Reproductive Cycle Research Articles

Progesterone increases metabolism via the pentose phosphate pathway in bovine uterine epithelial cells.

During early pregnancy, glucose is essential for the uterine epithelium and the developing embryo. In cows, progesterone increases the secretion of glucose into the uterine lumen. The uterine epithelium can convert glucose to fructose, but other fates of glucose in the uterine epithelium have been sparsely investigated. Therefore, our objective was to investigate how progesterone influences glucose metabolism in immortalized bovine uterine epithelial (BUTE) cells. BUTE cells were grown to 80% confluence and treated with vehicle (DMSO) or 10 µM progesterone for 24h. Cells were collected and analyzed. Immunohistochemistry was performed on endometrial samples collected from the bovine endometrium on days 1 and 11 of the reproductive cycle. Progesterone treatment increased glucose consumption of BUTE cells. RNAseq identified 3,072 genes regulated by progesterone. KEGG analysis indicated that progesterone altered genes associated with metabolic pathways and glutathione metabolism. Manually examining genes unique to specific glucose metabolic pathways identified an increase in the rate-limiting enzyme in the pentose phosphate pathway-glucose-6-phosphate dehydrogenase. Functionally, a major product of the pentose phosphate pathway is NADPH, and progesterone treatment increased NADPH levels in BUTE cells. In cows, immunohistochemistry confirmed that glucose-6-phosphate dehydrogenase levels were higher in the uterine epithelium in the luteal phase when progesterone concentrations are high. Progesterone increased glucose-6-phosphate dehydrogenase expression and metabolism via the pentose phosphate pathway in the bovine uterine epithelium. This metabolism could provide substrates for cell proliferation, molecules to be secreted into the uterine lumen, or maintain reduction/oxidation balance in the uterine epithelium.

Reproductive biology of three oyster species from a lagoon in the southeastern Gulf of California

ABSTRACT Oyster fishing in Mexico holds significant importance, but official records show a consistent drop in production. To understand the reproductive behaviour of key oyster species —Crassostrea corteziensis, Saccostrea palmula, and Striostrea prismatica— in a southeastern Gulf of California lagoon (May 2019 to April 2020), this research delved into their reproductive traits. C. corteziensis and S. palmula exhibited five phases of gonadal development, including: undifferentiated/resting, initial gametogenesis, advanced gametogenesis, maturation, and spawning; S. prismatica showed four: undifferentiated/resting, gametogenesis, maturation, and spawning phases. The three oysters displayed hermaphroditism. Spawning peaks varied: C. corteziensis from September to November, S. palmula from May to September, and S. prismatica from August to November. Sex ratio (female:male) of S. prismatica differed from the expected 1:1 proportion. C. corteziensis and S. palmula showed continuous reproduction; S. prismatica displayed a single annual reproductive cycle. Since the obtained peak spawning of C. corteziensis and S. prismatica presented discrepancy with the official protection period and there are no regulatory measures for S. palmula, the information on their reproductive behaviour aids in regulating their extraction for sustainability and conservation in the southeastern Gulf of California. Similar information can be replicated in coastal areas of other latitudes where several oyster species coexist.

Effect of individual quick freezing treatment and cold storage on the host egg (Lepidoptera: Saturniidae) quality for the production of the parasitoid Anastatus japonicus Ashmead (Hymenoptera: Eupelmidae)

