Differences In Ovarian Morphology Research Articles

Comparative analyses of laying performance and follicular development characteristics between fat and lean broiler lines

The deposition of high levels of fat in broiler breeder hens can have a profound impact on follicular development and laying performance. This study was formulated with the goal of comparing egg production and follicular development characteristics at different laying stages in the Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF). The egg production was analyzed using the birds from the 19th to 24th generations of NEAUHLF; the follicular development characteristics were analyzed by hematoxylin-eosin staining and quantitative real-time polymerase chain reaction using the birds from the 24th generation of NEAUHLF. The results showed that the age at first egg of lean hens was significantly earlier than that of fat hens in this study. While no significant differences in total egg output from the first egg to 50 wk of age were noted when comparing these 2 chicken lines, lean hens laid more eggs from the first egg to 35 wk of age relative to fat hens, whereas fat hens laid more eggs from wk 36 to 42 and 43 to 50 relative to their lean counterparts. No differences in ovarian morphology and small yellow follicle (SYF) histological characteristics were noted when comparing these 2 chicken lines at 27 wk of age. At 35 and 52 wk of age, however, lean hens exhibited significantly lower ovarian weight, ovarian proportion values, numbers of hierarchical follicles, hierarchical follicle weight, and SYF granulosa layer thickness as compared to fat hens, together with a significant increase in the number of prehierarchical follicles relative to those in fat hens. Gene expression analyses suggested that follicle selection was impaired in the fat hens in the early laying stage, whereas both follicle selection and maturation were impaired in the lean hens in the middle and late laying stages. Overall, these data highlight that fat deposition in broiler hens can have a range of effects on follicular development and egg production that are laying stage-dependent.

Normotensive rats with PCOS exhibit the hypertensive pattern: focus on oxidative stress.

Numerous evidence implies complex interrelations between polycystic ovary syndrome (PCOS) and hypertension (HT) in reproductive-age women. In this study, we aimed to investigate the potential strain differences in ovarian morphology, hemodynamic, and biochemical characteristics in an androgen-induced PCOS rat model. A total of 24 rats of 3 weeks old (12 Wistar Kyoto - WK and 12 spontaneously hypertensive rats - SHR) were divided into four groups: WK, WK PCOS, SHR, and SHR PCOS. PCOS was induced by daily s.c. injections of testosterone enanthate (1 mg/100 g body weight) administered for 5 weeks. PCOS induction led to estrus cyclicity cessation, cystic ovarian appearance, and sex hormones disturbances in both strains. The morphometric parameters in ovaries were altered in a manner of PCOS-related changes in both strains (higher number in preantral, atretic, and cystic follicles). Ultrasonographically, a significant decrease in ovarian volume (OV) was registered in PCOS groups but also in SHR compared to WK rats. All blood pressure parameters were higher in SHR compared to WK. PCOS modeling increased systolic, mean arterial, and pulse pressure in WK strain, while in SHR, only mean arterial and pulse pressure were higher. Alterations in oxidative stress parameters could provide a molecular basis for PCOS-related changes: in PCOS groups, thiobarbituric acid reactive substance and superoxide anion radical levels were higher in both strains, while superoxide dismutase and glutathione were significantly lowered.

Impact of right–left differences in ovarian morphology on the ultrasound diagnosis of polycystic ovary syndrome

To assess right-left differences in ultrasonographic markers of ovarian morphology and determine the impact on the diagnosis of polycystic ovarian morphology (PCOM). A cross-sectional study of data collected from 2006 to2018. Academic clinical research centers. Women with polycystic ovary syndrome (PCOS; n = 87) and controls (n = 67). None. Follicle number per ovary (FNPO), follicle number per cross-section (FNPS), and ovarian volume (OV) were assessed in both ovaries using transvaginal ultrasonography. PCOM was identified based on recent international consensus guidelines or proposed diagnostic thresholds. Overall, mean right-left differences were two follicles for FNPO, one follicle for FNPS, and 2mL for OV. FNPO showed the strongest correlation between ovaries. Its assessment in a single ovary did not impact the diagnosis of PCOM in women with PCOS. However, there were differences in the probability of unilateral versus bilateral PCOM based on FNPS and OV in both groups. FNPO is the most reliable unilateral marker of PCOM in light of right-left differences in ovarian morphology. Use of FNPS or OV to define PCOM is discouraged when only one ovary is visualized.

