title: XX/XY System of Sex Determination in the Geophilomorph Centipede Strigamia maritima.
abstract: We show that the geophilomorph centipede Strigamia maritima possesses an XX/XY system of sex chromosomes, with males being the heterogametic sex. This is, to our knowledge, the first report of sex chromosomes in any geophilomorph centipede. Using the recently assembled Strigamia genome sequence, we identified a set of scaffolds differentially represented in male and female DNA sequence. Using quantitative real-time PCR, we confirmed that three candidate X chromosome-derived scaffolds are present at approximately twice the copy number in females as in males. Furthermore, we confirmed that six candidate Y chromosome-derived scaffolds contain male-specific sequences. Finally, using this molecular information, we designed an X chromosome-specific DNA probe and performed fluorescent in situ hybridization against mitotic and meiotic chromosome spreads to identify the Strigamia XY sex-chromosome pair cytologically. We found that the X and Y chromosomes are recognizably different in size during the early pachytene stage of meiosis, and exhibit incomplete and delayed pairing.
authors.affiliation: Laboratory for Development and Evolution, Department of Zoology, Downing Street, Cambridge, United Kingdom.
authors.forename: Jack E
authors.initials: JE
authors.lastname: Green
authors.affiliation: Laboratory of Molecular Cytogenetics, Institute of Entomology, Biology Centre CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic.
authors.forename: Martina
authors.initials: M
authors.lastname: Dalíková
authors.affiliation: Laboratory of Applied Entomology, Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Sahara
authors.affiliation: Laboratory of Molecular Cytogenetics, Institute of Entomology, Biology Centre CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic.
authors.forename: František
authors.initials: F
authors.lastname: Marec
authors.affiliation: Laboratory for Development and Evolution, Department of Zoology, Downing Street, Cambridge, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Akam
mesh_terms: D000818:Animals; D001181:Arthropods / Q000196:embryology / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D055028:Comparative Genomic Hybridization; D005260:Female; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D060888:Real-Time Polymerase Chain Reaction; D019849:Sex Determination Processes / Q000235:genetics*; D014960:X Chromosome / Q000648:ultrastructure; D014998:Y Chromosome / Q000648:ultrastructure