Fig. 4
ACD components that control mitotic spindle orientation. a-d Schematic drawings illustrating dynamic molecular mechanisms of spindle orientation derived from previous studies in C. elegans and Drosophila. Individual ACD components are shown (orange), spindle microtubule (green). a Mitotic spindle orientation proteins Insc and Pins bind Par3 (cortical domain complex). Pins binds Gαi linking Pins to cortex. Aurora A phosphorylates Pins linker region allowing Dlg binding. b Plus end tracking microtubule-associated protein Khc-73 binds Dlg capturing microtubules at the cortex. c NuMA out-competes Insc to bind Pins. Dynein/Dynactin complex is transported to microtubule plus end by CLIP-170. d NuMA binds Dynactin complex while BicD (not shown) activates Dynein initiating pulling forces. e, f Transcriptional profiles of spindle orientation components during early development of P. dumerilii based on RNA-seq: x-axis shows time in hours post fertilization (hpf), y-axis shows median level of transcripts in fragments per kilobase per million reads (FPKM) (Additional file 5). Expression levels for most components are high at 2 hpf, decreasing during later stages. e Expression profiles for ACD components known to connect cortical cues to motor complexes. g αi shows atypical expression possibly due to multiple functions as a G-protein. pins exhibits low level expression. f Expression profiles for components encoding force-generating motor complexes. Dynactin complex contains 23 subunits including Dynamitin, and Dynactin 4 (two representative transcripts shown here). Dynein contains multiple subunits, represented by transcripts coding for Dynein Heavy Chain 1. Transcripts for six Dynactin and multiple Dynein complex components show similar expression patterns (data not shown). clip-170, which codes for a protein that aids in Dynein/Dynactin recruitment to the cortex, is expressed at low levels. Dynein cofactors BicD2 and Lis1, which regulate Dynein function and processivity, show similar expression patterns with bicd2 expressed at high levels at 2 hpf. ndel1 shows increasing expression throughout early embryogenesis. For error bars see Additional file 10