Endocrine and metabolic differences between Bos taurus and Bos indicus cows andimplications for reproductive management

Based on the considerable differences in ovarian morphology and function, as well as circulating hormones and metabolites between Bos indicus (B. indicus) and Bos taurus (B. taurus), researchers are using this acquired knowledge to optimize protocols for fixed-time artificial insemination (FTAI), and production of in vivo derived embryos by multiple ovulation or by in vitro embryo production (IVP). In B. indicus, at the time of follicle deviation, the dominant follicle is smaller and acquires ovulatory capacity at a smaller diameter than B. taurus. Moreover, despite ovulating smaller follicles and having smaller corpora lutea (CL), circulating concentrations of estradiol (E2) and progesterone (P4) are greater in B. indicus than B. taurus. These physiological differences may be related to greater circulating cholesterol, insulin and IGF1 in B. indicus than in B. taurus. For both genetic groups there is a negative relationship between circulating P4 and ovulatory response to the first GnRH treatment of a fixed-time AI (FTAI) protocol. Moreover, despite lower clearance rates of steroid hormones in B. indicus than B. taurus, the dose of 2 mg estradiol benzoate seems to be the most effective either for Nelore (B. indicus beef), Angus (B. taurus beef), or Holstein (B. taurus dairy) cows at the initiation of an E2/P4-based FTAI protocol to optimize synchronization and pregnancy per AI (P/AI). Several studies have shown that only one recommended dose of PGF2α at a FTAI protocol may be insufficient for adequate luteolysis in B. indicus and B. taurus. When submitted to multiple ovulation and embryo transfer, B. indicus cows and heifers need less FSH than B. taurus to achieve superovulation. Moreover, IVP has been more successful in B. indicus than B. taurus due to greater antral follicle count and anti-mullerian hormone, and better oocyte quality

Body weight-associated differences in ovarian morphology in captive common marmoset (Callithrix jacchus)

In captivity, Callithrix jacchus (common marmoset) is on average heavier than their wild-living counterparts, and has a tendency to produce triplet litters rather than the normal twins. To provide initial basic information about possible weight-related differences among the ovaries, a morphometric study of follicular phase ovaries from 48 young adult marmosets has been carried out. Nearly 90% of these ovaries were found to contain some degree of luteal tissue composed of large and/or small cells. The luteal structures, follicles of all stages, and stroma were subjected to morphometric analysis, and these results were compared with body weight, circulating triglyceride, androstenedione, and total estrogens. Where only large luteal cells were present, the median body weight was the highest (only this group included animals over 500g) compared with mixed, or only small luteal cells, or absence of luteal cells. Furthermore, in this group plasma triglycerides were significantly higher compared to other groups, suggesting possible role of triglycerides in promoting luteinisation. Plasma androstenedione was also a critical discriminating factor, and was elevated where large luteal cells were present even as a mixture with small cells suggesting the large luteal cells to be the likely major ovarian source of this hormone and its metabolites. Additionally, the ovaries with large luteal cells compared to those containing only small or no luteal cells, had lower primordial follicle reserve associated with high levels of atresia and luteinisation among growing non-ovulatory follicles, indicating an accelerated activation, but at the same time a suboptimal environment for follicular growth.

Strength in numbers: Large and permanent colonies have higher queen oviposition rates in the invasive Argentine ant (Linepithema humile, Mayr)

Polydomy associated with unicoloniality is a common trait of invasive species. In the invasive Argentine ant, colonies are seasonally polydomous. Most follow a seasonal fission–fussion pattern: they disperse in the spring and summer and aggregate in the fall and winter. However, a small proportion of colonies do not migrate; instead, they inhabit permanent nesting sites. These colonies are large and highly polydomous. The aim of this study was to (1) search for differences in the fecundity of queens between mother colonies (large and permanent) and satellite colonies (small and temporal), (2) determine if queens in mother and satellite colonies have different diets to clarify if colony size influences social organization and queen feeding, and (3) examine if colony location relative to the invasion front results in differences in the queen’s diet. Our results indicate that queens from mother nests are more fertile than queens from satellite nests and that colony location does not affect queen oviposition rate. Ovarian dissections suggest that differences in ovarian morphology are not responsible for the higher queen oviposition rate in mother vs. satellite nests, since there were no differences in the number and length of ovarioles in queens from the two types of colonies. In contrast, the higher δ15N values of queens from mother nests imply that greater carnivorous source intake accounts for the higher oviposition rates.

