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L Skow

Publications and source records attributed to L Skow.

10 recordsLinked to original sources

Genetic mapping of GBE1 and its association with glycogen storage disease IV in American Quarter horses.

Comparative biochemical and histopathological data suggest that a deficiency in the glycogen branching enzyme (GBE) is responsible for a fatal neonatal disease in Quarter Horse foals that closely resembles human glycogen storage disease type IV (GSD IV). Identification of DNA markers closely linked to the equine GBE1 gene would assist us in determining whether a mutation in this gene leads to the GSD IV-like condition. FISH using BAC clones as probes assigned the equine GBE1 gene to a marker deficient region of ECA26q12-->q13. Four other genes, ROBO2, ROBO1, POU1F1, and HTR1F, that flank GBE1 within a 10-Mb segment of HSA3p12-->p11, were tightly linked to equine GBE1 when analyzed on the Texas A&M University 5000 rad equine radiation hybrid panel, while the GLB1, MITF, RYBP, and PROS1 genes that flank this 10-Mb interval were not linked with markers in the GBE1 group. A polymorphic microsatellite (GBEms1) in a GBE1 BAC clone was then identified and genetically mapped to ECA26 on the Animal Health Trust full-sibling equine reference family. All Quarter Horse foals affected with GSD IV were homozygous for an allele of GBEms1, as well as an allele of the most closely linked microsatellite marker, while a control horse population showed significant allelic variation with these markers. This data provides strong molecular genetic support for the candidacy of the GBE1 locus in equine GSD IV.

1,4-alpha-Glucan Branching Enzyme↗

Mapping of 13 horse genes by fluorescence in-situ hybridization (FISH) and somatic cell hybrid analysis.

We report fluorescence in-situ hybridization (FISH) and somatic cell hybrid mapping data for 13 different horse genes (ANP, CD2, CLU, CRISP3, CYP17, FGG, IL1RN, IL10, MMP13, PRM1, PTGS2, TNFA and TP53). Primers for PCR amplification of intronic or untranslated regions were designed from horse-specific DNA or mRNA sequences in GenBank. Two different horse bacterial artificial chromosome (BAC) libraries were screened with PCR for clones containing these 13 Type I loci, nine of which were found in the libraries. BAC clones were used as probes in dual colour FISH to confirm their precise chromosomal origin. The remaining four genes were mapped in a somatic cell hybrid panel. All chromosomal assignments except one were in agreement with human-horse ZOO-FISH data and revealed new and more detailed information on the equine comparative map. CLU was mapped by synteny to ECA2 while human-horse ZOO-FISH data predicted that CLU would be located on ECA9. The assignment of IL1RN permitted analysis of gene order conservation between HSA2 and ECA15, which identified that an event of inversion had occurred during the evolution of these two homologous chromosomes.

Animals↗

Comparative FISH-mapping of villin (VIL) gene in river buffalo, sheep and goat chromosomes.

Two genomic clones of the villin (VIL) gene were independently hybridized on river buffalo (Bubalus bubalis, BBU), sheep (Ovis aries, OAR) and goat (Capra hircus, CHI) chromosomes by using sequential fluorescence in situ hybridization (FISH) and R-banding (RBP- and RBA-banding). Clear hybridization signals revealed that VIL is located in BBU 2q33, OAR 2q33 and CHI 2q33. These chromosomes and chromosome bands are believed to be homologous and the VIL locus is the same as that previously found on cattle chromosome 2q43. VIL localization in these three species allows us tentatively to assign all cattle U17 to BBU and CHI 2q and to extend the physical map to OAR 2q.

Animals↗

Three-dimensional visualization of physiologically based kinetic model outputs.

Outputs from a physiologically based toxicokinetic (PB-TK) model for fish were visualized by mapping time-series data for specific tissues onto a three-dimensional representation of a rainbow trout. The trout representation was generated in stepwise fashion: 1) cross-section images were obtained from an anesthetized fish using a magnetic resonance imaging system, 2) images were processed to classify tissue types and eliminate unnecessary detail. 3) processed images were imported to a visualization software package (Application Visualization System) to create a three-dimensional representation of the fish, encapsulating five volumes corresponding to the liver, kidney, muscle, gastrointestinal tract, and fat, Kinetic data for the disposition of pentachloroethane in trout were generated using a PB-TK model. Model outputs were mapped onto corresponding tissues volumes, representing chemical concentration as color intensity. The workstation software was then used to animate the images, illustration the accumulation of pentachloroethane in each tissue during a continuous branchial (gill) exposure.

