Number Of Litters Research Articles

Antifertile and Estrogenic Effects of Sida acuta Root on Experimental Animal Models

Background: Herbal medications have been used for centuries in traditional Indian medicine to reduce fertility in several regions. Among them, Sida acuta (S. acuta) is a traditional herb having antifertility effects with other broad medicinal properties. In this work, it was studied for its effect on fertility in female rats. Objective: The purpose of this research was to conduct effectiveness and safety investigations on S. acuta root, an antifertility plant widely used in Asian countries. Methods: Fertile albino Wistar female rats (200-250 gm) were used for antifertility investigations. The animals were separated into four groups, each with six members, and treated with 200 and 400 mg/kg of the methanolic extract in combination with Ethinyl Estradiol (0.3 mg/kg body weight) as per schedule. They all took place for seven days. On the 8th day, every positive rat was decapitated under ether anesthesia, and the uterus and surrounding tissues were taken from it for fast weight measurement. Results: The phytochemical screening revealed the presence of alkaloids, tannins, and flavonoids as secondary metabolites. RP-HPLC analysis was used to determine the concentration of colchicine in S. acuta roots extract, and it was found to have a retention period of 7.35 minutes. The female Wistar rats treated with S. acuta root study showed that the litter weight of the experimental group with MESA (200) was 42.13 ± 0.77 and MESA (400) was 18.53 ± 0.94 lower than the control group 61.5 ± 0.29 which reveals that there was a decrease in litter weight, indicating the potential antifertility activity of the experimental group. It was shown that the extract was more effective in reducing the number of litters born (50 percent) and causing considerable anti-implantation activity (3.29) than the control in postcoital testing. The uterotrophic response was less pronounced than that elicited by ethinylestradiol alone when the extract was administered simultaneously (p<0.01). The estrogenic activity of the extract was, therefore, low at the contraceptive dosage level when taken alone. Both ethinylestradiol and these compounds, on the other hand, showed considerable antiestrogenic properties. Conclusion: The methanolic extract of S. acuta root showed significant antifertility effects and was found to be safe when used at the effective dosages found in this research.

Target silencing of porcine SPAG6 and PPP1CC by shRNA attenuated sperm motility

The quality of sperm significantly influences the reproductive efficiency of pig herds. High-quality sperm is necessary for efficient fertilization and to maximize the litter numbers in commercial pig farming. However, the understanding of genes regulating porcine sperm motility and viability is limited. In this study, we validated porcine sperm/Sertoli-specific promoters through the luciferase reporter system and identified vital genes for sperm quality via loss-of-function means. Further, the shRNAs driven by the ACE and SP-10 promoters were used to knockdown the SPAG6 and PPP1CC genes which were provisionally important for sperm quality. We assessed the effects of SPAG6 and PPP1CC knockdown on sperm motility by using the sperm quality analyzer and flow cytometry. The results showed that the ACE promoter is active in both porcine Sertoli cells and sperms, whereas the SP-10 promoter is operating exclusively in sperm cells. Targeted interference with SPAG6 and PPP1CC expression in sperm cells decreases the motility and increases apoptosis rates in porcine sperms. These findings not only offer new genetic tools for targeting male germ cells but also highlight the crucial roles of SPAG6 and PPP1CC in porcine sperm function.

The effect of groyne field on trapping macroplastic. Preliminary results from laboratory experiments