BackgroundThe augmentative release of the parasitoid species Anastatus japonicus Ashmead (Hymenoptera: Eupelmidae) is essential for managing the recent invasion of litchi stink bugs (Tessaratoma papillosa (Drury)) (Hemiptera: Tessaratomidae) in Taiwan. The mass release program in the spring targets this univoltine pest’s reproduction cycle. Low-temperature storage for the host eggs and parasitoids is required to maximize the production for the annual release program. This study aimed to enhance the shelf life of Samia cynthia (Lepidoptera: Saturniidae) eggs using the combination of refrigeration and individual quick freezing (IQF) as a storage treatment. Storage of A. japonicus in the IQF-treated S. cynthia eggs was evaluated to determine the optimal production process during the short preparation window before the release.ResultsThe influences of cold storage and IQF treatment on the host eggs were evaluated for different storage durations. The host quality was determined according to the emergence rate and female ratio of A. japonicus. The study’s results demonstrated that the host quality of S. cynthia eggs did not change significantly compared to the control group after 28 d of refrigeration at 7 °C. IQF treatment extended S. cyathia’s shelf life to 5 months without significantly affecting the host quality. Applying IQF at different developmental stages of the host eggs affected the parasitism rates of A. japonicus. Significantly higher emergence rates of A. japonicus were recorded in the eggs treated during the initial development (D0 to D2). However, storing parasitoids in the IQF-treated eggs under the current storage condition for one month at 12 °C significantly impacted the parasitoid’s emergence rate.ConclusionsThe results of this study highlight the potential benefits of the individual quick freezing technique. This technique didn’t alter the egg quality of S. cynthia, a crucial factor for the mass production of A. japonicus. The IQF treatment extends the shelf life of the host eggs to 5 months when stored at − 20 °C, a significant improvement compared to the 4-week shelf life without IQF treatment. This technology offers a promising and efficient approach for the mass production of A. japonicus and supports field releases. The treatment allowed for the stockpiling of host eggs during the off-season, which can help expedite the mass production of A. japonicus to fit an eight-week production window.

Targeting Leishmaniasis with Nitrovinyl Derivatives: Their Synthesis, In Vitro Assessment, and Computational Exploration.

Leishmaniasis is an affliction caused by the protozoan parasites of the Leishmania genus. This disease impacts a substantial global populace, exceeding one million individuals, leading to disability-adjusted life years and fatalities, particularly within tropical regions. At present, the existing drug therapies have not attained a degree of efficacy that can be unequivocally classified as genuinely triumphant. In this context, the conception of novel compounds possessing the capacity to impede the parasite's life cycle at various stages holds considerable significance. In this research endeavor, an exploration was undertaken involving the design and synthesis of nineteen derivatives incorporating the nitrovinyl pharmacophore. The subsequent evaluation of their impacts on L. major was conducted through a combination of in vitro (amastigote and promastigote inhibition) and in silico (molecular docking) investigations. All of the compounds were synthesized and purified with good yields. In the amastigote inhibition assay, compounds 10, 15, and 18 showed better inhibitory effects than the standard drug meglumine antimonate (MA). Regarding the synergistic impact of synthesized compounds and MA together, all outcomes were significantly better than those of monotherapy of each in amastigote and macrophage forms. In the promastigote assay, compounds 2, 8, 12, 15, 16, 17, and 19 demonstrated superior inhibitory effects compared to MA. Moreover, compounds 4, 12, and 15 showed the best synergies with MA in inhibiting amastigotes. According to docking scores, 1XTP (a SAM-dependent methyltransferase) and 4G5D (Prostaglandin F synthase) receptors were found to be the most probable targets in their mechanism of action. In vitro evaluations and computational analyses strongly suggest that these compounds could be effective against both L. major amastigotes and promastigotes. Additionally, they exhibited notable synergistic interactions with MA against both living forms of the parasite.

A multistage Plasmodium CRL4WIG1 ubiquitin ligase is critical for the formation of functional microtubule organization centers in microgametocytes.

