Molecular basis of the silkworm mutantrelcausing red egg color and embryonic death

The coloration and hatchability of insect eggs can affect individual and population survival. However, few genetic loci have been documented to affect both traits, and the genes involved in regulating these two traits are unclear. The silkworm recessive mutantre(l)shows both red egg color and embryo mortality. We studied the molecular basis of there(l)phenotype formation. Through genetic analysis, gene screening and sequencing, we found that two closely linked genes,BGIBMGA003497(Bm-re) andBGIBMGA003697(BmSema1a), control egg color and embryo mortality, respectively. Six base pairs of theBm-regene are deleted in its open reading frame, andBmSema1ais expressed at abnormally low levels in mutantre(l).BmSema1agene function verification was performed using RNA interference and clustered randomly interspersed palindromic repeats (CRISPR)/CRISPR-associate protein 9. Deficiency of theBmSema1agene can cause the death of silkworm embryos. This study revealed the molecular basis of silkwormre(l)mutant formation and indicated that theSema1agene is essential for insect embryo development.

Automated summary

The study revealed the molecular basis of silkworm re(l) mutant formation, identifying two genes that control egg color and embryo mortality, with BmSema1a gene being essential for insect embryo development.