| | Phenotype | [C.elegansII] b284 : Mel, embryonic lethality, abnormal oocyte meiosis leading to lethal aneuploidy. Normal male meiosis.OA>20: ct46dm,ts (gf allele, normal meiosis followed by abnormal mitoses), intragenic revertants of ct46 eg ct44ct99 (putative null, abnormal meiosis), ct46ct82 (antimorphic), ct46ct103 (viable, weak Him), additional phenotypic classes. See also mei-2, mel-26, zyg-9. Cloned: two transcripts encoding 472 and 475 aa predicted proteins with similarity to ATPases. Antibody stains meiotic spindles I and II. [Mains et al. 1990, Clark-Maguire and Mains 1994; HR] |
| | | Concise_description | mei-1 encodes, by alternative splicing, two slightly different isoforms of an ortholog of the catalytic subunit of katanin (OMIM:606696) that is required for oocyte meiotic spindle formation, for stable association of the meiosis I spindle with the oocyte cortex, and for microtubule severing; MEI-1 exists in a physical complex with MEI-2 at the polar ends of meiotic spindle microtubules and meiotic chromatin; MEI-1 must be inactivated for meiosis to give way to mitosis, and ectopic expression of MEI-1/MEI-2 during mitosis is normally lethal; MEI-1 is bound by the BTB protein MEL-26 (both in vivo and in vitro), which physically links MEI-1 to CUL-3 (an E3 ubiquitin ligase); CUL-3, in turn, promotes MEI-1 proteolysis by the 26S proteasome during the transition from meiosis to mitosis; the MEI-1/MEI-2 complex requires tubules containing the germline-enriched beta tubulin TBB-2 in vivo, but does not require tubules made from TBB-2's (superficially) redundant paralog TBB-1. |