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Reproduction (Cambridge, England) May 2020We previously demonstrated that 5'-AMP-activated protein kinase (AMPK) is essential for normal reproductive functions in female mice. Conditional ablation of Prkaa1 and...
We previously demonstrated that 5'-AMP-activated protein kinase (AMPK) is essential for normal reproductive functions in female mice. Conditional ablation of Prkaa1 and Prkaa2, genes that encode the α1 and α2 catalytic domains of AMPK, resulted in early reproductive senescence, faulty artificial decidualization, uterine inflammation and fibrotic postparturient endometrial regeneration. We also noted a delay in the timing of embryo implantation in Prkaa1/2d/d female mice, suggesting a role for AMPK in establishing uterine receptivity. As outlined in new studies here, conditional uterine ablation of Prkaa1/2 led to an increase in ESR1 in the uteri of Prkaa1/2d/d mice, resulting in prolonged epithelial cell proliferation and retention of E2-induced gene expression (e.g. Msx1, Muc1, Ltf) through the implantation window. Within the stromal compartment, stromal cell proliferation was reduced by five-fold in Prkaa1/2d/d mice, and this was accompanied by a significant decrease in cell cycle regulatory genes and aberrant expression of decidualization marker genes such as Hand2, Bmp2, Fst and Inhbb. This phenotype is consistent with our prior study, demonstrating a failure of the Prkaa1/2d/d uterus to undergo decidualization. Despite these uterine defects, ovarian function seemed to be normal following ablation of Prkaa1/2 from peri-ovulatory follicles in which ovulation, luteinization and serum progesterone levels were not different on day 5 of pregnancy or pseudopregnancy between Prkaa1/2fl/fl and Prkaa1/2d/d mice. These cumulative findings demonstrate that AMPK activity plays a prominent role in mediating several steroid hormone-dependent events such as epithelial cell proliferation, uterine receptivity and decidualization as pregnancy is established.
Topics: AMP-Activated Protein Kinases; Animals; Cell Proliferation; Embryo Implantation; Epithelial Cells; Estradiol; Estrogen Receptor alpha; Female; Mice; Mice, Knockout; Stromal Cells; Uterus
PubMed: 32191914
DOI: 10.1530/REP-19-0402 -
Scientific Reports Feb 2020Embryo transfer has been used as one of the essential reproductive technologies for production of new strains and maintenance of genetic resources in animals. Mating...
Embryo transfer has been used as one of the essential reproductive technologies for production of new strains and maintenance of genetic resources in animals. Mating with vasectomised male rats is a requirement for inducing pseudopregnancy in female rats selected for embryo transfer. Although this procedure has been used routinely, large breeding space and high expenditure are required to maintain a sufficient number of females and vasectomised males. This study was performed to induce pseudopregnancy in females by artificial stimulation using sonic vibration instead of vasectomised males. The females continued to be in the dioestrus stage for at least 14 days after artificial stimulation was performed. Of fresh 2-cell embryos that transferred into the oviducts of females after artificial stimulation, 56% was implanted and 50% was developed to offspring. Approximately 46% of the frozen 2-cell embryos were implanted and 24% developed into offspring. Furthermore, 66% of the fresh pronuclear embryos were implanted and 60% developed into offspring. This study successfully induced pseudopregnancy in rat females by artificial stimulation using a sonic vibration. This method, 'Easy-ET', was useful for efficient production and maintenance of rat strains.
Topics: Animals; Breeding; Cryopreservation; Embryo Implantation; Embryo Transfer; Embryo, Mammalian; Estrus; Fallopian Tubes; Female; Male; Pregnancy; Pseudopregnancy; Rats; Sound; Vasectomy; Vibration
PubMed: 32066799
DOI: 10.1038/s41598-020-59611-1 -
Molecular Human Reproduction Mar 2020The study investigated the effect of normal and supraphysiological (resulting from gonadotropin-dependent ovarian stimulation) levels of estradiol (E2) and progesterone...
Uterine aquaporin expression is dynamically regulated by estradiol and progesterone and ovarian stimulation disrupts embryo implantation without affecting luminal closure.
