PT  - JOURNAL ARTICLE
AU  - Huimin Na
AU  - Olga Ponomarova
AU  - Gabrielle E. Giese
AU  - Albertha J.M. Walhout
TI  - <em>C. elegans</em> MRP-5 Exports Vitamin B12 from Mother to Offspring to Support Embryonic Development
AID  - 10.1101/204735
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 204735
4099  - http://biorxiv.org/content/early/2018/01/16/204735.short
4100  - http://biorxiv.org/content/early/2018/01/16/204735.full
AB  - Vitamin B12 functions as a cofactor for methionine synthase to produce the anabolic methyl donor S-adenosylmethionine (SAM) and for methylmalonyl-CoA mutase to catabolize the short chain fatty acid propionate. In the nematode Caenorhabditis elegans, maternally supplied vitamin B12 is required for the development of her offspring. However, the mechanism for exporting vitamin B12 from the mother to her offspring is not yet known. Here, we use RNAi of more than 200 transporters with a vitamin B12-sensor transgene to identify the ABC transporter MRP-5 as a candidate vitamin B12 exporter. We show that injection of vitamin B12 into the gonad of mrp-5 deficient mothers rescues embryonic lethality in her offspring. Altogether, our findings identify a maternal mechanism for the transit of an essential vitamin to support the development of the next generation.