The pea aphid (Acyrthosiphon pisum) genome encodes two divergent early developmental programs

The pea aphid (Acyrthosiphon pisum) can reproduce either sexually or asexually (parthenogenetically), giving rise, in each case, to almost identical adults. These two modes of reproduction are accompanied by differences in ovarian morphology and the developmental environment of the offspring, with sexual forms producing eggs that are laid, whereas asexual development occurs within the mother. Here we examine the effect each mode of reproduction has on the expression of key maternal and axis patterning genes; orthodenticle (otd), hunchback (hb), caudal (cad) and nanos (nos). We show that three of these genes (Ap-hb, Ap-otd and Ap-cad) are expressed differently between the sexually and asexually produced oocytes and embryos of the pea aphid. We also show, using immunohistochemistry and cytoskeletal inhibitors, that Ap-hb RNA is localized differently between sexually and asexually produced oocytes, and that this is likely due to differences in the 3′ untranslated regions of the RNA. Furthermore, Ap-hb and Ap-otd have extensive expression domains in early sexually produced embryos, but are not expressed at equivalent stages in asexually produced embryos. These differences in expression likely correspond with substantial changes in the gene regulatory networks controlling early development in the pea aphid. These data imply that in the evolution of parthenogenesis a new program has evolved to control the development of asexually produced embryos, whilst retaining the existing, sexual, developmental program. The patterns of modification of these developmental processes mirror the changes that we see in developmental processes between species, in that early acting pathways in development are less constrained, and evolve faster, than later ones. We suggest that the evolution of the novel asexual development pathway in aphids is not a simple modification of an ancestral system, but the evolution of two very different developmental mechanisms occurring within a single species.

Ovarian maturation and oogenesis in the blue swimmer crab, Portunus pelagicus (Decapoda: Portunidae)

AbstractThe study was aimed at understanding the process of reproduction and the changes happening in the ovary of Portunus pelagicus during maturation, which would be useful for its broodstock development for hatchery purposes. For that, tissue samples from different regions of the ovary at various stages of maturation were subjected to light and electron microscopy, and based on the changes revealed and the differences in ovarian morphology, the ovary was divided into five stages such as immature (previtellogenic oocytes), early maturing (early vitellogenic oocytes), late maturing (late vitellogenic oocytes), mature (vitellogenic oocytes), and spent (resorbing oocytes). The ovarian wall comprised of an outermost thin pavement epithelium, a middle layer of connective tissue, and an innermost layer of germinal epithelium. The oocytes matured as they moved from the centrally placed germinal zone toward the ovarian wall. The peripheral arrangement of nucleolar materials and the high incidence of cell organelles during the initial stages indicated vitellogenesis I. Movement of follicle cells toward oocytes in the early maturing stage and low incidence of mitochondria and endoplasmic reticulum in the ooplasm during late vitellogenic stage marked the commencement and end of vitellogenesis II, respectively. Yolk granules at various stages of development were seen in the ooplasm from late vitellogenic stage onwards. The spent ovary had an area with resorbing oocytes and empty follicle cells denoting the end of one reproductive cycle and another area with oogonial cells and previtellogenic oocytes indicating the beginning of the next.

Females with Reduced Fertility Have Excess Androstenedione in Follicular Fluid, Altered Theca Gene Expression and Increased VEGFA164b, Maternal Effect, and microRNA Processing mRNA Levels in Cumulus-Oocyte Complexes.

Ovarian dysfunction contributes significantly to female infertility. However, the intrinsic and exogenous factors that result in abnormal ovarian function are poorly defined. Thus, we have established a cow model of fertility to identify mechanisms regulating follicular growth, steroidogenesis and oocyte growth and maturation. Culling age due to failure to establish pregnancy was used to classify animals with low (>/= 2 years-of-age), moderate (> 2 - < 6 years-of-age), and high (>/= 6 years-of-age) fertility. Previous experiments using this model identified class-dependent changes in mural granulosa cell gene expression. The objective of this study was to identify the effect of ovarian and follicular environment on the oocyte molecular phenotype. To attain this objective, females from each fertility group were synchronized using a modified Co-Sync (CIDR) protocol and ovariectomies were performed 36 h after PGF2-alpha injection and CIDR removal. Surface antral follicle counts (AFC) for each ovary pair and the follicular fluid, theca cells, mural granulosa cells and cumulus-oocyte complex (COC) from each dominant follicle were collected. Dominant follicles were confirmed based on size (i.e. largest follicle on the ovaries) and an estrogen- to-progesterone ratio greater than 1.0 in the follicular fluid. Antral follicle counts were lower in low fertility (n = 14) than moderate (n = 17) or high fertility (n = 17) cows. Furthermore, androstenedione (A4) concentrations were 4 fold (P < 0.002) greater in follicular fluid from low compared to high fertility group cows. Given that increased androgens is a hallmark characteristic of the PCOS phenotype, gene expression in theca cells from the different fertility groups was compared. The affect of increased intrafollicular androgen levels on cumulus-oocyte gene expression in the dominant follicle was also examined. Quantitative, real-time RT-PCR demonstrated that mRNA abundance of maternal effect genes NLRP5 (8-fold P < 0.0001), Zar1 (2-fold; P < 0.0001) and Dnmt1 (P < 0.006) and miRNA processing genes DGCR8 (P < 0.005) and RNAsen (P < 0.005) were increased in low compared to high fertility cows. Increased mRNA abundance in low fertility animals is consistent with previous findings in PCOS oocytes and suggests that abnormal endocrine profiles of follicular fluid has a global effect on transcriptional and post-transcriptional regulation of mRNAs in the oocyte. Previous studies identified differences in the expression profile of vascular endothelial growth factor A (VEGFA) isoforms in mural granulosa cells between low, moderate, and high fertility group cows. In the current study, VEGFA_164B mRNA abundance was also increased in cumulus granulosa cells of low fertility cows (P < 0.005). Taken together, these data indicate that females with low fertility have intrinsic differences in ovarian morphology and steroidogenesis. Furthermore, the data suggest that increased androgen production in low fertility animals alters gene expression and/or mRNA stability during oocyte growth and maturation. These changes in oocyte gene expression may reduce the developmental competence of the oocyte and contribute to the reduced pregnancy rates in low fertility cows. USDA is an equal opportunity employer. (poster)

