title: Unscrambling butterfly oogenesis.
abstract: BACKGROUND
  Butterflies are popular model organisms to study physiological mechanisms underlying variability in oogenesis and egg provisioning in response to environmental conditions. Nothing is known, however, about; the developmental mechanisms governing butterfly oogenesis, how polarity in the oocyte is established, or which particular maternal effect genes regulate early embryogenesis. To gain insights into these developmental mechanisms and to identify the conserved and divergent aspects of butterfly oogenesis, we analysed a de novo ovarian transcriptome of the Speckled Wood butterfly Pararge aegeria (L.), and compared the results with known model organisms such as Drosophila melanogaster and Bombyx mori.
  
  
  RESULTS
  A total of 17306 contigs were annotated, with 30% possibly novel or highly divergent sequences observed. Pararge aegeria females expressed 74.5% of the genes that are known to be essential for D. melanogaster oogenesis. We discuss the genes involved in all aspects of oogenesis, including vitellogenesis and choriogenesis, plus those implicated in hormonal control of oogenesis and transgenerational hormonal effects in great detail. Compared to other insects, a number of significant differences were observed in; the genes involved in stem cell maintenance and differentiation in the germarium, establishment of oocyte polarity, and in several aspects of maternal regulation of zygotic development.
  
  
  CONCLUSIONS
  This study provides valuable resources to investigate a number of divergent aspects of butterfly oogenesis requiring further research. In order to fully unscramble butterfly oogenesis, we also now also have the resources to investigate expression patterns of oogenesis genes under a range of environmental conditions, and to establish their function.
authors.affiliation: Evolutionary Developmental Biology Research Group, Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford, OX3 0BP, UK.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Carter
authors.forename: Simon C
authors.initials: SC
authors.lastname: Baker
authors.forename: Ryan
authors.initials: R
authors.lastname: Pink
authors.forename: David R F
authors.initials: DR
authors.lastname: Carter
authors.forename: Aiden
authors.initials: A
authors.lastname: Collins
authors.forename: Jeremie
authors.initials: J
authors.lastname: Tomlin
authors.forename: Melanie
authors.initials: M
authors.lastname: Gibbs
authors.forename: Casper J
authors.initials: CJ
authors.lastname: Breuker
mesh_terms: D000818:Animals; D012831:Bombyx / Q000235:genetics; D002080:Butterflies / Q000235:genetics* / Q000254:growth & development; D030541:Databases, Genetic; D004331:Drosophila melanogaster / Q000235:genetics; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D019476:Insect Proteins / Q000502:physiology; D009866:Oogenesis / Q000235:genetics* / Q000502:physiology; D010053:Ovary / Q000166:cytology / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology; D059467:Transcriptome; D014818:Vitellogenesis / Q000235:genetics
chemical_list: D019476:Insect Proteins