[Further steps in regional localization of the gene coding for human arylsulfatase B (ARSB): gene assignment to the section q11-qter of chromosome 5].

The structural gene coding for human arylsulfatase B (ARSB) has been assigned to chromosome 5 and then to 5p11-5qter by means of somatic cell hybridization. The somatic cell hybrids used in the present studies were derived from fusion experiments between Chinese hamster, a3 line (TK-) and human leukocytes from a patient carrying the reciprocal balanced translocation t (5;21) (q11;q22) according to the method described previously. About 90 independent hybrid clones were selected for further analysis. They were tested for the presence of human markers employing the methods routinely used. ARSB activity was checked upon as previously. Giemsa banding technique was used to identify human and hamster chromosomes in the hybrid cells. Human ARSB activity was detected in 12 hybrid clones; 6 of them appeared to be informative. Out of 78 clones negative for human ARSB, 3 containing the product of translocation, 5pter-5q11: 21q22-21qter were found. Human superoxide dismutase-1 (SOD1) activity, a marker for chromosome 21, was found in 27 clones. The informative hybrid clones both positive and negative for ARSB are presented in table I. Six informative clones retained the region 5q11-5qter as the only portion of chromosome 5 and they expressed the activity of human ARSB and hexosaminidase B (HEXB), a marker for 15q13. It seems worth-while to point out that human ARSB activity was found only in the hybrids which retained the product of the translocation carrying 5q11-5qter in high percentage of the cells.(ABSTRACT TRUNCATED AT 250 WORDS)