Construction of male and female PAC genomic libraries suitable for identification of Y‐chromosome‐specific clones from the liverwort, Marchantia polymorpha

• Published in: The Plant journal : for cell and molecular biology Vol. 24; no. 3; pp. 421 - 428
• Main Authors: Okada, Sachiko, Fujisawa, Masaki, Sone, Takefumi, Nakayama, Shigeki, Nishiyama, Rie, Takenaka, Mizuki, Yamaoka, Shohei, Sakaida, Megumi, Kono, Kaoru, Takahama, Masayoshi, Yamato, Katsuyuki T., Fukuzawa, Hideya, Brennicke, Axel, Ohyama, Kanji
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.11.2000; Blackwell Science
• Subjects: Base Sequence; Biological and medical sciences; Chromosomes - genetics; dioecious plant; DNA Primers - genetics; fluorescence in situ hybridization (FISH); Fundamental and applied biological sciences. Psychology; Genes. Genome; Genome, Plant; Genomic Library; In Situ Hybridization, Fluorescence; Marchantia polymorpha; Molecular and cellular biology; Molecular genetics; Nucleic Acid Hybridization; PAC libraries; Plants - genetics; Polymerase Chain Reaction; sex chromosomes; Y‐chromosome‐specific clone; Dioecy; Bryophyta; Female; Male; Gene library; Y-Chromosome; Hepaticae; Artificial chromosome; Sexual differentiation; Clone
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.1365-313x.2000.00882.x

Summary Unlike higher plants, the dioecious liverwort, Marchantia polymorpha, has uniquely small sex chromosomes, with X chromosomes present only in female gametophytes and Y chromosomes only in male gametophytes. We have constructed respective genomic libraries for male and female plantlets using a P1‐derived artificial chromosome (pCYPAC2). With an average insert size of approximately 90 kb, each PAC library is estimated to cover the entire genome with a probability of more than 99.9%. Male‐specific PAC clones were screened for by differential hybridization using male and female genomic DNAs as separate probes. Seventy male‐specific PAC clones were identified. The male specificity of one of the clones, pMM4G7, was verified by Southern hybridization and PCR analysis. This clone was indeed located on the Y chromosome as verified by fluorescence in situ hybridization (FISH). This result shows that the Y chromosome contains unique sequences that are not present either on the X chromosome or any of the autosomes. Thus, the respective male and female libraries for M. polymorpha offer an opportunity to identify key genes involved in the process of sex differentiation and this unique system of sex determination.