Size and oligoprobe signal variation of chromosome 15 alpha satellite DNA. (A) Partial metaphases from two individuals, hybridized with pTRA-20 and 15VAR2.4. Individual III-2 has one large and one small pTRA-20 signal. The chromosome with the large pTRA-20 signal is positive for 15VAR2.4, while the chromosome with the small pTRA-20 signal is negative for 15VAR2.4. Individual III-8 has two large pTRA-20 signals and is positive for 15VAR2.4 on both chromosomes. (B) Mendelian inheritance of a small pTRA-20 array and no oligonucleotide probe signal. Open symbol, 15VAR1.4–15VAR2.4 and large pTRA-20 array homozygote; half-cross hatched symbol, 15VAR1.4–15VAR2.4/15VAR2.4 heterozygote and large pTRA-20 array homozygote; half-shaded symbol, 15VAR1.4–15VAR2.4 hemizygote and large pTRA-20 array/small pTRA-20 array heterozygote.
