Azen E A, Denniston C
Biochem Genet. 1979 Oct;17(9-10):909-20. doi: 10.1007/BF00504312.
Genetic polymorphism of the vitamin B12 binding (R) proteins of parotid saliva is determined by autosomal inheritance of codominant alleles. This hypothesis is supported by studies in 43 families including 152 children. For randomly collected salivas from 143 whites, 104 blacks, and 75 Chinese, gene frequencies are as follows: for whites, Rs1=0.88, Rs2=0.12; for blacks, Rs1=0.94, Rs2=0.06; for Chinese, Rs1=1.00. This genetic marker is also shared by R proteins of milk, tears, and leukocytes. In the Rs 1--2 salivary type there is less labeling of the protein products of Rs2 v. Rs1 with 57Co B12 as assessed by the intensity of the bands on the autoradiogram. There is no evidence for close linkage (theta less than 0.01) between Rs and TC II (transcobalamin II) or between Rs and salivary protein locus Pr, Db, Gl, or Ps.
腮腺唾液中维生素B12结合（R）蛋白的遗传多态性由共显性等位基因的常染色体遗传决定。这一假说得到了对包括152名儿童在内的43个家庭的研究支持。对于从143名白人、104名黑人及75名中国人中随机采集的唾液，基因频率如下：白人中，Rs1 = 0.88，Rs2 = 0.12；黑人中，Rs1 = 0.94，Rs2 = 0.06；中国人中，Rs1 = 1.00。这种遗传标记在乳汁、眼泪和白细胞的R蛋白中也存在。在Rs 1--2唾液类型中，通过放射自显影片上条带的强度评估，与Rs1相比，Rs2的蛋白产物用57Co B12标记较少。没有证据表明Rs与转钴胺素II（TC II）之间或Rs与唾液蛋白位点Pr、Db、Gl或Ps之间存在紧密连锁（θ小于0.01）。
