. Author manuscript; available in PMC: 2013 Jun 27.

Published in final edited form as: Wiley Interdiscip Rev Dev Biol. 2012 Jul 30;2(3):405–418. doi: 10.1002/wdev.81

TABLE 1.

Developmental Pathways Currently Implicated in the Development and Diversification of Beetle Horns. Listed are Pathways and Focal Genes Studied thus Far, Observed or Inferred Functions during Horn Development, Whether Functions Appeared to Exhibit Distinct Differences Depending on Horn Type (Head- vs. Thoracic Horn, or Resorbed vs. Maintained), Sex, or Species, and Corresponding References

Pathway	Genes	Functions During Horn Development	Specificity			References
Pathway	Genes	Functions During Horn Development	Horn type	Sex	Species	References
Leg patterning	Dll, dac, hth, exd, dac, al	p/d axis patterning	✓	✓	✓	^7,9,10
Hox	Scr	Growth, resorption	✓	✓	✓	¹¹
TGF-β	dpp	Growth	✓	✓	✓	¹²
Wnt	pan	Growth	✓	✓	✓	¹³
Programmed cell death	caspase, br, E93	Resorption, sculpting	✓	✓	✓	⁸
Insulin-signaling	foxo	Growth	?	?	?	¹⁴
Juvenile hormone-signaling	N/A	Growth, sculpting	✓	✓	✓	¹⁵