Thu, 21 Aug 2008 02:22:30 BST CiteULike: xico chemotype http://www.citeulike.org/user/xico/tag/chemotype CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/xico/article/2835225 <i>Genetics, Vol. 163, No. 1. (January 2003), pp. 335-346.</i><br /><br />Four crosses were made between inbred Cannabis sativa plants with pure cannabidiol (CBD) and pure Delta-9-tetrahydrocannabinol (THC) chemotypes. All the plants belonging to the F(1)'s were analyzed by gas chromatography for cannabinoid composition and constantly found to have a mixed CBD-THC chemotype. Ten individual F(1) plants were self-fertilized, and 10 inbred F(2) offspring were collected and analyzed. In all cases, a segregation of the three chemotypes (pure CBD, mixed CBD-THC, and pure THC) fitting a 1:2:1 proportion was observed. The CBD/THC ratio was found to be significantly progeny specific and transmitted from each F(1) to the F(2)'s derived from it. A model involving one locus, B, with two alleles, B(D) and B(T), is proposed, with the two alleles being codominant. The mixed chemotypes are interpreted as due to the genotype B(D)/B(T) at the B locus, while the pure-chemotype plants are due to homozygosity at the B locus (either B(D)/B(D) or B(T)/B(T)). It is suggested that such codominance is due to the codification by the two alleles for different isoforms of the same synthase, having different specificity for the conversion of the common precursor cannabigerol into CBD or THC, respectively. The F(2) segregating groups were used in a bulk segregant analysis of the pooled DNAs for screening RAPD primers; three chemotype-associated markers are described, one of which has been transformed in a sequence-characterized amplified region (SCAR) marker and shows tight linkage to the chemotype and codominance. The inheritance of chemical phenotype in Cannabis sativa L. EP de Meijer M Bagatta A Carboni P Crucitti VM Moliterni P Ranalli G Mandolino Genetics, Vol. 163, No. 1. (January 2003), pp. 335-346. 2008-05-26T17:24:16-00:00 2003 Genetics 0016-6731 163 1 335 346 cannabidiol cannabinoid cannabis cdb chemical chemotype codominance cross inheritance locus marker phenotype plant rapd sativa scar selfing synthase tetrahydrocannabinol thc http://www.citeulike.org/user/xico/article/2800291 <i>FEBS letters, Vol. 581, No. 16. (26 June 2007), pp. 2929-2934.</i><br /><br />Cannabidiolic-acid (CBDA) synthase is the enzyme that catalyzes oxidative cyclization of cannabigerolic-acid into CBDA, the dominant cannabinoid constituent of the fiber-type Cannabis sativa. We cloned a novel cDNA encoding CBDA synthase by reverse transcription and polymerase chain reactions with degenerate and gene-specific primers. Biochemical characterization of the recombinant enzyme demonstrated that CBDA synthase is a covalently flavinylated oxidase. The structural and functional properties of CBDA synthase are quite similar to those of tetrahydrocannabinolic-acid (THCA) synthase, which is responsible for the biosynthesis of THCA, the major cannabinoid in drug-type Cannabis plants. Cannabidiolic-acid synthase, the chemotype-determining enzyme in the fiber-type Cannabis sativa. F Taura S Sirikantaramas Y Shoyama K Yoshikai Y Shoyama S Morimoto doi:10.1016/j.febslet.2007.05.043 FEBS letters, Vol. 581, No. 16. (26 June 2007), pp. 2929-2934. 2008-05-14T23:34:48-00:00 2007 FEBS letters 0014-5793 581 16 2929 2934 acid cannabidiol cannabidiolic cannabis cbd-synthase cdb chemotype fiber hemp marijuana psychoactivity sativa synthase thc