Animal ReproductionPub Date : 2024-08-26eCollection Date: 2024-01-01DOI: 10.1590/1984-3143-AR2024-0064
Mariani Farias Fiorenza, Alessandra Bridi, Gislaine Dos Santos, Paola Maria Rosa, Luana Alves, Juliana Germano Ferst, Priscila Assis Ferraz, Guilherme Pugliesi, Ky Pohler, Felipe Perecin, Flávio Vieira Meirelles, Juliano Coelho da Silveira
{"title":"Labeled extracellular vesicles can be found in the blood plasma shortly after intrauterine infusion in bovine.","authors":"Mariani Farias Fiorenza, Alessandra Bridi, Gislaine Dos Santos, Paola Maria Rosa, Luana Alves, Juliana Germano Ferst, Priscila Assis Ferraz, Guilherme Pugliesi, Ky Pohler, Felipe Perecin, Flávio Vieira Meirelles, Juliano Coelho da Silveira","doi":"10.1590/1984-3143-AR2024-0064","DOIUrl":"https://doi.org/10.1590/1984-3143-AR2024-0064","url":null,"abstract":"<p><p>This study explored the migration of follicular fluid (FF)-derived extracellular vesicles (EVs) of the uterine environment to the bloodstream and their interaction with neutrophils <i>in vivo</i> and <i>in vitro</i>. For the <i>in vivo</i> experiment, six Nellore heifers (<i>Bos indicus</i>) received an intrauterine infusion seven days after ovulation with 1X PBS only (sham group; n=1), 1X PBS stained with lipophilic dye PKH26 (control group; n=2), or FF-derived EVs stained with PKH26 (treated group; n=3). Plasma was collected at 0, 10, 30, 60-, 180-, 360-, 720-, and 1440-min post-infusion to obtained EVs for analysis by nano flow cytometry. Labeled EVs were present in the bloodstream at 30- and 60-min post-infusion in the treatment group. Additionally, plasma derived-EVs from all groups were positive for Calcein-AM, Alix, Syntenin, and Calnexin, which confirm the presence of EVs. The second experiment utilized the plasma-derived EVs from the heifers from 30 and 60 min timepoints to evaluate if neutrophils can uptake EVs <i>in vitro</i>. As results, it was possible to observe the presence of labeled EVs in neutrophils treated with plasma derived-EVs from the treatment group. In summary, our results suggest that labeled EVs can migrate from the uterine environment rapidly and interact with circulating immune cells in bovine.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"21 3","pages":"e20240064"},"PeriodicalIF":1.6,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11404864/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142279390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Animal ReproductionPub Date : 2024-08-16eCollection Date: 2024-01-01DOI: 10.1590/1984-3143-AR2024-0068
Patrick Lonergan
{"title":"Embryo transfer: past, present, future - a personal perspective.","authors":"Patrick Lonergan","doi":"10.1590/1984-3143-AR2024-0068","DOIUrl":"10.1590/1984-3143-AR2024-0068","url":null,"abstract":"<p><p>Embryo transfer is just one of a range of assisted reproductive technologies - often the last one in a sequence of others - that has revolutionised the cattle breeding industry. The number of in vitro-produced embryos transferred annually now surpasses the number derived by traditional superovulation by a factor of four. Although issues with cryotolerance of IVP embryos, embryo loss, and, in some cases, calf birth weight remain to be fully resolved, IVP embryos are likely here to stay as a tool for genetic improvement in dairy herds, offering increased flexibility in sire usage allowing multiple pregnancies from elite dam-bull combinations to be generated and the ability to produce more embryos per unit time than traditional superovulation. What follows is a short personal look back at the last 30 years; if you are looking for deep insights into the underlying biology regulating embryo development, this is not the place to look! Please refer to some of the excellent recent reviews and research papers cited herein.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"21 3","pages":"e20240068"},"PeriodicalIF":1.6,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11340787/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142034953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sperm hyperactivation in the uterus and oviduct: a double-edged sword for sperm and maternal innate immunity toward fertility.","authors":"Ihshan Akthar, Mohamed Samy Yousef, Alireza Mansouri, Masayuki Shimada, Akio Miyamoto","doi":"10.1590/1984-3143-AR2024-0043","DOIUrl":"10.1590/1984-3143-AR2024-0043","url":null,"abstract":"<p><p>In cattle, artificial insemination (AI) is a technique that allows breeding by depositing frozen-thawed and extended semen into the female