The ABNORMAL GAMETOPHYTES (AGM) gene product of Arabidopsis demonstrates a role in mitosis during gamete development.
Screening a T-DNA mutagenized population of Arabidopsis thaliana for reduced seed set and segregation distortion led to the isolation of the ABNORMAL GAMETOPHYTES (AGM) mutant. Homozygous plants were never recovered, but heterozygous plants showed mitotic defects during gametogenesis resulting in approximately 50% abortion of both the male and female gametes. Isolation of the genomic sequence flanking the co-segregating T-DNA element led to the identification of a gene located on chromosome 5, predicted to encode a transmembrane protein. BLAST homology searches identified two homologous proteins that are not redundant, as is clear from the existence of the agm mutant. Unexpectedly, expression studies using the beta-glucuronidase reporter gene suggest that AGM and its closest Arabidopsis homolog are mostly expressed in cells undergoing mitosis. Thus, AGM is not a gametophytic gene as originally speculated on the basis of segregation distortion, but rather classified as an essential gene crucial to the process of mitosis in plants.
Max Planck Institute for Plant Breeding Research, Department of Molecular Plant Genetics, Carl-von-Linné Weg 10, D-50829-Cologne, Germany. sorensen@rsbs.anu.edu.au
Anna-Marie
AM
Sorensen
Sandra
S
Kroeber
Heinz
H
Saedler
D000595:Amino Acid Sequence / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001483:Base Sequence / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002874:Chromosome Mapping; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D005718:Gametogenesis / Q000235:genetics*; D018745:Genome, Plant; D005854:Germ Cells / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D008938:Mitosis / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D018514:Plant Structures / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D012639:Seeds / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
C492829:ABNORMAL GAMETOPHYTES protein, Arabidopsis; D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D008565:Membrane Proteins