A myeloid-related sequence that localizes to human chromosome 8q21.1-22

A myeloid-related sequence (mrs) has previously been identified that is highly expressed in selected subpopulations of myeloid leukocytes. Nucleotide sequence analysis indicates that mrs encodes what is apparently a unique 93-amino acid protein that includes an 18-amino acid leader sequence. Hybridization of an mrs cDNA probe to a Southern blot made from somatic cell hybrid DNAs shows 100% concordance with human chromosome 8, thus indicating that mrs localizes to this chromosome. In situ hybridization to metaphase chromosomes further sublocalizes mrs to bands 8q21.1–23 as 58% of the grains displayed on chromosome 8 were clustered in this region. This area encompasses the translocation breakpoint 8q22, which is rearranged in an estimated 18% of patients diagnosed with the M2 subclassification of acute nonlymphocytic leukemia (M2-ANLL). When Southern blot hybridization was performed by using somatic cell hybrid DNAs harboring either a single 8q- or a single 21q+ chromosome from two different patients with M2- ANLL, a signal was only detected in the hybrid containing the 8q- chromosome.

A myeloid-related sequence that localizes to human chromosome 8q21.1-22

A myeloid-related sequence (mrs) has previously been identified that is highly expressed in selected subpopulations of myeloid leukocytes. Nucleotide sequence analysis indicates that mrs encodes what is apparently a unique 93-amino acid protein that includes an 18-amino acid leader sequence. Hybridization of an mrs cDNA probe to a Southern blot made from somatic cell hybrid DNAs shows 100% concordance with human chromosome 8, thus indicating that mrs localizes to this chromosome. In situ hybridization to metaphase chromosomes further sublocalizes mrs to bands 8q21.1–23 as 58% of the grains displayed on chromosome 8 were clustered in this region. This area encompasses the translocation breakpoint 8q22, which is rearranged in an estimated 18% of patients diagnosed with the M2 subclassification of acute nonlymphocytic leukemia (M2-ANLL). When Southern blot hybridization was performed by using somatic cell hybrid DNAs harboring either a single 8q- or a single 21q+ chromosome from two different patients with M2- ANLL, a signal was only detected in the hybrid containing the 8q- chromosome.

DNA of AKODON (RODENTIA, CRICETIDAE). II. MOLECULAR HYBRIDIZATION OF REPETITIVE DNA SEQUENCES

Interspecies repetitive DNA homology was studied in akodont rodents related at generic and suprageneric levels. The homology was determined by taking the species Akodon molinae as the reference species. The 3H-DNA/DNA hybridization on filters showed a closer relationship between A. molinae and A. azarae, A. dolores and A. mollis than between A. molinae and Bolomys obscurus. These data agree with the taxonomical ranking of the species. The quantity and quality of the hybrid DNAs were measured by investigating their thermal stabilities and subsequent comparison to the results obtained on the reference species. These data indicate high similitude between the repetitive DNA of A. dolores and A. molinae. Increasing differences were shown to occur in the repetitive DNA of A. mollis, B. obscurus and A. azarae, respectively. Since these results coincide with the G-banding homologies and differ slightly from the taxonomical rank, it is speculated that the divergency between the DNA of A. molinae and A. azarae is the result of a differential process of DNA amplification which is not related to the phylogenetical distance separating the two species.

Localization of the casein gene family to a single mouse chromosome.

A series of mouse-hamster somatic cell hybrids containing a variable number of mouse chromosomes and a constant set of hamster chromosomes have been used to determine the chromosomal location of a family of hormone-inducible genes, the murine caseins. Recombinant mouse cDNA clones encoding the alpha-, beta-, and gamma-caseins were constructed and used in DNA restriction mapping experiments. All three casein cDNAs hybridized to the same set of somatic cell hybrid DNAs isolated from cells containing mouse chromosome 5, while negative hybridization was observed to ten other hybrid DNAs isolated from cells lacking chromosome 5. A fourth cDNA clone, designated pCM delta 40, which hybridized to an abundant 790 nucleotide poly(A)RNA isolated from 6-d lactating mouse mammary tissue, was also mapped to chromosome 5. The chromosomal assignment of the casein gene family was confirmed using a mouse albumin clone. The albumin gene had been previously localized to mouse chromosome 5 by both breeding studies and analogous molecular hybridization experiments. An additional control experiment demonstrated that another hormone-inducible gene, specifying a 620 nucleotide abundant mammary gland mRNA, hybridized to DNA isolated from a different somatic cell hybrid line. These studies represent the first localization of a peptide and steroid hormone-responsive gene family to a single mouse chromosome.