The fourth anterior mammary gland on the right side of the gilt was further dissected for the parenchymal or functional tissue. If the fourth mammary gland was not developed, the third anterior mammary gland was collected. A 12-mm biopsy punch was utilized over the teat area of the gland. Approximately 30 mg of tissue was taken from the tissue isolated from the biopsy punch for DNA extraction. After the biopsy punch was utilized, any remaining parenchymal tissue was dissected from the mammary gland (Figure 1 ). The parenchymal tissue was then weighed.
DNA extraction was then completed using a DNeasy Blood & Tissue kit (Qiagen, Germantown, MD) according to the manufacturer’s recommendations for “Purification of Total DNA from Animal Tissues” (Spin-Column Protocol). The entire process was performed at 20 °C, except where specified. Up to 30 mg of tissue was isolated for DNA extraction, and the tissue was disrupted using a Qiagen TissueLyzer II (Qiagen). The elution was quantified via a spectrophotometer (ND-100; Nanodrop Technologies, Inc., Rockland, DE) for DNA content, and all samples had a 260:280 ratio between 1.8 and 2.0 (Lucena-Aguilar et al., 2016 (link)).
The concentration of DNA was then used with the approximate 30 mg of tissue used for extraction and the 200 μL used in the final elution of DNA in the dissected parenchymal tissue using the following simplified equation:
DNA extraction was then completed using a DNeasy Blood & Tissue kit (Qiagen, Germantown, MD) according to the manufacturer’s recommendations for “Purification of Total DNA from Animal Tissues” (Spin-Column Protocol). The entire process was performed at 20 °C, except where specified. Up to 30 mg of tissue was isolated for DNA extraction, and the tissue was disrupted using a Qiagen TissueLyzer II (Qiagen). The elution was quantified via a spectrophotometer (ND-100; Nanodrop Technologies, Inc., Rockland, DE) for DNA content, and all samples had a 260:280 ratio between 1.8 and 2.0 (Lucena-Aguilar et al., 2016 (link)).
The concentration of DNA was then used with the approximate 30 mg of tissue used for extraction and the 200 μL used in the final elution of DNA in the dissected parenchymal tissue using the following simplified equation:
