Number Of Ova Research Articles

Geostatistical Methods to Build Citrus Cross-Pollination Risk Maps

Valencian citriculture is oriented towards fresh production, which requires fruits with few seeds or seedless fruits. Consequently, parthenocarpic and self-incompatible varieties are mainly cultivated. However, some mandarin varieties, under favorable circumstances, induce seed formation in other mandarins by cross-pollination. This phenomenon depends on the germination capacity of the pollen of the pollinating variety, the number of ovules of the pollinated variety, the distance between them, and the abundance of pollinating insects. Previous studies in Instituto Valenciano de Investigaciones Agrarias (IVIA) have determined the ability to pollinate and be pollinated by all commercial varieties in Europe. Moreover, the Regional Government, Generalitat Valenciana, has georeferenced information on the cultivated varieties. We present two geostatistical models to estimate the risk of plots to be pollinated, depending on the varieties present in their environment, the number of plants, and their distance. Models are used to generate local and regional cross-pollination risk maps. Moreover, the robustness of these models to changes in the values assigned to their main parameters is assessed using different similarity calculations.

A simple method to select high superovulatory responder goats

In most female mammals, a common drawback to multiple ovulation embryo transfer programs is the variability in the superovulatory response to the multidose pFSH treatment. The aim of the present study was to identify embryo donor goats based on their response to superovulation before the performance of a high-cost hormonal treatment, as we have previously done in sheep. To this end, we evaluated the number of ovulations obtained in response to the administration of a one-shot eCG treatment and related it with the subsequent ovarian response to a multiple-dose pFSH treatment in 33 goats of the Criolla-Neuquina breed. Goats received a one-shot eCG treatment of 800 IU at the end of a 17-day progestational treatment; 9 days later, started a second 17-day progestational treatment and then received a multiple-dose pFSH treatment on days 15–17 (116 mg pFSH, in six decreasing doses). The number of corpora lutea (CL) per goat was recorded laparoscopically after both hormonal treatments. On day 8 after the second pessary removal, embryos were surgically recovered and classified by quality. Results showed a significant positive correlation between the number of CL obtained in response to the eCG and pFSH treatments (r = 0.41; y = 0.8352x + 6.9906; P < 0.05), although of limited value to select high ovulatory responding goats, due to its low correlation value. Then, goats were grouped into high and low ovulatory responders to the eCG (High ≥9; Low <9 CL) and pFSH treatments (High ≥13; Low <13 CL). After the eCG and pFSH treatments, 60% of the goats maintained their classification as high or low superovulatory responders (expressed as recurrence rate). Significant differences were found in the number of CL (18.2 ± 1.3 vs 9.9 ± 1.3), number of embryos + oocytes (13.5 ± 1.7 vs 7.6 ± 1.7), number of embryos (10.8 ± 1.4 vs 5.1 ± 1.4) and number of Grade 1 and Grade 2 embryos (8.8 ± 1.4 vs 4.3 ± 1.4) between high and low superovulatory responder goats (P < 0.05), while no differences were observed in the number of oocytes and in the recovery of embryos + oocytes, embryos, Grade 1 and Grade 2 embryos and fertilization rates (P > 0.05). In conclusion, the recurrence rate in ovarian response between the one-shot eCG treatment and the multiple-dose pFSH treatment would confirm the existence of an “individual or intrinsic factor” of the donor goat that would respond as a high or low ovulatory responder to superovulatory treatments.

Interfamily wide hybridization between daylily (Hemerocallis, Xanthorrhoeaceae) and lycoris (Lycoris, Amaryllidaceae)

AbstractDaylily (Hemerocallis) is a perennial with high ornamental value. It is difficult to obtain innovative daylily germplasm by conventional crossbreeding. To enrich the genetic variation of Hemerocallis, daylily was used as male parent to cross with lycoris (Lycoris). Artificial pollination and embryo rescue were performed to overcome reproductive isolation. Cross‐compatibility and pollen germination were analysed to investigate interfamily reproductive isolation. Leaf morphological analysis and inter‐simple sequence repeat (ISSR) were performed to identify the hybrid at seedling stage. Results showed that most pollen grains failed to adhere to stigmas, and pollen tubes germinated in a disordered direction. Ten days after pollination, 77.19% of ovaries aborted. Ovaries were harvested only in 10 hybridization combinations, the fruit setting rates were 7.69%–42.86%, and the ovule numbers were 0–6.0 per ovary. One embryo developed into plantlets eventually, whose parental combination was L. aurea × H. ‘My Complementary’. The hybrid was identified and exhibited both intermediate and novel characteristics of parents. This research is the first attempt to explore a protocol to obtain interfamily hybrid between daylily and lycoris.