Malaria is a mosquito-borne infectious disease caused by unicellular eukaryotic parasites of the Plasmodium genus. Protein ubiquitination by E3 ligases is a critical post-translational modification required for various cellular processes during the lifecycle of Plasmodium parasites. However, little is known about the repertoire and function of these enzymes in Plasmodium. Here, we show that Plasmodium expresses a conserved cullin RING E3 ligase (CRL) complex that is functionally related to CRL4 in other eukaryotes. In P. falciparum asexual blood stages, a cullin-4 scaffold interacts with the RING protein RBX1, the adaptor protein DDB1, and a set of putative receptor proteins that may determine substrate specificity for ubiquitination. These receptor proteins contain WD40-repeat domains and include WD-repeat protein important for gametogenesis 1 (WIG1). This CRL4-related complex is also expressed in P. berghei gametocytes, with WIG1 being the only putative receptor detected in both the schizont and gametocyte stages. WIG1 disruption leads to a complete block in microgamete formation. Proteomic analyses indicate that WIG1 disruption alters proteostasis of ciliary proteins and components of the DNA replication machinery during gametocytogenesis. Further analysis by ultrastructure expansion microscopy (U-ExM) indicates that WIG1-dependent depletion of ciliary proteins is associated with impaired the formation of the microtubule organization centers that coordinate mitosis with axoneme formation and altered DNA replication during microgametogenesis. This work identifies a CRL4-related ubiquitin ligase in Plasmodium that is critical for the formation of microgametes by regulating proteostasis of ciliary and DNA replication proteins.IMPORTANCEPlasmodium parasites undergo fascinating lifecycles with multiple developmental steps, converting into morphologically distinct forms in both their mammalian and mosquito hosts. Protein ubiquitination by ubiquitin ligases emerges as an important post-translational modification required to control multiple developmental stages in Plasmodium. Here, we identify a cullin RING E3 ubiquitin ligase (CRL) complex expressed in the replicating asexual blood stages and in the gametocyte stages that mediate transmission to the mosquito. WIG1, a putative substrate recognition protein of this ligase complex, is essential for the maturation of microgametocytes into microgametes upon ingestion by a mosquito. More specifically, WIG1 is required for proteostasis of ciliary proteins and components of the DNA replication machinery during gametocytogenesis. This requirement is linked to DNA replication and microtubule organization center formation, both critical to the development of flagellated microgametes.

Effects of environmental factors on host-parasite interaction patterns in backyard-tethered goats of Kerala, India

The environment is the most important stratum in the epidemiological triad of a parasitic disease and any variations in the environmental factors may decide the dynamic occurrence and existence of different lifecycle stages of these parasites. The present study investigated the correlations between key biometeorological and demographical parameters with the incidence of different gastrointestinal parasites and hemoparasites among goats. Four hundred and thirty-two goats were screened for parasitic infection in a yearlong survey conducted from July 2022 to June 2023 in the Teaching Veterinary Clinical Complex, Mannuthy, Kerala, India. The weather parameters (Tmax, Tmin, RH, THI, and bright sunshine hours), air quality parameters [AQI, PM2.5, and PM10], and demographic parameters (gender and age) were recorded along with the test positivity of different categories of gastrointestinal parasites and hemoparasites in goats by routine fecal sample examination and blood smear examination, respectively. The infection level was ranked based on the severity of the infection. The mean and daily variations in biometeorological parameters were calculated and the data were statistically analyzed to figure out the pertinent correlations in host-parasite-environment interaction patterns. High levels of parasitic infections with significant month-wise variations and climate-correlated peak infection patterns were noticed. The incidence of parasites was negatively correlated to all parameters except humidity, indicating more severe parasitism during monsoon months. The significant variations in the host-parasite interaction dynamics point towards the need for detailed explorations concerning the lifecycle of each specific parasite with a focus on the possible environment-favourable and resistant lifecycle stages. Future studies may be designed from a biometeorological perspective to develop a crucial understanding of host-parasite-environment interactions in goats ensuring sustainable goat farming.

Dissecting the dynamic cellular transcriptional atlas of adult teleost testis development throughout the annual reproductive cycle.

Teleost testis development during the annual cycle involves dramatic changes in cellular compositions and molecular events. In this study, the testicular cells derived from adult black rockfish at distinct stages - regressed, regenerating and differentiating - were meticulously dissected via single-cell transcriptome sequencing. A continuous developmental trajectory of spermatogenic cells, from spermatogonia to spermatids, was delineated, elucidating the molecular events involved in spermatogenesis. Subsequently, the dynamic regulation of gene expression associated with spermatogonia proliferation and differentiation was observed across spermatogonia subgroups and developmental stages. A bioenergetic transition from glycolysis to mitochondrial respiration of spermatogonia during the annual developmental cycle was demonstrated, and a deeper level of heterogeneity and molecular characteristics was revealed by re-clustering analysis. Additionally, the developmental trajectory of Sertoli cells was delineated, alongside the divergence of Leydig cells and macrophages. Moreover, the interaction network between testicular micro-environment somatic cells and spermatogenic cells was established. Overall, our study provides detailed information on both germ and somatic cells within teleost testes during the annual reproductive cycle, which lays the foundation for spermatogenesis regulation and germplasm preservation of endangered species.

