PT - JOURNAL ARTICLE AU - S. Ramos AU - F. Chelemen AU - V. Pagone AU - N. Elshaer AU - P. Irles AU - M.D. Piulachs TI - Different roles of <em>eye absent</em> in the basal ovarian follicle and germarium of developing cockroach ovaries AID - 10.1101/839639 DP - 2019 Jan 01 TA - bioRxiv PG - 839639 4099 - http://biorxiv.org/content/early/2019/11/12/839639.short 4100 - http://biorxiv.org/content/early/2019/11/12/839639.full AB - Eye absent (Eya) is a protein which has been structurally conserved from hydrozoans to humans which has two functions: it is both a transcription cofactor and a protein tyrosine phosphatase. Eya was first described in the fly Drosophila melanogaster for its role in eye development, and the same functions were also later reported in less derived insects. Studies on the involvement of Eya in insect oogenesis are limited to D. melanogaster, which has meroistic ovaries. In this fly, Eya plays a fundamental role in the first stages of ovarian development because Eya mutations abolish gonad formation.In this present work we studied the function of Eya in the panoistic ovary of the cockroach Blattella germanica. We demonstrated that Eya is essential for correct ovary development also in this ovary type. In B. germanica ovaries, Eya affects both somatic and germinal cells in the germarium and the vitellarium, acting differently in different ovarian regions. Development of the basal ovarian follicles is arrested BgEya-depleted females, while in the germaria, BgEya helps to the maintain the correct number of somatic and germinal stem cells by regulating the expression of ecdysteroidogenic genes in the ovary.