Pengaturan Pembungaan pada Jambu Biji (Psidium guajava L.) 'Kristal' dengan Penggunaan Paklobutrazol dan BAP

Guava plant 'Crystal' is a horticultural commodity that can produce fruit throughout the year, but the availability of fruit must be maintained. In maintaining the continuity of the availability of the fruit, an alternative is needed to regulate the flowering of 'Crystal' guava plants in order to meet market demand. This can be done by giving Growth Regulators (ZPT) such as Paklobutrazol and Benzyl Amino Purines (BAP). This study aims to determine (1) the effect of Paklobutrazol in increasing the flowering of 'Kristal' guava plants, (2) the effect of BAP on increasing the flowering of 'Crystal' guava plants, and (3) the effect of the interaction of the best treatment between Paklobutrazol and BAP in increasing flowering. guava plant 'Crystal'. The method used in this study was factorial Randomized Block Design (RAK) with two treatment factors which included the administration of Paklobutrazole (P) with three levels and the treatment factor of giving BAP (N) with three levels. The results showed that 1) Paklobutrazol treatment with a concentration of 8,000 ppm increased the number of generative shoot variables, the number of blooms, the number of ovules, the number of fruits, and the weight of the fruit; 2) administration of 100 ppm BAP increased the number of vegetative shoots and number of leaves; 3) the treatment between Paklobutrazol and BAP only occurred in the variable number of vegetative shoots, the highest was produced by the 100 ppm BAP and 100 ppm Paklobutrazole treatments, namely 160 vegetative shoots.. Keywords: paclobutrazole, 'Crystal' guava, and BAP

Genome-wide association studies and genomic selection assays made in a large sample of cacao (Theobroma cacao L.) germplasm reveal significant marker-trait associations and good predictive value for improving yield potential.

A genome-wide association study (GWAS) was undertaken to unravel marker-trait associations (MTAs) between SNP markers and phenotypic traits. It involved a subset of 421 cacao accessions from the large and diverse collection conserved ex situ at the International Cocoa Genebank Trinidad. A Mixed Linear Model (MLM) in TASSEL was used for the GWAS and followed by confirmatory analyses using GAPIT FarmCPU. An average linkage disequilibrium (r2) of 0.10 at 5.2 Mb was found across several chromosomes. Seventeen significant (P ≤ 8.17 × 10−5 (–log10 (p) = 4.088)) MTAs of interest, including six that pertained to yield-related traits, were identified using TASSEL MLM. The latter accounted for 5 to 17% of the phenotypic variation expressed. The highly significant association (P ≤ 8.17 × 10−5) between seed length to width ratio and TcSNP 733 on chromosome 5 was verified with FarmCPU (P ≤ 1.12 × 10−8). Fourteen MTAs were common to both the TASSEL and FarmCPU models at P ≤ 0.003. The most significant yield-related MTAs involved seed number and seed length on chromosome 7 (P ≤ 1.15 × 10−14 and P ≤ 6.75 × 10−05, respectively) and seed number on chromosome 1 (P ≤ 2.38 × 10−05), based on the TASSEL MLM. It was noteworthy that seed length, seed length to width ratio and seed number were associated with markers at different loci, indicating their polygenic nature. Approximately 40 candidate genes that encode embryo and seed development, protein synthesis, carbohydrate transport and lipid biosynthesis and transport were identified in the flanking regions of the significantly associated SNPs and in linkage disequilibrium with them. A significant association of fruit surface anthocyanin intensity co-localised with MYB-related protein 308 on chromosome 4. Testing of a genomic selection approach revealed good predictive value (genomic estimated breeding values (GEBV)) for economic traits such as seed number (GEBV = 0.611), seed length (0.6199), seed width (0.5435), seed length to width ratio (0.5503), seed/cotyledon mass (0.6014) and ovule number (0.6325). The findings of this study could facilitate genomic selection and marker-assisted breeding of cacao thereby expediting improvement in the yield potential of cacao planting material.

