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The term 'mitochondrial vesicle' was first used in 2003 in a description of anuran sperm and persists to this day throughout the literature on assisted reproductive technologies (ART) for amphibians. In the present paper, we argue that the term is inappropriate because the widely accepted definition of a 'vesicle' refers to an integral structure with an enclosing lipid bilayer/membrane. Moreover, there are no electron micrographs that show a vesicular structure encapsulating mitochondria on amphibian sperm heads in the literature. In fact, in 1993, the mitochondria in the anuran sperm head had been described as positioned in 'mitochondrial collars' or 'mitochondrial sheaths' surrounded by the plasma membrane of the sperm head. On the other hand, mitochondrial-derived vesicles are defined as vesicles shed from mitochondria surfaces, potentially creating confusion. Therefore, our view is that the term 'mitochondrial vesicle' should be avoided in describing the positioning of mitochondria on sperm.

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This summary addresses the use of reproduction technologies in swine farming, with an emphasis on artificial insemination (AI). Brazilian swine farming has been growing significantly and seeks new technologies to achieve high productive indices sustainably and competitively. Pigs present favorable characteristics such as high prolificacy, fertility, rapid growth, feed efficiency, and carcass yield, which has led to intensive development of the activity with advanced genetic selection. AI is widely employed to disseminate genetic material among different regions and farms. Several AI techniques are used in modern swine farming: intrauterine insemination (IUI) allows semen deposition in the uterine region, reducing costs; fixed-time insemination (FTAI) synchronizes estrus in various females, facilitating management and increasing efficiency; deep intrauterine insemination (DIUI) deposits semen in the uterine horns, obtaining better results; and cervical insemination (CI), a traditional technique widely used, although it may be more time-consuming and present higher reflux rates. The success of AI is related to knowledge of the reproductive cycle of sows, proper nutrition, and genetic and environmental factors. Semen quality is essential, requiring collection by trained professionals and evaluation of sperm motility and morphology. Although it is a consolidated technique, there are issues to be further explored to optimize its application, defining the exact moment for insemination, reducing reflux, and adopting effective protocols. AI is an essential tool for the growth of Brazilian swine farming, but it requires continuous studies to maximize its efficiency and results, considering the farm's production goal and the size of the enterprise to achieve high reproductive and productive indices.

Este resumo aborda o uso de tecnologias de reprodução na suinocultura, com ênfase na inseminação artificial (IA). A suinocultura brasileira vem crescendo significativamente e busca novas tecnologias para alcançar altos índices produtivos de maneira sustentável e competitiva. Os suínos apresentam características favoráveis, como alta prolificidade, fertilidade, rápido crescimento, eficiência alimentar e rendimento de carcaça, o que levou ao desenvolvimento intensivo da atividade com seleção genética avançada. A IA é amplamente empregada para disseminar material genético entre diferentes regiões e granjas. Diversas técnicas de IA são utilizadas na suinocultura moderna: a inseminação intrauterina (IAIU) permite a deposição do sêmen na região uterina, reduzindo custos; a inseminação em tempo fixo (IATF) sincroniza o estro em várias fêmeas, facilitando o manejo e aumentando a eficiência; a inseminação intrauterina profunda (IAUP) deposita o sêmen nos cornos uterinos, obtendo melhores resultados; e a inseminação cervical (IAC), técnica tradicional amplamente utilizada, embora possa ser mais demorada e apresentar maiores taxas de refluxo. O sucesso da IA estar relacionado ao conhecimento do ciclo reprodutivo das matrizes, à nutrição adequada e aos fatores genéticos e ambientais. A qualidade do sêmen é essencial, exigindo coleta por profissionais treinados e avaliação da motilidade e morfologia dos espermatozoides. Apesar de ser uma técnica consolidada, há questões a serem aprofundadas para otimizar sua aplicação, definindo o momento exato para a realização da inseminação, a redução do refluxo e adoção de protocolos eficazes. A IA é uma ferramenta essencial para o crescimento da suinocultura brasileira, mas requer estudos contínuos para maximizar sua eficiência e resultados, considerando o objetivo produtivo da granja e o tamanho do empreendimento para alcançar altos índices reprodutivos e produtivos.

