Background
The ovary is a central organ in the reproductive system that produces oocytes and synthesizes and secretes steroid hormones. Healthy development and regular cyclical change in the ovary is crucial for regulating reproductive processes. However, the key genes and metabolites that regulate ovarian development and pregnancy have not been fully elucidated. This study conducted high-throughput RNA sequencing and untargeted metabolite profiling of the ovarian tissues from Chenghua pigs at four stages, including postnatal day 3 (D3), puberty at the age of about 125 days (Pub), sexual maturity at the age of about 365 days (Y1), and 105 days after pregnancy at the age of about 360 days (Pre).
Results
A total of 9,264 and 1,593 differentially expressed genes (DEGs) were identified during ovarian development and pregnancy. Several key genes involved in ovarian development, including
SQLE
,
HMGCS1
,
MSMO1
,
SCARB1
,
CYP11A1
,
HSD3B1
,
HSD17B1
, and
SERPINE1
were identified. Similarly,
LUM
,
FN1
,
PLAUR
,
SELP
,
SDC1
, and
VCAN
were considered to be associated with pregnancy maintenance. Overexpression of
HSD17B1
in granulosa cells significantly upregulated estrogen synthesis-related genes (
HSD3B1
,
CYP11A1
, and
STAR
); meanwhile, overexpression of
PLAUR
promotes granulosa cell proliferation. Furthermore, 66, 24, 77, and 7 differentially expressed miRNAs (DEMis) were found, leading to the selection of key miRNAs such as
ssc-miR-206
,
ssc-miR-107
,
ssc-miR-429
,
ssc-miR-210
, and
ssc-miR-133a-3p
by differential miRNA-targeted mRNA interaction network; meanwhile,
ssc-miR-133a-3p
was validated to have a targeting relationship with
KCNA1
by dual-luciferase reporter systems assay. At the metabolic levels, androstenedione, 17a-hydroxyprogesterone, dehydroepiandrosterone, and progesterone were identified, with their synthesis regulated by these DEGs in the ovarian steroidogenesis pathway. Furthermore, treatment of cells with androstenedione upregulated the expression of
HSD3B1
,
CYP11A1
, and
STAR
.
Conclusions
This study revealed the dynamic changes in the transcriptome and metabolome of pig ovaries across developmental stages and gestation, indicating that it may provide new...
