An association analysis between the variability of the caprine CD36 and CD36-like genes and dairy traits

- CD36 and CD36-like genotypes are associated with the composition of milk fat in goats.
- Associations found for each gene encompass distinct subsets of fatty acids, emphasizing the need of studying with more detail the lipid binding properties of CD36 and CD36-like.
- Polymorphisms associated with a higher unsaturated fatty acid content may allow to produce a healthier milk through marker-assisted selection.

The CD36 molecule plays a key role in the uptake of long-chain fatty acids. In a previous study, we demonstrated that the CD36 gene is duplicated in goats. Moreover, both copies (CD36 and CD36-like) display highly divergent mRNA expression profiles. Herewith, we have analyzed whether four polymorphisms mapping to CD36 (c.394A > G, c.*141C > T and c.*427T > A) and CD36-like (c.390A > C) genes are associated with milk yield and composition. Murciano-Granadina goats with records for dairy traits (N = 309, 1005 registers) and milk fatty acid composition phenotypes (N = 176, 490 registers) were genotyped for these four markers and association analyses were carried out. We found a highly significant association between c.*427T > A CD36 polymorphism and milk palmitoleic content (P < 0.0001). Besides, the c.*141C > T CD36 SNP also showed a suggestive association (P = 0.04) with palmitoleic. These findings are consistent with previous studies showing that CD36 inactivation in adipocytes and neurons involves a decrease in palmitoleic content, thus suggesting a relevant role of this molecule in the specific uptake of this fatty acid. The remaining associations found (CD36 with polyunsaturated fatty acids and CD36-like with oleic and several saturated fatty acids) were significant at the nominal level but not after Bonferroni correction. These results, combined with previously reported expression data, reinforce the interest of investigating the lipid binding properties of CD36 and CD36-like through functional approaches.