Sexual Maturity Status Research Articles

Trace element concentrations in common dolphins (Delphinus delphis) in the Celtic Seas ecoregion: Interelement relationships and effects of life history and health status

Given the increased extraction of trace elements for use by new and emerging technologies, monitoring the environmental fate and potential effects of these compounds within the aquatic environment has never been more critical. Here, hepatic trace element concentrations were assessed in a key sentinel predator, the common dolphin (Delphinus delphis), using a long-term dataset. Variation in concentrations were assessed in relation to other elements, time period, decomposition state, sex, age, total body length, sexual maturity and nutritional status, and cause of death. Additionally, mercury toxicity thresholds for evaluating risk were reviewed and employed. Concentrations of elements which bioaccumulate, THg, MeHg, Cd, and Pb, in addition to Se and V, were strongly correlated with age, and/or body length. An association was observed between Zn concentrations and disease status, with significantly higher concentrations measured in individuals that died from infectious disease, compared to other causes. Strong inter-elemental relationships were detected, namely between Hg and Se, MeHg and Se, Cd and Se, and Cu and Zn. While THg:Se molar ratio values were observed to increase with age and body length, approaching equimolarity. THg was largely comprised of inorganic Hg in older individuals, potentially bound to Se, therefore the effects from THg toxicity may possibly be less important than originally assumed. In contrast, higher MeHg:Hg ratio values were reported in juveniles, suggesting a poorer efficiency in demethylation and a higher sensitivity. The generation of data on proportions of hepatic MeHg and inorganic Hg is highly informative to both future toxicity threshold assessments within pollutant indicator assessments, and to understanding the ultimate fate of mercury in the marine web.

Macroscopic and histologic characteristics of sexual maturation in the Burmeister’s porpoise Phocoena spinipinnis from Peru

The morphology and maturation process of gonads of 70 Burmeister’s porpoises Phocoena spinipinnis, with body lengths ranging 135 - 183 cm (n = 34 females) and 64.5 - 182 cm (n = 36 males) are described. Samples were collected in six ports of central and northern Peru from 1987 to 1999. In the field, sexual maturity was determined through macroscopic examination of gonads. Ovarian corpora indicated mature females (resting, lactating, pregnant). Semen in epididymides was considered evidence for mature males. The ovaries of Burmeister’s porpoises are ovoid or bean-shaped and flattened, with corpora modifying surface appearance. In the laboratory, ovaries were examined macro- and microscopically, measured, weighed and sliced. The number of corpora ovarica (lutea, albicantia, atretica) and their morphology were documented. The follicles, oocytes, and nuclei were measured. Follicular development was predominantly left-sided, but occurred in both ovaries in 16.3% of females, mainly in those with numerous corpora. Macroscopically, several corpora atretica with luteinization had characteristics similar to those of corpora albicantia, making microscopic determination essential. Inconclusive evidence of recent ovulation was reported for January. Two of three immature females showed good follicular development in March and April. The testes of Burmeister’s porpoise are elongated and cylindrical. Of 36 males examined macroscopically, seven were immature, five pubescent and 24 mature. The histological analysis allowed to confidently determine sexual maturity status. Field evaluation of maturity based on the presence of sperm in the epididymides is a useful but in 8.3% of cases not an exact method. No histological evidence of male reproductive seasonality was found. Spermatogenesis was perceptible year-round and tubule diameters showed stochastic monthly variations. The body length at 50% sexual maturity was estimated at 157 cm and 152.7 cm, for males and females, respectively. There was no evidence of reproductive senescence. This study is the first evaluation of the sexual maturation process in the Burmeister’s porpoise, using both macroscopic observations and elaborate gonads histology. It provides important new information on the natural history of the species, including parameters (e.g., mean body length at maturation, reproductive seasonality) highly relevant to its conservation.

