Gene: methyltryptophan resistant IVR
methyltryptophan resistant
locus: mtr
locus_name: methyltryptophan resistant
organism_type: B
chromosome_number: IV
chromosome_side: R
link_group: IVR
cultural_requirements: IVR. Between pdx-1 (2%) and col-4 (1%) (101, 1017).Resistant to 4-methyltryptophan and p-fluorophenylalanine. pmn (= Pm-N, pm n), selected by resistance to p-fluorophenylalanine, has been shown to be alletic with mtr(R. Sadler and S. Ogilvie-Villa, personal communication; see also reference 248). Defective in transport of neutral aliphatic and aromatic amino acids via amino acid transport system I (as defined in reference 777) (248, 602, 1017, 1152). Causes an alteration in surface glycoproteins (1038). Used extensively for transport studies (247a, 1150 [review], 1152), also for studies of the mechanism of intralocus recombination (1021). Resistance is recessive in duplications from T(S1229) (PB). Recessive resistance used in a heterokaryon test system for mutation studies (1020). Suppressors obtained and used for selecting other resistance mutants (106, 107, 555, 1018). Allele 26 is a putative frameshift mutation reverted by ICR170 (106, 107). mtrascospores are slow to darken and mature; up to 50% of the young ascospores from heterozygous crosses are white (152, PB). With probable allele MN18, ascospore viability is improved by the addition of peptone to the crossing medium when the male parent is added (152). mtr has been scored on media containing 10 or 70 µg of filter-sterilized 4-methyltryptophan per ml or on 20 or 60 µg of p-fluorophenylalanine per ml (550, 1021, PB). Unlike 4-methyltryptophan, p-fluorophenylalanine is heat stable and can be added before autoclaving. Strains with mutations at the mtr locus may be obtained by selection for resistance to numerous agents or for defects in uptake ability. Thus, there is confusion in nomenclature. Genes originally designated neua, neur, neut, tru(628) may be mtr alleles. mtr was initially called mt (602).
enzyme_id: 202
Enzyme: none
anid_name:
near_l: pdx-1 (2%)
near_r: col-4 (1%)
neu_name:
supplement:
image_url:
Strains
References