reproductive tract. The semen contains sperm with various motility patterns including dead, progressive and hyperactivated. Sperm hyperactivation is high amplitude, asymmetrical beating of sperm tail which usually occurs in the oviduct as part of the capacitation process, but it can also be induced by cryopreservation. After insemination, sperm enter the uterine glands and trigger a pro-inflammatory response in the uterus. Hyperactivated sperm, stimulated by sperm-Toll-like receptor 2 (TLR2), penetrates the mucus and uterine glands more efficiently and enhances the immune response. This facilitates the clearance of excess and dead sperm from the uterus. Some sperm escape the immune response and reach the oviduct either before or after the immune response is initiated. In the oviduct, sperm bind to the epithelium and form a reservoir. This triggers an anti-inflammatory response and preserves the fertilization potential of sperm. Hyperactivation facilitates sperm detaching from the epithelium, swimming through the viscous mucus and cumulus cells, and penetrating the egg's zona pellucida. Sperm-TLR2 activation enhances Ca<sup>2+</sup>-influx and acrosome reaction, which enables sperm to penetrate and fertilize oocytes during in vitro fertilization. Altogether, post-AI in cattle, sperm and maternal immunity interact differentially depending upon the site of sperm hyperactivation - whether it occurs within the uterus or oviduct. Specifically, hyperactivated sperm that enter the uterus after AI or are triggered via sperm-TLR2 activation or other stimuli contribute to sperm-induced uterine inflammation. Such hyperactivated sperm may impede their capacity to ascend to the oviduct. Conversely, sperm that become hyperactivated within the oviduct modulate their interactions with the oviduct and oocytes, which is pivotal during fertilization process. Indeed, the location and timing of sperm hyperactivation partially via TLR2 activation are critical determinants of their different influence on fertility.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"21 3","pages":"e20240043"},"PeriodicalIF":1.6,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11340796/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142035031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Animal ReproductionPub Date : 2024-08-16eCollection Date: 2024-01-01DOI: 10.1590/1984-3143-AR2024-0069
Joao Henrique Moreira Viana, Bianca Damiani Marques Silva, Rodrigo Martins de Moura, Luiz Fernando Rodrigues Féres, Ricardo Alamino Figueiredo
{"title":"Oocyte developmental potential and embryo production before puberty in cattle.","authors":"Joao Henrique Moreira Viana, Bianca Damiani Marques Silva, Rodrigo Martins de Moura, Luiz Fernando Rodrigues Féres, Ricardo Alamino Figueiredo","doi":"10.1590/1984-3143-AR2024-0069","DOIUrl":"10.1590/1984-3143-AR2024-0069","url":null,"abstract":"<p><p>With the development of <i>in vitro</i> technologies, embryos can be produced using oocytes retrieved directly from the ovaries, i.e., regardless of ovulation. This has allowed the use of different animal categories as oocyte donors, including prepubertal cattle. The advantages of using this strategy to shorten the generation interval and accelerate genetic gain over time were soon recognized, and the first offspring generated using oocytes collected from calves were born in the early 1990s. Nevertheless, embryo production from calves and prepubertal heifers remains a challenge. The oocytes collected before puberty present low <i>in vitro</i> developmental potential, and the subsequent blastocyst rates are consistently lower than those from pubertal females. The acquisition of developmental competence by the oocytes occurs progressively throughout the prepubertal period, which can be subdivided into an early, intermediate, and late prepubertal (or peripubertal) phases, each characterized by different physiological and endocrine features. Therefore, embryo yield increases with age but will only achieve its maximum after puberty. The most common strategy to improve oocyte developmental potential before puberty is the use of gonadotrophic stimulation prior to oocyte retrieval. The results with superstimulation, however, vary among studies, depending on the source, dose, and length of FSH treatment, as well as the age and breed of the donors. The use of calves and prepubertal heifers as oocyte donors should also consider the possible impacts of the oocyte retrieval technique (LOPU or OPU) and the use of exogenous hormones on their subsequent fertility and productive life.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"21 3","pages":"e20240069"},"PeriodicalIF":1.6,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11340790/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142034962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Animal ReproductionPub Date : 2024-08-16eCollection Date: 2024-01-01DOI: 10.1590/1984-3143-AR2024-0030
Lawrence Charles Smith, Luis Aguila Paredes, Rafael Vilar Sampaio, Ricardo Perecin Nociti, Jacinthe Therrien, Flavio Vieira Meirelles
{"title":"Haploid embryos and embryonic stem cells to produce offspring with predetermined parental genomes in cattle.","authors":"Lawrence Charles Smith, Luis Aguila Paredes, Rafael Vilar Sampaio, Ricardo Perecin Nociti, Jacinthe Therrien, Flavio Vieira Meirelles","doi":"10.1590/1984-3143-AR2024-0030","DOIUrl":"10.1590/1984-3143-AR2024-0030","url":null,"abstract":"<p><p>Selection strategies are performed post-fertilization when the random combination of paternal and maternal genomes has already occurred. It would be greatly advantageous to eliminate meiotic uncertainty by selecting genetically superior gametes before fertilization. To achieve this goal, haploid embryonic cells and embryonic stem cell lineages could be derived, genotyped, and used to substitute gametes. On the paternal side, androgenetic development can be achieved by removing the maternal chromosomes from the oocyte before or after fertilization. We have shown that once developed into an embryo, haploid cells can be removed for genotyping and, if carrying the selected genome, be used to replace sperm at fertilization. A similar strategy can be used on the maternal side by activating the oocyte parthenogenetically and using some embryonic cells for genotyping while the remaining are used to produce diploid embryos by fertilization. Placed together, both androgenetic and parthenogenetic haploid cells that have been genotyped to identify optimal genomes can be used to produce offspring with predetermined genomes. Successes and problems in developing such a breeding platform to achieve this goal are described and discussed below.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"21 3","pages":"e20240030"},"PeriodicalIF":1.6,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11340792/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142034958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Animal ReproductionPub Date : 2024-08-16eCollection Date: 2024-01-01DOI: 10.1590/1984-3143-AR2024-0033
Serge Leugoué Kameni, Notsile Hleliwe Dlamini, Jean Magloire Feugang
{"title":"Exploring the full potential of sperm function with nanotechnology tools.","authors":"Serge Leugoué Kameni, Notsile Hleliwe Dlamini, Jean Magloire Feugang","doi":"10.1590/1984-3143-AR2024-0033","DOIUrl":"10.1590/1984-3143-AR2024-0033","url":null,"abstract":"<p><p>Sperm quality is essential to guarantee the success of assisted reproduction. However, selecting high-quality sperm and maintaining it during (cryo)preservation for high efficiency remains challenging in livestock reproduction. A comprehensive understanding of sperm biology allows for better assessment of sperm quality, which could replace conventional sperm analyses used today to predict fertility with low accuracy. Omics approaches have revealed numerous biomarkers associated with various sperm phenotypic traits such as quality, survival during storage, freezability, and fertility. At the same time, nanotechnology is emerging as a new biotechnology with high potential for use in preparing sperm intended to improve reproduction in livestock. The unique physicochemical properties of nanoparticles make them exciting tools for targeting (e.g., sperm damage and sexing) and non-targeting bioapplications. Recent advances in sperm biology have led to the discovery of numerous biomarkers, making it possible to target specific subpopulations of spermatozoa within the ejaculate. In this review, we explore potential biomarkers associated with sperm phenotypes and highlight the benefits of combining these biomarkers with nanoparticles to further improve sperm preparation and technology.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"21 3","pages":"e20240033"},"PeriodicalIF":1.6,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11340799/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142034955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Animal ReproductionPub Date : 2024-08-12eCollection Date: 2024-01-01DOI: 10.1590/1984-3143-AR2024-0031