Novelties in the floral morphoanatomy of three Psychotria L. species (Rubiaceae)

The Psychotrieae alliance is a monophyletic group belonging to the Rubiaceae family, composed of nine tribes, with a problematic internal delimitation. The genus Psychotria L. is the most representative in the alliance, with about 2,000 species, and in the current circumscription is considered paraphyletic. Since Psychotria is morphologically uniform, the accurate circumscription of the genus is difficult to establish due to the large number of species and the absence of diagnostic characters. In this context, we studied the floral morphoanatomy of Psychotria leiocarpa Cham. & Schltdl., Psychotria carthagenensis Jacq., and Psychotria brachyceras Mull. Arg., aiming to provide informative characteristics for ongoing phylogenetic studies within the genus and the alliance. Our results showed that all species have cymose and terminal inflorescences, forming a dichasium. The anatomical structure of the floral organs demonstrated potentially informative traits, including: the presence of a set of secretory cells in the petals, raphides in the ovule integument, and papillose cells in the outer epidermis of the ovary in P. brachyceras; the presence of prismatic crystals in the ovary of P. brachyceras and P. leiocarpa; as well as the presence of non-glandular trichomes in the outer epidermis of the ovary, presence of phenolic compounds, and absence of prismatic crystals in all floral organs of P. carthagensis. Regarding the other tribes of the alliance, our results indicate that the traits related to the gynoecium seem to have more relevance in superior taxonomic categories, such as the structure of the ovary, number of ovules per locule, placentation, ovule curvature and presence/absence of an obturator. This is the first comprehensive attempt to clearly identify informative floral morphoanatomical traits among the three species of the genus. Psychotria L.

A Comparative Clinical Study of Shatavaryadi and Guduchyadi Churna on Rajonivrutti Avastha with special reference to Postmenopausal Syndrome

The menopause is permanent cessation of menstruation at the end of reproductive life due to loss of ovarian follicular activity. Shatavaryadi Churna and Guduchyadi Churna– both drugs are 6grams twice daily before meal with milk for 2 months in two groups has been given. Both are effective in the management of Postmenopausal Syndrome. Shatavaryadi Churna is more effective than Guduchyadi Churna in the management of Postmenopausal Syndrome but both are an effective, safe, promising and cost effective remedy. Vata-Pittashamaka, Rasayana, Dhatuvardhaka, Agnidipaka, Pachana, Medhya, Vedanasthapana, Hridya, Anidranash drug in Shatavaryadi Churna helped to deliver such promising results. Guduchyadi Churna had also delivered satisfactory results treating in Postmenopausal Syndrome due toits Tridoshahara &amp; Vata-Kaphashamaka activity along with Rasayana, Dipana, Pachana, Dhatuvardhaka, Balya, Hridya, Nidrajanana, Medhya and Vedanasthapana properties. The age at menopause appears to be genetically determined and is unaffected by race, socioeconomic status, age at menarche, or number of prior ovulations. Factors that are toxic to the ovary often result in an earlier age of menopause; for e.g., who smoke experience an earlier menopause. Women who have had surgery on their ovaries, have had a hysterectomy, despite retention of their ovaries, may also experience early menopause

Characteristics of a radish mutant with longer siliques

The silique is an important organ in plant reproduction and maintains biodiversity among species; however, little is known about the regulation of radish (Raphanus sativus L.) silique development. In this study, we conducted research on the radish long silique (ls) mutant and wild-type (WT) radish and compared their morphological and molecular markers. The results showed that the mutant obtained by ethyl methane sulfonate treatment had the following stable characteristics: the lengths of mutant and WT siliques were 20.50 and 9.10 cm, respectively; and the ovule number per silique of the mutant and WT was 9.5 and 4.5, respectively. Polymerase chain reaction (PCR) analysis revealed abundant polymorphisms between the ls mutant and WT in HZ001, SRC9-022, and OIL2F11 simple-sequence repeat molecular markers, and the expression of LS1 and LS2 (RsNAC66). Arabidopsis thaliana-transformed plants with RsNAC66 overexpression were obtained by the floral dip method. Quantitative PCR showed that LS2 (RsNAC66) was more highly expressed in transformed lines than in WT, and the expression of LS2 (RsNAC66) in the transformed lines was higher in siliques than leaves. Phenotypic analysis revealed abnormal ovule numbers and shoots, and altered plant height in the transformed plant. Phenotypic and gene expression analyses showed that LS2 (RsNAC66) plays an important role on silique length and the number of seeds per silique. Together, the results showed that the radish ls mutant is specific and stable, and thus constitutes an excellent research resource for improving the seed yield of radishes.

