Syntenic Group Research Articles

The structural gene for the M1 subunit of ribonucleotide reductase maps to chromosome 11, band p15, in human and to chromosome 7 in mouse

The genes for the M1 subunit of the enzyme ribonucleotide reductase have been mapped in the human and the murine species by use of two independently derived mouse cDNA clones. Southern blot analysis of rodent X human somatic cell hybrid DNAs confirmed the assignment of RRM1 to the short arm of human chromosome 11. In situ hybridization to human metaphase chromosomes revealed a peak of silver grains over the distal third of band 11p15, a region corresponding to subbands p15.4 → p15.5. The mouse Rrm1 locus was assigned to chromosome 7, where it forms part of a conserved syntenic group of at least seven other genes assigned to human chromosome band 11p15.

Chromosomal assignments of genes for tissue plasminogen activator and urokinase in mouse.

The genes encoding the two plasminogen activators, tissue plasminogen activator and urokinase, were mapped to mouse chromosomes using probes derived from the respective mouse cDNAs. DNA from mouse-Chinese hamster and mouse-rat somatic cell hybrids was digested with BamHI and EcoRI, respectively, and analyzed by Southern blot hybridization for the segregation of the two genes. Tissue plasminogen activator and urokinase cosegregated with mouse chromosomes 8 and 14, respectively. The plasminogen activator genes thus fall into two syntenic groups that are conserved in human and mouse.

Linkage ofaconitase-1 andmajor urinary protein-1 loci in male rats

A new major urinary protein alleleMup-lc with “null” activity was detected in males of the COP strain. The (BN X COP)F1 X COP backcross had significant segregation distortion of theMup-lc andAco-1 alleles that indicated a linkage between the genes, at a map distance of 13 ± 4 cM. The loci reside on the linkage group II of the rat with theb locus. According to our data and the results published previously, the map distance and the orientation of genes isb - 8 ± 4 -Mup-1 - 13 ±4-Aco-1. These genes form a syntenic group in both the mouse and the rat.

Chromosomal mapping of beta-globin and albino loci in the domestic cat. A conserved mammalian chromosome group.

Siamese cats are homozygous for the recessive cs allele of the color (albino) locus. The c locus is shown here by backcross analysis to be linked to the beta-hemoglobin (HBB) locus in the cat at a distance of approximately eight centiMorgans. The HBB locus and, by inference, the c locus were assigned to feline chromosome D1, by analysis of genomic DNAs from a panel of rodent X cat somatic cell hybrids with a molecular clone of the human beta-globin locus. Evolutionary conservation of the synthetic homology of feline chromosome D1 and human chromosome 11 is extensive. Comparison of high resolution G-trypsin-banded preparations of the two chromosomes permitted cytological alignment of the long arm of the conserved chromosomes providing that a minimum of one paracentric inversion is hypothesized. The placement of the albino locus on conserved syntenic groups of several markers (HBB, HRAS, LDHA) in both cat and mouse strongly indicates the conservative placement of the as yet unmapped human albino locus in the homologous syntenic group on human chromosome 11p.

Assignment of the gene for carboxypeptidase A to human chromosome 7q22----qter and to mouse chromosome 6.

A rat cDNA probe for preprocarboxypeptidase A was used to follow the segregation of the human gene for carboxypeptidase A (CPA) in 49 human X mouse somatic cell hybrids using Southern filter hybridization techniques. CPA was assigned to human chromosome 7q22----qter. Similarly, the probe was used to follow the segregation of the mouse gene for carboxypeptidase A (Cpa) in 19 mouse X Chinese hamster somatic cell hybrids. Cpa was assigned to mouse chromosome 6. The gene for carboxypeptidase A forms part of a syntenic group that is conserved in man and mouse.

The mouse IFN-alpha (Ifa) locus: correlation of physical and linkage maps by in situ hybridization.

The physical location of the mouse IFN-alpha locus (Ifa) on chromosome 4 was defined by in situ hybridization of a cloned mouse IFN-alpha probe to metaphase spreads in which one chromosome 4 was present as part of a single metacentric chromosome, all other chromosomes being acrocentric. (This approach greatly facilitates analysis and can be used even when it is difficult to obtain good banding). Using unbanded chromosomes, the grains were localized over the chromosome 4 part of the metacentric, in a region 0.61 +/- 0.07 (SD) of the distance from the centromere to the telomere. In Giemsa-banded spreads, the majority of the grains were in the region 4C3----C6. Consideration of these results and of the known linkage maps for mouse and man indicates that the Galt - Aco-1 - Ifa syntenic group spans a distance of approximately 14 cM and suggests that the same group on human 9p will also occupy a similarly sized region, with GALT proximal and IFL distal to the centromere.

