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E Wijsman

Publications and source records attributed to E Wijsman.

22 records · Page 2Linked to original sources
PubMed1988

High recombination between two physically close human basement membrane collagen genes at the distal end of chromosome 13q.

Two basement membrane collagen genes coding for the pro alpha 1 chain and pro alpha 2 chain of type IV collagen map to 13q34 and are linked with a maximum likelihood estimate of recombination of 0.028 at a logarithm of odds (lod) score of 19.98. The single-copy sequence that identifies the locus D13S3 is also closely linked to both collagen genes. Four enzymes reveal polymorphisms with COL4A1, and 10 haplotypes have been observed in Caucasoids. Within COL4A1 a nonrandom association of alleles exists only between alleles defined by Hae III and those defined by the other three enzymes. A random association of alleles of COL4A1 and COL4A2 is observed. Between the two collagen genes were detected three meiotic recombination events that contributed to the estimate of 2.8% recombination. This is higher than expected for two genes that lie within 650 kilobases of each other. The lack of linkage disequilibrium between COL4A1 and COL4A2 is in agreement with the relatively high recombination that is observed.

Basement Membrane↗
PubMed1985

A systematic approach for detecting high-frequency restriction fragment length polymorphisms using large genomic probes.

Thirteen phage clones containing low-copy sequences were isolated from a human DNA library and tested for their ability to detect restriction fragment length polymorphisms (RFLPs). Reported are the RFLPs revealed with each clone, all found in frequencies useful for linkage studies. Cytological data are available for five of the 13 clones, with regional assignments made for three of the markers by in situ hybridization. It is concluded that phage clones containing large unique DNA inserts detect multiple RFLPs with high efficiency. An analysis of the relative efficiency of 20 restriction enzymes for detecting single nucleotide changes is discussed by comparing the observed data to those expected on the basis of recognition and potential site frequencies, as computed from the dinucleotide distribution. Finally, in an effort to facilitate linkage studies using polymorphic DNA sequences, experiments were made with pools of probes from various sources.

Bacteriophages↗
PubMed1984

Surnames in Sardinia. II. Computation of migration matrices from surname distributions in different periods.

A method is described for obtaining migration matrices from data on frequency distributions of transmissible traits in at least two different periods. In the present case, surname frequency distributions were used. In this way migration matrices describing rates of movement among nine areas of Sardinia were found for the period 1850-1970. Data were kinship matrices from surname distributions over two or three time periods. Population growth was included in the model under the assumption that expected family size in all areas was constant, or that outside estimates of the relative family sizes exist. Use of variable vs. constant growth rates did not drastically affect the estimated matrices. The matrices estimated for different time periods are similar. Estimates of net migration into the different areas were relatively insensitive to different methods of summarizing statistics. The elements of the matrices indicate strong effects on migration rates of distance between areas, and somewhat weaker effects of economic differences. The diagonal elements of the matrices show a high negative correlation with independent estimates of rates of immigration into the same areas.

Emigration and Immigration↗