Deterioration of mitochondrial biogenesis and degradation in the endometrium is a cause of subfertility in cows

Abstract

To investigate possible causes of reproductive failure, we conducted global endometrial gene expression analyses in fertile and subfertile cows. Ingenuity pathway analysis showed that RICTOR and SIRT3 are significant upstream regulators for highly expressed genes in fertile cows, and are predicted to be activated upstream regulators of normal mitochondrial respiration. Canonical pathway analysis revealed that these highly expressed genes are involved in the activation of mitochondrial oxidative phosphorylation. Therefore, in subfertile cows, the inactivation of RICTOR and SIRT3 may correlate with decreased capacity of mitochondrial respiration. Furthermore, the expression levels of most mitochondrial DNA genes and nuclear genes encoding mitochondrial proteins were higher in subfertile cows. The mitochondrial DNA copy number was significantly higher in the endometrium of subfertile cows, whereas the ATP content did not differ between fertile and subfertile cows. Quantitative reverse transcription‐PCR analysis demonstrated that the expression of PGC1a, TFAM, MFN1, FIS1, and BCL2L13 were significantly lower in subfertile cows. In addition, transmission electron microscopy images showed mitochondrial swelling in the endometrial cells of the subfertile cow. These results suggest that poor‐quality mitochondria accumulate in the endometrium owing to a reduced capacity for mitochondrial biogenesis, fusion, fission, and degradation in subfertile cows, and may contribute to infertility.

Genome-wide scan for runs of homozygosity in South American Camelids

“…Similarly, it can be assumed that environmental selective pressure has driven the shaping of guanaco and vicugna genome leading to the signature of selection detected in KAT6B . This assumption is also corroborated by the selective signal for high feeding efficiency [ 64 ] found in DLG1 for vicugna.…”

“…In the vicugna, DLG1 , already proposed as putative signature of selection for reproductive traits in Iranian dromedary camels [ 60 ], was also associated with fertility in other species being implied in oocyte polarization during maturation in cattle [ 61 ] and ovary development and litter size in sheep [ 62 ]. Similarly, ATP6V1E1 and BCL2L13 were found to be under selection in guanaco; these genes are known to play an important role in mouse and cattle fertility [ 63 , 64 ]. Four loci indicate adaptation driven by environmental conditions in wild SACs.…”