Dual function of the transcription factor Ftz‐f1 on oviposition in the cockroach Blattella germanica

Abstract

The transcription factor Ftz‐f1 has multiple functions in insect development in a spatial‐temporal line. One of these roles is in the insect ovaries, specifically in the regulation of steroidogenic enzymes production. We studied the function of F in Blattella germanica oogenesis, as it shows two moments of high expression in ovaries: before the imaginal moult, and just before ovulation in the adult. Injecting dsftz‐f1 into adult females, either just after the imaginal moult or just prior to choriogenesis, prevented oviposition, with differences between the two approaches. In 3‐day‐old adult females treated with dsftz‐f1 just after the emergence, the expression of ftz‐f1 was not modified, but the steroidogenic genes increased their expression. ftz‐f1 transcript levels in the ovaries of 5‐day‐old dsftz‐f1‐treated females were significantly depleted, and the expression levels of the same steroidogenic genes began to decrease. These results suggest that Ftz‐f1 regulates the expression of steroidogenic genes in B. germanica, with phm possibly being a key target. Ftz‐f1 has a different temporal function in the cytoskeleton of follicular cells of the basal ovarian follicles. Early in the gonadotrophic cycle, Ftz‐f1 promotes the expression of genes related to the cytoskeleton and muscle proteins, while at the end of the cycle it maintains the expression levels of these genes, thus ensuring correct ovulation.

CHMP4B contributes to maintaining the follicular cells integrity in the panoistic ovary of the cockroachBlattella germanica

“…regulates the correct distribution of actin fibers in the BOF, essential to complete ovulation and oviposition (Alborzi & Piulachs, 2023). All these data help to understand the oogenesis in a basal insect with panoistic ovaries.…”

“…CHMP4B is needed to maintain the correct expression of cytoskeleton proteins to allow the BOF to grow and mature properly, incorporating yolk proteins. CHMP4B regulates the correct distribution of actin fibers in the BOF, essential to complete ovulation and oviposition (Alborzi & Piulachs, 2023). All these data help to understand the oogenesis in a basal insect with panoistic ovaries.…”