The influence of reproductive stage on cerebellar network connectivity across adulthood

Sex-specific differences in the aging cerebellum may be related to hormone changes with menopause. We evaluated the influence of reproductive stage on lobular cerebellar network connectivity using data from the Cambridge Centre for Ageing and Neuroscience repository. We used raw structural and resting state neuroimaging data and information regarding age, sex, and menopause-related variables. Crus I and II and Lobules V and VI were our cerebellar seeds of interest. We characterized reproductive stage using the Stages of Reproductive Aging Workshop criteria. Results show that postmenopausal females have lower cerebello-striatal and cerebello-cortical connectivity, particularly in frontal regions, along with lower connectivity within the cerebellum, compared to reproductive females. Postmenopausal females also exhibit greater connectivity in some brain areas as well. Differences begin to emerge across transitional stages of menopause. Further, results reveal sex-specific differences in connectivity between female reproductive groups and age-matched male control groups. This suggests that menopause may influence cerebellar network connectivity in aging females, and sex differences in the aging brain may be related to this biological process.

Examination of the Trexler-DeAngelis Model of Maternal Provisioning Reveals That Matrotrophy Is Costly

The evolution of matrotrophy (post-fertilization maternal provisioning to developing embryos) has been explained through several hypotheses. Trexler and DeAngelis proposed in 2003 a theoretical model that defines the ecological conditions under which matrotrophy would be favored over lecithotrophy (pre-fertilization maternal provisioning). According to this model, matrotrophy offers a selective advantage in environments with abundant and constantly available food, whereas environments with limited and fluctuating food resources should instead promote a lecithotrophic mode of maternal provisioning. This model also proposes that matrotrophy entails the consequence of leaner reproductive females and in turn shorter lifespans. In this study, we examined the Trexler-DeAngelis model using data from 45 populations of five viviparous species from the fish genus Poeciliopsis (family Poeciliidae). We used the matrotrophy index (MI) as a measure of post-fertilization maternal provisioning, and the index of stomach fullness and individual body condition (BC) as proxies for food availability. We also estimated the magnitude of fluctuations in food availability by calculating the temporal variances of these two proxies. Neither abundant nor constantly available food were associated with greater degrees of matrotrophy, which fails to support the predictions of the Trexler-DeAngelis model with respect to the ecological drivers of increased post-fertilization provisioning to embryos. Nonetheless, in all five species we observed that females with greater degrees of matrotrophy had poorer BC compared to females that provided less nutrients to embryos after fertilization. This finding is consistent with one of the expected consequences of advanced matrotrophy according to the Trexler-DeAngelis model, namely, a detriment to the nutritional status of females. Our study provides compelling evidence that gestating females experience a trade-off between post-fertilization provisioning to embryos and self-maintenance, revealing in turn that matrotrophy is a costly reproductive strategy.

Characterization and Gene Expression of Vitellogenesis-Related Transcripts in the Hepatopancreas and Ovary of the Red Swamp Crayfish, Procambarus clarkii (Girard, 1852), during Reproductive Cycle

The major component of the animal egg yolk is the lipoglycoprotein vitellin, derived from its precursor vitellogenin (VTG), which is produced species-specifically in decapod crustaceans in the hepatopancreas and/or in the ovary of reproductive females. Previous studies on Procambarus clarkii vitellogenesis report the existence of two single VTGs. Here, from a multiple tissue transcriptome including ovaries and hepatopancreas of P. clarkii, we characterized four different VTG and two VTG-like transcriptomes encoding for the discoidal lipoprotein-high density lipoprotein/β-glucan binding protein (dLp/HDL-BGBP). The relative expression of the various genes was evaluated by quantitative Real-Time PCR in both the ovary and hepatopancreas of females at different reproductive stages (from immature until fully mature oocytes). These studies revealed tissue-specificity and a reproductive stage related expression for the VTGs and a constitutive expression in the hepatopancreas of dLp/HDL-BGBP independent from the reproductive stage. This study may lead to more detailed study of the vitellogenins, their transcription regulation, and to the determination of broader patterns of expression present in the female hepatopancreas and ovary during the vitellogenesis. These findings provide a starting point useful for two different practical aims. The first is related to studies on P. clarkii reproduction, since this species is highly appreciated on the market worldwide. The second is related to the study of new potential interference in P. clarkii reproduction to delay or inhibit the worldwide spread of this aggressively invasive species.

