Free Access
Genet. Sel. Evol.
Volume 35, Number Suppl. 1, 2003
Second International Symposium on Candidate Genes for Animal Health
Page(s) S121 - S133
Genet. Sel. Evol. 35 (2003) S121-S133
DOI: 10.1051/gse:2003021

The relationship between the presence of extra $\alpha$-globin genes and blood cell traits in Altamurana sheep

Elisa Pieragostinia, Ferruccio Petazzib and Aldo Di Lucciac

a  Department of Engineering and Management of the Agricultural, Livestock and Forest Systems, University of Bari, Via Amendola, 165/A, 70100 Bari, Italy
b  Department of Animal Health and Well-being, University of Bari, Provinciale per Casamassima km 3, 70010 Valenzano (BA), Italy
c  Department of Animal Production, University of Bari, Via Amendola, 165/A, 70100 Bari, Italy

(Accepted 4 February 2003)

Additional $\alpha$-globin genes in sheep might produce extra $\alpha$-globin chains and, consequently, the subject carrying triplicated ( $\alpha\alpha\alpha$) or quadruplicated ( $\alpha\alpha\alpha\alpha$) haplotypes may exhibit different hematological phenotypes when compared to the normal duplicated ( $\alpha\alpha$) homozygotes (NN). Both $\alpha\alpha\alpha$ and $\alpha\alpha\alpha\alpha$ heterozygous (ND) and $\alpha\alpha\alpha$ and $\alpha\alpha\alpha\alpha$ homozygous (DD) individuals were obtained by selection and inbreeding. Chromatographic RP-HPLC analyses of the globin chains of 65 subjects (15 DD, 20 ND and 30 NN) were performed. A highly significant linear regression ( ${\rm r}^2=
0.967$ ) of the $\alpha/\beta$ ratio on the number of $\alpha$-globin genes was found, and the $\alpha/\beta$ ratio ranged on average from 1.0 in NN individuals to 1.2 in the ND and 1.6 in the DD subjects. Values for blood fell within the range of normality but were rather peculiar as a whole. When the erythrocytes of individuals carrying normal arrangements were compared with those of subjects with extra $\alpha$-genes, the latter had fewer erythrocytes that were bigger in size and had a higher Hb content and a greater osmotic fragility. This hematological picture is consistent with the existence of an unbalanced $\alpha/\beta$ ratio.

Key words: erythrocytes / hemoglobin / $\alpha/\beta$ ratio / endemic TBD

Correspondence and reprints: Elisa Pieragostini

© INRA, EDP Sciences 2003