Requirements for Design Methods from Circular Design to Support the Product Development of Products for the Circular Economy in SMEs

Against the backdrop of increasing ecological challenges, in connection with excessive use of resources, a rethinking of the current mode of operation of the economy and consumers is required. The circular economy, which describes a system in which products, components, and materials are preserved in recurring cycles, is seen as a counter-design to the currently dominant form of economy. The development of circular products plays a central role in the development of both consumer and capital goods. Design methods from circular design—a part of circular economy—form the basis for the development of circular products. Therefore, this contribution identifies and investigates evaluation criteria for the optimal selection of these design methods for use in small and medium-sized enterprises (SMEs). It is shown that design methods shall promote circular development of a product and focus on a systemic consideration of the product context along the entire product life cycle as well as closing technical and biological cycles. The contribution formulates evaluation criteria that address the assessment of the applicability, integrability in SMEs, and circularity of a design method and thus provide a basis for the evaluation of design methods from circular design. Product developers in SMEs are thus provided with a set of criteria to support them in product development for the circular economy.

Plasmodium falciparum protein phosphatase PP7 is required for early ring-stage development.

Plasmodium falciparum causes malaria and is responsible for more than 600,000 deaths each year. Although effective drugs are available to treat disease, the spread of drug-resistant parasites endangers their future efficacy. It is hoped that a better understanding of the biology of malaria parasites will help us to discover new drugs to tackle the resistance problem. Our work is focused on the cell signaling mechanisms that control the development of the parasite throughout its complex life cycle. All signal transduction pathways are ultimately regulated by reversible protein phosphorylation by protein kinase and protein phosphatase enzymes. In this study, we investigate the function of calcium-dependent protein phosphatase PP7 and show that it is essential for the development of ring-stage parasites following the invasion of human erythrocytes. Our results contribute to the understanding of the erythrocytic stages of the parasite life cycle that cause malaria pathology.

Branched-chain amino acids modulate the proteomic profile of Trypanosoma cruzi metacyclogenesis induced by proline.

Trypanosoma cruzi, the causative agent of Chagas disease, has a complex life cycle that involves triatomine insects as vectors and mammals as hosts. The differentiation of epimastigote forms into metacyclic trypomastigotes within the insect vector is crucial for the parasite's life cycle progression. Factors influencing this process, including temperature, pH, and nutritional stress, along with specific metabolite availability, play a pivotal role. Amino acids like proline, histidine, and glutamine support cell differentiation, while branched-chain amino acids (BCAAs) inhibit it. Interestingly, combining the pro-metacyclogenic amino acid proline with one of the anti-metacyclogenic BCAAs results in viable metacyclics with significantly reduced infectivity. To explore the characteristics of metacyclic parasites differentiated in the presence of BCAAs, proteomics analyses were conducted. Metacyclics obtained in triatomine artificial urine (TAU) supplemented with proline alone and in combination with leucine, isoleucine, or valine were compared. The analyses revealed differential regulation of 40 proteins in TAU-Pro-Leu, 131 in TAU-Pro-Ile, and 179 in TAU-Pro-Val, as compared to metacyclics from TAU-Pro. Among these, 22%, 11%, and 13% of the proteins were associated with metabolic processes, respectively. Notably, enzymes related to glycolysis and the tricarboxylic acid (TCA) cycle were reduced in metacyclics with Pro-BCAAs, while enzymes involved in amino acid and purine metabolic pathways were increased. Furthermore, metacyclics with Pro-Ile and Pro-Val exhibited elevated enzymes linked to lipid and redox metabolism. The results revealed five proteins that were increased and four that were decreased in common in the presence of Pro+BCAAs, indicating their possible participation in key processes related to metacyclogenesis. These findings suggest that the presence of BCAAs can reshape the metabolism of metacyclics, contributing to the observed reduction in infectivity in these parasites.

Mechanisms of tamoxifen resistance: insight from long non-coding RNAs.