Marja Mikkola, Karolien Leen Jan Desmet, Elisabeth Kommisrud, Michael A Riegler
{"title":"Recent advancements to increase success in assisted reproductive technologies in cattle.","authors":"Marja Mikkola, Karolien Leen Jan Desmet, Elisabeth Kommisrud, Michael A Riegler","doi":"10.1590/1984-3143-AR2024-0031","DOIUrl":"10.1590/1984-3143-AR2024-0031","url":null,"abstract":"<p><p>Assisted reproductive technologies (ART) are fundamental for cattle breeding and sustainable food production. Together with genomic selection, these technologies contribute to reducing the generation interval and accelerating genetic progress. In this paper, we discuss advancements in technologies used in the fertility evaluation of breeding animals, and the collection, processing, and preservation of the gametes. It is of utmost importance for the breeding industry to select dams and sires of the next generation as young as possible, as is the efficient and timely collection of gametes. There is a need for reliable and easily applicable methods to evaluate sexual maturity and fertility. Although gametes processing and preservation have been improved in recent decades, challenges are still encountered. The targeted use of sexed semen and beef semen has obliterated the production of surplus replacement heifers and bull calves from dairy breeds, markedly improving animal welfare and ethical considerations in production practices. Parallel with new technologies, many well-established technologies remain relevant, although with evolving applications. <i>In vitro</i> production (IVP) has become the predominant method of embryo production. Although fundamental improvements in IVP procedures have been established, the quality of IVP embryos remains inferior to their <i>in vivo</i> counterparts. Improvements to facilitate oocyte maturation and development of new culture systems, e.g. microfluidics, are presented in this paper. New non-invasive and objective tools are needed to select embryos for transfer. Cryopreservation of semen and embryos plays a pivotal role in the distribution of genetics, and we discuss the challenges and opportunities in this field. Finally, machine learning (ML) is gaining ground in agriculture and ART. This paper delves into the utilization of emerging technologies in ART, along with the current status, key challenges, and future prospects of ML in both research and practical applications within ART.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"21 3","pages":"e20240031"},"PeriodicalIF":1.6,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11340803/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142035029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Animal ReproductionPub Date : 2024-08-12eCollection Date: 2024-01-01DOI: 10.1590/1984-3143-AR2024-0034
José Nélio de Sousa Sales, Guilherme Pugliesi, Laís Reis Carvalho, Luiz Manoel Sousa Simões, Lucas Araujo Lemos, Matheus Pedroso Vicente, Rafael Resende Rabelo Silva, Pietro Sampaio Baruselli
{"title":"Evolution over the last 40 years of the assisted reproduction technologies in cattle - the Brazilian perspective I - timed artificial insemination.","authors":"José Nélio de Sousa Sales, Guilherme Pugliesi, Laís Reis Carvalho, Luiz Manoel Sousa Simões, Lucas Araujo Lemos, Matheus Pedroso Vicente, Rafael Resende Rabelo Silva, Pietro Sampaio Baruselli","doi":"10.1590/1984-3143-AR2024-0034","DOIUrl":"10.1590/1984-3143-AR2024-0034","url":null,"abstract":"<p><p>The reproductive efficiency of the herd is correlated with higher productivity in livestock. Reproduction biotechniques, such as ovulation synchronization protocols, are important to optimize production and accelerate genetic profit in beef and dairy herds. The objective of this review is to describe the evolution over the last 40 years of the artificial insemination (AI) and the timed-AI (TAI) protocols in cattle from a Brazilian perspective. TAI protocols are based on synchronizing emergence of the wave of follicular growth, controlling circulating progesterone (P4) concentrations, stimulating the final growth of the follicle and inducing a synchronized ovulation. Hormonal alternatives that optimize the response at the end of the protocol and strategies to induce final follicle growth and ovulation in categories of females with low expression of estrus are described. Furthermore, the potential positive effect of previous exposure to injectable P4 on fertility of <i>Bos indicus</i> and <i>Bos taurus</i> cows is also discussed.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"21 3","pages":"e20240034"},"PeriodicalIF":1.6,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11340793/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142034954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Animal ReproductionPub Date : 2024-08-12eCollection Date: 2024-01-01DOI: 10.1590/1984-3143-AR2024-0041