Este resumen aborda el uso de tecnologías de reproducción en la producción porcina, con énfasis en la inseminación artificial (IA). La producción porcina brasileña ha crecido significativamente y busca nuevas tecnologías para alcanzar altos índices de productividad de manera sostenible y competitiva. Los cerdos presentan características favorables, como alta prolificidad, fertilidad, rápido crecimiento, eficiencia alimentaria y rendimiento de la canal, lo que ha llevado al desarrollo intensivo de la actividad con selección genética avanzada. La IA se utiliza ampliamente para difundir material genético entre diferentes regiones y granjas. Diversas técnicas de IA son utilizadas en la producción porcina moderna: la inseminación intrauterina (IAIU) permite la deposición del semen en la región uterina, reduciendo costos; la inseminación a tiempo fijo (IATF) sincroniza el estro en varias hembras, facilitando el manejo y aumentando la eficiencia; la inseminación intrauterina profunda (IAUP) deposita el semen en los cuernos uterinos, obteniendo mejores resultados; y la inseminación cervical (IAC), técnica tradicional ampliamente utilizada, aunque puede ser más demorada y presentar mayores tasas de reflujo. El éxito de la IA está relacionado con el conocimiento del ciclo reproductivo de las hembras, la nutrición adecuada y los factores genéticos y ambientales. La calidad del semen es esencial, requiriendo la recolección por profesionales capacitados y la evaluación de la motilidad y morfología de los espermatozoides. A pesar de ser una técnica consolidada, hay aspectos que deben ser profundizados para optimizar su aplicación, como la definición precisa del momento de la inseminación, la reducción del reflujo y la adopción de protocolos eficaces. La IA es una herramienta esencial para el crecimiento de la producción porcina brasileña, pero requiere estudios continuos para maximizar su eficiencia y resultados, considerando el objetivo productivo de la granja y el tamaño del emprendimiento para alcanzar altos índices reproductivos y productivos.

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Methane emission from beef and dairy cattle combined contributes around 4.5-5.0% of total anthropogenic global methane. In addition to enteric methane (CH4) produced by the rumen, cattle production also contributes carbon dioxide (CO2) (feed), nitrous oxide (N2O) (feed production, manure) and other CH4 (manure) to the total greenhouse gas (GHG) budget of beef and dairy production systems. The relative contribution in standard dairy systems is typically enteric CH4 58%, feed 29% and manure 10%. Herds with low production efficiency can have an enteric CH4 contribution up to 90%. Digestibility of feed can impact CH4 emission intensity. Low fertility herds also have a greater enteric CH4 contribution. Animals with good feed conversion efficiency have a lower emission intensity of CH4/kg of meat or milk. Feed efficient heifers tend to be lean and have delayed puberty. Fertility is a major driver of profit in both beef and dairy cattle, and it is highly important to apply multi-trait selection when shifting herds towards improved efficiency and reduced CH4. Single nucleotide polymorphisms (SNPs) have been identified for feed efficiency in cattle and are used in genomic selection. SNPs can be utilized in artificial insemination and embryo transfer to increase the proportion of cattle that have the attributes of efficiency, fertility and reduced enteric CH4. Prepubertal heifers genomically selected for favourable traits can have oocytes recovered to produce IVF embryos. Reproductive technology is predicted to be increasingly adopted to reduce generation interval and accelerate the rate of genetic gain for efficiency, fertility and low CH4 in cattle. The relatively high contribution of cattle to anthropogenic global methane has focussed attention on strategies to reduce enteric CH4 without compromising efficiency and fertility. Assisted reproductive technology has an important role in achieving the goal of multiplying and distributing cattle that have good efficiency, fertility and low CH4.(AU)

