Female Mammals Research Articles

Examination of Microbial Contamination of Fresh Cow Milk in the Limau Manis Area, Tanjung Morawa, Deli Serdang

Background: Milk serves as a crucial source of human nutrition, particularly for infants who rely on it before they can digest solid foods. The mammary glands of female mammals produce it and is typically characterized by its pure white appearance. Objective: This study aimed to assess the levels of mesophilic aerobic bacteria and yeast mould present in fresh cow's milk obtained from farms in Limau Manis Tanjung Morawa. Methods: The investigation into contamination levels employed the Total Plate Count (TPC) method for aerobic bacteria and the Yeast Mold Count (YMC) method, both of which are based on the guidelines outlined in the Indonesian National Standard (SNI) No. 3141.1 of 2011. Results: Findings revealed that the levels of aerobic mesophilic bacteria, as determined by the TPC method, met the stipulated requirements of SNI No. 3141.1 of 2011 across all five farms surveyed. However, the research utilizing the YMC method indicated that the yeast mould counts in the milk from all five farms did not meet the established criteria. Conclusion: The analysis of microbial contamination using the TPC and YMC methods demonstrated compliance and non-compliance, respectively, with the standards outlined in SNI No. 3141.1 of 2011.

Mary Frances Lyon. 15 May 1925 — 25 December 2014

Mary Lyon was a central figure in twentieth-century mouse genetics. She is best known for the phenomenon that bears her name, ‘Lyonization’ or X chromosome inactivation, the process whereby one of the two X chromosomes in female mammals becomes heterochromatic and genetically inert, resulting in dosage compensation for X-linked genes between XX females and XY males. Her work on the t -complex, developing the concept of responder and distorter loci in the mouse, led to fundamental insights into non-Mendelian inheritance in mammals and exemplifies her exceptionally clear thinking. Her broader work in mouse genetics helped to lay the foundations for the widespread use of the mouse as an essential model organism in molecular medicine, cell and developmental biology and deciphering the function of the human genome.

Expression and localization of apelin and apelin receptor protein in the oviduct of letrozole-induced hyperandrogenized mice.

Apelin and its receptor (APJ) are expressed in the reproductive organs of some mammalian females. The function of oviduct has also been suggested to be compromised in the hyperandrogenism condition. However, expression of apelin and APJ has not been shown in the oviduct of hyperandrogenized mice. Thus, the present study has investigated the localization and expression of apelin and APJ in the letrozole-induced hyperandrogenized mice oviduct. Histomorphometric analysis showed decreased lumen of oviduct in the hyperandrogenized mice. Our results showed elevated expression of APJ and decreased abundance of apelin in the hyperandrogenized mice oviduct. This finding suggests impaired apelin signaling in the oviduct of hyperandrogenized mice. The expression of androgen receptor was upregulated while estrogen receptors were downregulated in the hyperandrogenized mice. The expression of HSP70 was also downregulated along with increased expression of active caspase 3 and BAX and decreased expression of BCL2 in hyperandrogenized mice. Furthermore, the phosphorylation of phospho-Ser473-Akt and phospho-Thr308-Akt also showed differential levels in the oviduct of hyperandrogenized mice. Whether this differential phosphorylation of Akt was solely due to impaired apelin signaling in the oviduct, remains unclear. Moreover, increased androgen signaling and suppressed estrogen signaling coincides with elevated apoptosis. In conclusion, hyperandrogenized conditions could also impair the gamete transport and fertilization process due to apoptosis in the oviduct. However, further study would be required to unravel the exact role of apelin signaling in the oviduct in relation to apoptosis.

Identification of skewed X chromosome inactivation using exome and transcriptome sequencing in patients with suspected rare genetic disease.