Macroplastic, a precursor of microplastic pollution, has become a new scope of research interest. However, the physical processes of macroplastic transport and deposition in rivers are poorly understood, which makes the decisions of where to locate macroplastic trapping infrastructure difficult. In this research, we conducted a series of experiments in a laboratory channel, exploring the impact of groynes and flexible artificial vegetation on the floating macroplastic litter. The goal was to investigate the litter paths with different obstruction arrangements, which was done by implementing a particle tracking technique on video recordings from each experimental run. We found that increasing discharge correlated with the number of plastic litter floating into the recirculation zone within the groyne fields, especially if the upstream groyne had an extended length. This produced a strong mixing interface between the main flow and the groyne field, while a vegetation patch added in the same groyne field changed the paths of plastic litter by deflecting the flow. We noticed that during a moderate discharge rate, the litter pieces flowing into the groyne field with the vegetation circulated there for the longest period, and some of them got entangled between floating stems when discharge was at its lowest. This phenomenon points to the conclusion that low flow velocity paired with the presence of vegetation can be a primer for plastic deposition and consequently, its degradation. The insights from the experiment allowed us to recommend a place downstream of an extended groyne as the desirable (efficient) area for installing a plastic trapping infrastructure or conducting plastic cleaning actions.

Alteration in Effects of Endometriosis on Fecundity According to Pregnancy Experience in Mouse Model.

This study is aimed at identifying variations in the effect of endometriosis on fecundity in a mouse model based on prior pregnancy experience. Endometriosis is one of the most prevalent gynecological diseases and is known to impact female fecundity adversely. In this study, an endometriosis mouse model was established by allografting uterine horn tissue using Pelch's method. The effect of endometriosis on fecundity was confirmed in primiparous and multiparous female mice. As fecundity indicators, the pregnancy rate, number of litters, pregnancy period, and survival rate of the pups were investigated. As a result of the experiment, the pregnancy rate decreased, and the pregnancy period tended to be shorter in primiparous female mice. However, there was no significant change in the multiparous mice. In addition, it has been established that correlations exist between the size of lesions and certain fecundity indicators of the lesion, even among primiparous and multiparous females with endometriosis. The study attempted to demonstrate a link between pregnancy experience and fecundity changes caused by endometriosis by experimentally reproducing clinical results using mouse models. These results suggest strategies for identifying several pathophysiological characteristics of endometriosis.

Effects of Refined Handling on Reproductive Indices of BALB/cJ and CD-1 IGS Mice.

Current mouse handling methods during cage change procedures can cause stress and potentially compromise animal welfare. Our previous study of breeding C57BL/6J mice found modest increases in pup production and a significant reduction in preweaning litter losses when mice were handled using a tunnel as compared with a tail-lift with padded forceps. The current study evaluated how these 2 handling methods affected reproduction by 2 additional mouse strains, BALB/cJ (a low- to intermediate-fecundity strain) and CD-1 IGS (a high-fecundity stock). We predicted that refined handling would have minimal effects on the high-fecundity line with a satisfactory production rate and greater effects on the low-fecundity line. Handling method (tunnel compared with tail-lift) was randomly assigned to monogamous breeding pairs of mice. Reproductive metrics (litter size at birth and weaning, numbers of litters, litter attrition, between-litter intervals, pup wean- ing weight, and sex ratio) were prospectively monitored for 80 BALB/cJ and 77 CD-1 pairs that were bred continuously for 6 mo. Both strains of mice were highly productive, exceeding previously published breeding data. However, neither strain demonstrated operational or statistically significant differences between handling methods for any reproduction metric. As we detected no negative effects in these 2 strains and the benefits are clear in other strains, refined handling should be considered for all breeding mice.

Burlap and buddies: the effects of social enrichment (preweaning mixing) and object enrichment (burlap) on piglet performance, behavior, and welfare in the preweaning environment.