DNA fragmentation, antioxidant activity and histological structure of cryopreserved testicular tissue depending on sexual maturity and immunological status

The objective of this work was to determine a relationship between a frequency of DNA fragmentation, a level of antioxidant activity and a preservation of histological structure depending on initial status of fragments of seminiferous tubules of testes (FSTT) of rats at the stages of cryopreservation. FSTT of animals of different ages (immature, mature), as well as animals with changed immunological status (adjuvant arthritis) were cryopreserved. Slow uncontrolled freezing was used in a cryomedium of fibrin gel with 0.7 M glycerol. The results showed that viability, TAS, γGGT and G6PD activities had the highest values in the group of intact immature animals both in fresh FSTT and after exposure to cryomedium or cryopreservation, while the indexes of DNA fragmentation and ROS content had the lowest values. It was found that an increase in the DNA fragmentation rate occurred in parallel with a decrease in the values of antioxidant activity and membrane integrity. The spermatogenenic epithelium after cryopreservation differed between the groups in a relative number of cells with pathologically changed nuclei and the frequency of exfoliation of epithelial cells into the tubule cavity namely, there was a tendency to an increase in the damaging effects in the series, “Immature → Sexually mature → Autoimmune arthritis”. The obtained data can be taken into account in the development of low-temperature preservation protocols using cryotechnologies, which will ensure the maintenance of the morphological and functional characteristics of FSTT depending on sexual maturity and immunological status.

Multidimensional trace metals and nutritional niche differ between sexually immature and mature common dolphins (Delphinus delphis)

There is a need to understand the links between metals and nutrition for apex marine predators, which may be subject to different ecotoxicological effects at different life stages. We combined stomach content analyses (SCA), prey composition analysis (PCA), the Multidimensional Niche Framework (MNNF) with Bayesian multivariate ellipses, trace metal analysis and nicheROVER to investigate nutrition and trace metals across sex, age, and sexual maturity status in common dolphins (Delphinus delphis) from New Zealand. A broader prey composition niche breadth (SEAc) was estimated for immature compared to mature conspecifics, showing a higher degree of prey and nutrient generalism driven by protein (P) intake. Cd and Zn niche similarities suggests these metals were incorporated through similar prey in both immature and mature dolphins, whereas Hg and Se niche divergence indicates uptake occurred via different prey. Our multidisciplinary assessment demonstrated how nutrients and metal interactions differ in common dolphins depending upon sexual maturity. This approach has relevance when considering how marine pollution, environmental fluctuations and climate change may affect nutritional and trace metal interactions during different reproductive stages within marine predators.

Use of underwater contactless ultrasonography to elucidate the internal anatomy and reproductive activity of manta and devil rays (Fam. Mobulidae).

The ability to visualise the internal anatomical structures of fish provides important information on their reproductive status and body condition and has made important contributions to many areas of fish biology. Obtaining information about the internal anatomy of fish has traditionally required euthanasia and dissection. However, although ultrasonography is now increasingly used to study internal fish anatomy without the need for euthanasia, traditional techniques still require restraint and contact with the animal, both of which are known to cause stress. This has prompted the development of waterproof, contactless, and portable equipment to allow ultrasonographic examinations to be carried out in free-swimming individuals which also facilitates the application of this tool in wild populations of endangered species. This study reports the validation of this equipment using anatomical examinations of nine manta and devil ray (Mobulidae) specimens landed at fish markets in Sri Lanka. Species studied were Mobula kuhlii (n = 3), M. thurstoni (n = 1), M. mobular (n = 1), M. tarapacana (n = 1) and M. birostris (n = 3). The use of this equipment was further validated with ultrasonographic examinations in 55 free-swimming reef manta rays Mobula alfredi, which enabled maturity status to be quantified in 32 females. Structures successfully identified in free-swimming individuals were the liver, spleen, gallbladder, gastrointestinal tract, skeletal structures, developing follicles and uterus. The study demonstrated that ultrasonography provided a reliable method of determining both sexual maturity and gestational status in free-swimming M. alfredi. The methodology induced no detectable signs of disturbance to the animals involved and therefore offers a viable and practical alternative to invasive techniques currently used to study anatomical changes in both captive and wild marine organisms. This article is protected by copyright. All rights reserved.

Regulatory roles of Pawpaw (Carica papaya) seed extract on growth performance, sexual maturity, and health status with resistance against bacteria and parasites in Nile tilapia (Oreochromis niloticus)

