Chromosomal mapping of mouse myelin basic protein gene and structure and transcription of the partially deleted gene in shiverer mutant mice

The gene for mouse myelin basic protein (MBP) was mapped to chromosome 18 by hybridization of cloned MBP probes to DNA from hamster-mouse hybrid cell lines, showing it to be linked to the shiverer mutation which causes abnormal CNS myelination. Genomic blotting experiments show that in the mutants five of six exons which constitute the wild-type gene have been deleted. In shiverer brains the steady state level of transcripts that initiate correctly at the 5' end of the remaining exon 1 is reduced 16-fold. These RNAs are not spliced correctly and are not efficiently polyadenylated. It is proposed that the partial deletion of the MBP gene is an important part of the shiverer lesion.

Chromosomal locations of the murine T-cell receptor alpha-chain gene and the T-cell gamma gene

Two independent methods were used to identify the mouse chromosomes on which are located two families of immunoglobulin (Ig)-like genes that are rearranged and expressed in T lymphocytes. The genes coding for the alpha subunit of T-cell receptors are on chromosome 14 and the gamma genes, whose function is yet to be determined, are on chromosome 13. Since genes for the T-cell receptor beta chain were previously shown to be on mouse chromosome 6, all three of the Ig-like multigene families expressed and rearranged in T cells are located on different chromosomes, just as are the B-cell multigene families for the Ig heavy chain, and the Ig kappa and lambda light chains. The findings do not support earlier contentions that genes for T-cell receptors are linked to the Ig heavy chain locus (mouse chromosome 12) or to the major histocompatibility complex (mouse chromosome 17).

Chromosomal location of the structural gene cluster encoding murine immunoglobulin heavy chains

To determine the chromosomal location of mouse immunoglobulin heavy chain structural genes unambiguously, a panel of somatic cell hybrids was scored for the presence of DNA sequences homologous to gamma 2b-, mu-, and alpha-heavy chain-constant region DNA probe molecules. The hybrids, formed between mouse and hamster cells, contained various combinations of mouse chromosomes plus a full set of hamster chromosomes. Hybrids that retained mouse chromosome 12 reacted with the probes, whereas hybrids that had lost the chromosome, or its distal half, failed to react. These results indicate that structural genes for the gamma 2b-, mu-, and alpha-heavy chain-constant regions map to the distal half of this chromosome.

Mouse Hox-3.4: homeobox sequence and embryonic expression patterns compared with other members of the Hox gene network

A putative mouse homeobox gene (Hox-3.4) was previously identified 4kb downstream of the Hox-3.3 (Hox-6.1)* gene (Sharpe et al. 1988). We have now sequenced the Hox-3.4 homeobox region. The predicted amino acid sequence shows highest degree of homology in the mouse with Hox-1.3 and -2.1. This, together with similarities in the genomic organisation around these three genes, suggests that they are comembers of a subfamily, derived from a common ancestor. Hox-3.4 appears to be a homologue of the Xenopus Xlhbox5 and human cp11 genes (Fritz and De Robertis, 1988; Simeone et al. 1988). Using a panel of mouse-hamster somatic cell hybrids we have mapped the Hox-3.4 gene to chromosome 15. From the results of in situ hybridization experiments, we describe the distribution of Hox-3.4 transcripts within the 12 1/2 day mouse embryo, and we compare this with the distributions of transcripts shown by seven other members of the Hox gene network. We note three consistencies that underlie the patterns of expression shown by Hox-3.4. First, the anterior limits of Hox-3.4 transcripts in the embryo are related to the position of the Hox-3.4 gene within the Hox-3 locus. Second, the anterior limits of Hox-3.4 expression within the central nervous system are similar to those shown by subfamily homologues Hox-2.1 and Hox-1.3, although the tissue-specific patterns of expression for these three genes show many differences. Third, the patterns of Hox-3.4 expression within the spinal cord and the testis are very similar to those shown by a neighbouring Hox-3 gene (Hox-3.3), but they are quite different from those shown by Hox-1 genes (Hox-1.2, -1.3 and -1.4).

Localization of a lymphocyte-specific protein tyrosine kinase gene (lck) at a site of frequent chromosomal abnormalities in human lymphomas

The murine lck gene is closely related to a family of cellular protooncogenes and encodes a lymphocyte-specific, membrane-associated protein tyrosine kinase. We and others have demonstrated that the lck gene is rearranged and overexpressed in the murine lymphoma LSTRA, most likely as a result of the insertion of Moloney murine leukemia virus DNA immediately adjacent to the gene. We now report that the lck gene is located at the distal end of murine chromosome 4 and on human chromosome 1 at position 1p32-35 near a site of frequent structural abnormalities in human lymphomas and neuroblastomas. These results raise the possibility that structural alteration of the lck gene through chromosomal rearrangement may contribute to transformation in human malignant disease.