When weaned in commercial operations, piglets are not only separated from their sow but also mixed with unfamiliar pigs in an unfamiliar environment with a new diet. These abrupt changes can be stressful for piglets, often having negative welfare consequences. Our objective was to study the effects of early-life preweaning socialization and object enrichment in the preweaning environment. We compared piglet performance, behavior, and welfare across six treatments that combined multi-litter group size (1 vs. 2 vs. 4 litters) and burlap (yes vs. no). We recorded piglet behavior and lesion-scored sows and piglets. Normal conforming data, expressed per experimental unit (and behavior data were averaged over time), were analyzed by ANOVA. When given the opportunity in the sow barn, piglets in multi-litter groups socialized with other litters. Burlap use (P = 0.08) was observed in < 5% of the observations but tended to increase in mixed litter groups. Cross-sucking was observed in ~12% of the observations within mixed litter groups and tended to increase with mixed group size (P = 0.08). While there was no difference in the proportion of piglets nursing (P > 0.10), piglets were less active in the single crate groups and most active in the groups of two litters mixed (P = 0.03). Additionally, observed piglet/sow biting behaviors did not differ between treatments; however, piglet-piglet biting (P = 0.07), and pen object manipulation (P = 0.07) tended to be observed more frequently in non-enriched groups. Piglet displacements were observed more often in non-enriched groups around the pen (P = 0.03) but tended to be observed more often in enriched groups at the teat (P = 0.07). Preweaning socialization and object enrichment had no impact on the average number of piglets weaned per sow or total piglet mortality (P > 0.10). However, the proportion of laid-on piglets decreased as the number of mixed litters increased (P = 0.02). The average number of lesions per piglet did not differ between treatments. Although the final lesion scores of sow teat and udder condition did not differ between treatments (P > 0.10), sow udder scores tended to worsen more in the single litters than in the mixed litters (P = 0.08). Overall, social and object enrichment allows piglets to socialize at a younger age and to redirect their attention toward an object (burlap) which does not negatively impact piglet or sow performance, or behavior, and may improve piglet welfare around weaning.

Trans 10, cis 12-conjugated linoleic acid reduced reproductive ability by disrupting the estrus cycle in female mice

Trans 10, cis 12-conjugated linoleic acid reduced reproductive ability by disrupting the estrus cycle in female mice

Role for Nongenomic Estrogen Signaling in Male Fertility.

Estrogen actions are mediated by both nuclear (n) and membrane (m) localized estrogen receptor 1 (ESR1). Male Esr1 knockout (Esr1KO) mice lacking functional Esr1 are infertile, with reproductive tract abnormalities. Male mice expressing nESR1 but lacking mESR1 (nuclear-only estrogen receptor 1 mice) are progressively infertile due to testicular, rete testis, and efferent ductule abnormalities similar to Esr1KO males, indicating a role for mESR1 in male reproduction. The H2NES mouse expresses only mESR1 but lacks nESR1. The goal of this study was to identify the functions of mESR1 alone in mice where nESR1 was absent. Breeding trials showed that H2NES males are fertile, with decreased litter numbers but normal pup numbers/litter. In contrast to Esr1KO mice, H2NES testicular, and epididymal weights were not reduced, and seminiferous tubule abnormalities were less pronounced. However, Esr1KO and H2NES males both had decreased sperm motility and a high incidence of abnormal sperm morphology. Seminiferous tubule and rete testis dilation and decreased efferent ductule epithelial height characteristic of Esr1KO males were reduced in H2NES. Consistent with this, expression of genes involved in fluid transport and ion movement that were reduced in Esr1KO (Aqp1, Car2, Car14, Cftr) were partially or fully restored to wild-type levels in H2NES. In summary, in contrast to Esr1KO males, H2NES males are fertile and have reduced phenotypic and functional abnormalities in the testis and efferent ductules. Thus, mESR1 alone, in the absence of nESR1, can partially regulate male reproductive tract structure and function, emphasizing its importance for overall estrogen action.