Papaya (Carica papaya) is one of the plants that represent a major source of bioactive substances that are cheaper and non-toxic, such as antibiotics. It is globally used as a supplement diet for positive effects in pharmacological activities. In this regard, the current study sheds light on the possible roles of papaya seed methanolic extract (PSE) as a dietary supplement to improve growth performance, sexual maturity, carcass composition, immunity responses, histological structure of gonads, and anti-pathogenic activity (Aeromonas hydrophila) at the end of a feeding trial extend for ten days of Nile tilapia, with special reference to its potential effect as resistance against parasitic (Cichlidogyrus tilapiae). Four experimental groups with four replications of Nile tilapia fry (0.5 ± 0.1 g as 20 fish per replication) were fed (0, 0.5, 1.0, and 2.0 g/kg PSE in diets) for 20 weeks. Results showed that fish dietary supplementation with PSE had a significantly positive (P < 0.05) effect on growth performance, feed utilization, digestive enzyme, carcass composition, antioxidant, immunity responses, and hematological and biochemical indices, especially PSE 2.0 g/kg than control diet. Furthermore, PSE had a positively affected fish mortality after injection with A. hydrophila and in vitro positive efficacy against C. tilapiae. Fish fed with dietary PSE increased the sex ratio in favor of male fish by achieving a 77% male phenotype. Conclusively, this study declared that PSE extract, specifically 2 g/kg, could enhance growth and health through the modulation of innate immunity and a positive effect against disease in fish. Additionally, it reduced the reproductive performance of Nile tilapia by reducing GSI, which subsequently affected the gonadal histology leading to infertility.

281 The Relationship between Postnatal Hormone Concentrations and the Development of Boar Taint at Puberty

Abstract The development of boar taint is dependent on the balance between the rate of androstenone synthesis and metabolism, which regulates the quantity of androstenone available for accumulation in the fat. The pubertal production of androstenone and other sex steroids is influenced by sexual maturity status and preceded by a significant period of hormone production during postnatal development that occurs from 14 to 35 days of age (DOA). However, the relationship between postnatal and pubertal hormone production is not well understood. Therefore, the purpose of this study was to determine if postnatal hormone concentrations can be used to predict sexual maturity status and boar taint development at puberty. Crossbred [(Yorkshire x Landrace) x Duroc] boars (n=90)] were housed in groups of 10. Blood samples were taken at 14, 21, 28, and 35 DOA and again at 120, 130, and 140kg live weights (LWs) along with backfat samples. Plasma and fat androstenone concentrations were quantified using an androstenone-specific ELISA. Plasma estrone sulfate (E1S) concentrations were determined by RIA and used as an indicator of sexual maturity status. Statistical analysis was performed using Spearman correlation. Several nonlinear monotonic relationships were identified between postnatal and pubertal hormone concentrations and are presented in Table 1. A moderate positive correlation was identified between plasma androstenone concentrations at 21 and 28 DOA and fat androstenone concentrations at 120, 130, and 140kg LWs, and between E1S concentrations at 21 DOA and E1S concentrations at 120, 130, 140kg LWs. However, the strength of the relationship between postnatal and pubertal hormone concentrations was insufficient for accurately predicting sexual maturity status or boar taint at puberty. These results suggest that additional factors regulating the development of boar taint, such as the rate of metabolism or accumulation, should be considered in future efforts to develop a predictive model using postnatal hormone concentrations.

Age-, sex-, and maturity-associated variation in the phase angle after adjusting for size in adolescents.

BackgroundApplied research using the phase angle (PhA) in children and adolescents has increased notably. Using multilevel modeling in a fully Bayesian framework, we examined the relationships between PhA, age, sex, biological maturity status, and body size in 10–16-year-old adolescents.MethodsThe sample comprised 519 adolescents (women, n = 241; men, n = 278) from Campinas, São Paulo, Brazil. Biological maturity status was assessed with self-examination of pubertal development for sexual maturity and maturity offset protocol to estimate age at peak height velocity (PHV) for somatic maturity status. Stature and body mass were measured by anthropometry. Phase angle was calculated based on raw resistance and reactance values (50 kHz frequency) obtained by bioelectrical impedance with the foot-to-hand technology.ResultsThe multilevel regression analysis revealed that boys had significantly higher values of phase angle than girls, adjusting for age group and sexual maturity status. Overall, older and more mature adolescents had higher values of phase angle. When considering aligning variation in the phase angle by distance to estimated PHV (maturity offset), there was a higher association between the phase angle and time before and after predicted age at PHV for boys (r = 0.31, 90% CI: 0.23 to 0.39) than girls (r = 0.2, 90% CI: 0.11 to 0.28). When including body mass in the multilevel models, corresponding changes in the overall body mass mediate most of the influence of the maturity status and age group on the phase angle.ConclusionThe present study demonstrated that the variability in phase angle is related to inter-individual variation in sex, age, and maturity status, as well as differences in body size. Research with adolescents considering phase angle should use multilevel modeling with standardized parameters as default to adjust for the concurrent influence of sex, age, maturity status, and body size.