Tubectomy of Pregnant and Non-pregnant Female Balinese Macaques (Macaca Fascicularis) With Post-operative Monitoring

Worldwide, primates, and humans increasingly share habitats and often enter in conflict when primates thrive in human-dominated environments, calling for special management measures. Reproductive control is increasingly used to manage population growth but very few monitoring data are available. Therefore, the efficiency and implications of such programs require a careful examination. In the context of a contraception program in wild female long-tailed macaques in Ubud, Bali, conducted over four successive campaigns between 2017 and 2019, including 140 females (i.e., 41.9% of the reproductive females of the population in 2019), modifications of an endoscopic tubectomy procedure, a permanent sterilization method, clinical evaluation of this method, and the post-operative monitoring results of the neutered females after release are described. This surgical approach was applicable for pregnant females: 28.6% of the treated females were pregnant at the time of the surgery. The procedure used a single lateral port to reach and cauterize both oviducts in non-pregnant as well as in early to mid-term pregnant females. Pregnant females nearer to term required a second lateral port to access both oviducts masked by the size of the gravid uterus. Moreover, bipolar thermocauterization was utilized successfully without resection to realize the tubectomy. The average duration of the laparoscopic surgery was 14 min for non-pregnant females and 22 min for pregnant females. Animals were released 3 h 22 min in average following their capture. This short holding time, recommended for free-ranging primates, was made possible by the minimal invasiveness of the sterilization approach. A laparoscopic post-operative evaluation conducted on two patients during the following campaign confirmed that the oviducts were definitely disrupted and no longer patent. Moreover, no new pregnancies in sterilized females were recorded during the 3-year observation period. The survival rate of the treated females 6 months after sterilization was high (96.3%) with no major post-operative complications clinically recorded. Among females that were pregnant during surgery, 81.1% were confirmed to experience term delivery. This study demonstrates the safety and efficiency of endoscopic tubectomy, even for pregnant females, as a mean of wild macaques' population control.

Effect of sex, age, and reproductive status on daily activity levels and activity patterns in jaguars (Panthera onca)

All animals, including carnivores, adapt their daily activity duration and distribution to satisfy food demands, breed, or avoid mortality risk. We used the kernel density method to estimate daily movement activity levels and movement activity patterns of jaguars in Hato Piñero, in Venezuelan Western Llanos, based on 3,656 jaguar detection time records from two and a half years of camera trapping. Jaguars were active for 11.7 h per day on average and exhibited mostly nocturnal and crepuscular activity pattern, however, with marked differences between sex/age/reproductive groups. Reproductive females had the highest daily activity level (13.2 h/day), followed by adult males (10.9 h/day), non-reproductive females (10.5 h/day), and cubs (8.7 h/day). Activity patterns also differed, with males and reproductive females having activity peaks at the same hours after sunset and before sunrise, cubs in the night and after sunrise, while non-reproductive females were most active during night hours. This study was the first to document the effect of sex, age, and reproductive status on daily level and activity pattern in the jaguar.

Structure of small rodent communities in orchards from the central part of the Republic of Moldova and Bacau district, Romania

The studies were performed in the period 2008-2015 in orchards from the central part of the Republic of Moldova and Bacău County, Romania. In both areas 12 species rodent were registered, of which in central Moldova orchards the species R. norvegicus and P. subterraneus were not registered, while in Bacau orchards the species A. uralensis, M. rossiaemeridionalis and D. nitedula weren’t recorded. In CM orchards the dominant species was M. rossiaemeridionalis with about 30%, followed by A. sylvaticus and A. flavicollis. In BC orchards the dominant species was A. flavicollis with more that 41%, followed by A. sylvaticus and M. arvalis.The analysis of demographic structure in spring period showed a high proportion of reproductive females in all species, being the highest at M. rossiaemeridionalis in CM orchard and in A. flavicollis in BC orchard. The share of young individuals constituted up to 40% depending on the species being the highest at M. rossiaemeridionalis in CM orchard and in A. flavicollis in BC orchard. A significant difference in the area of the individual sectors of M.rossiaemeridionalis males and females in the orchard in summer (t = 3.46) and autumn (t = 3.39) was established, as well as for A. sylvaticus in the spring and summer period (t = 2.06; 2.03), and for A.uralensis in spring and autumn (t = 2.99; 3.44).

