Physiology and modulation factors of ovulation in rabbit reproduction management

Rabbit is an induced ovulatory species, so ovulation takes place after mating. Traditionally, exogenous and synthetic hormonal factors (administered by intramuscular and intravaginal route) such as GnRH and analogues, or different physical procedures (i.e. stimulation by intravaginal cannula) have been used to induce ovulation in females when artificial insemination is applied in rabbit farms. Restriction and public rejection of the use of hormones is leading to the study of the seminal plasma components with potential action on ovulation induction. The aim of the present review is to collect and summarise the strategies used in recent years to trigger ovulation and improve rabbit fertility management with respect to more animal-friendly manipulation methods. Furthermore, special attention has been paid to the use of a semen component (as endogen molecule) such as beta nerve growth factor (β-NGF) in male and female rabbit reproductive physiology. This neurotrophin and its receptors (TrKA and p75NTR) are abundantly distributed in both male and female rabbit reproductive tracts, and it seems to have an important physiological role in sperm maturation and behaviour (velocity, apoptosis and capacitation), as well as a modulatory factor of ovulation. Endogen β-NGF is diluted in the seminal doses with the extenders; hence it could be considered an innovative and alternative strategy to avoid the current exogenous (by intramuscular route) and stressful hormonal treatments used in ovulation induction. Their addition in seminal dose could be more physiological and improve animal welfare in rabbit farms.

Adolescents’ Perceptions of Sexual and Reproductive Health: Does the Adolescent School Health Club Intervention Matter?

Background: The aim of this study was to examine variations in perceptions of sexual and reproductive health of adolescents in Junior High Schools that implement the Adolescent health club intervention and those that do not. Methods: A cross-sectional quasi-experimental study design was used consisting of 424 adolescents (255 females) between 11years and 19 years old in schools that implement (private) and schools that do not implement (private and public) the intervention. Data was collected using a standardised questionnaire eliciting information about participants’ knowledge, attitude and behaviour towards their sexual and reproductive health. Chi squares, multiple regression analysis and one-way analysis of variance statistical techniques were used to analyse the data.Results: There were significant variations in knowledge about reproductive physiology and knowledge about condom use. Private schools with the health club intervention reported higher scores on both knowledge about reproductive physiology and knowledge about condom. Adolescents in private schools with the intervention had a more positive attitude towards abstinence. Adolescents in schools with the intervention were less likely to have had sex, use condoms, or have friends who have had sex compared to adolescents in schools that do to implement the intervention. Conclusion: The Adolescent health club intervention has a significant influence on Ghanaian adolescents’ sexual and reproductive health particularly knowledge about reproductive physiology and knowledge about condoms. It is recommended that the intervention be scaled up and intensified in Junior High Schools in Ghana.

Interneuron Control of C. elegans Developmental Decision-making

Animals integrate external stimuli to shape their physiological responses throughout development. In adverse environments, Caenorhabditis elegans larvae can enter a stress-resistant diapause state with arrested metabolism and reproductive physiology. Amphid sensory neurons feed into both rapid chemotactic and short-term foraging mode decisions, mediated by amphid and pre-motor interneurons, as well as the long-term diapause decision. We identify amphid interneurons that integrate pheromone cues and propagate this information via a neuropeptidergic pathways to influence larval developmental fate, bypassing the pre-motor system. AIA interneuron-derived FLP-2 neuropeptide signaling promotes reproductive growth and AIA activity is suppressed by pheromone. FLP-2 acts antagonistically to the insulin-like INS-1. FLP-2's growth promoting effects are inhibited by upstream metabotropic glutamatergic signaling and mediated by the broadly-expressed neuropeptide receptor NPR-30. Conversely, the AIB interneurons and their neuropeptide receptor NPR-9/GALR2 promote diapause entry. These neuropeptidergic outputs allow reuse of parts of a sensory system for a decision with a distinct timescale.