X-chromosome inactivation (XCI) is an epigenetic process that occurs during early development in mammalian females by randomly silencing one of two copies of the X chromosome in each cell. The preferential inactivation of either the maternal or paternal copy of the X chromosome in a majority of cells results in a skewed or non-random pattern of X inactivation and is observed in over 25% of adult females. Identifying skewed X inactivation is of clinical significance in patients with suspected rare genetic diseases due to the possibility of biased expression of disease-causing genes present on the active X chromosome. The current clinical test for the detection of skewed XCI relies on the methylation status of the methylation-sensitive restriction enzyme (Hpall) binding site present in proximity of short tandem polymorphic repeats on the androgen receptor (AR) gene. This approach using one locus results in uninformative or inconclusive data for 10-20% of tests. Further, recent studies have shown inconsistency between methylation of the AR locus and the state of inactivation of the X chromosome. Herein, we develop a method for estimating X inactivation status, using exome and transcriptome sequencing data derived from blood in 227 female samples. We built a reference model for evaluation of XCI in 135 females from the GTEx consortium. We tested and validated the model on 11 female individuals with different types of undiagnosed rare genetic disorders who were clinically tested for X-skew using the AR gene assay and compared results to our outlier-based analysis technique. In comparison to the AR clinical test for identification of X inactivation, our method was concordant with the AR method in 9 samples, discordant in 1, and provided a measure of X inactivation in 1 sample with uninformative clinical results. We applied this method on an additional 81 females presenting to the clinic with phenotypes consistent with different hereditary disorders without a known genetic diagnosis. This study presents the use of transcriptome and exome sequencing data to provide an accurate and complete estimation of X-inactivation and skew status in a cohort of female patients with different types of suspected rare genetic disease.

Characterization and Comparative Analysis of Whole-Transcriptome Sequencing in High- and Low-Fecundity Chongming White Goat Ovaries during the Estrus Phase.

Reproductive performance is one of the most important economic traits in the goat industry. Increasing the number of goats is an effective measure to improve production efficiency and reduce production costs. Ovaries are important reproductive organs in female mammals that directly affect the estrous cycle and reproductive abilities. Understanding the complex transcription network of non-coding RNAs (lncRNAs, circRNAs, and miRNAs) and messenger RNA (mRNA) could lead to significant insights into the ovarian regulation of the reproductive processes of animals. However, the whole-transcriptome analysis of the non-coding RNAs and mRNA of the ovaries in Chongming white goats between high-fecundity (HP) and low-fecundity (LP) groups is limited. In this study, a whole-transcriptome sequencing approach was used to identify lncRNA, circRNA, miRNA, and mRNA expression in the ovaries of Chongming white goats during the estrus phase using RNA-Seq technology. More than 20,000 messenger RNAs (mRNAs), 10,000 long non-coding RNAs (lncRNAs), 3500 circular RNAs (circRNAs), and 1000 micro RNAs (miRNAs) were identified. A total of 1024 differential transcripts (724 mRNAs, 112 lncRNAs, 178 circRNAs, and 10 miRNAs) existing between the HP and the LP groups were revealed through a bioinformatics analysis. They were enriched in the prolactin signaling pathway, the Jak-STAT signaling pathway, and the GnRH signaling pathway, as well as various metabolic pathways. Differentially expressed mRNAs (such as LYPD6, VEGFA, NOS3, TNXB, and EPHA2) and miRNAs (such as miR-10a-5p) play key roles in the regulation of goat ovaries during the estrus phase. The enrichment of pathways related to reproduction, such as the Hippo, Hedgehog, PI3K-AKT, and MAPK signaling pathways, suggests that they might be involved in the prolificacy of goat ovaries. Overall, we identified several gene modules associated with goat fecundity and provided a basis for a molecular mechanism in the ovaries of Chongming white goats.

Developmental programming of the ovarian reserve in livestock

Mammalian females are born with a finite number of follicles in their ovaries that is referred to as the ovarian reserve. There is a large amount of variation between females in the number of antral follicles that they are born with, but this number is positively correlated to size of the ovarian reserve, has a strong repeatability within a female, and a moderate heritability. Although the heritability is moderate, numerous external factors including health, nutrition, ambient temperature, and litter size influence the size and function of the ovarian reserve throughout life. Depletion of the ovarian reserve contributes to reproductive senescence, and genetic and epigenetic factors can lead to a more rapid decline in follicle numbers in some females than others. The relationship of the size of the ovarian reserve to development of the reproductive tract and fertility is generally positive, although some studies report antagonistic associations of these traits. It seems likely that management decisions and environmental factors that result in epigenetic modifications to the genome throughout life may cause variability in the function of ovarian genes that influence fecundity and fertility, leading to differences in reproductive longevity among females born with ovarian reserves of similar size. This review summarizes our current understanding of factors influencing size of the ovarian reserve in cattle, sheep, and pigs and the relationship of the ovarian reserve to reproductive tract development and fertility. It provides strategies to apply this knowledge to improve diagnostics for better assessment of fertility and reproductive longevity in female livestock.

