Genetic mapping of the gene for a novel tyrosine kinase, Blk, to mouse chromosome 14

The gene Blk, which encodes a novel tyrosine kinase expressed preferentially in B-lymphoid cells, was mapped by Southern blot analysis of DNA from the progeny of an intersubspecific backcross. Blk maps to the proximal region of chromosome 14 with the gene order centromere-(Np-1, Tcra)-Blk-sys-Es-10.     

Genetic mapping of a new homeobox gene to mouse chromosome 7

A newly identified homeobox gene designated Dbx has been mapped to mouse Chromosome (Chr) 7. This gene is expressed in a restricted manner in developing mouse brain and spinal cord and has amino acid sequence similarities with members of the homeobox gene family such as Drosophila H2.0 and mouse Hlx. Using a fragment of the Dbx cDNA as a probe, a PstI restriction fragment length polymorphism was used to determine genotypes of 144 progeny from an interspecific backcross. Segregation analysis revealed linkage of Dbx with six prepositioned reference loci on mouse Chr 7. No recombination was observed between Dbx and Odc-rs6, indicating that Dbx lies approximately 25 cM distal to the Chr 7 centromere in a region that has conserved linkage relationships with regions of human Chrs 11 and 19.     

Genetic mapping of the mouse interleukin 3 gene to chromosome 11

Interleukin 3 (IL 3) is a T cell-derived lymphokine that induces the proliferation and differentiation of early hematopoietic stem cells. By using a cDNA clone for IL 3, a single Eco-RI restriction fragment of 8.5 kbp was detected in Southern blot hybridizations of DNA from BALB/c and C57BL/10 mice, whereas an Eco-RI restriction fragment of 10.8 kbp was detected in NFS and A/J mice. Under the conditions used, no hybridization was detected to Chinese hamster DNA. The species and strain differences were used to analyze a series of hamster X mouse somatic cell hybrids and genetic crosses between NFS and C57BL/10 mice. The results demonstrate that the IL 3 gene is located on chromosome 11.     

Bidirectional transcription of a novel chimeric gene mapping to mouse chromosome Yq

Background  

The male-specific region of the mouse Y chromosome long arm (MSYq) contains three known highly multi-copy X-Y homologous gene families, Ssty1/2, Sly and Asty. Deletions on MSYq lead to teratozoospermia and subfertility or infertility, with a sex ratio skew in the offspring of subfertile MSYqdel males     

Genetic mapping of the polycystic kidney gene,pcy, on mouse chromosome 9

The murine polycystic kidney disease gene,pcy, is an autosomal recessive trait located on chromosome 9. To determine the genetic locus ofpcy, 222 intraspecific backcross mice were obtained by mating C57BL/6FG-pcy andMus molossinus. Restriction fragment length polymorphism analysis of 70 of the 222 backcross progeny showed thatpcy, dilute coat color (d), and cholecystokinin (Cck) were located in the orderd—pcy—Cck from the centromere. Simple sequence repeat length polymorphism analysis of DNA of all 222 backcross mice was carried out using four markers which were located near the central regions ofd andCck. One and eight recombinations were detected betweenD9Mit24 andpcy and betweenD9Mit16 andpcy, respectively. However, no recombinant was observed amongpcy, D9Mit14, andD9Mit148. These findings strongly suggest thatD9Mit14 andD9Mit148 are located near thepcy gene and are good markers for chromosomal walking to this gene.     

Genetic mapping of the gene for Ca2+/calmodulin-dependent protein kinase IV (Camk-4) to mouse chromosome 18

Southern blot analysis of Chinese hamster x mouse somatic cell hybrids was used to map the gene for a serine/threonine protein kinase expressed in brain and testis. This locus, termed Camk-4, encodes Ca2+/calmodulin-dependent protein kinase IV. Progeny of an interspecific backcross were analyzed to position Camk-4 in the centromeric region of chromosome 18 near two mutations known to affect neurological function and fertility. This raises the possibility that a defect in Camk-4 may be responsible for one of these mutant phenotypes.     

Genetic mapping of the gene for androgen-binding protein/sex hormone-binding globulin to mouse chromosome 11

Southern blot analysis of DNAs from Chinese hamster x mouse and rat x mouse somatic cell hybrids showed that the mouse gene encoding androgen-binding protein/sex hormone-binding globulin (ABP-SHBG) is on Chromosome 11. Progeny from an intersubspecies backcross were analyzed to position this locus, termed Shbg, between Il-3 and Int-4 in the middle of this chromosome. Shbg is thus closely linked to several neurological mutations, one of which, Tr, is also associated with male sterility. The recent finding that ABP-SHBG is found throughout the rat brain raises the possibility that one of these mutations may be due to a defect in Shbg.     