Size is not everything: Nuanced effects of female multiple mating and annual litter number on testes size in terrestrial mammals

AbstractSperm production represents a costly reproductive investment by males. High reproductive competition within the female reproductive tract may select for higher sperm counts or quality resulting in selection for larger testes size. In species where females mate multiply or have more offspring per litter (litter size), or more litters per year (litter rate), male reproductive competition may select for larger relative testes size (i.e., scaled by body mass). Given that different mating systems vary in the alternative forms of reproductive investment available to males, sperm production levels may vary with social system. Here, we examined the relationship between testes size and mating systems, litter size, and litter rate while considering male lifespan and investment in paternal care in 224 terrestrial mammalian species in 15 orders. Relative testes size was larger in species where females mated with multiple males. Furthermore, in species with multiple mating females, species with higher litter rates had larger testes compared to species with fewer litters per year. In contrast, in monogamous species, species that had multiple litters per year had smaller relative testes sizes compared to species with fewer litters per year. Neither longevity nor paternal care influenced testes size. Our results elucidate the effect of female reproductive strategies on relative testes size is nuanced and varies between mating systems. Our findings suggest that the interplay between male reproductive investment and female reproductive investment may be different within similar social mating systems.

Repeated Exposure to High-THC Cannabis Smoke during Gestation Alters Sex Ratio, Behavior, and Amygdala Gene Expression of Sprague Dawley Rat Offspring.

Because of the legalization of Cannabis in many jurisdictions and the trend of increasing Δ9-tetrahydrocannabinol (THC) content in Cannabis products, an urgent need exists to understand the impact of Cannabis use during pregnancy on fetal neurodevelopment and behavior. To this end, we exposed female Sprague Dawley rats to Cannabis smoke daily from gestational day 6 to 20 or room air. Maternal reproductive parameters, offspring behavior, and gene expression in the offspring amygdala were assessed. Body temperature was decreased in dams following smoke exposure and more fecal boli were observed in the chambers before and after smoke exposure in dams exposed to smoke. Maternal weight gain, food intake, gestational length, litter number, and litter weight were not altered by exposure to Cannabis smoke. A significant increase in the male-to-female ratio was noted in the Cannabis-exposed litters. In adulthood, male and female Cannabis smoke-exposed offspring explored the inner zone of an open field significantly less than control offspring. Gestational Cannabis smoke exposure did not affect behavior on the elevated plus maze test or social interaction test in the offspring. Cannabis offspring were better at visual pairwise discrimination and reversal learning tasks conducted in touchscreen-equipped operant conditioning chambers. Analysis of gene expression in the adult amygdala using RNA sequencing revealed subtle changes in genes related to development, cellular function, and nervous system disease in a subset of the male offspring. These results demonstrate that repeated exposure to high-THC Cannabis smoke during gestation alters maternal physiological parameters, sex ratio, and anxiety-like behaviors in the adulthood offspring.

Effects of maternal taxane chemotherapy exposure on daughters’ ovarian reserve and fertility potential

To investigate the long-term effects of in utero taxane exposure on exposed daughters' ovarian reserve and reproductive potential. Pregnant dams were treated with a single, human-relevant animal-equivalent dose of saline, docetaxel, or paclitaxel at embryonic day 16.5. In utero-exposed daughters were aged to multiple postnatal time points for ovarian and endocrine analysis or were bred to assess fertility and fecundity. Granddaughters of treated dams were assessed also for ovarian follicle composition and atresia. Laboratory study. C57BL/6 mice. In utero exposure to saline, docetaxel, or paclitaxel. Ovarian follicle composition, rates of follicle atresia, and rates of multioocyte follicles were analyzed in all exposure groups. Serum hormone levels and oocyte retrieval outcomes following ovarian hyperstimulation were also assessed. Finally, animals from all exposure groups were bred with the number of litters, pups per litter, live births, interlitter time interval, and age at the last litter analyzed. We found that docetaxel and paclitaxel exposure in utero results in ovarian toxicity later in life, significantly affecting folliculogenesis as well as increasing the rate of follicular abnormalities, including follicle atresia and multioocyte follicles. Furthermore, viability staining indicates that the ovaries of daughters exposed to taxanes in utero demonstrate a significantly higher number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive follicles. Hormone measurements also revealed that serum follicle-stimulating hormone concentration was significantly altered in taxane-exposed daughters, with the ratio of luteinizing hormone to follicle-stimulating hormone significantly elevated, specifically after paclitaxel exposure, coincident with the inability of these animals to properly respond to ovarian stimulation. Breeding studies over the course of a year also suggest that these taxane-exposed mice are fertile, although the duration of their fertility is shortened and they produce significantly fewer litters. Finally, ovarian effects are apparent in granddaughters of mice treated with docetaxel, suggesting persistent and multigenerational effects of taxane exposure. Our studies demonstrate that in utero exposure to taxane-based therapy during late gestation has a significant effect on the long-term reproductive health of exposed daughters (as well as their daughters) and will be instrumental in helping clinicians better understand which chemotherapies for maternal malignancy are least detrimental to a developing fetus.