51 A preliminary study of the effect of dietary cottonseed on the follicular reserve of does artificially infected with Haemonchus contortus.

Abstract Numerous studies have reported the negative effect of cottonseed gossypol on the ovarian reserve of the follicles, impairing female fertility. Injuries resulting in the depletion of primordial follicles can lead to permanent infertility. At birth, female mammals possess a fixed number of ovarian primordial follicles, which develop into primary, secondary, and antral follicles in a continuous and irreversible process. In this study, we evaluated the potential effects of dietary cottonseed gossypol in combination with parasitic infection on ovarian follicular reserve in meat goats. A total of 40 Boer x Spanish cross does were randomly subjected to cottonseed (CS) and parasite (P: Haemonchus contortus) in a 2x2 factorial arrangement of does (n = 8) per treatment groups (CS-/P-; CS+/P-; CS-/P+, and CS+/P+). Does were artificially infected with Haemonchus contortus for 2 d, and after 25 d, they began shedding parasite eggs. Thereafter, does were fed a hay diet supplemented with cottonseed (0.5% BW; CS+) or concentrate (CS-), to meet the nutritional requirements. Ten weeks later, animals were slaughtered, and ovaries of each treatment group (n = 4) were fixed with formalin and subjected to a standard procedure of histology staining (Periodic acid–Schiff and Hematoxylin counterstaining). Cuts of one left and one right ovary of two does were placed on microscope slides, and 48 slides were subjected to a microscope visualization (EVOS FL Auto; 20x magnification). Primordial follicles were classified as healthy (stained nucleus), unhealthy (pycnotic), and undetermined. Data were analyzed with ANOVA 1 and expressed as mean ± sem. P < 0.05 indicates a significant difference. A total of 20,562 primordial follicles corresponding to 10,410 (50.6%) healthy; 3,729 (18.1%) unhealthy; and 6,909 (33.6%) undetermined were examined; of which 26%, 20%, 31%, and 23% of total primordial follicles belonged to the CS-/P-, CS-/P+, CS+/P-, and CS+/P+ treatment groups, respectively. A significantly (P < 0.05) greater number of follicles were counted on left vs. right ovary sections (11,584 vs. 8,978) corresponding to 56.3% vs. 43.7% of total follicle counts. Averages of 121 ± 6 vs. 101±6 follicles were calculated per left and right ovary sections. Diets containing cottonseed (CS+/P-) increased the average number of follicles per ovary section, while parasite infections significantly (P < 0.05; CS-/P+ and CS+/P+) decreased these numbers. Regardless of the treatment group, the proportions of healthy follicles remained comparable between treatment groups. We concluded that dietary cottonseed and parasitic infections inversely affect ovarian follicle reserve, while the proportions of healthy follicles were unaffected across treatment groups. Nevertheless, higher microscopic magnification is needed to better characterize the large proportion of undetermined follicles.

Faecal glucocorticoid analysis as indicator of stress and its effect on the reproduction hormones of the female Malayan sun bear (Helarctus malayanus) in captivity.

Faecal glucocorticoid metabolite (FGM) is frequently used as a non-invasive tool to assess adrenocortical activity in animal conservation and welfare studies. However, studies assessing the stress level and its effect on the reproductive hormones of female Malayan sun bear is lacking. This study aims to assess the level of stress of the female Malayan sun bear in captivity and its effect on the female reproductive hormones of the female Malayan sun bears in captivity in Malaysian Borneo. Through FGM analysis via the enzyme-linked immunoassay (ELISA) method, it was found that the bear living in BSBCC has the lowest level of glucocorticoid. as for the relationship between the level of stress and the female reproductive hormones, the level of estrogen which was indicated by estradiol, decreases as the level of FGM increases. In contrast, the level of progesterone increase as the level of FGM increases. It can be concluded that the level of stress in captivity could affect the level of estrogen and progesterone and a high level of progesterone does not always indicate a good reproductive function in female mammals.

Neonatal Aromatase Inhibition Blocked Defeminization of AVPV Kiss1 Neurons and LH Surge-Generating System in Male Rats.