Genetic mapping of a mouse ocular malformation locus, tcm, to chromosome 4

The Tcm mutation in the mouse is an autosomal dominant ocular malformation manifesting as microphthalmia, iris dysplasia, cataract, and coloboma. As a first step to cloning the Tcm gene, we report the localization of the Tcm mutation with respect to known microsatellite markers. Backcross progeny carrying the Tcm mutation were produced by mating Tcm/+ heterozygous mice to normal C57BL/6 partners. Genomic DNA from each mouse was subjected to PCR analysis to identify simple sequence length polymorphisms. Our results locate Tcm to Chr 4 and suggest candidate genes responsible for the Tcm phenotype. Finally, ocular histopathology was done in 3-week-old animals to define the extent of the malformation. Received: 14 April 1996 / Accepted: 13 October 1996     

Assignment of a novel protein tyrosine phosphatase gene (Hcph) to mouse chromosome 6.

Hematopoietic cell phosphatase (Hcph) was identified by amplification of conserved protein tyrosine phosphatase sequences from a myeloid cell line and is predominantly expressed in hematopoietic cells. Hcph is unique in containing two, tandemly repeated, src-homology 2 domains in the amino terminal region of the phosphatase. Using a genomic probe in interspecific backcross analysis, the murine Hcph gene maps to mouse Chromosome 6 and is tightly linked to the Tnfr-2 and Ly-4 genes.     

Genetic mapping of the mouse c-fms proto-oncogene to chromosome 18.

Chinese hamster X mouse somatic cell hybrids were analyzed by Southern blot hybridization with a probe specific for the cellular c-fms proto-oncogene. Results demonstrate that Fms, the genetic locus containing this sequence, maps to mouse chromosome 18. Mouse Fms is thus not linked to the same set of genes involved in growth regulation that human FMS is linked to.     

Genetic and physical mapping of the human cannabinoid receptor gene to chromosome 6q14-q15

A cDNA encoding a G protein-coupled receptor that appears to mediate the behavioral effects of cannabinoids, the psychoactive ingredients of marijuana, has recently been cloned from rat cerebral cortex and expressed. We have now determined the genomic location of the human cannabinoid receptor gene (CNR) by a combination of genetic linkage mapping and chromosomal in situ hybridization. The segregation pattern of a CNR DNA polymorphism was analyzed in 508 individuals from two or three generations of 40 families. Linkage of CNR to chromosome 6 centromeric loci and to DNA markers on the long and short arms was detected. CNR was tightly linked to D6S27, which is known to be located at 6q (log10 odds ratio [lod score, Zmax] of 10.54 at a recombination fraction [theta] of 0.02). Close linkage was suggested between CNR and CGA, the locus for the alpha subunit of human chorionic gonadotropin (Zmax = 2.71 at theta = 0). Moreover, CNR was linked to the two markers 308/BamHI (theta = 0.14) and 308/TaqI (theta = 0.20) defining locus D6Z1, an extended, highly repetitive, and highly conserved sequence localized exclusively to centromeres of all chromosomes and enriched on chromosome 6. In situ hybridization using a biotinylated cosmid probe localizes the gene to 6q14-q15, thereby confirming the linkage analysis and defining a precise alignment of the genetic and cytogenetic maps.     

Assignment of pancreatic ribonuclease gene to mouse chromosome 14

A pancreatic ribonuclease cDNA was used as a probe for Southern blot hybridization of genomic DNA from recombinant inbred strains of mice. The results indicated that the gene coding for pancreatic ribonuclease (Rib-1) can be assigned to mouse chromosome 14. Analysis of the congenic strain B10.D2(57N)Sn confirmed this assignment and indicated that Rib-1 is closely linked to the genes encoding the T-cell receptor alpha subunit (Tcra) and nucleoside phosphorylase-2 (Np-2).     

Genetic mapping of the structural gene for antithrombin III to human chromosome 1

Summary Using a purified cDNA probe of human antithrombin III (AT3) gene and a series of human/Chinese hamster cell hydrids, we established the chromosomal location of the structural gene for AT3 in human chromosome 1 by Southern blot analysis.     

Genetic mapping of the rat Lcn2 gene to chromosome 3

The expression of rat 24p3, encoded by the Lcn2 gene, has been associated with rat mammary carcinomas initiated by the neu oncogene (Stoesz and Gould, 1995). In this study, we assign the Lcn2 gene to rat chromosome band 3q12 by genetic linkage analysis.     

Genetic mapping of the integrin alpha 1 gene (Vla1) to mouse chromosome 13.

The integrin alpha 1 chain (Vla1) associates with the beta 1 chain to form a heterodimer that functions as a dual laminin/collagen receptor in neural cells and hematopoietic cells. We have used an interspecies backcross gene-mapping technique to map the Vla1 gene to the distal end of chromosome 13 in the mouse genome. The Vla1 locus is located 3.5 cM distal to Ctla-3 and 7.8 cM distal to Htrla. We have further characterized this locus in recombinant inbred (RI) mice by examining the strain distribution patterns of nine genomic DNA restriction fragment length variants detected with alpha 1 cDNA probes. The RI gene mapping did not show linkage to previously mapped genes or mutants in the AXB, BXA, or AKXD RI sets and therefore defines a new genetic marker for the distal end of chromosome 13 in these RI sets.