PSII-2 Evaluation of Meloxicam in Sows Post-Farrowing on Sow and Piglet Performance

Abstract Meloxicam is a non-steroidal anti-inflammatory drug (NSAID) often used in humans and companion animals to treat arthritis, having strong anti-inflammatory and fever-reducing properties. The objectives of this study were to evaluate the effects of a new compounded oral drench suspension formulation of Meloxicam on sow body temperature in the first 24 hours after farrowing, piglet survivability, and piglet growth. A total of 851 sows in a commercial farm were randomly assigned to receive a single, 90 mg dose (6 mL of a 1.5% suspension) of Meloxicam via oral drench at completion of farrowing (MEL, n = 428) or receive no drug after farrowing (CON, n = 423). Rectal temperatures were taken at the end of farrowing, and 12 and 24 hours after farrowing to monitor sow body temperatures. As standard practice on this farm, sows with a temperature ≥ 39.7 °C at 24 hours post-farrowing were treated with flunixin (NSAID) and ampicillin injectables for 3 consecutive days (MEDS). Litter size and weights were recorded on day 0 and again on the day before weaning. Piglet deaths and reasons were recorded daily to determine piglet survivability and the body weights of dead piglets were recorded. The Mixed procedure of SAS 9.4 (Cary, North Carolina) was used to analyze the interaction between treatment (MEL or CON) and parity (P1 vs. P2 and P3 vs. P&amp;gt;3) as the main effects. A 2x2 factorial design was used to reanalyze the interaction of Meloxicam treatment with additional medicated pigs (MEDS) using PROC Mixed in SAS with MEL and MEDS as main effects, and litter birthweight quartile and number nursed covariates where appropriate. MEL was successful in reducing the temperature of sows by 0.16 °C in the first 12 hours after farrowing (P = 0.0013). For all groups, sows greater than parity 3 had lower temperatures in the first 24 hours after farrowing (P = 0.0083). Gilts in the MEL group required less additional medication than gilts in the CON group (P = 0.0102). Treating sows with Meloxicam tended to reduce the incidence of scours in piglets (P = 0.0907). MEL did not significantly (P &amp;gt; 0.05) impact preweaning mortality (CON = 12.9%, MEL = 12.3%), piglet weaning weight (CON: 5.4 kg ± 0.10; MEL: 5.5 kg ± 0.04), and no differences were observed between piglet weight and age at death between the treatment groups. This study exhibits the ability of a single dose of Meloxicam at farrowing to reduce fever within the first 12 hours of dosing and its potential to reduce the incidence of scours in piglets. Future studies investigating a longer Meloxicam therapy period post-farrowing will give insight into the use of Meloxicam as a fever-reducer to improve sow and piglet lactation performance and survivability.

