Novel restriction fragment length polymorphism of the growth hormone gene in inbred rats

A novel restriction fragment length polymorphism in inbred rats was detected by Southern blot analysis with rat growth hormone cDNA as a probe. Four alleles, characterized by PstI fragments of 1.2, 1.1, 0.9, and 0.7 kb, respectively, were detected in 27 strains examined. The same distribution of polymorphisms was observed on digestion of DNAs of these strains with three other enzymes, PvuII, HindIII, and BamHI. Moreover, the same differences in length of allelic restriction fragments were obtained with these restriction enzymes as with PstI. These findings suggested that the polymorphism was caused by insertion or deletion of variable DNA segments in the second intron of the growth hormone gene. Linkage analyses using backcross progeny provided no evidence for close linkage between the restriction fragment length polymorphism locus and 10 other loci examined.     

Restriction fragment length polymorphisms in dairy and beef cattle at the growth hormone and prolactin loci

Two bovine populations, a Holstein-Friesian dairy stock and a synthetic (Baladi X Hereford X Simmental X Charolais) beef stock, were screened for restriction fragment length polymorphisms (RFLPs) at the growth hormone and prolactin genes. Most RFLPs at the growth hormone gene are apparently the consequence of an insertion/deletion event which was localized to a region downstream of the structural gene. The restriction map for the genomic region including the growth hormone gene was extended. Two HindIII RFLPs at the growth hormone locus, as well as several RFLPs at the prolactin gene, seemed to be the consequence of a series of point mutations. The results are discussed in terms of the possibility that minor genomic variability underlies quantitative genetic variation.     

Growth hormone restriction fragment length polymorphisms that segregate with 42-day live weight of mice

The known correlation between growth hormone levels and growth rate in a number of species prompted us to examine if polymorphic restriction fragment alleles at the growth hormone locus in mice might be associated with differentiable rates of growth. An F2 population of mice was generated from crosses between a line selected for high 42-day weight and an unselected control line. The original selected and control lines exhibited mean 42-day weights of 30.6 +/- 3.8 and 20.5 +/- 2.6 g, respectively. Since the two lines also differed with respect to the restriction fragments detected by hybridization to a rat growth hormone cDNA probe, an analysis of the F2 generation was carried out to determine whether this polymorphism could be considered a quantitative trait locus for 42-day weight. The results of the analysis indicated that a polymorphic HindIII restriction fragment was correlated (P less than 0.05) with 42-day weight. However, the allele that was positively correlated with weight was the one that was fixed in the original control line, rather than the one from the selected line. While these findings support the potential use of restriction fragment length polymorphisms in quantitative trait evaluation of livestock, they also emphasize the requirement for testing such potential quantitative trait loci in the appropriate genetic background.     

The duplicated gene copy of the ovine growth hormone gene contains a PvuII polymorphism in the second intron

PvuII restriction fragment length polymorphism (RFLP) was found at the growth hormone locus in sheep carrying the GH2 allele where the gene is duplicated. By restriction analysis and using the polymerase chain reactibn we demonstrated that this RFLP is due to a mutation at the Pvu II site located in the second intron of the 3′ copy of the GH2 allele.     

Restriction fragment length polymorphisms at the growth hormone gene in pigs

Pigs from four Danish and two Swedish populations were examined for restriction fragment length polymorphism (RFLP) at the growth hormone (GH) gene. Polymorphism was detected with the restriction enzymes DraI and TaqI. A comparison of the Danish populations showed significant differences among their allelic frequencies.     

Allele frequencies of apolipoprotein A-I and A-II gene locus DNA polymorphisms in Boston-based whites

Allele frequencies for four restriction fragment length polymorphisms of the apolipoprotein A-I gene locus and one restriction fragment length polymorphism of apolipoprotein A-II gene locus were determined in more than 100 North American whites and are reported herein.     

DNA fingerprinting of human cell lines using PCR amplification of fragment length polymorphisms

Summary Methods for monitoring cell line identification and authentication include species-specific immunofluorescence, isoenzyme phenotyping, chromosome analysis, and DNA fingerprinting. Most previous studies of DNA fingerprinting of cell lines have used restriction fragment length polymorphism analysis. In this study, we examined the utility of an alternative and simpler method of cell line DNA fingerprinting—polymerase chain reaction (PCR) amplification of fragment length polymorphisms. Fourteen human cell lines previously found by other methods to be either related or disparate were subjected to DNA fingerprinting by PCR amplification of selected fragment length polymorphism loci. Cell identification patterns by this method were concordant with those obtained by isoenzyme phenotyping and restriction fragment length polymorphism-DNA fingerprinting, and were reproducible within and between assays on different DNA extracts of the same cell line. High precision was achieved with electrophoretic separation of amplified DNA products on high resolution agarose or polyacrylamide gels, and with fragment length polymorphism (FLP) loci-specific “allelic ladders” to identify individual FLP alleles. Determination of the composite fingerprint of a cell line at six appropriately chosen fragment length polymorphism loci should achieve a minimum discrimination power of 0.999. The ability of PCR-based fragment length polymorphism DNA fingerprinting to precisely and accurately identify the alleles of different human cell lines at multiple polymorphic fragment length polymorphism loci demonstrates the feasibility of developing a cell line DNA fingerprint reference database as a powerful additional tool for future cell line identification and authentication.     

