Transcriptomic analysis of skin pigmentation variation in the Virginia opossum (Didelphis virginiana).

We investigated the gene expression changes associated with skin pigmentation variation between Virginia opossum populations inhabiting tropical and temperate environments. We found that gene expression variation in genes with melanocytic and immune functions is associated with the degree of skin pigmentation variation. Further, we found evidence suggesting that the Wnt/ß-catenin signaling pathway might be regulating the depigmentation observed in temperate populations. We present several alternative hypotheses that may explain Gloger’s rule pattern of skin pigmentation variation in the Virginia opossum. Skin samples from 13 Virginia opossums we collected, eight from tropical populations and five from temperate populations. The mRNA was extracted, sequenced (RNA-Seq) and analyzed.

本研究探究了栖息于热带与温带环境的北美负鼠（Virginia opossum）种群间，与皮肤色素沉着差异相关的基因表达变化。研究发现，具备黑素细胞功能与免疫功能的基因，其表达变异与皮肤色素沉着程度的差异存在显著关联。此外，本研究获得的证据提示，Wnt/β-连环蛋白信号通路（Wnt/ß-catenin signaling pathway）可能调控了温带种群中观测到的色素减退现象。本研究还提出了若干替代性假说，用以解释北美负鼠皮肤色素沉着变异的格洛格尔法则（Gloger’s rule）模式。本次研究共采集13只北美负鼠的皮肤样本，其中8只来自热带种群，5只来自温带种群；随后对样本中的信使核糖核酸（mRNA）进行提取、RNA测序（RNA-Seq）及分析。