Identification Of Differentially Expressed Genes In The Developing Antler Of Sika Deer (Cervus Nippon Hortulorum)

Deer antlers are the only mammalian appendages capable of regeneration, and thus provide a unique model for researching the mechanisms of mammalian organ regeneration. Antler development is based on stem cells and belongs to endochondral ossification, but not involves cell differentiation. During the development, cell differentiation, proliferation and apoptosis were regulated under gene expression. However, the molecular mechanism remains poorly understood.Here we applied differential display reverse transcription PCR (DDRT-PCR) to screen transcripts differentially expressed during Sika deer antler development and identified the antler growing-related genes through profiling the differential gene expression between three different stages of the mesenchymal layer at the very tip of the velvet antler. We totally gained45differentially expressed ESTs, and14ESTs were sequenced successfully. The sequences were compared in NCBI.5(EST1、EST2、EST3、EST4and EST5) out of14sequences respectively shows high homology with COL9A3、MALAT1、LOX、BCLAF1gene,while others are not. EST3. EST5are derived from LOX gene. Finally, we used real-time PCR to detect the quantitative level of LOX gene expression.We preliminarily found the expression differences of the5ESTs:COL9A3only expressed at mRM and aRM; MALAT1expressed at all periods,moreover, the expression levels of mRM were the highest that it was up-regulated from pRM to mRM while down-regulated from mRM to aRM; LOX was also expressed at all periods,and the expression levels of mRM and aRM were higher than pRM; BCLAF1was only expressed at aRM. Quantitative results showed that:the level of LOX mRNA expression was up-regulated. Compared to pRM, LOX of mRM is significantly expressed (P<0.05), but the LOX of aRM is not (P>0.05). There were also no significant differences between mRNA and aRM. This suggested that LOX gene involved in antler development and possiblely promoted the proliferation of mesenchymal cells, maked the collagen and elastin to form intermolecular crosslinking with other factors and stabilized the extracellular matrix to maintain a stable environment of the cells.