Growth hormone gene polymorphism associated with selection for milk fat production in lines of cattle

Summary
Fifty-eight calves of both sexes from lines of Red Danish dairy breed selected for high ( n = 36) and low ( n = 22) milk fat production, and 32 heifers from lines of Norwegian Red dairy breed selected for high ( n = 16) and low ( n = 16) milk fat yield were typed for two previously reported restriction fragment length polymorphisms (RFLPs) in the growth hormone gene. The RFLPs are consistent with: (1) an insertion(I)/deletion(D) of approximately 0.9kb in the 3'-region of the growth hormone gene and (2) a polymorphic Msp I(+/−) site in the third intron. A traditional RFLP procedure was used for typing the I/D polymorphism and a polymerase chain reaction (PCR) procedure was developed for typing the Mspl polymorphism. Only the I-MspI(+) and D- Msp I(-) haplotypes were found. In the Red Danish lines the frequency of D- Msp I(-) haplo-type was 0.28 in high line and 0.05 in low line calves, this difference was significant ( P <0.01). The corresponding frequencies in the Norwegian Red lines were 0.09 in the high line and 0.0 in the low line. Attempts to screen for RFLPs in the growth hormone receptor gene and in the insulin-like growth factor-I gene were unsuccessful.     

PCR-RFLP typing of the bovine myoglobin gene

We have identified substitutions in the 3₁ untranslated region of the bovine myoglobin gene, one of which affects an MboII restriction enzyme site resulting in a bi-allelic restriction fragment length polymorphism. Co-dominant inheritance of the alleles in three reference families was observed using a polymerase chain reaction—restriction fragment length polymorphism assay. The distribution of the alleles seems characteristic of cattle type—one of the alleles was not detected in purely taurine breeds. Furthermore, we mapped, using the polymerase chain reaction on a bovine–rodent somatic cell hybrid panel, the myoglobin gene to bovine chromosome five. It is therefore syntenic with γ-interferon and insulin-like growth factor in which we have not found polymorphism. The myoglobin locus therefore serves as a type one marker on bovine chromosome five.     

Norrie disease: Linkage analysis using a 4.2-kb RFLP detected by a human ornithine aminotransferase cDNA probe

Previous study has shown that the usual DNA marker for Norrie disease, the L1.28 probe which identifies the DXS7 locus, can recombine with the disease locus. In this study, we used a human ornithine aminotransferase (OAT) cDNA which detects OAT-related DNA sequences mapped to the same region on the X chromosome as that of the L1.28 probe to investigate the family with Norrie disease who exhibited the recombinational event. When genomic DNA from this family was digested with the PvuII restriction endonuclease, we found a restriction fragment length polymorphism (RFLP) of 4.2 kb in size. This fragment was absent in the affected males and cosegregated with the disease locus; we calculated a lod score of 0.602, at theta = 0.00. No deletion could be detected by chromosomal analysis or on Southern blots with other enzymes. These results suggest that one of the OAT-related sequences on the X chromosome may be in close proximity to the Norrie disease locus and represent the first report which indicates that the OAT cDNA may be useful for the identification of carrier status and/or prenatal diagnosis.     

Human restriction fragment length polymorphisms and cancer risk assessment

The polymorphic restriction fragments of the human Ha-ras locus, produced by the variable tandem repetition (VTR) of a short consensus sequence, fall into three classes based on allelic frequencies. Alleles of the "rare" class (individual frequencies less than 0.5%) have been detected only in white blood cell and tumor DNA of cancer patients. This phenomenon is independent of ethnic origin. No significant association of rare alleles with cancer patients has been demonstrated at an independent tandem repeat locus, VTR4.1. The results suggest that the Ha-ras restriction fragment length polymorphism is useful in cancer risk assessment.     