Breast cancer(BC) is the second most prevalent tumor in the world and one of the most lethal tumors in women. Patients with estrogen receptor-positive breast cancer can obtain significant advantages from endocrine therapies including tamoxifen, aromatase inhibitors, and others. However, the development of primary or acquired drug resistance ultimately leads to discontinuation of treatment with adverse consequences for breast cancer patients, and the underlying mechanisms have not been fully elucidated. Long non-coding RNAs (lncRNAs) play pivotal roles in orchestrating fundamental biochemical and cellular processes. They exert regulatory control over various processes including epigenetics, gene transcription, post-transcriptional modifications, and translation. Additionally, they influence key biological events like cell cycle progression, cell differentiation, and development. For the past few years, the relationship between lncRNAs and endocrine resistance has gained increasing attention, leading to a surge in related studies. LncRNAs mediate tamoxifen resistance in cancer by utilizing a variety of molecular mechanisms, including enhanced estrogen receptor (ER) signaling, inhibition of apoptosis, autophagy, exosome-mediated transfer, epigenetic alterations, epithelial-to-mesenchymal transition, and acting as competitive endogenous RNAs(ceRNAs). In this comprehensive review, we systematically summarize the critical role and intricate molecular mechanisms by which lncRNAs influence the development of tamoxifen resistance in breast cancer. Furthermore, we propose the potential clinical significance of lncRNAs as innovative therapeutic targets and prognostic biomarkers for breast cancer.

Половая структура поселений двустворчатого моллюска Macoma calcarea (Gmelin, 1791) в районах с разным гидрологическим режимом

The influence of changes in environmental conditions on the reproductive cycles of benthic organisms (sexual structure, size of puberty, stages of gonad maturity, oocyte size) of the bivalve mollusk Macoma calcarea in the western part of the Spitsbergen archipelago (Grenfjord Bay) and the eastern part of the Barents Sea (coastal archipelago) was studied New Earth). In a settlement of M. calcarea in the warmer waters of Grenfjord, intensive reproductive processes were observed. In this area, females reach sexual maturity with a shorter shell length than males and individuals from other areas of the Barents Sea; In terms of sex ratio, females dominate over males, and a large number of juveniles are noted. Females at the spawning stage were found only near Novaya Zemlya. The diameter of the oocytes varied from 30 to 200 µm depending on the stage of maturity. In the mollusks M. calcarea, the breeding season is extended in time in both study areas.

7170 Plasticity of the Hypothalamic Tuberoinfundibular Dopaminergic Neuronal Network in Lactating Rats

Abstract Disclosure: P. Papaioannou: None. T. Georgescu: None. D.R. Grattan: None. S. Bunn: None. S. Yip: None. The tuberoinfundibular dopaminergic (TIDA) neurons play a crucial role in regulating prolactin secretion. Their synchronized network activity with slow but highly rhythmic firing pattern is important for dopamine release in rats[1]. While this unique TIDA network activity is vital for prolactin negative feedback in non-lactating conditions, its behaviour during lactation, when prolactin demand is high, remains unknown. Our hypothesis posited that the TIDA neuronal network in lactating rats becomes desynchronized, disrupting the negative feedback loop. To test this, we utilized ex-vivo Ca2+ imaging to simultaneously monitor population-wide TIDA neuron activity in non-lactating (NL; n=13) and lactating (L; n=10) rats injected with a cre-inducible adeno-associated virus (AAV) containing the Ca2+ indicator, GCaMP6s, into their arcuate nucleus. Analysis of neuronal network synchronicity revealed significant desynchronization in the TIDA network during lactation, as indicated by a markedly lower mean correlation coefficient matrix (CM) compared to non-lactating conditions (NL: 0.87±0.02, n= 26 sections vs L: 0.22±0.03, n=29 sections; p<0.001, Student’s t-test). Furthermore, the oscillatory activity patterns of these desynchronized TIDA neurons displayed a significantly lower cell rhythmicity index (RI) in lactating animals compared to non-lactating ones (NL: 0.17±0.01, n=186 cells vs L: 0.70±0.02, n=77 cells; p<0.001, Student’s t-test). Interestingly, within these low rhythmic neurons, some exhibited higher while others showed lower firing frequencies compared to non-lactating TIDA neurons. After 7 days post-weaning (n=4 animals), the TIDA network activity returned to non-lactating behaviour (CM = 0.85 ± 0.04, n=6 sections and RI = 0.17±0.01; n=47 cells). In summary, our findings demonstrate a reversible reconfiguration of the TIDA neuronal networks during lactation, characterized by low rhythmic oscillations and individual unique firing patterns, leading to diminished intercellular synchrony that may impede dopamine release, ultimately facilitating prolactin release to support lactation. Once weaned, the TIDA neuronal network reset to NL state to allow a new reproductive cycle. [1] Lyons, D. J., Horjales-Araujo, E. & Broberger, C. Synchronized network oscillations in rat tuberoinfundibular dopamine neurons: switch to tonic discharge by thyrotropin-releasing hormone. Neuron 65, 217-229, doi:10.1016/j.neuron.2009.12.024 (2010). Presentation: 6/2/2024

