title: GSM7111230: gestational day 19.5, 3; Rattus norvegicus; ATAC-seq
library_construction_protocol: Rats timed pregnancies were obtained by mating adult males (>10 weeks of age) and adult females (8-12 weeks of age). Uterine-placental interface tissue (also called metrial glands) were dissected from gd 15.5 (n=3 pregnancies) and 19.5 rat placentation sites (n= 3pregnancies) and put in ice cold Hank's balanced salt solution (HBSS). Tissues were minced into fine pieces with a razor blade and digested in Dispase II (1.25 units/mL), 0.4 mg/mL collagenase IV , and DNase I (80 units/mL,) in HBSS for 30 min. Red blood cells were lysed using ACK lysis buffer. Samples were washed with HBSS supplemented with 2% fetal bovine serum (FBS, Thermo-Fisher), and DNase1  and passed through a 100 ìm cell strainer. Following enzymatic digestion, cell debris was removed using MACS Debris Removal Solution. Cells were isolated from gd 15.5 and 19.5 uterine-placental interface tissue as described above, and nuclei were isolated from the cell suspension according to the 10X Genomics Nuc  lei Isolation protocol. Briefly, cells were washed with HBSS supplemented with 2% FBS (Thermo-Fisher) and cell number determined. Approximately 500,000 cells were centrifuged, and 100 mL 10X Genomics Nuclei Isolation Lysis Buffer was added. The suspension was incubated for 3 min, then 10X Genomics Nuclei Isolation Wash Buffer was added. Cells were passed through a 40 mm cell strainer and centrifuged. Cells were resuspended in 50 mL chilled 10X Genomics Nuclei Isolation Buffer. Single nuclei were captured using the Chromium Controller into 10X barcoded gel beads. Libraries were generated using Chromium Next GEM Single Cell ATAC Library & Gel Bead Kit v1.1 (10X Genomics) and sequenced in a NovaSeq6000 sequencer at the KUMC Genome Sequencing Core.