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This article provides an overview of assisted reproductive technologies (ART) and genome engineering to improve livestock production systems for the contribution of global sustainability. Most ruminant production systems are conducted on grassland conditions, as is the case of South American countries that are leaders in meat and milk production worldwide with a well-established grass-feed livestock. These systems have many strengths from an environmental perspective and consumer preferences but requires certain improvements to enhance resource efficiency. Reproductive performance is one of the main challenges particularly in cow-calf operations that usually are conducted under adverse conditions and thus ART can make a great contribution. Fixed-time artificial insemination is applied in South America in large scale programs as 20 to 30% of cows receive this technology every year in each country, with greater calving rate and significant herd genetic gain occurred in this region. Sexed semen has also been increasingly implemented, enhancing resource efficiency by a) obtaining desired female replacement and improving animal welfare by avoiding newborn male sacrifice in dairy industry, or b) alternatively producing male calves for beef industry. In vitro embryo production has been massively applied, with this region showing the greatest number of embryos produced worldwide leading to significant improvement in herd genetics and productivity. Although the contribution of these technologies is considerable, further improvements will be required for a significant livestock transformation and novel biotechnologies such as genome editing are already available. Through the CRISPR/Cas-based system it is possible to enhance food yield and quality, avoid animal welfare concerns, overcome animal health threats, and control pests and invasive species harming food production. In summary, a significant enhancement in livestock productivity and resource efficiency can be made through reproductive technologies and genome editing, improving at the same time profitability for farmers, and global food security and sustainability.(AU)

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The establishment and maintenance of a pregnancy that goes to term is sine qua non for the long-term sustainability of dairy and beef cattle operations. The oocyte plays a critical role in providing the factors necessary for preimplantation embryonic development. Furthermore, the female, or maternal, environment where oocytes and embryos develop is crucial for the establishment and maintenance of a pregnancy to term. During folliculogenesis, the oocyte must sequentially acquire meiotic and developmental competence, which are the results of a series of molecular events preparing the highly specialized gamete to return to totipotency after fertilization. Given that folliculogenesis is a lengthy process in the cow, the occurrence of disease, metabolic imbalances, heat stress, or other adverse events can make it challenging to maintain oocyte quality. Following fertilization, the newly formed embryo must execute a tightly planned program that includes global DNA remodeling, activation of the embryonic genome, and cell fate decisions to form a blastocyst within a few days and cell divisions. The increasing use of assisted reproductive technologies creates an additional layer of complexity to ensure the highest oocyte and embryo quality given that in vitro systems do not faithfully recreate the physiological maternal environment. In this review, we discuss cellular and molecular factors and events known to be crucial for proper oocyte development and maturation, as well as adverse events that may negatively affect the oocyte; and the importance of the uterine environment, including signaling proteins in the maternal-embryonic interactions that ensure proper embryo development. We also discuss the impact of assisted reproductive technologies in oocyte and embryo quality and developmental potential, and considerations when looking into the prospects for developing systems that allow for in vitro gametogenesis as a tool for assisted reproduction in cattle.(AU)

