Polymorphism and sequence variations of the HumCD4 pentameric microsatellite in an Italian population sample.
A sample of 265 subjects from central Italy was analyzed at the HumCD4 locus by polymerase-chain-reaction (PCR). Phenotypes were identified by comparison with a sequenced ladder, after high-resolution horizontal polyacrylamide gel electrophoresis (PAGE) followed by silver staining. A set of representative alleles was sequenced by Taq-cycle-sequencing with dye terminator labeling and capillary gel electrophoresis strategies. Eight common alleles--5, 6, 7, 8, 9, 10, 11, 12--and a rare larger 14, never before described in Caucasians, were found. Allele and genotype frequencies were similar to those described in former studies on Caucasians, with a prevalency of alleles number 5, 6, 10. Sequence analysis showed that the polymorphism is due to a pentameric TTTTC basic motif, tandemly repeated, and that from allele number 10 onwards the fourth repeat presents a T to C translation (CTTTC). Instead, allele number 9 may exist in two forms, because 75% of alleles examined in this study presented the CTTTC motif at the fourth position, while the remaining 25% had the basic repeat structure.
Istituto di Medicina Legale, Università degli Studi di Ancona, Policlinico Torrette, Italy.
A
A
Tagliabracci
L
L
Buscemi
F
F
Bianchi
C
C
Sassaroli
U
U
Ricci
T M
TM
Neri
D
D
Rodriguez
D000483:Alleles; D016172:DNA Fingerprinting / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D005787:Gene Frequency; D005819:Genetic Markers; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007558:Italy; D018895:Microsatellite Repeats / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA
D005819:Genetic Markers