35 High Fiber Top Dress Effects on Sows During Farrowing and Lactation

Abstract There have been several studies on high fiber diets during late gestation and lactation which have shown an increase in body condition score as well as showing an increase in piglet born alive with multiple cycles. The objective of this study was to determine the effects of two high fiber top dress protocols on the performance of lactating sows and piglets in the farrowing phase. The top dress contained sugar beet pulp, wheat bran, vitamins, enzymes, and an attractant. A total of 459 sows were balanced by parity and genetics among 3 treatments. Treatment 1, Control, contained no additional fiber. Treatment 2, 5D, was fed 0.45 kg. top dress/day for 5 days upon entry into farrowing. Treatment 3, 23D, was fed 0.45 kg top dress for 5 days upon entry into farrowing and then 0.23 kg top dress/day until pigs were weaned. After each room had finished farrowing, piglets were cross fostered within the room, balanced on litter size and number of teats on the sow, and then individually weighed. Piglets were weighed again the day prior to weaning. Calipers were used to record body condition score prior to farrow and weaning. A fecal softness score using a numeric system of 3 = normal 2 = soft 1 = cow patty 0 = liquid was utilized. Fecal scores were recorded daily. Data were analyzed using mixed linear model in SAS. Ending body condition scores were increased with the addition of fiber (Control = 2.59, 5D = 2.59, 23D = 2.69, P = 0.002). Sow mortality was numerically reduced with the addition of 23D fiber (control = 3.97%, 5D = 3.87%, 23D = 1.31%, P = 0.31). Piglet average daily gain (kg/d) was not statistically impacted by fiber (Control = 0.25, 5D = 0.25, 23D = 0.26, P = 0.27). Wean pigs per litter showed no change between treatments (Control = 12.57, 5D = 12.70, 23D = 12.47, P = 0.38) Wean to estrus days were not statistically impacted from treatments (Control 4.28, 5D = 4.20, 23D = 4.1, P = 0.53.) Fecal softness scores continued to decline in the 23D after the initial five days on treatment (P &amp;lt; 0.01.) In conclusion, sows on 23D fiber maintained more body weight through lactation and had consistently looser stools than sows on 5D or Control treatments.

Spatial distribution and composition of marine litter on sandy beaches along the Indian Ocean coastline in the south Java region, Indonesia

Marine litter in coastal areas can bring economic, social, and environmental damage, especially the loss of aesthetic value of a tourist site. Therefore, research on the composition of marine litter to identify its sources is important for planning strategic action to minimize the problem. This study analyzed beach litter composition on five beaches (Kondangmerak, Balekambang, Ungapan, Ngudel, and Goa Cina) along the Indian Ocean coastline in the eastern part of the south Java region, Indonesia. All the beaches are known as the famous touristic beaches of Malang City, and receive many visitors, especially during the holiday season. Beach litter composition was obtained by collecting different types of litter in a 5 x 5 m square transect. Five square transects were placed along the beach strandline at each beach, and intervals of 20 m separated each transect. In each transect, the litter was collected and counted based on its category (plastic, paper, rubber, fabric, processed wood, metal, glass, ceramic, and hazardous items) and size (0.5–2.5cm, 2.5–5cm, 5–10 cm, and &amp;gt; 10 cm). There was a statistically significant variation in the number of litters among the sizes (p&amp;lt;0.05). However, the distribution of beach litter remained consistent across beaches regardless of its size. In general, beach litter with a size &amp;gt; 10 cm was found least on all beaches (&amp;lt; 15%), while the other three size categories were found in similar numbers (in the range of 20% to 50%). Plastic was the dominating type of litter on all beaches. Based on the Clean Coastal Index, all beaches were considered dirty to extremely dirty. All litter on the beaches was the product of tourism activities, and littering habits play a significant role as the source of marine litter in the study areas. Since this is the first study on the marine litter composition in the eastern part of south Java, the results of this study can be used as a baseline for future studies to prevent marine debris pollution and to develop management strategies for reducing the impact of marine debris on the environment.