The terminal deoxynucleotidyltransferase gene is located on human chromosome 10 (10q23→q24) and on mouse chromosome 19

Terminal deoxynucleotidyltransferase (TdT) is a DNA polymerase expressed in immature lymphocytes of the thymus and bone marrow, as well as certain leukemic cells. Chromosomal assignment of the gene coding for human TdT was accomplished by in situ hybridization of a 3H-labeled cDNA probe to human chromosome preparations and by Southern blot analysis of somatic cell hybrid DNAs. The human TdT gene was mapped to the region q23----q24 of chromosome 10. Breaks at this site have been reported in different translocations in human leukemias. The mouse TdT gene was assigned to chromosome 19 by Southern blot analysis of mouse X Chinese hamster somatic cell hybrids. This result adds a fourth locus to the conserved syntenic group on mouse chromosome 19 and human chromosome 10.

Genes for insulin I and II, parathyroid hormone, and calcitonin are on rat chromosome 1

Insulin, parathyroid hormone, and calcitonin are polypeptide hormones that regulate important physiological processes in target tissues. Rat genes encoding each hormone were chromosomally assigned to rat chromosome 1. Both rats and mice have two insulin genes (I and II). However, in contrast to mice in which insulin I and II are asyntenic, rat insulin I and II were both localized to chromosome 1. This study identifies a conserved syntenic group on rat chromosome 1, and implies that mouse insulin I and II genes were chromosomally separated after rats and mice diverged 20–35 million years ago.

Chromosomal assignments of genes for trypsin, chymotrypsin B, and elastase in mouse.

The mouse genes for the serine proteases trypsin (Try-1), chymotrypsin B (Ctrb), and elastase (Ela-1) were chromosomally assigned using Southern blot hybridization of mouse X Chinese hamster cell hybrid DNA. cDNA probes for the three genes were hybridized to cell hybrid DNA cleaved with BamHI or HindIII and the segregation of Try-1, Ctrb, and Ela-1 was correlated with the segregation of mouse chromosomes. Try-1 is located on chromosome 6, Ctrb is on chromosome 8, and Ela-1 is on chromosome 15. The three genes fall into three syntenic groups that are conserved in the mouse and human genomes.

Chromosome mapping in cattle using mouse myeloma/calf lymph node cell hybridomas.

A study correlating the presence of bovine isozymes in mouse myeloma/calf hybridomas with specific banded chromosomes of their bovine complement has enabled tentative assignments to be made of the bovine isozyme locus for peptidase C (PEP C) to chromosome 5 and the syntenic group lactate dehydrogenase B/peptidase B (LDH B/PEP B) to chromosome 19. There was some evidence for the association of LDH A with one of the last seven small pairs (23-29) of the complement and of superoxide dismutase 1 (SOD 1) with chromosome 13.

Tracing linkage groups from fishes to mammals

Assignment of a locus coding for a muscle pyruvate kinase to linkage group II of Xiphophorus fishes suggests at least partial homology throughout vertebrates of a syntonic group of enzyme loci including mitochondrial isocitrate dehydrogenase, a muscle pyruvate kinase locus, mannosephosphate isomerase, all or part of the duplicated and reduplicated lactate dehydrogenase genes, nucleoside phosphorylase, and peptidase B. An ancestral vertebrate syntenic group is proposed, representing the first case of identifiable linkage group stability maintained through 400 million years of evolutionary divergence.

Parallels of genomic organization and of endogenous retrovirus organization in cat and man

AbstractA combination of technical advances (most notably heterologous cell fusion, high resolution G‐banding, and molecular cloning) has contributed to an accelerated advance in genetic analysis in mammals. The present human genetic map contains over 400 gene assignments and the map is growing rapidly as each new molecular clone or immunological reagent is developed. In our laboratory, we have developed a panel of rodent X human somatic cell hybrids that have been utilized in chromosome assignment of several classes of genes including oncogenes (ras, raf) and endogenous human retroviral sequences (ERVL, 2, etc). Using similar techniques, a biochemical genetic map of the domestic cat has been derived. The cat has 19 chromosome pairs and, to date, 40 genes have been mapped to 16 linkage or syntenic groups. Comparison of linkage relationships between homologous enzymes has revealed a striking conversation of chromosomal linkage association between cat and man. A comparison of syntenically homologous, highly extended high resoultion G‐banded chromosomes between the two mammalian families revealed that 20–25%, by length, of the human karyotype can be precisely aligned (chromomere to chromomere) between cats and man despite the evolutionary divergence of the species nearly 80 million years ago.Moderately repetitive families of retrovirus‐related DNAs exist within the feline and the human genomes. We have isolated molecular clones of several members of the feline RD‐114 retrovirus family from a genomic library of normal cat cellular DNA. The endogenous sequences analyzed were similar to each other in that they were colinear with RD‐114 proviral DNA, were bounded by long terminal redundancies, and conserved many restriction sites in the gag and pol regions. Several sequences were apparently deleted, relative to the previously characterized inducible RD‐114 genome. The env regions of a number of endogenous RD‐114 sequences examined were substantially deleted or diverged; a subset of these sequences contained information at the position of the env region that was not homologous to inducible RD‐114. The RD‐114 virogenes were dispersed to several cat chrosomes that were localized using a panel of rodent x cat somatic cell hybrids. A comparison of the genetic properties of endogenous human retroviral sequences revealed several similarities between the human and feline status of endogenous retroviruses.