The neuroendocrine system that controls the preovulatory surge of gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH), which triggers ovulation in female mammals, is sexually differentiated in rodents. A transient increase in circulating testosterone levels in male rats within a few hours of birth is primarily responsible for the defeminization of anteroventral periventricular nucleus (AVPV) kisspeptin neurons, which are critical regulators of the GnRH/LH surge. The present study aimed to determine whether neonatal estradiol-17β (E2) converted from testosterone by aromatase primarily causes the defeminization of AVPV kisspeptin neurons and the surge of GnRH/LH in male rodents. The results of the present study showed that the neonatal administration of letrozole (LET), a nonsteroidal aromatase inhibitor, within 2 hours of birth rescued AVPV Kiss1 expression and the LH surge in adult male rats, while the neonatal administration of testosterone propionate (TP) irreversibly attenuated AVPV Kiss1 expression and the LH surge in adult female rats. Furthermore, the neonatal LET-treated Kiss1-Cre-activated tdTomato reporter males exhibited a comparable number of AVPV Kiss1-Cre-activated tdTomato-expressing cells to that of vehicle-treated female rats, while neonatal TP-treated females showed fewer AVPV Kiss1-Cre-activated tdTomato-expressing cells than vehicle-treated females. Moreover, neonatal TP administration significantly decreased the number of arcuate Kiss1-expressing and Kiss1-Cre-activated tdTomato-positive cells and suppressed LH pulses in adult gonadectomized female rats; however, neonatal LET administration failed to affect them. These results suggest that E2 converted from neonatal testosterone is primarily responsible for the defeminization of AVPV kisspeptin neurons and the subsequent GnRH/LH surge generation in male rats.

Knockdown of DNMT1 Induces SLCO3A1 to Promote Follicular Growth by Enhancing the Proliferation of Granulosa Cells in Mammals.

In female mammals, the proliferation and apoptosis of granulosa cells (GCs) have been shown to determine the fate of follicles. DNA methyltransferases (DNMTs) and SLCO3A1 have been reported to be involved in the survival of GCs and follicular growth. However, the molecular mechanisms enabling DNMTs to regulate the expression of SLCO3A1 to participate in follicular growth are unclear. In this study, we found that the knockdown of DNMT1 enhanced the mRNA and protein levels of SLCO3A1 by regulating the chromatin accessibility probably. Moreover, SLCO3A1 upregulated the mRNA and protein levels of MCL1, PCNA, and STAR to promote the proliferation of GCs and facilitated cell cycle progression by increasing the mRNA and protein levels of CCNE1, CDK2, and CCND1, but it decreased apoptosis by downregulating the mRNA and protein levels of CASP3 and CASP8. Moreover, SLCO3A1 promoted the growth of porcine follicles and development of mice follicles. In conclusion, the knockdown of DNMT1 upregulated the mRNA and protein levels of SLCO3A1, thereby promoting the proliferation of GCs to facilitate the growth and development of ovarian follicles, and these results provide new insights into investigations of female reproductive diseases.

Prolactin Mediates Long-Term, Seasonal Rheostatic Regulation of Body Mass in Female Mammals.

A series of well-described anabolic and catabolic neuropeptides are known to provide short-term, homeostatic control of energy balance. The mechanisms that govern long-term, rheostatic control of regulated changes in energy balance are less well characterized. Using the robust and repeatable seasonal changes in body mass observed in Siberian hamsters, this report examined the role of prolactin in providing long-term rheostatic control of body mass and photoinduced changes in organ mass (ie, kidney, brown adipose tissue, uterine, and spleen). Endogenous circannual interval timing was observed after 4 months in a short photoperiod, indicated by a significant increase in body mass and prolactin mRNA expression in the pituitary gland. There was an inverse relationship between body mass and the expression of somatostatin (Sst) and cocaine- and amphetamine-regulated transcript (Cart). Pharmacological inhibition of prolactin release (via bromocriptine injection), reduced body mass of animals maintained in long photoperiods to winter-short photoperiod levels and was associated with a significant increase in hypothalamic Cart expression. Administration of ovine prolactin significantly increased body mass 24 hours after a single injection and the effect persisted after 3 consecutive daily injections. The data indicate that prolactin has pleiotropic effects on homeostatic sensors of energy balance (ie, Cart) and physiological effectors (ie, kidney, BAT). We propose that prolactin release from the pituitary gland acts as an output signal of the hypothalamic rheostat controller to regulate adaptive changes in body mass.

