Inheritance of RAPD markers in the guppy fish, Poecilia reticulata

Random Amplified Polymorphic DNA (RAPD) fingerprinting offers a rapid and efficient method for generating a new series of DNA markers in fishes. Three oligonucleotide primers (two 10-mers and one 9-mer) and their paired combinations were found to generate different but reproducible RAPD fingerprints in the guppy. Of these, a 10-mer primer (designated S3D2) was used to detect DNA polymorphisms in two guppy varieties, Green Snakeskin (GSS) and 3/4Black (3/4B). High Genetic Similarity (SI) was found among individuals of the GSS and 3/4B varieties indicating low intra-variety genetic variability. The average SI values for the Green Snakeskin and 3/4Black varieties were 0.78 +/- 0.104 and 0.81 +/- 0.083, respectively. The average SI value between individuals of the GSS and 3/4B varieties was 0.66 +/- 0.066, indicating higher genetic variability between the two varieties. To study the inheritance of RAPD markers, single-pair crosses were set up between males of the GSS variety and females of the 3/4B variety. The S3D2 primer was used to generate RAPD fingerprints of the parents and their F1 offsprings. A total of 14 RAPD markers were scored from these crosses. Of these markers, eight (60.0%) of them were polymorphic. The RAPD markers were shown by the F1 to exhibit dominant Mendelian inheritance and could thus be used for subsequent genetic linkage mapping of the guppy.