Chromosomal location and gene paucity of the male speciWc region on papaya Y chromosome
نویسندگان
چکیده
Sex chromosomes in Xowering plants evolved recently and many of them remain homomorphic, including those in papaya. We investigated the chromosomal location of papaya’s small male speciWc region of the hermaphrodite Y (Y) chromosome (MSY) and its genomic features. We conducted chromosome Xuorescence in situ hybridization mapping of Y-speciWc bacterial artiWcial chromosomes (BACs) and placed the MSY near the centromere of the papaya Y chromosome. Then we sequenced Wve MSY BACs to examine the genomic features of this specialized region, which resulted in the largest collection of contiguous genomic DNA sequences of a Y chromosome in Xowering plants. Extreme gene paucity was observed in the papaya MSY with no functional gene identiWed in 715 kb MSY sequences. A high density of retroelements and local sequence duplications were detected in the MSY that is suppressed for recombination. Location of the papaya MSY near the centromere might have provided recombination suppression and fostered paucity of genes in the male speciWc region of the Y chromosome. Our Wndings provide critical information for deciphering the sex chromosomes in papaya and reference information for comparative studies of other sex chromosomes in animals and plants.
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Multiplex-Polymerase Chain Reaction for Detecting Microdeletions in The Azoospermia Factor Region of Y Chromosome in Iranian Couples with Non-Obstructive Infertility and Recurrent Pregnancy Loss
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