Laparoscopic surgeries for uterine fibroids and ovarian cysts reduce ovarian reserve via age- and surgical type-manner

Aim: Diminished ovarian reserve can be characterized by poor response to ovulation and low number of eggs. The risk factors include endometriosis, receiving cancer treatment, luteal phase deficiency and gynecologic surgery. Uterine fibroids and ovarian cysts are the most common benign gynecological diseases in women globally. This prospective study evaluated the influence of laparoscopic surgery treating benign gynecological diseases on ovarian reserve. Methods: A total of 121 patients with uterine fibroids or benign ovarian cysts who received laparoscopic surgeries (41 with hysterectomy, 36 with myomectomy, 18 with adnexectomy, and 26 with ovarian cystectomy) were included. The ovarian reserve status defined as serum anti-Mullerian hormone concentration was assessed at 1 month before and after surgery, respectively. Results: The anti-Mullerian hormone reduction level was 22.34% in cystectomy, 44.1% in adnexectomy, 24.92% in myomectomy, and 47.61% in hysterectomy (p < 0.001). Multivariate analysis showed that adnexectomy had significantly high risk of high serum anti-Mullerian hormone reduction level (adjusted odds ratio (aOR): 14.90, 95% confidence interval (CI): 2.56-86.93, p = 0.003). Conclusions: These 4 laparoscopic surgeries all reduced the AMH levels 1 month after the procedure. Further prospective studies with longer follow-up are necessary to know the real impact on the ovarian reserve. Adnexectomy was an independent factor of reduced ovarian reserve in 1 month after surgery.

Subindividual variation accounts for most of the variability in two reproductive traits in Cistusladanifer

There is increasing evidence of within species flower trait variability. In Cistus ladanifer, there is a great variation in the number of locules of the ovary (6–12). In this study, we assessed the variation in the number of ovary locules and ovule production at population, individual and intraindividual levels in 5 localities in the Madrid Region (Central Spain). We have answered the following questions: What level present larger variation? Is there a relationship between the number of ovary locules and ovule production? And if yes, does it hold across all levels? We sampled almost 500 flowers from 50 individuals for five localities. We counted the number of locules of the ovary and estimate the number of ovules per flower. The partitioning of total variation among populations, individuals and within-individuals was estimated for both variables. To analyze differences among locations, we performed general linear models. We found that within-individual variation was the main source of variation for all measured variables. Inter-individual variation was relevant only for the number of locules, and inter-population variation was almost negligible for all variables. Despite the positive correlation between the number of locules per flower and ovule production, populations with more locules did not present more ovules per flower. In summary, we found that variation in the number of locules and its relationship with ovule production is scale dependent.

Genetic dissection of the natural variation of ovule number per ovary in oilseed rape germplasm (Brassica napus L.).

Oilseed rape is one of the world’s largest oil and industrial crops, providing humans with various products, such as vegetable oil and biofuel. Ovules are the direct precursors of seeds, and ovule number per ovary (ONPO) largely determines seed number per fruit that affects both yield and fitness of seed crops. The ONPO shows wide variation in oilseed rape, whereas the underlying genes and mechanisms are poorly known. The present study performed the genetic, physiological and transcriptomic analyses of ovule number per ovary using an association panel and the extreme lines. The ONPO of 327 accessions planted in four environments showed a large variation from 19.2 to 43.8, indicating a great potential for the further genetic improvement of ovule number. The genome-wide association study (GWAS) identified a total of 43 significant SNP markers. Further, these SNPs were integrated into 18 association loci, which were distributed on chromosomes A01, A03, A06, A07, A09, C01, C03, C06, C07, and C09, explaining 4.3–11.5% of the phenotypic variance. The ONPO decreased as their appearance order on the inflorescence and was associated with the level of several types of endogenous phytohormones but not related to leaf area and photosynthetic rate. Comparative transcriptomic analysis identified a total of 4,449 DEGs enriched in 30 classes, including DNA, RNA, protein, signaling, transport, development, cell wall, lipid metabolism, and secondary metabolism. Nearly half of DEGs were involved in the known pathways in regulating ovule number, of which 12 were homologous to know ovule number regulating genes, indicating a strong link between the identified DEGs and ovule number. A total of 73 DEGs were located within the genomic regions of association loci, of which six were identified as candidates based on functional annotation. These results provide useful information for the further genetic improvement of ovule and seed number in oilseed rape.