YTHDF2 as a Mediator in BDNF-Induced Proliferation of Porcine Follicular Granulosa Cells.

In female mammals, the proliferation and apoptosis of granulosa cells (GCs) are critical in determining the fate of follicles and are influenced by various factors, including brain-derived neurotrophic factor (BDNF). Previous research has shown that BDNF primarily regulates GC proliferation through the PI3K/AKT, NF-kB, and CREB tumour pathways; however, the role of other molecular mechanisms in mediating BDNF-induced GC proliferation remains unclear. In this study, we investigated the involvement of the m6A reader YTH domain-containing family member 2 (YTHDF2) in BDNF-stimulated GC proliferation and its underlying mechanism. GCs were cultured in DMEM medium supplemented with varying BDNF concentrations (0, 10, 30, 75, and 150 ng/mL) for 24 h. The viability, number, and cell cycle of GCs were assessed using the CCK-8 assay, cell counting, and flow cytometry, respectively. Further exploration into YTHDF2's role in BDNF-stimulated GC proliferation was conducted using RT-qPCR, Western blotting, and sequencing. Our findings indicate that YTHDF2 mediates the effect of BDNF on GC proliferation. Additionally, this study suggests for the first time that BDNF promotes YTHDF2 expression by increasing the phosphorylation level of the ERK1/2 signalling pathway. This study offers a new perspective and foundation for further elucidating the mechanism by which BDNF regulates GC proliferation.

(326) Intrauterine Insemination: A Story of Husbandry and Husbands

Abstract Introduction Intrauterine insemination (IUI) is one of the most common methods of reproductive assistance in the modern era. As most female mammals have an estrous cycle, IUI as a procedure can be broadly applied to a wide array of species. Objective We sought to explore the history of IUI from its origins to modern application in assisted human reproduction. Methods We reviewed articles from Google Scholar, PubMed, and MedLine. Results Unverified accounts of the artificial insemination of an Arabian Mare can be traced back to the French translation of a 14th century equine veterinary textbook. A century later, King Henry IV of Castile, given the unfortunate nickname the Impotent, holds the first unsubstantiated claim of successfully using IUI. However, subsequent accounts dispute the paternity of the princess. It was not until the 18th century that Italian scientist Lazzaro Spallanzani would successfully conduct canine IUI with the birth of three puppies. Concurrently, famed surgeon John Hunter advised an impotent hypospadias patient to collect his post-coital semen. Hunter would subsequently instill it into the wife’s vaginal vault with reported successful pregnancy. Jumping forward to the mid 1800s J. Marion Sims, the so-called Father of Gynecology, instilled semen in six enslaved African American women, unfortunately time with their menstrual cycles, resulting in one pregnancy and subsequent miscarriage. In 1884 Dr. William Pancoast successfully performed IUI using a medical student’s semen, unbeknownst to the husband and wife. The results were published 25 years after the procedure. Human artificial reproduction had gained enough notoriety at the time to attract the attention of the Catholic Church. Pope Leo XIII condemned the practice as illicit. The majority of IUI research would then be largely conducted in Europe for the purpose of superior dairy cattle and stallions. In 1938 New Jersey dairy farm operator EJ Perry was the first American to institute cattle artificial insemination using Danish practices. Just one year later Gregory Pincus at Harvard University would remove and fertilize the egg of a female rabbit. Implantation into a second donor female resulted in a successful litter. Vast improvements in sperm preservation were made utilizing bull semen, egg yolks, sodium citrate, and glycerol. Contamination rates were reduced with the invention of the reputed Cornell Extender, and by 1953 Dr. Jerome Sherman was able to freeze, thaw, and successfully fertilize a human oocyte. Although the first successful pregnancy using frozen spermatozoa was reported in 1953, a conception rate of 3.4% reported by Mastriani et al led them to conclude the practice should be abandoned if no improvements made. The introduction of in-vitro fertilization in 1978 by Steptoe and Edwards effected subsequent improvements in sperm washing techniques, sperm selection and use of adjunctive hormones for induction of ovulation. IUI would go on to become one of the most common assisted reproduction techniques world-wide. Conclusions IUI has undergone numerous, major breakthroughs across several species with, at times, questionable ethical practices. Nonetheless, it provides an additional option to couples globally and appears here to stay Disclosure No.