OR19-03 SIK2 Regulates Granulosa Cell Response to Exogenous Gonadotropins

Abstract Disclosure: E. Hayes: None. O. Lakomy: None. M. Hassan: None. R. Filzen: None. M. Rodriguez Esquivel: None. M. Foretz: None. C.O. Stocco: Grant Recipient; Self; NIH R01HD097202. Forty percent of cases of infertility are attributed to ovulatory defects. Successful ovulation requires the coordinated development of the ovarian follicle, the functional unit of the ovary that is composed of the oocyte surrounded by steroidogenic granulosa cells. However, the mechanisms that govern follicle development remain incompletely understood. Previously, our group showed that loss of salt-inducible kinase 2 (SIK2) in a murine knockout model resulted in a significantly increased number of ovulated oocytes in response to an ovarian hyperstimulation protocol. Here, we aimed to further characterize the reproductive phenotype of SIK2 knockout mice, as well as to understand the role of SIK2 in granulosa cells by creating and characterizing a granulosa cell-specific knockdown of SIK2 using the Cre-Lox system. Loss of SIK2 resulted in no changes in the number of litters or litter size as well as a normal estrus cycle. Interestingly, granulosa cell-specific knockdown of SIK2 resulted in a significantly increased number of ovulated oocytes in response to ovarian hyperstimulation. However, SIK2 knockout mice do not ovulate more oocytes under physiologic conditions. Furthermore, knockdown of SIK2 in granulosa cells resulted in significantly increased Cyp19a1 gene expression and serum estradiol concentration. The data reveal that SIK2 plays an important role in the regulation of the response of granulosa cells to gonadotropins. These data support the potential of SIK2 as a pharmacologic target for improving oocyte yield for women receiving gonadotropins during in vitro fertilization as a treatment to trigger follicular maturation and ovulation. SIK2-regulated mechanisms could reveal new targets for the development of innovative methods of contraception. Presentation Date: Saturday, June 17, 2023

SAT389 Reproductive And Metabolic Characterization of Mice Overexpressing CYP17 in Ovarian Theca Cells

Abstract Disclosure: S. Joseph: None. V. Ubba: None. M. K DSilva: None. S. Wu: None. Androgens, in physiological levels are important to normal ovarian function. However, excess androgens are detrimental to ovarian function, and is seen in PCOS, Congenital Adrenal Hyperplasia and Transgender Males undergoing testosterone therapy. Current models of androgen excess in females, mostly involve external administration of the causative agent. Hence, we developed an endogenous model of excess testosterone in female mice. To achieve this, a Triple mutant (TM) mouse was developed using the doxycycline inducible tet- on system, which involved RTTA, Cyp17 Cre and teto operator specifically inserted into CYP17 gene (purpose- double secure CYP17 specifically expressed in theca cells). These mice were fed with Doxycycline 625 mg/kg at 2 months of age. The TM mice showed significantly increased testosterone levels and Cyp17 protein expression in the ovaries. Estradiol, progesterone was unchanged. Reproductive characterization of the mice showed impaired estrous cyclicity and reduced fertility (number of pups and litters). Ovarian histology showed increased number of atretic follicles, with no changes in the number of developmental follicles and corpus leuteum. In the pituitary, mRNA expression of LHβ was significantly decreased, while GnRHR and FSHβ was unchanged. GnRH stimulation showed a decrease in LH levels in the TM mice. Immunoblotting showed increased expression of Androgen Receptor (Ar). Although increased androgens in females is associated with metabolic dysfunction, we did not observe any changes in Glucose, pyruvate and insulin tolerance in TM mice. Comprehensive Laboratory Animal Monitoring System (CLAMS) did not show any changes in the Respiratory Exchange Ratio, heat production and ambulatory movement. These studies show a unique strategy to develop an endogenous excess testosterone producing transgenic mice with decreased fertility. Presentation Date: Saturday, June 17, 2023

Patterns of reproduction and autozygosity distinguish the breeding from nonbreeding gray wolves of Yellowstone National Park.

