2.1 Spider and sample collection
Adult
specimens of P . astrigera (n = 80; female, n = 40; male, n
= 40) were randomly collected by pipe buckle method on 10 April, 2021
from corn field (41°56′N, 123°22′E) aside by Puhe River, Northern
Shenyang city, China.
All
spiders were transported to laboratory
(Insect
Ecology Laboratory, College of Life Science) and kept singly in plastic
tubes (each 30 mm in diameter and 110 mm long) with moistened cotton at
the bottom to maintain air humidity.
Spiders were starved for 10 days before dissection to remove the
non-native microorganisms in the gut (Hu et al., 2019).
To ensure the sterile condition
during dissection, the
aseptic
table was wiped with 75% ethanol for 3 times and irradiated with
ultraviolet
lamp for
60
min. Before dissection, each spider
was sterilized by 75% ethanol for 5 min while rinsing 3 times by
sterile water before and after sterilization to remove contaminants
on its body surface.
Then
the residual water on surface of
spider was sucked dry
by
sterilized filter paper. The gut was dissected in sterile
phosphate-buffered saline (PBS) solution with a sterilized scissor under
a microscope and washed with sterile water, placed into 1.5 ml
microcentrifuge tube and temporarily stored in refrigerator
(Haier
BCD-252WBCS, Qingdao, China) at -20℃. The dissection was done on ice.
Ten guts were added in a tube as 1 sample and
instantly
quick- freezed in liquid nitrogen, finally stored in a -80°C
freezer
(AUCMA DW-86L500, Qingdao, China) until DNA extraction. Each female and
male has four biological replicates.