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Advancements in assisted reproduction (AR) methodologies have allowed significant improvements in live birth rates of women who otherwise would not be able to conceive. One of the tools that allowed this improvement is the possibility of embryo selection based on genetic status, performed via preimplantation genetic testing (PGT). Even though the widespread use of PGT from TE biopsy helped to decrease the interval from the beginning of the AR intervention to pregnancy, especially in older patients, in AR, there are still many concerns about the application of this invasive methodology in all cycles. Therefore, recently, researchers started to study the use of cell free DNA (cfDNA) released by the blastocyst in its culture medium to perform PGT, in a method called non-invasive PGT (niPGT). The development of a niPGT would bring the diagnostics power of conventional PGT, but with the advantage of being potentially less harmful to the embryo. Its implementation in clinical practice, however, is under heavy discussion since there are many unknowns about the technique, such as the origin of the cfDNA or if this genetic material is a true representative of the actual ploidy status of the embryo. Available data indicates that there is high correspondence between results observed in TE biopsies and the ones observed from cfDNA, but these results are still contradictory and highly debatable. In the present review, the advantages and disadvantages of niPGT are presented and discussed in relation to tradition TE biopsy-based PGT. Furthermore, there are also presented some other possible non-invasive tools that could be applied in the selection of the best embryo, such as quantification of other molecules as quality biomarkers, or the use artificial intelligence (AI) to identify the best embryos based on morphological and/or morphokitetic parameters.(AU)

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A reprodução ex situ de felinos silvestres assegura a sobrevivência das espécies ameaçadas por meio do estabelecimento e manutenção de populações viáveis em cativeiro. O conhecimento da biologia reprodutiva básica é essencial para o desenvolvimento de planos de manejo reprodutivo (PMRs) eficientes, seja pela reprodução natural ou pela aplicação de técnicas de reprodução assistida (TRAs). Os PMRs visam garantir a representatividade das espécies quanto à variabilidade genética e demográfica baseada nos studbooks. Entretanto, o pareamento de animais selecionados pelos PMRs deve levar em conta, além de fatores genéticos e demográficos, fatores comportamentais e o fenótipo dos animais, uma vez que pode haver consequências negativas caso descendentes de gerações futuras sejam reintroduzidos na natureza. As TRAs estão cada vez mais sendo desenvolvidas para auxiliar na manutenção de populações geneticamente viáveis ex situ que possam contribuir geneticamente com populações in situ. A criopreservação de sêmen e a inseminação artificial (IA) são as TRAs utilizadas atualmente pelos PMR nacionais e internacionais, no entanto, são muitos os desafios para que as populações cativas se reproduzam de maneira adequada visando a manutenção de uma população viável que possa contribuir com populações de vida livre no futuro.(AU)

Reproductive management plans are essential to ensure that imperiled populations maintain adequate genetic and demographic variability and remain representative of the species as a whole. Basic reproductive biology knowledge is essential for the development of efficient reproductive management plans (PMPs), either through natural breeding or through assisted reproductive techniques (ARTs). The PMPs aim to ensure the representativeness of the species in terms of genetic and demographic variability based on studbooks. However, the specific animal pairings should be maintaining adequate genetic, behavioral and the phenotype of the animals, ensuring proper reintroduction of animals into the wild. ARTs have been explored as a means to enhance the conservation of endangered species, focused on maintaining genetic diversity through enhanced animal propagation. Semen cryopreservation and artificial insemination (AI) are used by national and international PMRs, however, there are many challenges for captive populations reproduction in order to maintain a viable population that can contribute for freeliving populations in the future.(AU)

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This study aimed to compare domestic cats' pregnancy rates using fresh semen for the bilateral intrauterine insemination (BIUI) method and the novel uterine body insemination (UBI) method. Queens received a single injection of equine chorionic gonadotropin (eCG) (200 IU; IM) to induce ovarian follicular development and, after 83 h, an injection of human chorionic gonadotropin (hCG) (100 IU; IM) for final oocyte maturation and ovulation induction. Thirty-four hours after hCG administration, 3 × 106fresh spermatozoa were used for insemination by the BIUI (n = 8 queens) or by the UBI (n = 7 queens) techniques,respectively. Pregnancy rates were 75.00% (6/8) by BIUI and 42.85% (3/7) by the UBI method. Themean litter size was 3.0 ± 0.86 for the BIUI, and 2.0 ± 1.0 for the UBI method. Spontaneous abortion occurred on day 35 of pregnancy in one queen following the UBI method. Our findings showed that the BIUI of queens with fresh semen resulted in higher pregnancy rates than the novel UBI method; also, acceptable pregnancy rates were achieved following BIUI with fresh semen in the domestic cat.(AU)