Murine Ly-6 multigene family is located on chromosome 15

Murine Ly-6-encoded molecules play an important role in the antigen-independent activation of lymphocytes. We have described the cloning of a cDNA encoding the protein component of an Ly-6 molecule. Hybridization studies indicated that this cDNA identified multiple DNA fragments on Southern blots. The banding pattern exhibits a restriction fragment length polymorphism from mice bearing either the Ly-6a or the Ly-6b allele. We have employed three independent chromosomal mapping techniques, somatic cell hybrids, in situ hybridization, and strain distribution pattern analysis of the restriction fragment length polymorphism of DNA from recombinant inbred lines, to ascertain the chromosomal origins of these bands. We report that all members of the Ly-6 multigene family are tightly linked on chromosome 15 and have been regionalized by in situ hybridization analysis to band 15E on the distal portion of this chromosome. Linkage analysis has indicated that the Ly-6 genes are located within 1 map unit of Env-54 (a retroviral envelope restriction fragment length polymorphism probe), 3 map units from ins-1, (insulin-related gene), and 4 map units from the protooncogene c-sis. The possible involvement of the Ly-6 lymphocyte activation and differentiation antigen genes in chromosome 15-related lymphoid malignancies is discussed.

Assignment of the gene coding for the T3-delta subunit of the T3-T-cell receptor complex to the long arm of human chromosome 11 and to mouse chromosome 9

The gene encoding the 20-kDa glycoprotein of the T3-T-cell receptor complex (T3-delta chain) has been mapped to human chromosome 11 by hybridization of a T3-delta cDNA clone (pPGBC#9) to DNA from a panel of human-rodent somatic cell hybrids. In Southern blotting experiments with DNAs of somatic cell hybrids that contained segments of chromosome 11, we were able to assign the T3-delta gene to the distal portion of the long arm of human chromosome 11 (11q23-11qter). By use of a newly developed cDNA clone (pPEM-T3 delta) that codes for the murine T3-delta chain, the mouse T3-delta gene was mapped on chromosome 9. The importance of the T3-delta map position and its relationship to the other genes on the long arm of human chromosome 11 and to those on mouse chromosome 9 is discussed.

Chromosomal mapping of the prolactin/growth hormone gene family in the mouse

The chromosomal assignments of genes in the PRL/GH family in the mouse have been determine in mouse-hamster hybrid cell lines. Mouse GH (mGH) appears to be encoded by a single copy gene located on chromosome 11 and is part of a highly conserved region between mouse chromosome 11 and human chromosome 17. All of the other genes in this hormone family, including those encoding mPRL, mouse placental lactogens I and II, and mouse proliferin and proliferin-related protein, map to chromosome 13.

Murine T cell receptor beta chain is encoded on chromosome 6

Southern blot analysis of somatic cell hybrid lines indicates that the beta chain of the T cell receptor for antigen maps to chromosome 6 of the mouse. An experiment testing hybridization of the constant region of this gene to DNA from a hybrid cell line containing a translocation of chromosome 6 supports the localization of this gene to the proximal (centromeric) one-third of chromosome 6, in the same general region as the immunoglobulin kappa chain locus. This may be another indication of the shared evolutionary origins of the genes encoding both T and B cell antigen recognition.

Localization of the cryptdin locus on mouse chromosome 8

Cryptdin is a defensin-related peptide, and its mRNA accumulates to high abundance in epithelial cells of intestinal crypts beginning in the second week of postnatal development. The cryptdin (Defcr) locus was assigned to mouse chromosome 8 by Southern blotting of DNAs from mouse/hamster somatic hybrid cell lines. Analysis of somatic hybrid DNAs for mouse-specific restriction fragments showed zero discordance and perfect concordance with chromosome 8. The Defcr locus was localized on chromosome 8 by analysis of DNAs from recombinant inbred (RI) strains of mice after identification of three potential Defcr alleles based on restriction fragment length polymorphisms (RFLPs) in inbred strains. The strain distribution patterns of the Defcr locus were compared with those of chromosome 8 markers in five panels of RI strains. Analysis of cosegregation of Defcr with xenotropic proviral locus Xmv-26 and additional loci confirmed the chromosomal assignment and showed that Defcr is on proximal chromosome 8 within approximately 6 (1.3 to 21.3) cM of Xmv-26. The mouse Defcr locus and the human defensin gene(s) located on chromosome 8p23 appear to map to homologous regions.