7788 Importance of Neuronal STAT3, but Not ERK2 or mTOR, for Pubertal Timing and Reproductive Activity in Mice

Abstract Disclosure: R.A. Lord: None. M.A. Inglis: None. G.M. Anderson: None. The adipose-derived hormone leptin is important for regulating reproduction. The canonical JAK2/STAT3 pathway is the best-characterised leptin receptor signalling pathway. Neural STAT3 deletion is known to cause obesity; however, its reproductive influence is less understood. This experiment investigated whether STAT3 knockout from brain neurons or AgRP neurons, a neuronal population necessary for normal pubertal timing and reproduction, would unveil the necessity of STAT3 in reproductive function. We also tested the role of ERK2 and mTOR, two alternative leptin signalling molecules.Transgenic mice with a neuronal knockout were created via the Cre-loxP system. CamKinaseIIα-Cre mice were crossed with STAT3, mTOR or ERK2 floxed mice. AgRP-Cre mice were crossed with STAT3 floxed mice for STAT3 knockout in AgRP neurons. All groups were compared to Cre-negative littermate controls (n=6-12/group). Puberty onset was assessed post-weaning by examining genitalia development. Reproductive cyclicity and organ weights were measured in adults. Metabolic effects were evaluated through body weight, abdominal fat and fasting glucose measurements. Brain tissue analysis evaluated cellular responses to leptin for STAT3, ERK2, and mTOR. Data presented as mean ± SEM.Mice with ERK2 KO or mTOR KO showed no reproductive or metabolic deficits compared to controls. In marked contrast, neuronal STAT3 KO mice showed significantly increased body weight by 5 weeks of age and a 6-fold increase in abdominal adiposity as adults (both p<0.001 using two-way ANOVA and Student’s t-test respectively) compared to controls. Males had a significant 5-day delay in age at preputial separation (KO: 32.1±2.09 d; Control: 26.8±0.45 d, p<0.01, Student’s t-test) while females had a significant 7-day delay in vaginal opening (KO: 33.0±1.85 d, Control: 26.6±0.37 d, p<0.05, Student’s t-test), a 9-day delay in first estrus (KO: 37.8±1.89 d; Control: 29.4±0.65 d, p<0.01, Student’s t-test) and pronounced acyclicity. Neuronal STAT3 KO mice also had a >2-fold elevation in fasting glucose levels (p<0.001, Student’s t-test) and regressed reproductive organs. Female mice with STAT3 knockout in AgRP neurons showed significantly increased body weight (by 3 weeks [p<0.001], two-way ANOVA) and a significant 3-day delay in first estrus (KO: 31.1±0.71 d, Control: 28.6±0.45 d, p<0.01, Student’s t-test). These data show that neuronal STAT3 is critical for correctly timed puberty and subsequent fertility in male and female mice, whereas mTOR and ERK2 are not essential. These results have prompted a re-evaluation of previous conclusions about the role of STAT3 from experiments using LepR-Cre mice. Additionally, AgRP neuronal requirements for STAT3 exactly recapitulate AgRP requirements for leptin receptors. A better grasp of leptin signalling pathways will improve our understanding of how infertility arises due to metabolic disease. Presentation: 6/3/2024

Tylvalosin tartrate inhibits the replication stage of the porcine reproductive and respiratory syndrome virus life cycle

