Armor plating variation in sticklebacks is primarily influenced by which gene?

Armor plating variation in sticklebacks is primarily influenced by which gene?

• A. Pitx1_Pel
• B. EDA
• C. SHH
• D. GHR

Answer: (B)

Armor plating variation in sticklebacks is driven by the EDA gene, which encodes ectodysplasin A, a signaling protein essential for the development of skin appendages like plates. A regulatory change near EDA in freshwater populations reduces its activity during plate formation, leading to fewer lateral plates. This pattern has been repeatedly observed across populations, showing EDA's major role in this trait. By contrast, Pitx1_Pel mainly affects pelvic spines, while SHH and GHR are involved in broader developmental or growth processes and do not primarily control plate number. So, the gene most closely tied to armor plating variation is EDA.

Armor plating variation in sticklebacks is driven by the EDA gene, which encodes ectodysplasin A, a signaling protein essential for the development of skin appendages like plates. A regulatory change near EDA in freshwater populations reduces its activity during plate formation, leading to fewer lateral plates. This pattern has been repeatedly observed across populations, showing EDA's major role in this trait. By contrast, Pitx1_Pel mainly affects pelvic spines, while SHH and GHR are involved in broader developmental or growth processes and do not primarily control plate number. So, the gene most closely tied to armor plating variation is EDA.