Clinical Effects of Bushen Culuan Prescription on Infertility Due to Decreased Ovarian Reserve of Kidney Deficiency and Liver Depression Pattern

Abstract Objective The objective of this study was to explore the clinical effects of Bushen Culuan prescription on infertility due to decreased ovarian reserve of kidney deficiency and liver depression pattern. Methods Totally 100 infertile patients with ovarian hypofunction treated from October 2019 to January 2022 were selected and divided into the observation group and the control group by a random number table. The control group was treated with estrogen sequential therapy, and the observation group was treated with Bushen Culuan prescription. The clinical efficacy, sex hormone levels including (follicle-stimulating hormone [FSH], luteinizing hormone [LH], and estradiol [E2]), ovarian function, ovarian blood flow status (peak systolic velocity [PSV], antral follicle count [AFC], arterial pulse index [PI], and resistance index [RI]), and pregnancy outcome in the two groups were compared and analyzed. Results The total effective rate of the observation group (96.00%) was significantly higher than that of the control group (80.00%). The difference was statistically significant (p &lt; 0.05). Before treatment, there was no significant difference in sex hormone levels (FSH, LH, E2, and FSH/LH), ovarian function (number of primary follicles, number of dominant follicles, ovulation number, and endometrial thickness), and ovarian blood flow (PSV, RI, PI, and AFC) between the two groups (p &gt; 0.05). After treatment, the levels of serum hormones FSH, LH, E2, and FSH/LH decreased significantly in both groups. The number of primary follicles, dominant follicles, and ovulation increased significantly, and the thickness of endometrium decreased significantly; the indexes of PSV, RI, and AFC of ovarian blood flow increased significantly, and the PI index decreased significantly. The levels of each index in the observation group were better than those in the control group (p &lt; 0.05). In the control group, 32 cases were pregnant within 1 year after treatment, and the pregnancy rate was 64.00%; 21 cases in the observation group were pregnant within 1 year after treatment, and the pregnancy rate was 42.00%; the pregnancy rate in the observation group was higher than that in the control group, and the difference was statistically significant (χ2 = 4.014, p = 0.045 &lt; 0.05). Conclusion Bushen Culuan prescription has a definite effect on infertility due to ovarian hypofunction. The action mechanism may involve multicomponent and multitarget stimulation to improve patients' ovarian function, regulate the level of sex hormones, and improve the pregnancy outcome.

Ovarian assessment for pre-selection of embryo donor ewes

The present study aimed to evaluate whether two-dimensional ovarian measurements and the identification of antral follicle populations by ultrasound at different stages of the estrous cycle are related to the superovulatory response and embryo production in ewes. The estrous cycle of 57 Santa Inês ewes was synchronized by administering two doses of 75 μg of prostaglandin (PGF) 10 days apart. After 2.5 (proestrus/estrus), 4.5 (metestrus), and 9.5 (diestrus) days from the last PGF injection, ultrasound examinations were performed to quantify antral follicles ≥ 2 mm and ovarian measurements. Subsequently, the number of follicles and ovarian measurements were correlated with the superovulatory response and embryo production of each ewe. The mean follicle population (≥ 2 mm) and ovarian dimensions were similar in all phases of the estrous cycle (P > 0.05). Positive correlations were identified between the number of follicles and ovarian dimensions (P < 0.05) in different phases of the estrous cycle. Donor ewes with a high number of follicles (≥ 7) in the metestrus phase showed a significant increase in the number of ovulations, total structures, total embryos, and viable embryos (P < 0.05). In conclusion, ultrasonographic assessment of the number of follicles ≥ 2 mm, performed during metestrus (4.5 days after synchronization pre-treatment), is an easy-to-perform approach and can be used for pre-selection of embryo donor ewes.

Do Reproductive Traits of Invasive Populations of Scotch Broom, Cytisus scoparius (Fabaceae), Outperform Native Populations?