Genetic mapping in mammals: chromosome map of domestic cat.

A genetic map of 31 biochemical loci located on 17 feline syntenic (linkage) groups has been derived by somatic cell genetic analysis of cat-rodent hybrids. Most of these syntenic groups have been assigned to one of the 19 feline chromosomes. Comparative linkage analysis of the feline biochemical loci and homologous human loci revealed considerable conservation of linkage associations between the primates and the Felidae (order Carnivora). Many of these same linkage groups have not been conserved in the murine genome. The genetic and evolutionary implications of comparative mapping analysis among mammalian species are discussed.

The gene map of the rabbit, <i>Oryctolagus cuniculus </i>L.

The segregation of 11 enzyme markers was analyzed in 74 independent rabbit X hamster hybrid clones. Two syntenic groups were observed, LDHB-TPI and LDHA-ACP2. No syntenic relationship was found for the seven other markers, PEPB, PGM1, ENOl, GPI, NP, MDH1, and MDH2.

Sheep gene mapping by somatic cell hybridization: four syntenic groups: ENO1-PGD, ME1-PGM3, LDHB-PEPB-TPI, and G6PD-PGK-GALA.

Gene segregation for 16 ovine enzyme markers was studied in 25 independently derived hamster-sheep hybrids. The results show four syntenic groups, ENOl-PGD, ME1-PGM3, LDHB-PEPB-TPI, G6PD-PGK-GALA, and markers for six different chromosomes: PGM1 (or PGM2?), IDH1, GPI, LDHA, MDH2, and ADA.

Cattle gene mapping by somatic cell hybridization study of 17 enzyme markers.

In 38 independent hamster-bovine hybrids, the segregation of 17 bovine enzyme markers was studied. The results showed three syntenic groups; LDHB-PEPB-TPI, PGM3-ME1-SOD2, and PGD-ENOl, whereas nine other markers did not show any syntenic relationship: LDHA, MDH2, LDH1, SOD1, PKM2, PGM1, PGM2, AK1, and MPI.

Conserved autosomal syntenic group on mouse (MMU) chromosome 15 and human (HSA) chromosome 22: assignment of a gene for arylsulfatase A to MMU 15 and regional mapping of DIA1, ARSA, and ACO2 on HSA 22.

We have utilized a panel of Chinese hamster x mouse somatic cell hybrids segregating mouse chromosomes to assign a gene for arylsulfatase A (ARSA) to mouse chromosome 15. Considering our previous assignment of a gene for diaphorase-1 (DIA1) to the same mouse chromosome, we have evidence for another syntenic relationship that has been conserved, since the homologous loci for human ARSA and DIA1 are both located on human chromosome 22. Because MMU 15 and HSA 22 are quite dissimilar in size and banding patterns, we have attempted to identify the conserved portion by regional mapping of human DIA1 and ARSA using somatic cell hybrids segregating a human chromosome translocation t(15;22)(q14;q13.31). The results assign human DIA1 and ARSA to the distal sub-band of 22q13 (region 22q13.31 leads to qter). The locus for mitochondrial aconitase (ACO2) has been separated by the breakpoint from DIA1 and ARSA and is located more proximally.

Human gene mapping 2. Rotterdam Conference (1974). 2d International Workshop on Human Gene Mapping. Report of the committee on unassigned syntenic groups and theoretical considerations.

Human gene mapping 2. Rotterdam Conference (1974). 2d International Workshop on Human Gene Mapping. Report of the committee on unassigned syntenic groups and theoretical considerations.

The Rhesus syntenic group in man.

THE two principal approaches to mapping human autosomes—the study of pedigrees and of cell hybrids—may sometimes complement each other.