应用mRNA差异显示技术寻找调控白腰纹鸟前脑发声控制神经核RA性双态性发育的基因

Sexually dimorphic expression of the genes in the forebrain vocal-control nucleus RA of juvenile white-rumped munia Lonchura striata by mRNA differential display technique

Song behavior and its song-control nuclei (such as the robust nucleus of the arcopallium-RA) are highly sexually dimorphic in passerine songbirds. These dimorphisms are not present early in development, but arise through processes during sensitive periods in life. There are no sex differences in RA volume and neuron numbers of white-rumped munia at P35 (date after birth), but sexual dimorphism in RA volume became very markedly at P45. It is thought that the development of neural dimorphism is controlled by genes. In this experiment, the female and male RAs at developmental ages P35 (females only) and P45 (females and males) were studied by mRNA differential display (DD) technology. For the DDRT-PCR, combinations of the four T_ 12MN primers together with sixteen arbitrary primers, AP1-16, were used. This analysis yielded 1 158 bands in total, of which 273 bands were differentially generated. There were 161 differential bands which size was between 100 bp and 500 bp. The aim of this study was focused on the cDNAs co-expressed in P35 female and P45 male (sixty-one bands) or expressed only in female at P45 (nineteen bands), which might play a role in the dimorphic development of RA. After the second PCR amplification, sixteen differential bands were screened out, of which eleven were co-expressed in P35 female and P45 male, five were only expressed in female at P45, which might underlie the genetic mechanism of the RA dimorphic development in white-rumped munia. A differential segment named T3, which had 81% homology with Bcl complex in chichen, might be a member of Bcl-2 protein family or relate to the retaining of RA volume, was chosen to sequence and analyse. However, the information about T3 segment in detail needed further research. These results show that mRNA DD methodology can represent a potential tool for investigation of the gene expression in the brain of songbird development .