Maternal melanization defines wing spot area of male Drosophila nepalensis: supporting evidence through genetic crosses

Males of Drosophila nepalensis show dimorphism in wing melanization, but how do they evolve and coordinate during evolution is unknown. Heterogeneity in the environment helps individuals to adapt accordingly either through genetic polymorphism or through phenotypic plasticity. In this study, we tried to untangle the genetic architecture underlying differences in wing melanization in males because in nature the frequency of spotted and spotless males is different. We investigated the genetic basis of the inheritance of the sexually dimorphic characteristic of wing spot area (WSA) in D. nepalensis males with the aid of genetic crosses. We found spot formation on wings in male is directly correlated to female body melanization. In addition to this, we studied the phenotypic plasticity in the degree of wing spot melanization in males with respect to changes in temperature. We observed that increased WSA is negatively correlated with higher temperature. We found dark and light females only at 21 degrees C. Dark females always produced males with spotted wing, whereas lighter females always produced males without wing spots. Finally, we found wing spot is highly correlated in reciprocal progeny due to linkage or pleiotropy which could help in evolution.

Automated summary

In this study, we investigated the genetic architecture underlying differences in wing melanization in male fruit flies (Drosophila nepalensis). We found that spot formation on wings is directly correlated to female body melanization. Additionally, we studied the phenotypic plasticity in the degree of wing spot melanization in males with respect to changes in temperature, and observed a negative correlation between increased wing spot area and higher temperature.