Cloning and physical localization of male-biased repetitive DNA sequences in Spinacia oleracea (Amaranthaceae)

Spinach ( Spinacia oleracea Linnaeus, 1753) is an ideal material for studying molecular mechanisms of early-stage sex chromosome evolution in dioecious plants. Degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR) technique facilitates the retrotransposon-relevant studies by enriching specific repetitive DNA sequences from a micro-dissected single chromosome. We conducted genomic subtractive hybridization to screen sex-biased using DOP-PCR amplification products spinach Y The screening yielded 55 male-biased with 30 576 bp length, which, 32 (12 049 bp) contained repeat sequences, including LTR/Copia , LTR/Gypsy simple repeats, and DNA/CMC-EnSpm. Among these four that fragment Ty3-gypsy retrotransposons (SP73, SP75, SP76, SP77) were selected as fluorescence probes on male female karyotypes. Fluorescence situ (FISH) signals SP73 SP75 captured mostly centromeres their surrounding area each homolog. Hybridization primarily appeared near putative homologous pair SP76 SP77 FISH, sporadic existed long arms. Results can be served basis study function spinach.