Gut microbiota variations in wild yellow baboons (Papio cynocephalus) are associated with sex and habitat disturbance

Although male and female mammals differ in biological traits and functional needs, the contribution of this sexual dimorphism to variations in gut bacteria and fungi (gut microbiota) in relation to habitat type has not been fully examined. To understand whether the combination of sex and habitat affects gut microbiota variation, we analyzed 40 fecal samples of wild yellow baboons (Papio cynocephalus) living in contrasting habitat types (intact, well-protected vs. fragmented, less protected forests) in the Udzungwa Mountains of Tanzania. Sex determination was performed using the marker genes SRY (Sex-determining Region Y) and DDX3X-DDX3Y (DEAD-Box Helicase 3). Samples were attributed to 34 individuals (19 females and 15 males) belonging to five social groups. Combining the results of sex determination with two amplicon sequencing datasets on bacterial (V1–V3 region of the 16S rRNA gene) and fungal (ITS2) gut communities, we found that overall, baboon females had a significantly higher gut bacterial richness compared to males. Beta diversity estimates indicated that bacterial composition was significantly different between males and females, and this was true for individuals from both well- and less protected forests. Our results highlight the combined role of sex and habitat type in shaping variation in gut microbial communities in wild non-human primates.

Lycium barbarum berry extract improves female fertility against aging-related oxidative stress in the ovary.

Reproductive aging in female mammals is characterized by ovarian senescence, leading to a significant fertility decline. Lycium barbarum berry, or goji berry, is a food and medicine that appears in various formulas for treating infertility in traditional Chinese medicine. We investigated the function of an aqueous extract of Lycium barbarum berry (LB extract) to improve health status, fertility, and offspring development during female aging. Aged female mice were supplemented with LB extract, and its effects on fertility, locomotor activity, and offspring development were assessed. The results demonstrated that LB extract significantly increased pregnancy and live birth rates in naturally aged female mice. It also effectively improved aged animals' locomotor activity. Moreover, LB extract promoted the growth and development of offspring delivered from the aged animals and reduced the offspring's anxiety. During aging, fertility-related hormones gradually decline. However, the decline of anti-Müllerian hormone (AMH) and estradiol (E2) in the serum of aged mice was restored by LB extract supplementation. Immunohistochemical analysis revealed that the levels of oxidation and the inflammatory IL-6 in intra-ovarian cells were reduced by LB extract, while the antioxidant-associated proteins peroxiredoxin 4 (PRDX4) and nuclear factor erythroid 2-related factor 2 (NRF2) were increased. Bioinformatics analysis revealed a decline in egg PRDX4 expression with age across various species. This suggests that the antioxidant function protected by LB extract through PRDX4 may consistently promote fertility enhancement by improving ovarian function across different species. Importantly, LB extract did not induce significant adverse effects on aged female mice and their offspring. These findings highlight the potential of LB as a protective agent against ovarian oxidative stress, which preserves ovarian function and improves fertility rates in naturally senescent females.

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

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

Analysis of Meiotic Progression by Ex Vivo Culture of Mouse Embryonic Ovaries.

Oogenesis is the central process required to produce viable oocytes in female mammals. It is initiated during embryonic development, and it involves the specification of primordial germ cells (PGCs) and progresses through the activation of the meiotic program, reaching a crucial phase in prophase I before pausing at diplotene around the time of birth. The significance of meiosis, particularly the prophase I stage, cannot be overstated, as it plays a pivotal role in ensuring the formation of healthy gametes, a prerequisite for successful reproduction. While research has explored meiosis across various organisms, understanding how environmental factors, including radiation, drugs, endocrine disruptors, reproductive age, or diet, influence this complex developmental process remains incomplete. In this chapter, we describe an ex vivo culture method to investigate meiotic prophase I and beyond and the disruption of oogenesis by external factors. Using this methodology, it is possible to evaluate the effects of individual xenobiotics by administering chemicals at specific points during oogenesis. This culture technique was optimized to study the effects of two selected endocrine disruptors (vinclozolin and MEHP), demonstrating that vinclozolin exposure delayed meiotic differentiation and MEHP exposure reduced follicle size. This approach also opens avenues for future applications, involving the exploration of established or novel pharmaceutical substances and their influence on essential events during prophase I, such as homologous recombination and chromosome segregation. These processes collectively dictate the ultimate fitness of oocytes, with potential implications for factors relevant to the reproductive age and fertility.

