Furthermore, unlike diploid mitotic divisions, these polyploid papillar divisions are frequently error prone, suggesting papillar structures may accumulate long-term aneuploidy.
Here, we demonstrate an indispensable requirement for pre-mitotic endocycles during papillar development and also demonstrate that such cycles seed papillar aneuploidy.
By contrast, we discovered pre-mitotic endocycles in precursors of Drosophila rectal papillae (papillar cells).
Unlike all known proliferative Drosophila adult precursors, papillar cells endocycle before dividing.
Here, we show that continued division and normal organ development occurs in polyploid, DDR-impaired Drosophila papillar cells.
We find blocking pre-mitotic endocycles disrupts papillar morphogenesis and causes organismal lethality under high-salt dietary stress.
In papillae, this centriole retention contributes to aneuploidy, as centrioles amplify during papillar endocycles, causing multipolar anaphase.
As papillar cells become polyploid, they naturally accumulate broken acentric chromosomes but do not apoptose/arrest the cell cycle.
To survive mitosis with acentric chromosomes, papillar cells require Fanconi anemia proteins FANCD2 and FANCI, as well as Blm helicase, but not canonical DDR signaling.
Clinically, microskin transplantation is still an effective method to treat extensive burns and traumas, but due to lack of dermis, especially the papillar layer, hair follicles, sweat glands and other skin appendages, the neoregenerative skin possesses poor mechanical strength and elasticity, and cannot sweat.
Characteristic papillae and tale with papillar comb indicate they belong to family Onchocercidae, Dirofilariinae, Setaria digitata.