Associação entre sexo, maturação sexual, faixa etária, classe econômica e estado nutricional com os diferentes pontos de corte do tempo de tela em adolescentes

Abstract Objectives: to estimate the prevalence of adolescents’ screen time in three different scenarios and possible associations with gender, sexual maturation, age group, economic class, and nutritional status. Methods: a cross-sectional study conducted with a representative sample of 3,979 adolescents from Greater Curitiba. Screen time (television, computer, and video game) was self-reported and categorized as ≤2h/day, &gt;2 to ≤4h/day, and &gt;4h/day. Ordinal logistic regression tested the associations. Results: the sample consisted of adolescents of 14.60±1.88 years old, most girls (51.2%). The prevalence of screen time &gt;4h/day was 89.3%. Girls (OR=0.61; CI95%=0.49-0.76) and the older age groups (“14 to 16 years” OR=0.29; CI95%=0.22-0.39, and “17 to 19 years” OR=0.11; CI95%=0.08-0.16) were less likely to be in the groups of higher screen time. Conclusions: screen time above four hours seems to be the most prevalent among adolescents. Older girls and teens are less likely to have higher screen time.

Biological maturation influences selection process in youth elite soccer players

This study examined the influence of birth date, salivary testosterone [sT] concentration, sexual maturity status, and general strength on the selection process of an elite Brazilian soccer club during a 12-month period, which was a 2nd phase of a 24-month selection process. The stature, body mass, sT, sexual maturity status [Tanner scale], and hand grip strength were assessed for 143 players during 2 weeks. From these 143 players, 100 players were dismissed [DIS] and 43 players were selected to integrate the club’s under-14 squad. Following 1-year training period, the under-14 team was assembled with 9 players designated as starters [STA], and then, comparisons were conducted taking into account a group of non-starters (selected; SEL = 34 players) and STA (n = 09). The DIS, SEL, STA players, and reference population, were compared for birth distribution. A greater proportion of players was born in the first trimester in the STA [75.0%], SEL [57.1%] and DIS [50.0%] groups compared to the reference population [25.8%]. One-way ANOVA showed a higher sT for STA group [516.0 ± 129.9 pmol·L-1], compared to SEL [415.5 ± 117.9 pmol·L-1] and DIS groups [390.9 ± 84.9 pmol·L-1; p = 0.003), and Kruskall-Wallis test showed a higher gonadal development for STA compared to DIS [p = 0.001]. The current findings suggest a strong influence of birth date and biological maturation on young soccer players selection process. Soccer coaches should consider these influences when making decisions about player selection of elite youth players.

Scientific and Regulatory Policy Committee Best Practices: Documentation of Sexual Maturity by Microscopic Evaluation in Nonclinical Safety Studies.

The sexual maturity status of animals in nonclinical safety studies can have a significant impact on the microscopic assessment of the reproductive system, the interpretation of potential test article-related findings, and ultimately the assessment of potential risk to humans. However, the assessment and documentation of sexual maturity for animals in nonclinical safety studies is not conducted in a consistent manner across the pharmaceutical and chemical industries. The Scientific and Regulatory Policy Committee of the Society of Toxicologic Pathology convened an international working group of pathologists and nonclinical safety scientists with expertise in the reproductive system, pathology nomenclature, and Standard for Exchange of Nonclinical Data requirements. This article describes the best practices for documentation of the light microscopic assessment of sexual maturity in males and females for both rodent and nonrodent nonclinical safety studies. In addition, a review of the microscopic features of the immature, peripubertal, and mature male and female reproductive system and general considerations for study types and reporting are provided to aid the study pathologist tasked with documentation of sexual maturity.

Growth and Maturity Status of Female Soccer Players: A Narrative Review.

Reported mean ages, heights and weights of female soccer players aged <19 years in 161 studies spanning the years 1992–2020 were extracted from the literature or calculated from data available to the authors; 35 studies spanning the years 1981–2020 also included an indicator of biological maturation. Heights and weights were plotted relative to U.S. reference data. Preece–Baines Model 1 was fitted to moving averages to estimate ages at peak velocity. Maturity indicators included skeletal age, pubertal status, age at menarche, percentage of predicted adult height and predicted maturity offset. Heights and weights showed negligible secular variation across the time interval. Heights were slightly above or approximated the reference medians through 14 years old and then varied between the medians and 75th percentiles through 18 years old. Weights were above the reference medians from 9 to 18 years old. Mean ages at menarche ranged from 12.7 to 13.0 years. The trend in heights and weights suggested the persistence and/or selection of taller and heavier players during adolescence, while estimated age at peak height velocity (PHV) and ages at menarche were within the range of mean ages in European and North American samples. Data for skeletal and sexual maturity status were limited; predicted maturity offset increased linearly with mean ages and heights at prediction.