The aetiological agent of porcine reproductive and respiratory syndrome, a deadly disease that affects pigs and seriously jeopardises the global swine industry, is a porcine reproductive and respiratory syndrome virus (PRRSV). Tylvalosin tartrate, which is a macrolide antibiotic, is the active ingredient in Aivlosin. In recent years, tylvalosin tartrate has widely been used to control porcine reproductive and respiratory syndrome in swine herds in China. However, whether tylvalosin tartrate has exerts anti-PRRSV effects remains controversial. In the present study, tylvalosin tartrate exhibited no effect on PRRSV susceptibility but suppressed the replication of PRRSV and the activity of infecting Marc-145 cells. Next, the relationship between the replication cycle of PRRSV and the activity of tylvalosin tartrate was further assessed. Tylvalosin tartrate did not affect the attachment and release stages of PRRSV or act during the internalisation stage of the virus in HuN4; however, contrasting effects were noted for strains CH-1a and SDVD-HN21. Tylvalosin tartrate acted on the replication stage of PRRSV and was not strain-specific in the replication stage of the PRRSV life cycle. The study findings provide an initial clarification of the inhibitory effects of tylvalosin tartrate on PRRSV, providing new insights into the treatment of PRRS.

Primary and Secondary Sexual Characteristics of Kuhli Loach (Pangio kuhlii)

Kuhli loach (Pangio kuhlii) a popular ornamental freshwater fish species with economic potential, originating from Sumatra, Kalimantan, Java, and Malaysia. The kuhli loach's appeal lies in its vibrant colors and distinctive eel-like body. This study aims to explores the sexual primary and secondary characteristics of the kuhli loach. Conducted at Universitas Airlangga in Banyuwangi, Indonesia, the study involved a thorough analysis of 50 kuhli loaches, evenly split between males and females. Morphological observations revealed significant differences (p < 0.05), such as the elongated body and expanded abdominal region in females, suggesting adaptations for reproduction. Internal examinations, including peritoneal dissections and histological analysis, unveiled distinct stages of spermatogenesis in males and ovarian development in females, providing insights into the reproductive cycle. Meristic and morphometric analyses identified noteworthy differences in pectoral fin rays, suggesting potential roles in reproductive behavior, while other traits exhibited similarity between genders. This study contributes to the understanding of kuhli loach ecology and reproductive biology, highlighting the importance of addressing sustainability concerns arising from the continuous exploitation of wild populations. This study serves as a foundational step towards advancing reproductive improvement in fish and supports the conservation of this unique ornamental fish species, with implications for aquaculture practices and economic considerations.

Physalia gonodendra are not yet sexually mature when released

The blue bottle genus Physalia is one of the well-known siphonophore belonging to the Cnidaria, Hydrozoa. Physalia is also known as a ferocious predator, occasionally stinging and fatally wounding humans, but key details of its life cycle and reproductive biology are unclear. Physalia have separate sexes, and sexual reproduction occurs through the release of complex structures called gonodendra that contain many gonophores that will release either eggs or sperm. It is not known how mature the gonophores are when the gonodendra are released. In this study, we aim to characterize germ cell maturation by conducting histological, cytological, and gene expression analyses of the gonodendron of Physalia utriculus from Japan. We found a layered structure of the gonophore, consistent with other studies; however, gametes were not found even in gonophores that were within the released gonodendra. Moreover, haploid cells were not detected by flow cytometry. Analysis of the expression of putative germ cell marker and meiosis related genes showed high expression in the gonophore. These results strongly suggest that germ cells do not mature until after gonodendra are released. These findings provide valuable insights into the reproductive ecology and life cycle of Physalia.

