A human Y-chromosome specific repeated DNA family (DYZ1) consists of a tandem array of pentanucleotides

Abstract

We have determined the complete nucleotide sequence of a 3564 bp EcoRI fragment which represents a major component of the human Y-chromosome specific repeated DNA family (DYZ1). Sequencing result showed a tandem array of pentanucleotides after five nucleotides were inserted or deleted at four positions. 229 out of the 713 pentanucleotides were TTCCA, and 297 were its single-base substituents. Southern hybridization analyses of male genomic DNAs showed that several endonuclease cleavage sites were located at intervals of 3.56kb in the DYZ1 locus. This indicates that the DYZ1 repeated DNA family evolved and expanded by unequal crossovers which occurred at distances of 3.56kb. As there is a uniformly distributed array of pentanucleotides on this locus, it is not a sequence homology that determines the distance of unequal crossovers. A higher order of chromatin structure may be involved in the determination of distance in unequal crossovers.

Hypervariable polymorphism of autosomal origin detected by the Y-chromosome derived probe, pHY10

“…Thus TaqI digestion of pHY10 generates an average of 56 bp fragments, the largest fragment being 221 bp (Nakahori et al, 1986). The major part of the DYZ1 family consists of pHY10 and shows minimal divergence (unpublished data).…”

“…Most DNA appeared to remain over 20 kb. Our previous work has shown that many TaqI sites overlap with HinfI sites on pHY10 (Nakahori et al, 1986). It was thus expected that HinfI also would produce polymorphic bands.…”

“…The DYZ1 family contains EcoRI-3564 bp fragments (pHY10) composed of a tandem array of pentanucleotides with a few insertions/deletions. Two hundred and twenty-nine (32.1~) of the pentanucleotides were TTCCA, 297 (41.7~) were single-base substituents of them and 139 (19.5~) were two-base substituents (Nakahori et al, 1986). The pHY10 has 64 TaqI sites and generates very small fragments (av.=56 bp) when digested wi~h TaqI.…”

PCR detection of structurally abnormal Y chromosomes

“…A primer set which detect the B segment of the DYZ1 locus was also used Jpn J Human Genet s. NAGAFUCHI el aL (Nakagome et aL,199ia). The locus represents a part of the repeating unit of the DYZI family on the distal long arm (Cooke, 1976;Nakahori et al, 1986). PCRprocedures.…”

Dimorphic Goat Amelogenin Alleles on Sex Chromosomes for Gender Determination of Preimplantation Embryos

“…These procedures are generally time-consuming or inaccurate. However, some of these problems have been improved by the use of polymerase chain reaction (PCR) [13], [14], such as amplification of the SRY gene, which is associated with the testis-determining factor [15], or relevant Y-specific repetitive sequences [16], [17].…”