2.2 Stomach content samples and DNA extraction
The all samples of Chinese mole shrew were thawed at room temperature.
We obtained stomach contents (SCs) collected from 72 individuals. We try
to collect the foods in the interior of SCs to avoid the interference of
host tissues or cells. The SCs samples were collected according to the
guidelines and approval of the Animal Ethics Committee of Sichuan Normal
University. After extracting from the stomach, the SCs was washed with
ultrapure water and wiped off with other tissue between each extraction.
Each SC was homogenized and stored in 95% ethanol for DNA extraction.
The SCs samples of three individuals derived from the same field or
woodland are homogeneously mixed into a mixed sample. Herein, six mixed
SCs samples are used for further sequencing in each season, and a total
of 24 mixed SCs samples are used for further molecular dietary analysis.
We extracted DNA used the QiaAmp Fast DNA Stool Mini Kit (ID: 51604,
QIAGEN), which is specifically developed for fecal and gut contents
samples, according to the manufacturer’s instructions. An extraction
blank was included at each extraction series. The extracted DNA was
further concentrated by evaporating samples in vacuum, and then was
stored for metabarcoding analysis.