Reproductive endocrinology

This chapter covers multiple aspects of reproductive endocrinology in both male and female patients. Gender dysphoria is also included. It begins with reproductive physiology, then goes on to regulation of gonadal function. Hirsuitism, PCOS, and CAH in adults are all discussed with reference to evaluation, investigation, and treatment. Menstrual function disorders are described, as is menopause and hormone replacement therapy regimens. Contraception and emergency contraception are discussed. Male hypogonadism, androgen replacement therapy, gynaecomastia, and testicular tumours are all evaluated, alongside erectile dysfunction. The investigation and management of male and female infertility are both described, alongside fertility preservation and the induction of ovulation.

The Emerging Roles and Therapeutic Potential of Extracellular Vesicles in Infertility

Infertility is becoming much more common and affects more couples. The past years witnessed the rapid development of the diagnosis and treatment upon infertility, which give numerous coupled more opportunities become parents. Extracellular vesicles are known as nano-sized membrane vesicles to play a major role in intracellular communication. In recent years, several basic and clinical studies have tried to investigate the correlation between the reproductive health/disorder and extracellular vesicles. However, the mechanism is still unclear. In this review, we reviewed the relationship between reproductive physiology and extracellular vesicles, and then collectively focused on the recent findings on the relationship between extracellular and infertility, and its consequent influence on the novel insight regarding the therapeutic strategies for infertility in the future clinical practice.

Neuropeptide Bursicon Influences Reproductive Physiology in Tribolium Castaneum

Bursicon is a neuropeptide belonging to the cystine knot family and is composed of burs and partner of burs (pburs) subunits. It can form heterodimers or homodimers to execute different biological functions. Bursicon heterodimers regulate cuticle sclerotization and wing maturation, whereas bursicon homodimers mediate innate immunity and midgut stem cell proliferation. A recent study has shown that bursicon potentially induces the expression of vitellogenin (Vg) in the black tiger shrimp Penaeus monodon; however, the underlying mechanism remains unknown. In this study, we investigated the role of bursicon in the reproductive physiology of the red flour beetle, Tribolium castaneum. The knockdown of burs, pburs, or its receptor T. castaneum rickets (Tcrk) in 2-day pupae significantly downregulated the expression levels of Vg1, Vg2, and Vg receptor (VgR) genes in females 3- and 5-day post-adult emergence, leading to abnormal oocytes with limited Vg content. The silencing of burs repressed the number of eggs laid and completely inhibited egg hatch, whereas the silencing of pburs dramatically decreased the number of eggs laid, hatch rate, and offspring larval size, and this RNA interference (RNAi) effects persisted to the next generation. Furthermore, the knockdown of burs or pburs downregulated the expression of the insulin/insulin-like signaling/target of rapamycin (TOR) signaling genes encoding insulin receptor (InR), protein kinase B (Akt), TOR, and ribosomal protein S6 kinase (S6K). Most importantly, the injection of recombinant pburs (r-pburs) protein was able to upregulate the expression of Vg, VgR, InR, Akt, TOR, S6K, JH synthesis (JHAMT), Methoprene-tolerant (Met), and Taiman (Tai) in normal females and rescue the expression of Vg and VgR in pburs RNAi females but failed to rescue Vg and VgR in Tcrk knockdown females. We infer that bursicon homodimers influence Vg expression via the receptor Tcrk, possibly by mediating the expression of the juvenile hormone (JH) and IIS/TOR pathway genes, thereby regulating reproduction in T. castaneum.

Reproductive management of the goat

Objective: To share technical aspects with specialists in animal reproduction and producers that could help to improve the reproductive capacity of caprine livestock. Design/Methodology/Approach: Scientific evidence and experience in the reproductive management of goats are the basis that sustains the information presented in this article. Results: The goat is widely distributed in Mexico; it is a species with seasonal reproductive activity, but of easy manipulation with hormonal and natural means. Presently there is a large variety of biotechnologies that can be applied in the production units, to potentiate the reproductive activity of the goat. Study Limitations/Implications: The lack of knowledge and the lack of consulting and technical training limit the productive and reproductive potential of goat breeding in Mexico. Findings/Conclusions: Knowledge of the reproductive physiology of the goat and understanding of the means available to manipulate it guarantees its reproduction at the time and in the conditions desired by the producer and the market