Detection and characterization of two novel hypervariable microsatellite repeat regions within intron 2 of the alpha-globin gene of the bivalve mollusc Anadara trapezia.
Synthetic oligonucleotide primers based on cDNA sequence were used to amplify the region spanning intron 2 of the alpha-globin gene of the bivalve mollusc Anadara trapezia. Amplification of this region from individual clams showed highly polymorphic patterns. The sequence of this intron was found to include a number of mono- [d(T)n and d(C)n], di- [d(CA)n and d(CT)n] and tetranucleotide d(CTGT)n repeats which were found to be polymorphic with respect to the types and numbers of repeats present. Two separate repeat-containing polymorphic regions were located near each end of this intron. The repeat at the 3' end consisted of an unusual example of a d(T)n polymorphism at the position of the polypyrimidine tract usually involved in intron splicing. Thirteen individual cloned intron 2 sequences, derived by PCR amplification from pooled genomic DNA, were sequenced without finding two identical sequences. All of the sequenced clones contained microsatellite sequences.
Nassif
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School of Biochemistry and Molecular Genetics, University of New South Wales, Sydney, Australia. najahn@med.su.oz.au
Mackinlay
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D000818:Animals; D001483:Base Sequence; D049872:Bivalvia / Q000235:genetics*; D003001:Cloning, Molecular; D005796:Genes / Q000235:genetics; D005914:Globins / Q000235:genetics*; D007438:Introns / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics*; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA
D005914:Globins