Additional file 1: Figure S1. of Identification and evolutionary analysis of long non-coding RNAs in zebra finch

Schematic presentation of natal down development in zebra finch and chicken and the six ssRNA-seq datasets used in this study. (A) Zebra finch embryos show two types of feather formation. The anterior dorsal (AD) tract and its two flanks show Type I feather formation (open circles) in which the feather buds do not develop into feather. On the other hand, the middle stripe of the posterior dorsal (PD) tract and the other regions shown in black circles show Type II feather formation in which the feather buds develop into down feathers, which are later replaced by contour feathers. In contrast, both the AD and the PD region of chicken embryos show Type II feather formation. (B) The skin regions and the six ssRNA-seq datasets used in this study. To reduce the complexity of skin regional specificity, only the dorsal skins (red dash boxes) were dissected and analyzed for the gene expressions. E8A: AD skin of embryo day 8; E8P: PD skin of embryo day 8; E9A: AD skin of embryo day 9; E9P: PD skin of embryo day 9; E12A: AD skin of embryo day 12; E12P: PD skin of embryo day 12; D7: 7 days post-hatch. Scale bar: 0.1 cm. The figure was modified from our previous study [27]. (TIF 20328 kb)