Reproductive traits are among the most important factors in determining the success of species establishment and invasion in a new area. Studies on transcontinental invasions have revealed that invasive species perform better in the invasive range than in their native ranges. We assumed that the same regularity exists in intracontinental invasions and thus investigated whether the reproductive traits of Scotch broom, Cytisus scoparius, perform better in the alien invasive range in Europe compared to its native range in the same continent. The aim of this research was to reveal the potential and realised fecundity of C. scoparius in its native and invasive ranges, as well as relationships with the size of pods, habitat type, and how these traits vary at the same site in different years. The results of this study were not able to unambiguously confirm our hypothesis that C. scoparius in the invasive range in Lithuania, specifically in the southern part of the Boreal biogeographical region, outperform plants in the native range with regard to the analysed reproductive traits. Potential fecundity of C. scoparius in the native range was significantly higher than in the invaded range; however, realised fecundity was not significantly different between the native and invasive ranges. The pod length was similar in both ranges, whereas the pod width was significantly greater in the invasive range than in the native range. The results suggest that the number of ovules per pod, number of matured seeds, and the size of pods are related with the type of habitat and local environmental conditions in the habitat. Although many studies on other species have confirmed higher fecundity and overall better performance of plants in the invasive range than in the native range on other continents, this rule probably cannot be applied for intracontinental invasive species occurring in relatively close geographical regions to their native ranges.

Wenshen Yangxue decoction promotes follicular development in aged female mice stimulation of the silent information regulator 3/forkhead transcription factor O1 3a pathway.

To primarily explore the effect and mechanism of Wenshen Yangxue decoction in promoting follicular development in elderly female mice. Fifty Institute of Cancer Research mice were randomly divided into blank, controlled ovarian hyperstimulation (COH), low-dose Wenshen Yangxue decoction, medium-dose Wenshen Yangxue decoction, and high-dose Wenshen Yangxue decoction groups, with 10 mice in each group. The number of ovulations, number of fertilizations, mitochondrial adenosine triphosphate (ATP) level, and mitochondrial DNA (mtDNA) of oocytes in each group were compared. Reverse transcription-polymerase chain reaction and Western blotting were used to detect the mRNA and protein expression levels of silent information regulator 3 (Sirt3) and forkhead transcription factor O1 3a (FOXO3a). Wenshen Yangxue decoction significantly increased the number of ovulations in mice (P < 0.05) and promoted the formation of fertilized eggs. The ATP level and mtDNA copy number of mice oocytes in the high-dose groups were significantly higher than those in the COH group (P < 0.05). Wenshen Yangxue decoction significantly increased the mRNA and protein levels of Sirt3 and FOXO3a in mouse oocytes. Wenshen Yangxue decoction promoted the development of follicles in elderly female mice, increased the number of ovulations and improved fertility. Its mechanism may be related to increased mitochondrial energy metabolism and regulation of the Sirt3/FOXO3a pathway.

Ovule initiation: the essential step controlling offspring number in Arabidopsis

AbstractSeed is the offspring of angiosperms. Plants produce large numbers of seeds to ensure effective reproduction and survival in varying environments. Ovule is a fundamentally important organ and is the precursor of the seed. In Arabidopsis and other plants characterized by multi‐ovulate ovaries, ovule initiation determines the maximal ovule number, thus greatly affecting seed number per fruit and seed yield. Investigating the regulatory mechanism of ovule initiation has both scientific and economic significance. However, the genetic and molecular basis underlying ovule initiation remains unclear due to technological limitations. Very recently, rules governing the multiple ovules initiation from one placenta have been identified, the individual functions and crosstalk of phytohormones in regulating ovule initiation have been further characterized, and new regulators of ovule boundary are reported, therefore expanding the understanding of this field. In this review, we present an overview of current knowledge in ovule initiation and summarize the significance of ovule initiation in regulating the number of plant offspring, as well as raise insights for the future study in this field that provide potential routes for the improvement of crop yield.

A Mechanism for Ovulation Number Control.

Every menstrual cycle, many follicles begin to develop but only a specific number ovulate. This ovulation number determines how many offspring are produced per litter, and differs between species. The physiological mechanism that controls ovulation number is unknown; a class of mathematical models can explain it, but these models have no physiological basis. Here, we suggest a physiological mechanism for ovulation number control, which enables selection of a specific number of follicles out of many, and analyze it in a mathematical model of follicular growth. The mechanism is based on a signal, intra-follicular androgen concentration, that measures follicle size relative to the other follicles. This signal has a biphasic effect, suppressing follicles that are too large or too small compared to others. The ovulation number is determined by the androgen inhibitory thresholds. The model has a scaling symmetry that explains why the dominant follicles grow linearly with time, as observed in human ultrasound data. This approach also explains how chronic hyperandrogenism disrupts ovulation in polycystic ovary syndrome (PCOS), a leading cause of infertility. We propose specific experiments for testing the proposed mechanism.

