Alsemgeest Jenifer, Old Julie M, Young Lauren J
Central Queensland University, Centre for Environmental Management, Rockhampton, Queensland 4702, Australia.
Vet Immunol Immunopathol. 2013 Sep 1;155(1-2):139-45. doi: 10.1016/j.vetimm.2013.06.009. Epub 2013 Jun 19.
The pro-inflammatory cytokine, Interleukin-6 (IL-6), has not yet been fully characterised in the model macropod, Macropus eugenii, due to incomplete sequence information in publically available genome databases. Using a Rapid Amplification of cDNA Ends strategy we have confirmed the expression and complete nucleotide sequence for this molecule in lymph node tissue and activated leukocytes. Structural conservation of the mature wallaby IL-6 molecule was high when compared with human IL-6, although there was only 34% amino acid sequence identity with the human IL-6 peptide, consistent with reports of the evolutionary divergence of this cytokine. We also report the discovery of MeIL-6Δ2, a splice variant missing exon 2, which directly translates to a truncated non-functional peptide, but which may also code for an alternative peptide that is translated downstream of the canonical IL-6 start site. This putative gene product is predicted to maintain some, if not all, of the functions of macropod IL-6 and is the first IL-6 isoform reported outside of eutherian mammals.
由于公开的基因组数据库中序列信息不完整，促炎细胞因子白细胞介素-6（IL-6）在模式有袋动物尤金袋鼠（Macropus eugenii）中尚未得到充分表征。我们采用cDNA末端快速扩增策略，在淋巴结组织和活化白细胞中证实了该分子的表达及完整核苷酸序列。与人类IL-6相比，成熟沙袋鼠IL-6分子的结构保守性较高，尽管其与人类IL-6肽的氨基酸序列同一性仅为34%，这与该细胞因子进化差异的报道一致。我们还报告了MeIL-6Δ2的发现，这是一种缺失外显子2的剪接变体，它直接翻译为截短的无功能肽，但也可能编码在经典IL-6起始位点下游翻译的另一种肽。这种推测的基因产物预计会保留沙袋鼠IL-6的部分（如果不是全部）功能，并且是有袋类哺乳动物之外报道的首个IL-6同种型。