271. Effect of season on sow ovarian morphology

Reduced farrowing rate caused by embryonic mortality is a manifestation of seasonal infertility in pigs. The ability of the oocyte to mature, be fertilised and sustain embryonic development is acquired gradually by the oocyte throughout folliculogenesis. This study was undertaken to determine if seasonal differences in ovarian morphology are associated with reduced reproductive performance displayed during seasonal infertility. Sows culled after weaning were sourced from two genetically distinct herds (Farms A and B). Pairs of ovaries were collected from sows 4 days post-weaning during winter (n = 131) and summer (n = 275). Ovarian weight (Farm A only) and the numbers of small (3–4 mm) and large (5–8 mm) follicles were assessed (Farms A and B). Data did not follow normality and was analysed using the Mann–Whitney test. Mean ovarian weight per sow during winter (20.0 ± 1.3 g) was significantly heavier than that during summer (15.3 ± 0.8 g; P &lt; 0.05). Farm A ovaries had a greater total number of antral follicles in winter compared with summer, and a greater number of antral follicles in winter compared with Farm B ovaries (P &lt; 0.05). In Farm A ovaries, the proportion of follicles that were large was greater in summer compared with winter (78% v. 66%; P &lt; 0.05), but the follicular distribution did not change with season in Farm B ovaries. While the findings demonstrate that ovarian weight was greater in winter compared with summer, they suggest that this difference was not the result of changes in the number or distribution of surface antral follicles. The difference in ovarian weight is possibly due to differences in ovarian tissue resulting from regressed corpora lutea. Further studies are being undertaken to assess the effect of season on oocyte developmental competence and the steroid content of follicular fluid isolated from small and large follicles.

Two coexisting lines of the endoparasitoid Venturia canescens show differences in reproductive success under conspecific superparasitism

In a laboratory colony of the endoparasitic wasp Venturia canescens Grav. (Hymenoptera: Ichneumonidae), two genetically distinct lines (RP, RM) appear to coexist sympatrically. The two lines display pronounced differences in ovarian morphology, parasitism behaviour and number of offspring produced under competing superparasitism. Since V. canescens is a solitary endoparasitoid, larvae inside superparasitised hosts must compete for host possession. We examined the outcome of conspecific superparasitism between the wasp lines with different time intervals between ovipositions. The results showed that the competitive abilities of the two lines were not symmetrical. Further, the RM-line won a significantly higher fraction (around 60%) of the overall contests. Dissection of parasitoid larvae from their hosts indicated that most contests between competing larvae had occurred within the first 24 h of the eggs hatching, suggesting the advantage of the RM-line relates to physical combat. It was previously thought that the coexistence of the two lines was exclusively due to maternal effects. The results of this study indicate for the first time that these differences are based on phenotypic variations in both the larval offspring and the mother.

Strategies of ovarian function of importance to gynecologic investigations.

The purpose of this article was to examine the similarities and differences in ovarian morphology and function that are known to exist among mammalian species. The previous difficulties and present solutions to the characterization of ovarian function in non-domestic or non-laboratory species are discussed. The current literature regarding comparative ovarian structure and function was reviewed to identify examples of the diversity found with mammals. Major differences in ovarian anatomy include location in the body cavity; the degree of membranous covering surrounding the ovary; vascularization of the ovary, oviduct, and uterus; and the organization of different cell types within the ovary. The differences in ovarian function are simplified in this review by categorizing the known examples into six groups according to patterns in follicle growth and development, mechanisms of ovulation, response of steroid target cells, and luteal function. Each mammalian species has a unique expression of its ovarian function. The differences between species range from quantitative differences in ovarian cycle phase length to qualitative differences in cell type, endocrine activity, and mechanism of ovulation. These differences present a special problem to research scientists when they attempt to select models for studying many aspects of female reproduction.