Necessary and sufficient to confer sensitivity to distortion irrespective of its association with an intact second chromosome or one that pairs meiotically with an SD chromosome. An SD chromosome is capable of causing efficient distortion in two Rsps bearing chromosomes within a spermatocyte nucleus.
sensitive
M(SD)1, Rspss/Rsps has male fertile phenotype
M(SD)1, Rspi/Rsps has male fertile phenotype
M(Sd)[+]/M(SD)1, Rspss/Rsps has male fertile phenotype
M(Sd)[+]/M(SD)1, Rspi/Rsps has male fertile phenotype
Segregation distortion can occur in the absence of RanGAPSd if flies are homozygous for E(SD)1 : Flies carrying chromosome SD-5[R7] (E(SD)1, Rspi M(SD)1 St(SD)1) / chromosome ReR-5 (E(SD)1 Rsps) exhibit moderate segregation distortion (k=0.74 +/-0.014) against ReR-5. This can be suppressed by the presence of RanβTub85D.PK or Rcc1βTub85D.PK.
Under certain genotypic conditions, the chromosome carrying the "sensitive" Rsps allele in a RanGapSD heterozygous Rspi/Rsps male can be transmitted to the progeny at frequencies greater than 0.5, or correspondingly, the chromosome carrying the "insensitive" Rspi allele can be distorted with respect to the chromosome carrying the "sensitive" Rsps allele. This "negative segregation distortion" indicates that the relative sensitivity and insensitivity of Rsps and Rspi to distortion in a male are not absolute, but relative, and they may be reversed depending on the residual genotype.
Rsps is a divisible element.
The sensitive state of Rsp.