Plant Transcription factor database - Universität Potsdam
version: 3.0

Sorghum bicolor RB Family

Description

Bremner et al. 2004: The data suggest that RB protein may not control the rate of progenitor division, but is critical for cell cycle exit when dividing retinal progenitors differentiate into postmitotic transition cells.

Ebel et al. 2004: Haploid spores of plants divide mitotically to form multicellular gametophytes. The female spore (megaspore) of most flowering plants develops by means of a well-defined programme into the mature megagametophyte consisting of the egg apparatus and a central cell. We investigated the role of the Arabidopsis retinoblastoma protein homologue and its function as a negative regulator of cell proliferation during megagametophyte development. Here we show that three mutant alleles of the gene for the Arabidopsis retinoblastoma-related protein, RBR1 (ref. 4), are gametophytic lethal. In heterozygous plants 50% of the ovules are aborted when the mutant allele is maternally inherited. The mature unfertilized mutant megagametophyte fails to arrest mitosis and undergoes excessive nuclear proliferation in the embryo sac. Supernumerary nuclei are present at the micropylar end of the megagametophyte, which develops into the egg apparatus and central cell. The central cell nucleus, which gives rise to the endosperm after fertilization, initiates autonomous endosperm development reminiscent of fertilization-independent seed (fis) mutants. Thus, RBR1 has a novel and previously unrecognized function in cell cycle control during gametogenesis and in the repression of autonomous endosperm development.

Members of this family
  SHOULD possess RB_B domain

Domain alignments

This family is also present in:

References

There are 4 gene models in this family



Gene modelDescriptionDomains
4764709 estExt_Genewise1.C_chr_77431 RB_A RB_B
4821448 e_gw1.5.14244.1 RB_A RB_B
5041554 Sb06g011641 RB_B
5045723 Sb09g001110 RB_A RB_B

General references

Ebel, C; Mariconti, L; Gruissem, W. 2004. Plant retinoblastoma homologues control nuclear proliferation in the female gametophyte. Nature 429(6993):776-80 PUBMEDID:15201912