseases.Ducks,as the natural host of avian influenza A virus(AIV),have become one of the important models for the study of zoonoses.Because of the rapid evolution in learning and cognition,genome correlation analysis of great tit can provide evidence for species evolution,ecological and behavioral studies,social cognition and other aspects.The vermilion hummingbird is one of the most mobile and professional vertebrate fliers,and the study of its whole genome can provide reference value for exploring the flight control mechanism of vertebrates.In order to study the quantitative distribution and regulation of bHLH transcription factors in birds,four interested members of the avian bHLH gene family were analyzed.According to data on the genomes of four bird species published on the NCBI website,The database of Refseq protein,Anotated protein and Gnomon protein and 7 nucleic acid databases including HTGS,ESTs and Traces-other DNA were searched with 118 human bHLH sequences and 104 chicken bHLH sequences,respectively.The bHLH sequence was searched for subsequent analysis.The main conclusions of this study are as follows: 1.78 bHLH moieties were identified in Turkey,which could be classified into six large groups(A-F),with 34 bHLH moieties in group A,10 in group B,20 in group C,4 in group D,6 in group E,and 3 in group F,respectively.In addition,one Orphan factor was found.A total of93 bHLH sequences were found in Great Tits and classified into 41 subfamilies,in which there were 40,13,22,4,10,3 bHLH sequences in high-order groups A,B,C,D,E and F,respectively,and an orphan factor was found.Ninety-three bHLH sequences were identified in vermilion hummingbird,and the distribution of bHLH sequences in 6 subfamilies was 42 in group A,9 in group B,23 in group C,4 in group D,9 in group E,and 4 in group F,and two orphan factors were found.A total of 102 bHLH moines were identified in mallard ducks,which can be classified into six large groups(A-F).There were 43 Orphan factors in group A,13 in group B,25 in group C,4 in group D,12 in group E,and 3 in group F.In addition,2orphan factors were found.2.bHLH motifs in the same group have similar or the same conserved domain or motifs.3.The biological functions involved in the four species of birds mainly include DNA binding activity,growth and development of organisms,skeletal muscle generation,transcriptional regulation,etc.The main pathways involved are transcription factors,signaling pathways regulating stem cell pluripotency,Notch signaling pathway,cancer pathway,circadian rhythm,TGF-beta signaling pathway.4.The results of collinear block analysis indicated that bHLH gene was highly conserved between species.5.There are significant differences in the number of bHLH transcription factor family members between vertebrates and invertebrates.Most vertebrates have more than 100 BHLHS.6.Each Hes gene family member has its own evolutionary origin and ancestral genes,which are highly conserved during evolution.