Isolation and regional localization of the murine homeobox-containing gene Hox-3.3 to mouse chromosome region 15E

A murine homeobox-containing cDNA clone has been isolated from an adult spinal cord library. Using in situ hybridization and somatic cell genetics techniques, the newly isolated homeobox gene has been mapped to mouse chromosome region 15E. Because of its chromosomal location, we called this gene locus Hox-3.3. Nucleotide sequence analysis revealed that the Hox-3.3 gene represents the murine cognate of the human homeobox gene c8. The presumptive organization of the murine Hox-3 homeobox gene cluster is discussed.

A new translocation in chronic myelogenous leukemia

A reciprocal translocation involving chromosomes Nos. 3 and 22 has been found in a patient with seemingly Ph-negative chronic myelogenous leukemia (CML). G-band analysis revealed, that deletion in No. 22 occurred at the same point, as in the typical cases of the disease. It was concluded, that breakage in No. 22 at a specific site with spatial disjunction of the resulting segments might be the crucial cytogenetic event in the genesis of CML, the Philadelphia chromosome not being an obligatory result of the rearrangement.

Localization of the murine lambda 5 gene on chromosome 16

The chromosomal location of the murine lambda 5 gene was analyzed by Southern hybridization using restriction enzyme-digested DNA from a panel of 15 mouse X hamster somatic cell hybrids. Sequences homologous with those of lambda 5 DNA were detected in DNA of 5 hybrids. In all 5 hybrids lambda 5 was contained in restriction fragments of equal sizes, the lengths of which indicated that the germline configuration of lambda 5 with three exons and the restriction sites expected from its genomic structure were present. Southern hybridization with the murine lambda 1 gene as a probe detected the same 5 hybrids as positive. The only mouse chromosome present on all of the positive hybrids, and absent from negative ones, was number 16. We conclude that lambda 5 is situated on the same chromosome as lambda 1, i.e., on the murine chromosome 16.

A novel 6:10 chromosomal translocation in the murine plasmacytoma NS-1

Specific chromosomal abnormalities are regularly associated with many murine and human malignancies. In particular, the majority of murine plasmacytomas and human Burkitt's lymphomas contain a characteristic translocation which results in the juxtaposition of a cellular oncogene, c-myc, with the immunoglobulin heavy-chain gene locus, and this rearranged c-myc directs the synthesis of qualitatively and quantitatively abnormal transcripts which may have an aetiological role in the development of the transformed state in lymphoid malignancies. Similarly, rearrangement and abnormal expression of c-myb (ref. 10) and c-mos (ref. 11) has been reported in other murine lymphoid tumours. Here we describe a novel 6:10 chromosomal translocation in the murine plasmacytoma cell line NS-1 which juxtaposes the immunoglobulin Ck gene with a single-copy sequence of unknown function. The NS-1 plasmacytoma is a frequently used fusion partner in hybridoma production and is known to contain a rearranged c-myc gene and a genetic element which transforms normal mouse fibroblasts in DNA-mediated transfection assays. We conclude that individual B-cell tumours may contain multiple chromosomal translocations perhaps relevant to oncogenesis.

Glial fibrillary acid protein, an astrocytic-specific marker, maps to human chromosome 17

The murine glial fibrillary acid protein (GFAP) gene is located on chromosome 11 in close proximity to the genes encoding transforming protein p53 (Trp53) and myeloperoxidase (Mpo). Both Trp53 and Mpo have been mapped to human chromosome 17, but the chromosomal assignment of human GFAP has not been previously determined. In this report, we have amplified a cDNA fragment encoding a portion of GFAP from human brain and have used this probe to screen a mouse x human somatic cell hybrid panel. The results show that a human-specific GFAP species of approx 3.7 kb maps to one of these lines, TMS5, which contains chromosome 17 as its only human chromosome. On the basis of these data we speculate that there may be evolutionary relatedness between GFAP and other genes that map to both murine chromosome 11 and human chromosome 17.