Luteal Tissue Area and Immunoreactive Concentration of Progesterone in Plasma of Bred and Non-bred Mares

Progesterone is pivotal to maintain pregnancy in the first trimester and low concentration (<4 ng/mL) has been associated with early pregnancy loss. Measurement of progesterone is widely used in practice to determine whether a mare needs progestin supplementation. Therefore, the objective of the present study was to determine progesterone concentration and the luteal tissue area in mares non-bred, and those bred becoming pregnant, and those failing to become pregnant. We hypothesized that pregnant mares have greater progesterone concentration than non-pregnant mares. Fifty-two cycles of mares (n = 14) were monitored by ultrasonography every other day until detection of a pre-ovulatory follicle. Then deslorelin acetate was administered to induce ovulation. Twenty-four hours later, mares were bred (∼2 billion progressively motile sperm extended in 50 mL; n = 37 cycles) or a sham-bred (50 mL of extender; n = 15 cycles). Ovulation was confirmed and number of corpora lutea and the luteal tissue area were recorded daily until 10-days post-ovulation. Progesterone concentration was assessed daily from the day of the ovulation up to 10-days post-ovulation. Pregnancy diagnosis was carried out at 10- and 13-days post-ovulation. Of the bred mares, 20 of them became pregnant and 17 did not. Data were analyzed with a mixed model, Tukey's test as post-hoc, and Pearson's coefficient of correlation. Progesterone concentration and luteal tissue area varied with time (P = .001) but not with group (P > .05). Multiple ovulations were associated with greater progesterone concentration and luteal tissue area (P = .0001). There was a moderate positive association between the number of ovulations and luteal tissue area (r = 0.54; P = .0001). The lack of change in the progesterone concentration and luteal tissue area between bred and non-bred mares suggests that horse seminal plasma does not affect luteal function in mares. As all mares had progesterone above 4 ng/mL after 5-days post-ovulation; it is possible that if mares with abnormal progesterone concentration were used, the results could have been different. In conclusion, pregnancy was not associated with greater progesterone concentration or luteal tissue area.

P-677 Increasing the efficacy of FSH with a potentiating monoclonal antibody

Abstract Study question Can we potentiate FSH activity with antibodies to improve ovarian stimulation? Summary answer IGYXOS developed a potentiating monoclonal antibody that improves FSH potency and efficacy in vitro and in vivo as demonstrated in different animal models. What is known already FSH plays a key role in reproduction. For a controlled ovarian stimulation in IVF cycles, FSH-containing preparations are injected to patients in order to obtain mature and fertilizable oocytes. However, the efficacy of these treatments is frequently limited and sometimes several attempts are needed before reaching a pregnancy and a live birth. It was previously demonstrated that breeding animals treated with gonadotropins could develop anti-gonadotropin antibodies that enhance their bioactivity instead of inhibiting it. These females had a high kidding rate and sometimes were hyperprolific. Study design, size, duration IGYXOS developed a monoclonal antibody (mAb) directed against human FSH. The mAb CF12 was selected based on its ability to increase FSH activity in vitro and in vivo in female rat. Its potentiating activity was tested on different human FSH preparations. The potentiating effect of CF12 was further investigated in ewe treated with mAb alone or FSH alone. Participants/materials, setting, methods CF12 was tested in vitro on HEK 293 cells expressing the human FSH receptor and a cell reporter system for cAMP. In vivo, the mAb was tested according to the Steelman and Pohley protocol on different human FSH preparations. Its potentiating effect was also investigated in an ovulation induction protocol on mature ewes. Main results and the role of chance In HEK 293 cells expressing the human FSH receptor, CF12 combined to FSH improved both the potency (EC50) and the efficacy (Emax) of FSH by increasing the cyclic AMP production at all tested FSH concentrations. The potentiating activity was confirmed in immature female rats treated with hCG+FSH alone or combined to mAb, twice a day, during 3 days. The animals were sacrificed the fourth day of treatment and the weight of the ovaries was compared. Ovaries weight was significantly increased in the group treated with hCG/FSH+CF12 compared to hCG/FSH only. To further analyze the effect of CF12 on ovulation induction, it was investigated in ewe as a breeding animal model. Animals were first synchronized with a progestagen and then treated either with FSH alone or with CF12 alone. The number of ovulations was investigated by endoscopy by counting corpora lutea and the progesterone secretion was measured over the luteal cycle. All females treated with CF12 ovulated (100%) by contrast 40% ovulated with FSH treatment. The ovulation rate was 1.8 fold higher in group treated with CF12 compared to FSH group. Moreover, progesterone secretion during luteal phase was increased in animals treated with CF12 suggesting a better quality of corpora lutea. Limitations, reasons for caution After several proofs of concept obtained in different animal models, the compound is currently in the humanization phase before starting the CMC process and then preclinical studies. Wider implications of the findings The potentiating antibody CF12 is a new concept. It represents an interesting strategy in reproductive health, particularly to improve the IVF outcome. CF12 is currently developed for human application by our company and could be a game changer in the field of ovarian stimulation by enhancing the efficacy of FSH. Trial registration number not applicable

