The aim of this study was to investigate the role of TP53 in buffalo lactation. The data showed that buffalo TP53 inhibited the expression of genes related to milk protein and milk fat in buffalo mammary epithelial cells by inhibiting the PI3K–AKT–mTOR pathway. These results suggest that TP53 negatively regulates the synthesis of milk protein and milk fat in buffalo through the PI3K–AKT–mTOR pathway. This study provides new insights into the functional role of TP53 in buffalo lactation.

The α_S2 casein (α_S2-CN) is an important component in milk, but the variation of buffalo CSN1S2 and its corresponding variants are not clear. In this study, 13 single nucleotide polymorphisms were identified in CSN1S2 by DNA sequencing. Based on them, 11 α_S2-CN variants were inferred and named. There are eight amino acid differences between buffalo and cattle in the sequences of α_S2-CN variants. The results provide insights into the variation, characteristics and function of buffalo CSN1S2.

In order to reveal whether peroxisome proliferator-activated receptor γ coactivator-1 α (PPARGC1A) gene is involved in the process of milk fat synthesis in buffalo, we analyzed the function and expression of this gene here. The results showed that buffalo PPARGC1A played a key role in the lipid synthesis of mammary gland. Eight SNPs were found in its coding region, of which three were non-synonymous. This study revealed that the PPARGC1A is closely related to buffalo milk fat synthesis.

The full CDS of buffalo DGAT2 was isolated and characterized here. Buffalo DGAT2 contains a conserved domain of DAGAT and a transmembrane region. It was expressed in the heart, liver, breast, and muscle during lactating and non-lactating stages, but the expression in the first three tissues of lactation was significantly higher than that of non-lactation. The results indicate that buffalo DGAT2 may play a role in the endoplasmic reticulum and participate in milk fat synthesis.

Kappa casein (κ-CN) plays an important role in the formation, size and stability of casein micelles. We identified a total of eight single nucleotide polymorphisms in buffalo CSN3. Based on these, seven κ-CN variants and four synonymous variants were inferred and named. The sequences of κ-CN variants were significantly different between buffalo and the Bos genus. This study can help reveal the different physicochemical and processing properties of milk between buffalo and the Bos genus.