Dissection of protein and RNA regions required for SPEN binding to XIST A-repeat RNA.

XIST noncoding RNA promotes the initiation of X chromosome silencing by recruiting the protein SPEN to one X chromosome in female mammals. The SPEN protein is also called SHARP (SMRT and HDAC-associated repressor protein) and MINT (Msx-2 interacting nuclear target) in humans. SPEN recruits N-CoR2 and HDAC3 to initiate histone deacetylation on the X chromosome, leading to the formation of repressive chromatin marks and silencing gene expression. We dissected the contributions of different RNA and protein regions to the formation of a human XIST-SPEN complex in vitro and identified novel sequence and structure determinants that may contribute to X chromosome silencing initiation. Binding of SPEN to XIST RNA requires RRM 4 of the protein, in contrast to the requirement of RRM 3 and RRM 4 for specific binding to SRA RNA. Measurements of SPEN binding to full-length, dimeric, trimeric, or other truncated versions of the A-repeat region revealed that high-affinity binding of XIST to SPEN in vitro requires a minimum of four A-repeat segments. SPEN binding to XIST A-repeat RNA changes the accessibility of the RNA at specific nucleotide sequences, as indicated by changes in RNA reactivity through chemical structure probing. Based on computational modeling, we found that inter-repeat duplexes formed by multiple A-repeats can present an unpaired adenosine in the context of a double-stranded region of RNA. The presence of this specific combination of sequence and structural motifs correlates with high-affinity SPEN binding in vitro. These data provide new information on the molecular basis of the XIST and SPEN interaction.

Activity budget and gut microbiota stability and flexibility across reproductive states in wild capuchin monkeys in a seasonal tropical dry forest

BackgroundEnergy demands associated with pregnancy and lactation are significant forces in mammalian evolution. To mitigate increased energy costs associated with reproduction, female mammals have evolved behavioural and physiological responses. Some species alter activity to conserve energy during pregnancy and lactation, while others experience changes in metabolism and fat deposition. Restructuring of gut microbiota with shifting reproductive states may also help females increase the energy gained from foods, especially during pregnancy. The goal of this study was to examine the relationships among behaviour, gut microbiota composition, and reproductive state in a wild, non-human primate to better understand reproductive ecology. We combined life history data with > 13,000 behavioural scans and 298 fecal samples collected longitudinally across multiple years from 33 white-faced capuchin monkey (Cebus imitator) females. We sequenced the V4 region of the 16S rRNA gene and used the DADA2 pipeline to analyze microbial diversity. We used PICRUSt2 to assess putative functions.ResultsReproductive state explained some variation in activity, but overall resting behaviours were relatively stable across pregnancy and lactation. Foraging was less frequent among females in the early stage of nursing compared to the cycling stage, though otherwise remained at comparable levels. Maximum temperature was a strong, significantly positive predictor of resting, while social dominance had a small but significantly negative effect on resting. Ecological variables such as available fruit biomass and rainfall had a small but significantly positive effects on measures of foraging time. Gut microbial community structure, including richness, alpha diversity, and beta diversity remained stable across the reproductive cycle. In pairwise comparisons, pregnant females exhibited increased relative abundances of multiple microbial ASVs, suggesting small changes in relation to reproductive state. Reproductive state was not linked to differential abundance of putative metabolic pathways.ConclusionsPrevious data suggest that activity budget and the gut microbiome shifts considerably during reproduction. The present study finds that both activity and gut microbial communities are less associated with reproduction compared to other predictors, including ecological contexts. This suggests that behavioural flexibility and gut microbial community plasticity is contrained by ecological factors in this population. These data contribute to a broader understanding of plasticity and stability in response to physiological shifts associated with mammalian reproduction.

The Integration of the Maternal Care with Sleep During the Postpartum Period.

Our entire life occurs in a constant alternation between wakefulness and sleep. The impossibility of living without sleep implies that any behavior must adapt to the need for sleep, and maternal behavior does not escape from this determination. Additionally, maternal behavior in mammals is a highly motivated behavior, essential for the survival ofthe offspring. Thus, the mother has to adapt her physiology of sleep to the constant demands of the pups, where each species will have different strategies to merge these two physiological needs. However, all studied female mammals will experience sleep disturbances at some point of the postpartum period.