RB
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. |
References:
| 1) | Bremner, R; Chen, D; Pacal, M; Livne-Bar, I; Agochiya, M. 2004. The RB protein family in retinal development and retinoblastoma: new insights from new mouse models. Dev Neurosci. 26(5-6):417-34 PubMed |
| 2) | Ebel, C; Mariconti, L; Gruissem, W. 2004. Plant retinoblastoma homologues control nuclear proliferation in the female gametophyte. Nature 429(6993):776-80 PubMed |
Summary
| Name: | RB |
|---|---|
| Class: | TF |
| Number of species containing the TAP: | 119 |
| Number of available proteins: | 207 |
The colour code corresponds to the rules for the domains:
should be contained
should not be contained
should not be contained
Domain rules:
(Domain names are clickable)
Phylogenetic tree for Archeaplastida:
No tree was calculated yet.
TAP distribution:
The following table shows the distribution of RB over all species included in TAPscan. The values for e.g. a specific kingdom are shown in the tree below if you expand the tree for that kingdom.
| Minimum | Maximum | Average | Median | Standard deviation |
|---|---|---|---|---|
| 0 | 12 | 1.71 | 1 | 1.37 |