Construction of the axolotl cell landscape using combinatorial hybridization sequencing at single-cell resolution.

The Mexican axolotl (Ambystoma mexicanum) is a well-established tetrapod model for regeneration and developmental studies. Remarkably, neotenic axolotls may undergo metamorphosis, a process that triggers many dramatic changes in diverse organs, accompanied by gradually decline of their regeneration capacity and lifespan. However, the molecular regulation and cellular changes in neotenic and metamorphosed axolotls are still poorly investigated. Here, we develop a single-cell sequencing method based on combinatorial hybridization to generate a tissue-based transcriptomic landscape of the neotenic and metamorphosed axolotls. We perform gene expression profiling of over 1 million single cells across 19 tissues to construct the first adult axolotl cell landscape. Comparison of single-cell transcriptomes between the tissues of neotenic and metamorphosed axolotls reveal the heterogeneity of non-immune parenchymal cells in different tissues and established their regulatory network. Furthermore, we describe dynamic gene expression patterns during limb development in neotenic axolotls. This system-level single-cell analysis of molecular characteristics in neotenic and metamorphosed axolotls, serves as a resource to explore the molecular identity of the axolotl and facilitates better understanding of metamorphosis.

Genome-wide identification and expression of YABBY genes family during flower development in Punica granatum L.

The plant-specific YABBY transcription factors have important biological roles in plant morphogenesis, growth and development. In this study, we identified six YABBY genes in pomegranate (Punica granatum) and characterized their expression pattern during flower development. Six PgYABBY genes were divided into five subfamilies (YAB1/3, YAB2, INO, CRC, and YAB5), based on protein sequence, motifs and similarity of exon-intron structure. Next, analysis of putative cis-acting element showed that PgYABBYs contained lots of hormone response and stress response elements. Subsequently, gene function prediction and protein-protein network analysis showed that PgYABBYs were associated with the development of apical meristem, flower, carpel, and ovule. Analysis of PgYABBY genes expression in various structures and organs suggested that PgYABBYs were highly activated in flower, leaf and seed coat. Analysis of expression during flower development in pomegranate showed that PgINO might play critical role in regulating the differentiation of flowers. This study provided a theoretical basis for function research and utilization of YABBY genes in pomegranate.