Does density-induced stress promote density-dependent reproduction in root voles? Two field experiments

Density dependence in reproduction plays an important role in stabilising population dynamics via immediate negative feedback from population density to reproductive output. Although previous studies have shown that density dependence is associated with strong spacing behaviour and social interaction between individuals, the proximal mechanism for generating density-dependent reproduction remains unclear. In this study, we investigated the effects of density-induced stress on reproduction in root voles. Founder population enclosures were established by introducing six (low density) and 30 (high density) adults per sex into per enclosure (four enclosures per density in total) during the breeding season from April to July 2012 and from May to August 2015. Faecal corticosterone metabolite (FCM) levels, reproductive traits (recruitment and the proportion of reproductive condition), and founder population numbers were measured following repeated live-trapping in both years. The number of founders was negatively associated with recruitment rates and the proportion of reproductive conditions, displaying a density-dependent reproduction. FCM level was positively associated with the number of founders. The number of founder females indirectly affected the proportion of reproductive females in 2012 and recruitment in 2015 through their FCM levels; the effect of the number of male founders on the proportion of reproductive condition was mediated by their FCM level in 2012, but the effect was not found in 2015. Our results showed that density-induced stress affected density-dependent reproduction and that density-induced stress is one ecological factor generating density-dependent reproduction.

Determining the Effect of Age on the Reproductive and Stress Physiology of Octopus Bimaculoides Using Dermal Hormones

Our goal was to validate the use of dermal swabs to evaluate both reproductive and stress physiology in the California two-spot octopus, Octopus bimaculoides. Our objectives were to: 1. use a biological stressor to validate glucocorticoid analysis; 2. compare the concentration of reproductive hormones (estrogen and progesterone in females; testosterone in males) of reproductive (N = 4) and senescent (N = 8) individuals to determine the effect of age on hormonal patterns; and 3. determine the relationship between glucocorticoid and reproductive hormone production. For the stress test, individuals were first swabbed and then chased around the aquarium with a net for five minutes. Afterwards, individuals were swabbed for 2 hours at 15-minute intervals to compare to a pre-stress test swab. Reproductive individuals responded to the stressor with a 2-fold peak of cortisol at 15 and 90 minutes. Six of eight senescent individuals did not produce a 2-fold increase in cortisol. Reproductive females had significantly higher sex hormone concentrations (progesterone, estrogen, and testosterone) compared to senescent females. Reproductive males also had significantly higher levels of testosterone compared to their senescent counterparts. After the stressor, only reproductive males produced a 2-fold increase in testosterone concentrations, while sex hormones in females showed no change. Dermal swabs provide an effective and non-invasive means for evaluating octopus hormones, which can provide indicators of both reproductive state and perceptions of acute stressors.

Multiple reproductive females in family groups of smooth-coated otters

Smooth-coated otters (Lutrogale perspicillata) are inhabitants of the waterways of India and Singapore. Otter families typically consist of a single mating pair with mature, nonbreeding siblings living in family groups, or "romps". We note here the presence of multiple reproductive female otters within some romps, as well as the possible existence of simultaneous litters by different mothers. This phenomenon has not been recorded among L. perspicillata before. Here we address possible influences leading to multiple reproductive females within romps of smooth-coated otters, including inclusive fitness, incomplete suppression of reproduction, and existing in an urban environment. The numerous, recurring observations of multiple reproductive females warrant further investigation; while uncommon, this phenomenon is not as rare as once thought.