Sperm storage in males of the Neotropical rattlesnake Crotalus durissus (Squamata: Viperidae): Structure and seasonal variation of the distal ductus deferens

In species with asynchronous reproductive cycles, where gamete production is not aligned with the mating season, either males or females must store sperm. This reproductive tactic is an obligatory feature of male rattlesnakes’ reproductive cycle due to asynchrony between spermatogenesis and mating. Given that the ductus deferens is the primary site of sperm storage in male snakes, we aimed to investigate the morphological and histochemical changes in the distal ductus deferens of C. durissus throughout its reproductive cycle. In this species, spermatogenesis begins in spring and peaks in summer, while testes regress during autumn and winter. The distal ductus deferens of 28 mature male specimens was evaluated using histomorphometric and histochemical methods. Spermatozoa were consistently observed within the lumen of the ductus deferens in almost all specimens. The principal cells of the distal region of ductus deferens reacted positively for Periodic Acid-Schiff and Bromophenol Blue. Secretions were observed in the apical region of the principal cells' cytoplasm and along the epithelium edge, which may be related to gamete maintenance. Increased secretory activity of the principal cells was observed during periods of testicular activity. A reduction in the lumen of ductus deferens occurs during testicular regression, indicating possible fluid resorption by epithelial cells. Fluid resorption might be one of the mechanisms to ensure stored sperm viability, as it provides an increase in the glycoprotein’s concentration.

Life History Strategies Drive Meso-Scale Distribution Patterns in Coastal Benthic Macroinvertebrates.

The environment shapes the spatial distribution of species, but species also comprise suites of traits which may indicate their adaptability to a specific environment. This forms the basis of trait biogeography studies. We thus examined how a species distribution is not only influenced by its environment and traits, but by interactions among its traits. Trait information was collected for 150 intertidal macroinvertebrates along a 3000 km environmental and biogeographic gradient on the South African coast. This information was analysed, as functional entities (FEs) were species performing similar functions that have the same trait values and were further condensed into two trait domains (Reproduction and Lifestyle). We then defined Life History Strategies (LHS) as specific combinations of Lifestyle and Reproduction FEs. Seven combinations of Lifestyle and Reproduction formed LHS that dominated total biomass. Some of these LHS were ubiquitous, while others showed geographic patterns across our west-east environmental gradient. For Lifestyle, filter-feeders exhibited high abundances on the East (subtropical, oligotrophic) and West (cool-temperate, eutrophic) extremes of the biogeographic gradient, but differed between the two in size at reproductive maturity and larval development type. This similarity in functionality of feeding mechanism and mobility with different reproductive strategies suggests a trait trade-off (investment in one trait reduces resources for others) between the Reproduction and Lifestyle domains. Within the Reproduction domain, gonochoristic, annual planktotrophic reproduction was common across bioregions, reflecting spin-offs (investment in one trait facilitates another trait) among these traits. Gonochoristic investment in less frequent episodic reproduction is another trade-off, with investment in large size and delayed maturation being a trade-off for many reproductive cycles. Overall, although our data supports the habitat templet model (i.e., the importance of environmental drivers), it further indicates that species distribution patterns observed along the South African coast reflect strong trait interactions and biomass patterns related to their LHS.

Effect of long-term oral administration of the flavonoid quercetin on the antioxidant profile of young and adult reproductive rabbit does.

In industrialized farms, rabbit does undergo intensive production rhythms which overlap lactation and gestation, leading to a high energy mobilization and increasing oxidative stress. Accordingly, we hypothesize that administration of the flavonoid quercetin (QUR) may improve the antioxidant status of young and adult rabbit reproductive females. In this study, the effect of daily oral administration of 300 mg/kg QUR for 8 weeks was assessed on the antioxidant profile of 24 New Zealand × Californian rabbit does, assigned to 4 experimental groups: rearing young (8-16 weeks old) and adult does at the end of their reproductive life (12-14 months old, with at least 3-4 reproductive cycles) treated (YQ and AQ) or not (YC and AC) with QUR, respectively. Plasma glutathione (GSH), as well as serum superoxide dismutase (SOD) and malondialdehyde (MDA) were measured during the experimental period. To assess the health status of the animals, a physical examination was also performed. GSH plasma concentrations were significantly higher in young does at weeks 1 and 4, but not at week 8 of the experiment, irrespectively of QUR administration. An increase in GSH plasma concentration was observed during the 8-week experiment in both AQ and AC groups. Furthermore, QUR administration did not alter either SOD or MDA serum activity and concentration in any group during the experimental period. Physical examination revealed no differences between the experimental groups. In conclusion, under our experimental conditions, QUR did not modify the general clinical or the antioxidant profile of young and adult reproductive rabbit females.