A unique AT-rich hypervariable minisatellite 3' to the ApoB gene defines a high information restriction fragment length polymorphism

A DNA restriction fragment length polymorphism has been found immediately 3' to the human apoB gene. Digestion of many different human DNAs at sites flanking the region and Southern blotting analysis reveal that this region can vary in length by approximately 300 base pairs with five alleles readily distinguishable. The length polymorphism is due to a unique AT-rich minisatellite that consists primarily of a 30-base pair tandem repeat with two structurally related subunit sequences, x (ATAATTAAATATTTT) and y (ATAATTAAAATATTT). In general, the sequences repeat in an x-y order. The AT-rich region also contains variant x and y sequences that result from C or G for A substitution. Sequence analysis of one large allele revealed the expected increased number of xy repeats. In addition, similar analysis of three different smaller alleles with the same apparent size on Southern blotting analysis showed that all were of slightly different size due to minor differences in the number of xy repeats. The heterogeneity of this AT-rich minisatellite provides the basis for a highly informative restriction fragment length polymorphism of the apoB gene and should be very useful in association and linkage analysis studies of the contribution of this locus to atherosclerosis susceptibility.     

不同生长时期基因调控对南阳牛生长发育的影响

以南阳牛为试验动物,利用PCR-SSCP和PCR-RFLP技术研究了南阳牛生长激素（GH）基因,IGF-I基因以及IGF-IBP3基因的遗传多态,并分析了遗传多态位点对南阳牛0月龄、6月龄、12月龄、18月龄、24月龄以及36月龄不同生长时期生长发育性状的影响。结果表明： 在6月龄～18月龄,GH基因的GH-P5位点的BB基因型对南阳牛的体长、体高显著的正效应;在生长的后期（24月龄～36月龄）,IGF-IBP3-P5基因位点对南阳牛的后躯发育起主要调控作用,BB基因型个体的尻宽显著高于AA型。这表明基因的正效应不是在所有的生长周期表现,而是在特定的时期表现对南阳牛生长发育的显著影响。     

A malic enzyme probe detects cross-hybridizing sequences closely linked to loci encoding other metabolic enzymes.

The cytoplasmic malic enzyme (Mod-1) catalyzes the oxidative decarboxylation of malate: malate + NADP+----pyruvate + CO2 + NADPH + H+. Using a cDNA clone of Mod-1 as a probe, two new DNA markers not at the Mod-1 locus (restriction fragment length polymorphisms, RFLP) were detected by Southern blot analysis that showed extensive homology to Mod-1 sequences. Linkage of each restriction fragment length polymorphism to loci other than Mod-1 was assessed using the BXD (C57BL/6J x DBA/2J) recombinant inbred strains and confirmed by backcrosses. One polymorphic site, designated D9Rti1, was found to be closely linked to the phosphoglucomutase (Pgm-3) locus on Chromosome 9. The other hybridization site, designated D1Rti2, was closely linked to the isocitrate dehydrogenase (Idh-1) locus on Chromosome 1. The data presented imply that Mod-1 homologous sequences are tightly linked to three different metabolic enzymes.     

Restriction fragment length polymorphism at the HLA-C locus

We have used the HLA-C-specific DNA probe pC250 to investigate restriction fragment length polymorphism (RFLP) at the HLA-C locus. Genomic Southern blot hybridization included DNA prepared from a panel of homozygous typing cells representing serological specificities Cw1 to Cw8 and also from samples representing Cw blanks. Although many restriction nucleases failed to reveal any polymorphism, RFLPs were evident with Taq I, Pvu II, Bst XI, Nde 1, and Nci I in addition to the previously reported Eco RI. In the case of Bst XI, a unique RFLP defined a subset of serologically defined Cw blanks. Comparison of RFLP sizes with restriction fragment lengths obtained from the known HLA-Cw3 gene sequence permitted the localization of intragenic C locus RFLLs and the identification of a variable Taq I site in the second intron, a variable Nci I site near the end of the fourth exon, and a variable Pvu lI site in the fifth intron.     

Use of growth hormone genes for the diagnosis of the disease of dwarfism

The pattern of BamHI fragments of DNA from three children suggested to suffer the isolated growth hormone deficiency type. IA was not different from normal pattern registered in blot hybridization with [32P]cDNA of the growth hormone gene. The data permits one to exclude the above mentioned disease that is characterized by the deletion of HGH-N gene. The analogous DNA restriction analysis using HindIII restriction endonuclease has shown, that neither the sick children, nor their parents carry the deletion in heterozygotic state. The study of normal polymorphism of the restriction fragments length has shown that as for as the frequency of polymorphic MspI restriction endonuclease sites A and B in the growth hormone gene cluster (0.67 and 0.75 respectively) is concerned the Russian population in Moscow is closer to Mediterranean one than to North-european.     

Evidence against close linkage of the loci for fraXq of Martin-Bell syndrome and for factor IX

Summary Linkage between the loci for fraXq of Martin-Bell syndrome and factor IX was studied in nine families exhibiting this syndrome by means of a restriction fragment length polymorphism at the factor IX locus. Computer analysis of the data indicates there to be no evidence for close linkage between the syndrome and the factor IX locus.