Submitted June 29, 2007
Returned for revision July 25, 2007
Accepted November 27, 2007
Ovary
Fbxw15/Fbxo12J Is an F-Box Protein-Encoding Gene Selectively Expressed in Oocytes of the Mouse Ovary
Elsa De La Chesnaye ,
Bredford Kerr ,
Alfonso Paredes ,
Horacio Merchant-Larios ,
Juan Pablo Méndez ,
and
Sergio R. Ojeda *
* To whom correspondence should be addressed. E-mail: ojedas{at}ohsu.edu.
Abstract
In recent years, several factors required for follicle assembly and/or early growth of newly formed primordial follicles have been characterized, but it is likely that additional factors remain to be identified. We have used cDNA arrays to compare gene expression in the neonatal mouse ovary 48 h after birth (when primordial follicles are being assembled), and at 96 h (when early follicular growth is taking place), to that of ovaries collected less than 24 h after birth (when follicles have not yet been formed). Segregating genes according to their pattern of expression revealed the presence of one cluster of 24 genes whose expression consistently increased at 48 and 96 h. The top increaser in this cluster encodes a ~1.5 Kb mRNA containing an open reading frame of 1,401 bp that encodes a protein of 466 amino acids. The predicted 52.3 kDa protein is a member of the F-box only (FBXO) protein family, termed FBXW15 or FBXO12J. It has a cytoplasmic localization that includes the endoplasmic reticulum. Fbxw15/Fbxp12J mRNA expression is oocyte-specific; the mRNA is first detected on Gestational Day 18, decreasing thereafter to minimal levels on the day of birth. Fbxw15/Fbxp12J mRNA prevalence increases again 48 and 96 h after birth, coinciding with the time of follicular assembly and the initiation of early follicular growth. The specific expression of Fbxw15/Fbxp12J in oocytes and its developmental pattern of expression suggest a role for this gene in the regulation of oocyte physiology.
Key words:
Follicular development
Oocyte development
F-box proteins
Ovarian development