Mario Binelli, Cecilia Constantino Rocha, Alexandra Bennett, Abdul Waheed, Halima Sultana, Mariângela Bueno Cordeiro Maldonado, Fernando Silveira Mesquita
{"title":"Solutions to the fertility equation in beef embryo recipients.","authors":"Mario Binelli, Cecilia Constantino Rocha, Alexandra Bennett, Abdul Waheed, Halima Sultana, Mariângela Bueno Cordeiro Maldonado, Fernando Silveira Mesquita","doi":"10.1590/1984-3143-AR2024-0041","DOIUrl":"10.1590/1984-3143-AR2024-0041","url":null,"abstract":"<p><p>In beef cattle operations that conduct embryo transfer, the overall success depends on the pregnancy outcome that results from every pregnancy opportunity. In this review, we dissected the main components that determine if a recipient will sustain the pregnancy after embryo transfer up to calving. Specifically, we describe the effect of the uterus on its ability to provide a receptive environment for embryo development. We then discuss the capacity of the embryo to thrive after transfer, and especially the contribution of the sire to embryo fitness. Finally, we review the interaction between the uterus and the embryo as an integrated unit that defines the pregnancy.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"21 3","pages":"e20240041"},"PeriodicalIF":1.6,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11340797/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142035030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Animal ReproductionPub Date : 2024-08-12eCollection Date: 2024-01-01DOI: 10.1590/1984-3143-AR2024-0048
Sarah West, Viviana Garza, Rodolfo Cardoso
{"title":"Puberty in beef heifers: effects of prenatal and postnatal nutrition on the development of the neuroendocrine axis.","authors":"Sarah West, Viviana Garza, Rodolfo Cardoso","doi":"10.1590/1984-3143-AR2024-0048","DOIUrl":"10.1590/1984-3143-AR2024-0048","url":null,"abstract":"<p><p>Reproductive maturation is a complex physiological process controlled by the neuroendocrine system and is characterized by an increase in gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) pulsatile secretion. Nutrition during early development is a key factor regulating puberty onset, which is defined as first ovulation in females. In heifers, nutrient restriction after weaning delays puberty, whereas elevated levels of nutrition and energy reserves advance reproductive maturation. Recent studies in cattle and other animal models have shown that the dam's nutrition during gestation can also program the neuroendocrine system in the developing fetus and has the potential to alter timing of puberty in the offspring. Among the metabolic signals that modulate brain development and control timing of puberty is leptin, a hormone produced primarily by adipocytes that communicates energy status to the brain. Leptin acts within the arcuate nucleus of the hypothalamus to regulate GnRH secretion via an upstream network of neurons that includes neurons that express neuropeptide Y (NPY), an orexigenic peptide with inhibitory effects on GnRH secretion, and alpha melanocyte-stimulating hormone (αMSH), an anorexigenic peptide with excitatory effects on GnRH neurons. Another important population of neurons are KNDy neurons, neurons in the arcuate nucleus that co-express the neuropeptides kisspeptin, neurokinin B, and dynorphin and have strong stimulatory effects on GnRH secretion. Our studies in beef heifers indicate that increased nutrition between 4 to 8 months of age advances puberty by diminishing NPY inhibitory tone and by increasing excitatory inputs of αMSH and kisspeptin, which collectively lead to increased GnRH/LH pulsatility. Our ongoing studies indicate that different planes of nutrition during gestation can alter maternal leptin concentrations and promote changes in the fetal brain. Nonetheless, at least in <i>Bos indicus</i>-influenced heifers, deficits programmed prenatally can be overcome by adequate postnatal nutrition without negatively impacting age at puberty or subsequent fertility.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"21 3","pages":"e20240048"},"PeriodicalIF":1.6,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11340802/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142035028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}