Associations of physical activity and sedentary time with lipoprotein subclasses in Norwegian schoolchildren: The Active Smarter Kids (ASK) study

Background and aimsPhysical activity is favourably associated with certain markers of lipid metabolism. The relationship of physical activity with lipoprotein particle profiles in children is not known. Here we examine cross-sectional associations between objectively measured physical activity and sedentary time with serum markers of lipoprotein metabolism. MethodsOur cohort included 880 children (49.0% girls, mean age 10.2 years). Physical activity intensity and time spent sedentary were measured objectively using accelerometers. 30 measures of lipoprotein metabolism were quantified using nuclear magnetic resonance spectroscopy. Multiple linear regression models adjusted for age, sex, sexual maturity and socioeconomic status were used to determine associations of physical activity and sedentary time with lipoprotein measures. Additional models were adjusted for adiposity. Isotemporal substitution models quantified theoretical associations of replacing 30 min of sedentary time with 30 min of moderate- to vigorous-intensity physical activity (MVPA). ResultsTime spent in MVPA was associated with a favourable lipoprotein profile independent of sedentary time. There were inverse associations with a number of lipoprotein measures, including most apolipoprotein B-containing lipoprotein subclasses and triglyceride measures, the ratio of total to high-density lipoprotein (HDL) cholesterol, and non-HDL cholesterol concentration. There were positive associations with larger HDL subclasses, HDL cholesterol concentration and particle size. Reallocating 30 min of sedentary time to MVPA had broadly similar associations. Sedentary time was only partly and weakly associated with an unfavourable lipoprotein profile. ConclusionsPhysical activity of at least moderate-intensity is associated with a favourable lipoprotein profile in schoolchildren, independent of time spent sedentary, adiposity and other confounders.

Sexual maturation in male long-finned pilot whales (Globicephala melas edwardii): defining indicators of sexual maturity

AbstractMale reproductive biology is described for the Southern Hemisphere long-finned pilot whale (Globicephala melas edwardii), a subspecies that regularly mass strands along the New Zealand coastline. Ten mass stranding events sampled over a 7-year period enabled assessments of key life history parameters. Sexual maturation in immature, maturing, and mature males was assessed using morphological data and histological examination of testicular tissue. Variation was observed in the age (11–15 years) and length (450–490 cm) at which individuals attained sexual maturity. Using Bayesian cumulative logit regression models, we estimated the average age and length at the attainment of sexual maturity to be 13.5 years and 472 cm, respectively. Combined testes weight, combined testes length, an index of testicular development (combined testes weight/combined testes length), and mean seminiferous tubule diameter were all good indicators of sexual maturity status. Combined testes length was the best nonhistological indicator, and all testicular measures were found to be better indicators of sexual maturation for G. m. edwardii than age or total body length. Sexual maturity was attained before physical maturity (&gt; 40 years and 570 cm), and at a younger age and smaller body length than previously reported for Globicephala melas melas in the North Atlantic. Given the ease of collection, minimal processing, and applicability to suboptimal material collected from stranding events, future studies should assess the value of testicular size as an indicator of sexual maturity in pilot whales and other cetacean species. Estimates of the average age and length at sexual maturity for G. m. edwardii provided in this study may be used to inform population models required for conservation management of the subspecies, which is subject to high levels of stranding-related mortality.

Anal scent gland secretions inform on sexual maturity, sex and social status in the Alpine marmot, Marmota marmota (Rodentia: Sciuridae): a role in intrasexual competition in cooperative breeders?

Anal scent gland secretions inform on sexual maturity, sex and social status in the Alpine marmot, Marmota marmota (Rodentia: Sciuridae): a role in intrasexual competition in cooperative breeders?

