Open AccessDownregulation of homeodomain protein Cut is essential for follicle maturation and ovulation
Author(s) -
Elizabeth M Knapp,
Wei Li,
Jianjun Sun
Publication year - 2019
Publication title -
development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.754
H-Index - 325
eISSN - 1477-9129
pISSN - 0950-1991
DOI - 10.1242/dev.179002
Subject(s) - biology , follicle , microbiology and biotechnology , folliculogenesis , transcription factor , ovulation , oogenesis , ovarian follicle , downregulation and upregulation , hair follicle , somatic cell , oocyte , endocrinology , embryogenesis , genetics , embryo , gene , hormone
Proper development and maturation of a follicle is essential for successful ovulation and reproduction; however, molecular mechanisms for follicle maturation, particularly for somatic follicle cell differentiation, are poorly understood. During Drosophila oogenesis, the somatic follicle cells encasing oocytes undergo two distinct well-established transitions: the mitotic to endocycle switch at stage 6/7 and the endocycle to gene amplification switch at stage10A/10B. Here, we identify a novel third follicle cell transition that occurs in the final stages of oogenesis (stage 13/14). This late follicle cell transition is characterized by a downregulation of the homeodomain transcription factor Cut and the zinc-finger transcription factor Tramtrack-69 (Ttk69), and an upregulation of the transcription factor Hindsight (Hnt). We demonstrate that inducing expression of Cut in stage 14 follicle cells is sufficient to inhibit follicle rupture and ovulation through its negative regulation of Hnt and promotion of Ttk69 expression. Our work illustrates the importance of the stage13/14 transition for follicle maturation and demonstrates the complex regulation required for somatic follicle cells to differentiate into a state primed for follicle rupture and ovulation.