Biochemical and molecular investigations on qualitative and quantitative Hb polymorphism in the river buffalo (Bubalus bubalis L. ) population reared in Southern Italy

RESUMO

On 398 river buffalo samples, randomly collected in distinct breeding areas of the Campania region, high-resolution analytical systems were used to identify both qualitative and quantitative variations of the Hb phenotype. Polyacrylamide gel isoelectric focusing and HPLC were used to determine the ratio between HBA1 and HBA2 globin chains; restriction endonuclease analysis was performed to assess whether quantitative variations in Hb bands were related to an unusual number of a-globin genes. In the two buffalo subpopulations, allele frequencies of the alpha and beta globin systems were calculated, and F statistics (FIS, FIT and FST) were estimated as parameters of genetic diversity. The results suggest that i) as shown by RFLP analysis, only a couple of associated a globin genes account for the quantitative variations recorded at the phenotypic level; ii) as expected, in the a globin gene system (HBA), the frequency of haplotype B (HBA-B) largely exceeded that of haplotype A (HBA-A) (95.1 percent vs 4.9 percent); iii) the frequency of the usual allele at the beta locus is 0.6, as opposed to 0.4 of the slow variant; iiii) the most significant component of variation of the genetic system of hemoglobin is between individuals within the same location.