The study investigated the effect of normal and supraphysiological (resulting from gonadotropin-dependent ovarian stimulation) levels of estradiol (E2) and progesterone (P4) on mouse uterine aquaporin gene/protein (Aqp/AQP) expression on Day 1 (D1) and D4 of pregnancy. The study also examined the effect of ovarian stimulation on uterine luminal closure and uterine receptivity on D4 of pregnancy and embryo implantation on D5 and D7 of pregnancy. These analyses revealed that the expression of Aqp3, Aqp4, Aqp5 and Aqp8 is induced by E2 while the expression of Aqp1 and Aqp11 is induced by P4. Additionally, P4 inhibits E2 induction of Aqp3 and Aqp4 expression while E2 inhibits Aqp1 and Aqp11 expression. Aqp9, however, is constitutively expressed. Ovarian stimulation disrupts Aqp3, Aqp5 and Aqp8 expression on D4 and AQP1, AQP3 and AQP5 spatial expression on both D1 and D4, strikingly so in the myometrium. Interestingly, while ovarian stimulation has no overt effect on luminal closure and uterine receptivity, it reduces implantation events, likely through a disruption in myometrial activity and embryo development. The wider implication of this study is that ovarian stimulation, which results in supraphysiological levels of E2 and P4 and changes (depending on the degree of stimulation) in the E2:P4 ratio, triggers abnormal expression of uterine AQP during pregnancy, and this is associated with implantation failure. These findings lead us to recognize that abnormal expression would also occur under any pathological state (such as endometriosis) that is associated with changes in the normal E2:P4 ratio. Thus, infertility among these patients might in part be linked to abnormal uterine AQP expression.
Topics: Animals; Aquaporins; Embryo Implantation; Embryo Transfer; Estradiol; Female; Gene Expression Regulation, Developmental; Mice; Mice, Inbred C57BL; Mifepristone; Ovulation Induction; Pregnancy; Progesterone; Pseudopregnancy; Uterus; Water
PubMed: 31977023
DOI: 10.1093/molehr/gaaa007 -
Animals : An Open Access Journal From... Sep 2019Aggressiveness is one of the main problems in group housing of rabbit does. The aim of the experiment was to investigate the frequency of aggressiveness and mating...
Aggressiveness is one of the main problems in group housing of rabbit does. The aim of the experiment was to investigate the frequency of aggressiveness and mating behaviour as well as the lifespan of does depending on group composition. The female and male rabbits were housed in one of the 7.7 m pens (four females and one male per pen). Based on the ages of female rabbits two homogenous groups (HOM) were formed containing four 17-week-old females and two heterogeneous groups (HET) containing three 17-week-old and one 1-year-old female. Twenty-four-hour video recordings were taken during the first month after assembling the groups, and the aggressive actions (fights) and matings were counted. The lifespan was examined over a 200-day experimental period. On the day after assembling the groups the number of fights among does was high in HET group. The same aggressive behaviour only started a week later in HOM group, and some fights between females and the male were also observed. The daily peaks of aggressiveness were in the morning (after the light on) and in the evening (before and after the lights off). The primary position of females in the hierarchy was clear but sometimes no differences were detected among the subordinate females. The mortality of does was connected with their rank order. The number of matings was very high on the day of assembling the groups and a second small peak was observed at the end of the hypothetical pseudo-pregnancy. In addition to mating between male and females, female-female and female-male mounting was also observed. Despite of the small sample size it seems that aggressive behaviour is frequent in group housing systems, which is contrary to animal welfare. Natural mating is not effective in group-housing system.
PubMed: 31547162
DOI: 10.3390/ani9100708 -
Scientific Reports Sep 2019Female giant pandas show complex reproductive traits, being seasonally monoestrus, displaying a variable length embryonic diapause and exhibiting pseudopregnancy....
Female giant pandas show complex reproductive traits, being seasonally monoestrus, displaying a variable length embryonic diapause and exhibiting pseudopregnancy. Currently, there is no confirmatory non-invasive biomarker of blastocyst implantation or pregnancy. This study aimed to monitor urinary estrogens across gestation in pregnancy (n = 4), pseudopregnancy (n = 4) and non-birth cycles (n = 5) in the giant panda. A pregnancy-specific profile of estrogens corrected for urinary specific gravity was identified during the gestation period. Pregnant females showed increasing concentrations of estrogens for 29 days until birth, no increase was observed during pseudopregnancy and the two profiles were distinguishable from each other for the final 2 weeks of the cycle suggesting the estrogens are of placental origin. This allowed a nomogram, starting at a known fixed point during the cycle, to be created and tested with cycles of known outcome, and cycles which were inseminated but did not result in a birth. Non-birth profiles showed deviations from that of pregnancy. We believe these deviations indicate the point of failure of the placenta to support a developing cub. Non-invasive longitudinal monitoring of estrogen concentrations therefore has the potential to be developed as a panda pregnancy test to predict viable cub development.
Topics: Animals; Biomarkers; Estrogens; Female; Pregnancy; Ursidae
PubMed: 31484972
DOI: 10.1038/s41598-019-49288-6