P-673 GnRH Agonist Early Follicular Challenge Test as a Predictor of Ovarian Response in Short Antagonist Cycles for Fertility Preservation

Abstract Study question Does the response to GnRH agonist can be used to predict ovarian function in short GnRH antagonist cycles in women undergoing oocyte cryopreservation IVF cycles? Summary answer Response to a single GnRH agonist dose at the beginning of stimulation during short antagonist cycle can predict the outcome of the fertility preservation cycle What is known already There is a need for a reliable test for ovarian reserve. Gonadotrophin agonist stimulation test (GAST) is considered a valid marker for ovarian reserve but the test was never validated for short antagonist protocol. The reported dose for this test was 0.1 mg, however, from the vast experience with GnRH agonist triggering, it is now agreed that the optimal dose for GnRH agonist flare effect is 0.2 mg. Study design, size, duration A prospective observational study of fertility preservation cycles patient in an academic hospital setting. Seventy-four Short GnRH antagonist cycles that underwent an oocyte retrieval between 1 December 2020 and 1 January 2022. Participants/materials, setting, methods On day 2, blood was sampled for basal FSH, LH, and E2 measurements, followed by a subcutaneous injection of 0.2mg GnRH agonist as part of the initial ovarian stimulation. Twelve hours later blood sampling was repeated. E2 response was used as test parameter. The major outcome was the number of cryopreserved oocytes. Main results and the role of chance Participants were divided to groups according to Day 3 E2 to Day 2 E2 response (E3/E2 ratio) to lower and upper third percentiles (&amp;lt;3.32, n = 24 and &amp;gt;5.41, n = 25). Age (32.68 vs. 32.79, p = 0.965), total gonadotropin dose injected 3216.67 vs. 2773.42 IU p = 0.16) and day 3 FSH levels (7.39 vs. 7.16, p = 0.768) were not significantly different between groups. Ovarian response as measured by E2 levels on ovulation trigger (7879.72 vs. 17572.54 pmol/ml, p = 0.001) and number of M2 oocytes retrieved were significantly different (17.92 vs. 6.24, p &amp;lt; 0.001). Linear correlation between E3/E2 ratio and number of M2 oocytes was calculated (R = 0.48, p &amp;lt; 0.001). ROC curve analysis of E3/E2 ratio for more than fifteen M2 oocytes indicate AUC value of 0.82 (cutoff value of 4.22, p &amp;lt; 0.001, 84.6% sensitivity, 70.8% specificity) and for less than five M2 oocytes AUC value of 0.84 (cutoff value of 3.34, p &amp;lt; 0.001, 76.3% sensitivity, 73.3% specificity). The results suggest that the testing response to 0.2mg GnRH agonist positively correlates with treatment outcome of the current cycle. Limitations, reasons for caution Although all patients were tested for FSH levels for ovarian reserve, they were not tested for AMH levels. Wider implications of the findings The response to single GnRH agonist dose during short antagonist cycle can be used as another biomarker of ovarian reserve. This simple, widely available marker, which reflect the estradiol response of small follicles, might predict accurately the outcome of the specific cycle, and potentially used to adjust the treatment dose. Trial registration number NCT04973969