O objetivo deste estudo foi comparar as taxas de prenhez em gatas domésticas usando sêmen fresco para o método de inseminação intrauterina bilateral (BIUI) e o novo método de inseminação do corpo uterino (UBI). As gatas receberam uma única injeção de gonadotrofina coriônica equina (eCG) (200 UI; IM) para induzir o desenvolvimento folicular ovariano e, após 83 h, uma injeção de gonadotrofina coriônica humana (hCG) (100 UI; IM) para maturação final do oócito e ovulação indução. Trinta e quatro horas após a administração de hCG, 3 × 106 espermatozoides frescos foram utilizados para inseminação pelas técnicas de BIUI (n = 8 gatas) ou UBI (n = 7 gatas), respectivamente. As taxas de gravidez foram de 75,00% (6/8) pela BIUI e 42,85% (3/7) pelo método UBI. O tamanho médio da ninhada foi de 3,0 ± 0,86 para o método BIUI e 2,0 ± 1,0 para o método UBI. Aborto espontâneo ocorreu no dia 35 de gestação em uma gata seguindo o método UBI. Nossos achados mostraram que a BIUI de gatas com sêmen fresco resultou em maiores taxas de prenhez do que o novo método UBI; também, taxas de prenhez aceitáveis foram alcançadas após BIUI com sêmen fresco no gato doméstico.(AU)

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As tecnologias de reprodução assistida (TRA) são de fundamental importância para a conexão de indivíduos em diferentes localidades, facilitando assim o intercâmbio genético e favorecendo a variabilidade genética de uma espécie. Por esta razão, as TRAS podem ser ferramentas importantes para a conservação de espécies ameaçadas de extinção. Apesar dos esforços nas últimas décadas, o avanço no desenvolvimento de tais tecnologias está aquém à urgência de reverter processos de baixa variabilidade genética em algumas espécies. A necessidade de refinamento das técnicas para as particularidades fisiológicas e comportamentais de cada espécie, somada à raridade de acesso aos animais são os principais fatores relacionados as dificuldades em se avançar com as TRAS. As técnicas mais recentes desenvolvidas para a recuperação de espermatozoides em animais selvagens são a colheita farmacológica, com uso de alfa-2-agonistas e a criopreservação / vitrificação testicular com posterior cultivo. Pouco de avançou, no entanto, em relação aos métodos de criopreservação, prevalecendo associação clássica de TRIS-gema-glicerol. Discutimos, então os métodos usados para acesso ao gameta masculino em espécies selvagens e suas aplicações na conservação animal.(AU)

Assisted reproduction technologies (ART) are of fundamental importance for connecting individuals in different locations, thus facilitating genetic exchange and favoring the genetic variability of a species. For this reason, TRAS can be important tools for the conservation of endangered species. Despite efforts in recent decades, the advance in the development of such technologies is short of the urgency of reversing processes of low genetic variability in some species. The need to refine the techniques for the physiological and behavioral particularities of each species, added to the rarity of access to animals, are the main factors related to the difficulties in advancing with TRAS. The most recent techniques developed for sperm collection in wild animals are pharmacological collection, with the use of alpha-2-agonists and testicular cryopreservation / vitrification with subsequent cultivation. Little progress has been made, however, in relation to cryopreservation methods, prevailing the classic association of TRIS-yolk-glycerol. We therefore discuss the methods used to access the male gamete in wild species and their applications in animal conservation.(AU)

