Figure 1
Spider silk gland sampling and proportion of total expression in spider tissues due to known silk structural protein encoding transcripts. (a) Representative images of silk gland types sampled (images from L. geometricus). Functions of each glands’ silk secretions also shown31, 32, 51, 63. Flagelliform glands synthesize the axial fiber of the capture spiral in orb-web weavers, but have an unknown function in cobweb weavers. Flagelliform glands are approximately the same size as aciniform glands in Latrodectus and Steatoda; the single pair of flagelliform glands was included with the multitude of aciniform glands in which they were nestled (Ac + F). (b) Proportion of total mean FPKM (fragments aligned per thousand base pairs per million aligned fragments) shown for transcripts classified according to BLASTX homology to known spider silk structural proteins (colors, see Supplementary File 1); only a spider non-silk structural protein (light grey); or to a protein found outside of spiders (dark grey, see Supplementary File 2). Transcripts without a BLASTX alignment to published proteins and that did not align with any other species’ transcripts using BlastClust are shown as “One Species Only” (lightest grey). Lg = Latrodectus geometricus, Lh = L. hesperus, Sg = Steatoda grossa. n = number of biological replicates for each tissue type (see also Supplementary Fig. S1). Multiple individuals were combined to generate sufficient RNA for each replicate.
