Table 1. A partial list of gene products shown to play a role in myoblast fusion.

Drosophila Protein	Vertebrate Protein	Proposed Function in Drosophila and Cellular/Subcellular Behavior	Models testeda	Actin focus classb	References
Sns	Nephrin	Myoblast adhesion; Figure 2B	d, m, zc	1	Kestila et al.,, 1998; Bour et al.,, 2000; Sohn et al.,, 2009
Hbs	Nephrin	Myoblast adhesion; Figure 2B	d, m, zc	Unknown	Kestila et al.,, 1998; Artero et al.,, 2001; Dworak et al.,, 2001 Sohn et al.,, 2009
Duf (Kirre)	Kirrel family	Myoblast adhesion/attraction; Figure 2A, B	d, z	1	Ruiz-Gomez et al., 2000; Strunkelnberg et al., 2001; Srinivas et al., 2007
Rst (Irre)	Kirrel family	Myoblast adhesion/attraction; Figure 2A, B	d	1	Strunkelnberg et al., 2001
Rols (Ants)	Tanc1	Adaptor, signaling; recycling	d	1	Menon and Chia 2001;Chen and Olson 2001; Rau et al., 2001; Menon et al., 2005
Rac1, Rac2, Mtl	Rac1, Rac2, Rac3, RhoG	Cytoskeleton, SCAR/WAVE complex regulation; Figure 2C	dd ze, me	3	Luo et al., 1994;Hakeda-Suzuki et al., 2002; Chen et al., 2003; Srinivas et al., 2007; Vasyutina et al., 2009
Kette (Hem)	Nap1	Cytoskeleton, SCAR/WAVE complex regulation; Figure 2C	d, m	3	Richardson et al., 2007
SCAR	WAVE	Cytoskeleton, Arp2/3 activation; Figure 2C	d	3	Richardson et al., 2007
WASp	WASp	Cytoskeleton, Arp2/3 activation; Figure 2C	d	2	Schafer et al., 2007; Unpublished observations
Arp2/3	Arp2/3	Cytoskeleton, Actin polymerization; Figure 2C	d	Unknown	Richardson et al., 2007
Mbc	Dock1/Dock5	Cytoskeleton, Rac activation; Figure 2C	d, z, m	3	Rushton et al., 1995; Erickson et al., 1997; Moore et al., 2007; Pajcini et al., 2008; Laurin et al., 2008 Galletta et al., 1999;
Crk	Crk/Crk-like	Adaptor, signaling Figure 2C	df, z	Unknown	Balagopalan et al., 2006; Kim et al., 2007; Moore et al., 2007
Blow	No known homolog	Unknown	d	3	Doberstein et al., 1997; Schroter et al., 2004
Sltr/D-WIP (Vrp1)	WIP	Cytoskeleton, WASP regulation; Figure 2C	d	2	Massarwa et al., 2007; Kim et al., 2007
Loner (Siz)	IQSec1/Brag2/GEP100	Cytoskeleton, Arf6/Rac regulation; Figure 2C	d, m	2	Chen et al., 2003; Richardson et al., 2007
Sing	(Caveolin-3)g	Vesicle fusion; Figure 2C	d, m	Unknown	Galbiati et al., 1999; Volonte et al., 2003; Estrada et al., 2007;

^ad: Drosophila; z: zebrafish; m: mouse;

^bActin foci classes from Richardson et al., (2007): 1, no/reduced number of foci; 2, increased number of normal-sized foci; 3, increased number of enlarged foci;

^cmutation results in a muscle defect, not fusion defect;

^dmutation of Rac1, Rac2 required for fusion defect;

^emutation of Rac1 is required for fusion defect;

^finferred;

^gCaveolin-3 is speculated to be the functional ortholog of singles bar (Estrada et al., 2007: Peckham 2008); however, this has not been functionally tested.