The rad9 gene of Coprinus cinereus encodes a proline-rich protein required for meiotic chromosome condensation and synapsis

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Genetics

OSTI ID:518183

Seitz, L C; Tang, Keliang; Cummings, W J; Zolan, M E ^[1]

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1. Indiana Univ., Bloomington, IN (United States)

The rad9 gene of Coprinus cinereus is essential for the normal completion of meiosis. We examined surface-spread preparations of wild-type and rad9-1 nuclei from the meiotic stages of karyogamy through metaphase I, and we determined the primary sequence, structure, and meiotic expression of the rad9 gene. In wild-type C. cinereus, karyogamy is followed by condensation and alignment of homologous chromosomes. Condensation and axial core development largely precede synapsis, which often initiates at telomeres. A diffuse diplotene phase coincides with dissolution of the synaptonemal complex, and subsequently chromosomes further condense as the cells progress into metaphase I. In contrast, although karyogamy and nucleolar fusion are apparently normal in rad9-1 basidia, only short stretches of synaptonemal complex form. These correlate with stretches of condensed chromatin, mostly at apparent chromosome ends, and regions of presumptive triple synapsis are numerous. rad9-1 basidia enter the diffuse stages of early diplotene, and then 50% of these cells enter metaphase I by the criteria of nucleolar elimination and at least some chromatin condensation. rad9 gene expression is induced after gamma irradiation and during meiosis. The gene has 27 exons and encodes a predicted protein of 2157 amino acids, with a proline-rich amino terminus. 62 refs., 10 figs.

• OSTI ID: 518183
• Journal Information: Genetics, Journal Name: Genetics Journal Issue: 4 Vol. 142; ISSN GENTAE; ISSN 0016-6731
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
AMINO ACID SEQUENCE
BIOLOGICAL EVOLUTION
CHROMATIN
CHROMOSOMES
CROSSING-OVER
DNA
DNA HYBRIDIZATION
DNA REPAIR
DNA SEQUENCING
ELECTROPHORESIS
FUNGI
GAMMA RADIATION
GENE MUTATIONS
GENE RECOMBINATION
GENE REGULATION
GENES
GENETIC RADIATION EFFECTS
MEIOSIS
POLYMERASE CHAIN REACTION
PROLINE
PROTEINS
RADIOSENSITIVITY
SIZE
STRUCTURE-ACTIVITY RELATIONSHIPS
TRANSCRIPTION