Embryological insights into the evolution of genome regulation using haploid and diploid whiteflies,Bemisia tabaci

Abstract

ABSTRACTThe whitefly,Bemisia tabaci, is a hemipteran with a haplodiploid sex determination system, which provides a natural experiment for examining genome function in haploid and diploid embryos. Yet the embryogenesis ofB. tabaciremains understudied. Our previous work has established a possible role ofDNA methyltransferase 1(Dnmt1) in genome stability. In this study we used maternal RNA interference (RNAi) and immunohistochemistry to study the complex dynamics between DNMT1 and ploidy during embryogenesis. We found that both haploid and diploidB. tabacihave a similar developmental timeline to other holometabolous insects. We also found that, like other obligatory haploid insects, ploidy does not affect developmental timing, suggesting that maternal factors play a greater role than ploidy in developmental timing. For embryos with reduced expression ofDnmt1, we found that the loss of DNMT1 disrupts blastoderm development and affects nuclei morphology in both haploid and diploid embryos. Our results suggest that DNMT1 is required for blastoderm development.