For species of management concern, accurate estimates of inbreeding and associated consequences on reproduction are crucial for predicting their future viability. However, few studies have partitioned this aspect of genetic viability with respect to reproduction in a group-living social mammal. We investigated the contributions of foundation stock lineages, putative fitness consequences of inbreeding, and genetic diversity of the breeding versus nonreproductive segment of the Yellowstone National Park gray wolf population. Our dataset spans 25 years and seven generations since reintroduction, encompassing 152 nuclear families and 329 litters. We found more than 87% of the pedigree foundation genomes persisted and report influxes of allelic diversity from two translocated wolves from a divergent source in Montana. As expected for group-living species, mean kinship significantly increased over time but with minimal loss of observed heterozygosity. Strikingly, the reproductive portion of the population carried a significantly lower genome-wide inbreeding coefficients, autozygosity, and more rapid decay for linkage disequilibrium relative to the nonbreeding population. Breeding wolves had significantly longer lifespans and lower inbreeding coefficients than nonbreeding wolves. Our model revealed that the number of litters was negatively significantly associated with heterozygosity (R = -0.11). Our findings highlight genetic contributions to fitness, and the importance of the reproductively active individuals in a population to counteract loss of genetic variation in a wild, free-ranging social carnivore. It is crucial for managers to mitigate factors that significantly reduce effective population size and genetic connectivity, which supports the dispersion of genetic variation that aids in rapid evolutionary responses to environmental challenges.

Observations about declining fertility in a feline breeding colony

Feline breeding colonies are important to the feline industry by preserving traits desirable for a particular breed or in research settings by maintaining medically valuable genetic traits. As breeding females age, their reproductive efficiency declines. The objective of this study was to determine the most common causes of infertility in breeding females that were producing fewer kittens. Knowing the cause and average age of infertility would allow management decisions to be made for the betterment of the colony. The medical records of 70 queens retired from breeding from a single research colony were examined for litter size and number, fertility over their lifespan, and age and reason for removal from breeding stock. Sections of uterus and ovaries were evaluated using gross and histopathological examination for a subset of these queens (46). The data suggests that mature, continuously breeding female cats may show signs of reduced fertility (infertile matings or reduced litter size) as early as 3 years of age and may be a result of undiagnosed Cystic Endometrial Hyperplasia (CEH), endometritis, pyometra and/or ovarian cysts. Evaluation of breeding queens should include periodic ultrasounds to monitor for ovarian cysts and evidence of CEH. Retiring animals from breeding once signs of infertility become apparent is recommended.

25 (P2-6). Source of organic zinc, manganese and copper did not influence average daily litter gain or number of weaned piglets per litter

25 (P2-6). Source of organic zinc, manganese and copper did not influence average daily litter gain or number of weaned piglets per litter

Paxillin knockout in mouse granulosa cells increases fecundity†.

Paxillin is an intracellular adaptor protein involved in focal adhesions, cell response to stress, steroid signaling, and apoptosis in reproductive tissues. To investigate the role of paxillin in granulosa cells, we created a granulosa-specific paxillin knockout mouse model using Cre recombinase driven by the Anti-Müllerian hormone receptor 2 gene promoter. Female granulosa-specific paxillin knockout mice demonstrated increased fertility in later reproductive age, resulting in higher number of offspring when bred continuously up to 26weeks of age. This was not due to increased numbers of estrous cycles, ovulated oocytes per cycle, or pups per litter, but this was due to shorter time to pregnancy and increased number of litters in the granulosa-specific paxillin knockout mice. The number of ovarian follicles was not significantly affected by the knockout at 30weeks of age. Granulosa-specific paxillin knockout mice had slightly altered estrous cycles but no difference in circulating reproductive hormone levels. Knockout of paxillin using clustered regularly interspaced short palindromic repeat-associated protein 9 (CRISPR-Cas9) in human granulosa-derived immortalized KGN cells did not affect cell proliferation or migration. However, in cultured primary mouse granulosa cells, paxillin knockout reduced cell death under basal culture conditions. We conclude that paxillin knockout in granulosa cells increases female fecundity in older reproductive age mice, possibly by reducing granulosa cell death. This study implicates paxillin and its signaling network as potential granulosa cell targets in the management of age-related subfertility.