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Although reproduction in small animals is relatively current, its objectives are very varied. Initially they were used as a study model in physiology and various pathologies. In the same way, many small animals are produced as food and finally, in the last 20 years, the importance of pets and the intensification in the selection of canine and feline breeds, has caused an important impulse in the development of new scientific information. Although currently technical resources have advanced substantially, there are still many basic and important issues that have not yet been elucidated by formal science. Global threats facing wild species include the consequences of climate change, population growth, urbanization, air and water pollution, and the release of chemicals into the environment, causing, on average, 25% of animals are in danger of extinction. Wild animal populations are small and dispersed in their habitat with little or no opportunity for genetic exchange, which has generated in recent years many programs to preserve wild species and design appropriate strategies that lead to sustainable populations. Fortunately, recent and inspiring advances in the science of wildlife reproduction have been reported that will set directions for future research and will surely lead to further successes in conservation biology.(AU)

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Male dog fertility disorders are usually troublesome and challenging for a practicing veterinarian. It may be generally assumed, that reproductive potential in this species is lower than in farm animals and it is still decreasing. This situation starts to be similar to human medicine, where we observe dramatic drop of reproductive capacity, which resulted in the need of implementation of Assisted Reproductive Technologies (ART). Situation in dogs is more complicated owing the fact, that the use of ART meets many obstacles. Low fertility potential in dogs appears to be the result of variable factors such as: specific criteria of selection for reproduction in which fertility performance in not a priority, lack of periodical obligatory fertility check, species specific predisposition for many reproductive diseases and no age limit for reproductive use of males. Dogs are kept in human environment and exposition for civilizational byproducts influences negatively not only on our health, but also on health our 'minor brothers'. It should be bear in mind, that reproductive organs are very sensitive for environmental factors disrupting homeostatic balance. The decline in male dog fertility over the past decades was proved, with potential link to environmental contaminants (4). They were found in pet foods and were also detected in the sperm and testes of adult dogs causing a detrimental effects on sperm function. Over the 26 years of the study of Lea et al. (4), authors found a decrease in the percentage of normal motile sperm. Between 1988 and 1998, sperm motility declined by 2.5 per cent per year. Then from 2002 to 2014 sperm motility continued to decline at a rate of 1.2% per year. In addition, the male pups had an increased incidence of cryptorchidism. Basics of physiology of reproduction of male dogs. Normally the puberty in males is associated with presence of normal sperm cells in genital organs. It is reached in male dogs at age around 5-6 months. Such a young dog obviously cannot be used for reproduction. Reproductive maturity is associated later, with development of normal sexual behavior and production of sufficient number of normal, fertilizing competent spermatozoa. It corresponds with 12-18 months of animal age. Testicular descent is completed usually before weaning period, but sometimes testicles may reach scrotum later, but never after the end of 6 month of age. That time inguinal canals start to be so narrow, that caudal passing of gonads is unlikely. Male dogs have only one accessory sexual gland - prostate, which produces vast portion of seminal plasma.(AU)

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In recent years, there has been a great interest of purebred cat breeders in the possibilities and benefits of implementing of consistent veterinary care on reproduction. This includes tools available in the field of Assisted Reproductive Technologies (ART). As in dogs before, there is a tendency to reduce the reproductive potential of purebred cats, which is partly due to the nature of the selection of animals for reproduction on the basis of phenotypic features, omitting the control of their fertility. It is worthy to note hazardous specificity of this selection where inbreeding is commonly used. If all this is imposed on the frequent occurrence of infectious diseases in a domestic cat, then the population of purebred cats appears as a group of animals, which is a kind of challenge for a specialist of reproduction. This is a paradoxical phenomenon, because regarding non-purebred cats, the main challenge for the veterinary community is to limit their population. Some of the most important barriers to the implementation of advanced control of reproduction of purebred cats over the years have been: 1) difficulties with sperm collection, 2) technically troublesome artificial insemination, 3) numerous and difficult to recognize and treat forms of fertility disorders. In recent years, progress has been observed within each of these areas. It is possible to implement into practice extremely valuable tools that are helpful in monitoring the reproductive status of these animals. The breakthrough was the development of effective methods of semen collection, its evaluation and preservation and the development of increasingly effective methods of artificial insemination. Therefore, there is a real prospect of organizing cat reproduction centers operating within veterinary facilities dealing with small animals. The time is coming to carry out veterinary care for cat reproduction at such an advanced level as it has been developed in recent decades for dogs. Development in this area is facilitated by progress in research on the field of the use of ART in programs of rescue of endangered feline species where domestic cat is treated as model animal.(AU)