Soy protein supplement intake for 12 months has no effect on sexual maturation and may improve nutritional status in pre‐pubertal children

To evaluate the intake of a soy protein-based supplement (SPS) and its effects on the sexual maturation and nutritional status of prepubertal children who consumed it for a year. Healthy children (n = 51) were recruited and randomly assigned to consume the lunch fruit juice with (n = 29) or without (n = 22) addition of 45 g of a commercial soy protein-based supplement (SPS) over 12 months. Nutritional assessment including anthropometry (bodyweight, height, triceps skinfold thickness, mid-upper arm circumference), body mass index (BMI), upper arm muscle area, arm muscle circumference, upper arm area, upper arm fat area data were derived from measures using usual procedures; age and gender-specific percentiles were used as reference. Sexual maturation was measured by Tanner stage. Isoflavones were quantified using liquid chromatography and tandem mass spectrometry. Height, BMI/age, weight/age and height/age were significantly different (P < 0.05) at 12 months between girls in the control and intervention groups. Statistically significant differences between groups by gender (P < 0.05) were found in boys in the control group for the triceps skinfold thickness and fat area. Nutritional status was adequate according to the World Health Organization parameters. On average, 0.130 mg/kg body weight/day of isoflavones were consumed by children, which did not show significant differences in their sexual maturation. Consumption of SPS for 12 months did not affect sexual maturation or the onset of puberty in prepubertal boys and girls; however, it may have induced an increase in height, BMI/age, height/age and weight/age of the girls, associated with variations in fat-free mass.

Characterization of circulating steroid hormone profiles in the bottlenose dolphin (Tursiops truncatus) by liquid chromatography–tandem mass spectrometry (LC–MS/MS)

Systemic steroid hormone measurements are often used in the assessment of reproductive, developmental, and stress physiology in vertebrates. In protected wildlife, such as the common bottlenose dolphin (Tursiops truncatus), these measures can provide critical information about health and fitness to aid in effective conservation and management. Circulating steroid hormone concentrations are typically measured by immunoassays, which have imperfect specificity and are limited to the measurement of a single hormone per assay. Here we demonstrate that reverse phase solid phase extraction (SPE) coupled to liquid chromatography tandem mass spectrometry (LC–MS/MS) allows for the simultaneous, precise (<15% relative standard deviation), and accurate (between 70% and 120% recovery of spiked quantities) measurement of at least seven steroid hormones in dolphin plasma. These seven steroid hormones include three hormones that have been measured previously in bottlenose dolphin blood (progesterone, testosterone, and cortisol) and three hormones which have never been quantified in dolphin blood (17-hydroxyprogesterone, androstenedione, cortisone, and corticosterone). While 17β-estradiol was not detected endogenously, we were able to accurately and precisely measure spiked quantities estradiol. Measures from plasma were more precise (i.e., lower RSD) than serum, and thus we recommend plasma as the preferred matrix for this analytical method. In order to facilitate comparison of current and future plasma-based studies to previous serum-based studies, we characterized the relationships between hormone measurements in matched plasma and serum, and found that measurements across matrices are significantly and positively correlated. Lastly, to demonstrate potential applications of this method, we examined how steroid hormone profiles vary by pregnancy, sexual maturity, and stress status – pregnancy was associated with elevated progesterone, adult males had higher testosterone, and capture stress was associated with elevated corticosteroids. Overall, we conclude that this method will enable investigators to more thoroughly and efficiently evaluate steroid hormone homeostasis in bottlenose dolphins compared to immunoassay methods. These methods can potentially be applied to the assessment of sexual maturity/seasonality, pregnancy status, and stress in free-ranging bottlenose dolphins as well as those maintained under human care, and potentially other marine mammals.

5 Live Offspring Produced from Reproductive Material Recovered During the Annual Cull of Bison from Yellowstone National Park