Mapping of gene encoding mouse placental alkaline phosphatase to chromosome 4

The gene encoding the mouse placental alkaline phosphatase (ALP; orthophosphoric-monoester phosphohydrolase, alkaline optimum, EC 3.1.3.1) is mapped to chromosome 4, based on Southern blot hybridization of the mouse cDNA with DNAs from mouse-Chinese hamster somatic cell hybrids. This assignment is consistent with the genetic analysis of the Akp-2 locus, which is responsible for the genetic variation of alkaline phosphatase enzyme in placenta as well as in liver, kidney, and bone.

Chromosomal assignment of the murine gene encoding the transformation-related protein p53

p53 is a transformation-related protein that is encoded by the cellular genome and is synthesized at elevated levels in a wide range of different cell line types and in primary tumors of various species. By using several independently established anti-p53 monoclonal antibodies, it was possible to distinguish between p53 of mouse origin and p53 of Chinese hamster origin. By analysis of a series of mouse X Chinese hamster hybrid cell lines containing various mouse chromosomes, we mapped the p53 gene product to mouse chromosome 11.

Chromosomal location of a human alpha interferon gene family

To determine the chromosomal location of the human alpha interferon genes, we scored a series of human/rodent somatic cell hybrids for the presence of DNA sequences hybridizing to an alpha 1 interferon DNA probe. The presence of human chromosome 9 in a hybrid correlated with the presence of a family of alpha interferon genes.

Association of foreign DNA sequence with male sterility and translocation in a line of transgenic mice

We have analyzed a line of transgenic mice derived from injection of a cloned human interferon cDNA. This line manifests total male sterility of males carrying the human sequence, while male littermates not harboring the foreign DNA are fertile. All females are fertile. Karyotypes of transgenic animals show 2:12 translocation. The microinjected sequence maps to one of the translocation chromosomes composed of a large portion of chromosome 12 to which has been translocated a segment of chromosome 2. Analysis of the sterile males reveals significant abnormalities of spermatogenesis and faulty chromosome synapsis that involves the translocation chromosomes. These findings show that transfer of foreign DNA into mouse embryos may lead to chromatin breakage and infertility of transgenic animals.

Chromosomal assignment of gene encoding the largest subunit of RNA polymerase II in the mouse

The gene encoding the largest subunit of RNA polymerase II was mapped to mouse chromosome 11 by Southern blotting analysis of mouse-Chinese hamster somatic cell hybrids and by in situ hybridization. This assignment extends the previously defined homology between mouse chromosome 11 and human chromosome 17.

Chromosome assignment of the murine Hox-4.1 gene

The murine homebox gene 4.1 was assigned to chromosome 2 by Southern analysis of somatic cell hybrids and by in situ hybridization. This assignment and the report of Featherstone et al. (M. S. Featherstone, A. Baron, S. J. Gaunt, M. G. Mattei, and D. Duboule, 1988, Proc. Natl. Acad. Sci. USA, 85, 4760-4764) indicate that a fourth group of homeobox genes is located on chromosome 2 in the mouse (in addition to the homeobox gene clusters on chromosomes 6, 11, and 15).

Chromosomal location and some structural features of human clathrin light-chain genes (CLTA and CLTB)

Two human clathrin light-chain genes have been defined. The gene (CLTA) encoding the LCa light chain maps to the long arm of chromosome 12 at 12q23-q24 and that encoding the LCb light chain (CLTB) maps to the long arm of chromosome 4 at 4q2-q3. Isolation and characterization of partial genomic clones encoding human LCa and LCb reveal the neuron-specific insertions of the LCa and LCb proteins to be encoded by discrete exons, thus proving that clathrin light chains undergo alternate mRNA splicing to generate tissue-specific protein isoforms. The insertion sequence of LCb is encoded by a single exon and that of LCa by two exons. The first of the two neuron-specific LCa exons is homologous to the corresponding LCb exon. An intronic sequence of the LCb gene with similarity to the second neuron-specific exon of the LCa gene has been identified.

D10S20, a previously unmapped RFLP (OS-3), is located on 10q near D10S4

The locus recognized by the probe OS-3 is assigned to chromosome 10 both by Southern blot analysis of a panel of somatic cell hybrid DNAs and by genetic linkage to markers already assigned to chromosome 10. In Caucasians this probe recognizes a three-allele TaqI RFLP as well as two-allele BanII and RsaI RFLPs which are both in strong linkage disequilibrium with each other and with the TaqI RFLP. The D10S20 locus defined by this probe maps 5.5 cM distal to D10S4 on the long arm of chromosome 10. Because this human clone hybridizes with mouse genomic DNA, it will be useful in comparative mapping studies.