Animals↗

Further genetic analyses of skin tumor promoter susceptibility using inbred and recombinant inbred mice.

To explore further the genetics of susceptibility to skin tumor promotion in inbred mice, several aspects of responsiveness to 12-O-tetradecanoylphorbol-13-acetate (TPA) were examined in C3H/He mice and segregating crosses between this mouse strain and C57BL/6 mice as well as BXD and BXH recombinant inbred (RI) strains. Dose-response relationships were established for skin tumor promotion by TPA following initiation with 7,12-dimethylbenz[a]anthracene in C3H/He and B6C3F1, as well as several other mouse stocks and strains included for comparison. The relative responsiveness to TPA skin tumor promotion was: SENCAR much greater than DBA/2 greater than C3H/He approximately B6D2F1 greater than B6C3F1 much greater than C57BL/6. Analyses of the susceptibility of B6C3F2 and B6C3F1 x C57BL/6 backcross mice suggested that a minimum of two dominant genetic loci control responsiveness to phorbol ester promotion in these mice. Further analysis of BXH and BXD RI strains suggested the presence of four distinct promotion-responsive phenotypes controlled by a minimum of two genetic loci. The existence of a 'hyper-responsive' phenotype in the sets of RI strains, however, suggests that a third, recessive locus also may play a role in controlling responsiveness to TPA promotion. At 48 h after the last of four applications of TPA, marked hyperplasia and an increase in dark basal keratinocytes were observed in C3H/He mice, whereas in B6C3F1 mice the response in these parameters was intermediate between C3H/He and C57BL/6 mice. A marked dermal inflammation, as determined by infiltration of polymorphonuclear cells, was observed in C3H/He and B6C3F1 mice, whereas little was noted in C57BL/6 mice. Furthermore, histological evaluations of selected BXD RI strains revealed a significant correlation between the magnitude of the hyperplasia response and the percentage of mice bearing tumors. The present data, in conjunction with our previous studies, confirm that the major gene(s) controlling susceptibility to tumor promoter induced by TPA in two sensitive strains (i.e. DBA/2 C3H/He) are similar or closely linked to those for induction of sustained hyperplasia. In addition, the present data provide new evidence for a model where allelic differences at a minimum of three loci contribute to gene differences in susceptibility to phorbol ester promotion DBA/2 and C3H/He versus C57BL/6 mice.

Animals↗

Gene family of male-specific testosterone 16 alpha-hydroxylase (C-P-450(16 alpha)) in mice. Organization, differential regulation, and chromosome localization.

Three genes in the testosterone 16 alpha-hydroxylase (C-P-450(16 alpha)) family, ca, cb, and cc, are characterized. The sizes of the genes are approximately 4.5 to 5.2 kilobase pairs, and all three consist of nine exons with junctions at identical sites. Gene ca is identified as the male-specific, androgen-dependent C-P-450(16 alpha) gene in adult mice, since the exonic sequence matched 100% to the cDNA, pc16 alpha-2 (Wong, G., Kawajiri, K., and Negishi, M. (1987) Biochemistry 26, 8683-8690). Gene cb and cc are organized in tandem within 18-kilobase pair DNA. Their encoded P-450s contain an approximate 94% nucleotide sequence similarity to the C-P-450(16 alpha). The high similarity in gene nucleotide sequences, including the introns and flanking regions, suggests a combination of an ancestral gene duplication and gene conversion as a mechanism for evolution of the C-P-450(16 alpha) family. Gene ca shows male-specific expression in mouse kidney as well as in liver; gene cb, neither sex-specific nor androgen-dependent, is seen only in liver; gene cc is not expressed in either adult mouse liver or kidney. Expression of these three genes is not detected in adult mouse lung. It appears, therefore, that the C-P-450(16 alpha) gene family includes a large number of genes whose expressions are differentially regulated. Southern hybridization of C-P-450(16 alpha) cDNA to genomic DNAs from mouse-hamster somatic hybrid cells localizes tentatively this gene family on mouse chromosome 15. The recombination frequency in BXD recombinant inbred mice suggests that the C-P-450(16 alpha) gene family is approximately 16M from the 55-kDa locus.

Animals↗