Bison from Yellowstone National Park (YNP) have a unique genetic history that makes them a conservation priority for the species. Unfortunately, there is a high prevalence of the zoonotic disease brucellosis in the herd. Part of the management strategy for controlling the disease and herd size in YNP is an annual culling process. This culling may result in loss of valuable genetic material and, until now, has been a missed opportunity to recover and preserve those genetics. The goal of this project was to demonstrate the feasibility of producing healthy offspring from reproductive material collected during the nonbreeding season from bison postmortem and to determine effects of donor parameters, including sexual maturity and pregnancy status on IVF outcomes. Oocytes were collected from ovaries harvested from bison within 2 h of slaughter during winters of 2014 to 2017 for use in in vitro embryo production (IVP). Frozen-thawed semen from 7 YNP bulls collected via electroejaculation in vivo or from epididymal flushes postmortem was used for IVF. Embryos were produced using standard cattle IVP procedures. On Days 7, 7.5, and 8 of in vitro culture, embryos were assessed for developmental stage and quality, and Grade 1 and 2 embryos were vitrified on Cryotops® (Kitazato, Tokyo, Japan) in a two-step equilibration process. Embryos were then stored until the breeding season when they were warmed, cultured for 6 h, evaluated for survival, and transferred to healthy bison recipients. Data were analysed using a Student’s t-test. Age did not affect the mean number of oocytes collected from a mature female (n = 254) v. juvenile (n = 27; 24 ± 16 v. 24 ± 13), embryo cleavage rates (54 ± 24% v. 45 ± 24%), or the rate of blastocyst development (8 ± 12% v. 7 ± 8%, respectively). Pregnancy status did have a significant effect on the number of oocytes collected per female (pregnant 22 ± 15%, n = 258; nonpregnant 26 ± 20%, n = 82; P = 0.04) and the percent of oocytes that cleaved (pregnant 56 ± 23%, n = 189; nonpregnant 47 ± 24, n = 61; P = 0.005). No difference was detected in the percent of embryos that reached the blastocyst stage of development (pregnant 8 ± 10%, nonpregnant 8 ± 15%). In August 2016, 12 embryos were transferred singly or in pairs to 10 recipient bison synchronized using a standard synch protocol. Ten days following removal of the CIDR, embryos were transferred to recipient bison with a palpable corpus luteum. In spring of 2017, a healthy female calf was born to a recipient who had received 2 Grade-2 blastocysts as graded at the end of the 6-h incubation period. The genetic dam of the calf was a pregnant adult bison cow. This calf demonstrates that live offspring can be generated from oocytes collected from bison postmortem in the nonbreeding season. Although cleavage rates were higher with oocytes from pregnant bison, viable embryos were generated from nonpregnant adults and juvenile females, warranting continued collection of their oocytes and banking of resulting embryos. To our knowledge, this is the first bison calf produced by in vitro production using postmortem reproductive material.

Testicular Fibrous Hypoplasia in Cynomolgus Monkeys ( Macaca fascicularis): An Incidental, Congenital Lesion.

Testicular fibrous hypoplasia is an incidental lesion characterized by replacement of the testicular parenchyma by mature collagen. A retrospective survey of hematoxylin and eosin-stained testicular sections from 722 purpose-bred Asian and 90 Mauritian cynomolgus monkeys from 56 safety assessment studies conducted between 1999 and 2011 was performed. The incidence of the lesion increased markedly over time. No cases occurred between 1999 and 2004. Between 2005 and 2009, the incidence ranged between 8.1% and 11.0% of the monkeys examined and then rose to 26.1% in 2010 and 30.9% in 2011. Overall, the lesion was identified in 10.94% of Asian monkeys with the highest incidence in animals originating from China and Vietnam; severity ranged from minimal to severe and it occurred unilaterally (38.5%) and bilaterally (61.5%). In Mauritian monkeys, the lesion was predominantly minimal in severity, bilateral in distribution, and affected 6.6% of the animals examined. The lesion occurred regardless of sexual maturation status but when present in mature monkeys was often associated with cystic tubular atrophy of the seminiferous epithelium. Based on the morphological characteristics of the lesion and the unilateral/bilateral distribution, the lesion is considered to be a congenital or developmental abnormality.

How do sex and sexual maturation influence the response of Monochamus galloprovincialis to host odours?

Finding the right host plant for feeding and reproduction is crucial for herbivorous insects. Usually they need both visual and olfactory cues to locate and colonize their host plants, but the respective role of the two types of stimuli is difficult to disentangle. Model plants mimicking the shape and colour of natural hosts, combined with odours dispensers, are relevant tools for this purpose. We used dummy pines and cut branches of natural pines to investigate host attraction in Monochamus galloprovincialis, the insect vector of the pine wood nematode in Europe. We compared the behavioural response of males and females, sexually mature or immature, in a large climatic chamber and in an olfactometer. Immature females were significantly attracted by the sole odours released by pines. Immature males and mature males and females needed a combination of visual and olfactory cues to find the host tree. These findings suggest that beetles use both visual and chemical cues to locate pine trees but that relevant stimuli likely differ between beetles of different sex and sexual maturation status. Our results question the implementation of precautionary clear‐cuts around infested trees for limiting the spread of PWN.