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Assisted Reproductive Technologies (ART) are currently used in animals usually in three main situations: 1. As a form of treatment of subfertility and infertility in females and/or males, 2. As a method to obtain genetically valuable progeny in relatively short time in healthy fertile animals, 3. As a modern smart tool to obtain progeny in endangered animal species in programs of rescue of wild animals threatened extinction. Generally the efficiency of reproductive biotechniques in dogs and cats is lower in comparison to obtained in farm animals and in human. Independently of the aim of their use, there are some techniques, which are better developed in dogs and some others seems to be better developed in cats. It may be assumed that simple, clinical techniques are well elaborated and more frequently used in dogs while more advanced techniques are better developed in cats. The level of effectiveness of ART is conditioned by anatomical and physiological factors specific for species, general demands for their use in veterinary practice and research, and general interest of breeders and scientific community in such activity.(AU)

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In vitro fertilization and somatic cell nuclear transfer are assisted reproduction technologies commonly used in humans and cattle, respectively. Despite advances in these technologies, molecular failures can occur, increasing the chance of the onset of imprinting disorders in the offspring. Large offspring syndrome/abnormal offspring syndrome (LOS/AOS) has been described in cattle and has features such as hypergrowth, malformation of organs, and skeletal and placental defects. In humans, Beckwith-Wiedemann syndrome (BWS) has phenotypic characteristics similar to those found in LOS/AOS. In both syndromes, disruption of genomic imprinting associated with loss of parental-specific expression and parental-specific epigenetic marks is involved in the molecular etiology. Changes in the imprinting pattern of these genes lead to loss of imprinting (LOI) due to gain or loss of methylation, inducing the emergence of these syndromes. Several studies have reported locus-specific alterations in these syndromes, such as hypomethylation in imprinting control region 2 (KvDMR1) in BWS and LOS/AOS. These LOI events can occur at multiple imprinted loci in the same affected individual, which are called multi-locus methylation defect (MLMD) events. Although the bovine species has been proposed as a developmental model for human imprinting disorders, there is little information on bovine imprinted genes in the literature, even the correlation of epimutation data with clinical characteristics. In this study, we performed a systematic review of all the multi-locus LOI events described in human BWS and LOS/AOS, in order to determine in which imprinted genes the largest changes in the pattern of DNA methylation and expression occur, helping to fill gaps for a better understanding of the etiology of both syndromes.

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A reprodução assistida se faz necessária em programas de conservação de espécies ameaçadas de extinção, sendo um facilitador de transporte e troca de material genético. Neste contexto, o acesso ao material de animais de vida livre é essencial para incrementar o banco genético da espécie em questão, no entanto adaptar os métodos possíveis à realidade do campo torna essa área de pesquisa desafiadora. Ainda hoje os espermatozoides são os gametas mais acessados em animais de vida livre, porém com pouco uso efetivo para criopreservação e produção de filhotes. É pungente a necessidade de mais pesquisas nesta área, uma vez que há centenas de espécies brasileiras ameaçadas, com especificidades fisiológicas e que habitam habitats variados, o que demanda adaptações espécie-específicas e hábitat específicas.

Assisted reproduction is necessary for conservation programs for endangered species, facilitating transport and exchange of genetic material. In this context, access to material from free-living animals is essential to increase the genetic bank of the species in question. However, adapting the possible methods to the reality of the fieldwork makes this area of research a challenge. Even today, sperm are the most accessed gametes in free-living animals, but with little effective use for cryopreservation and production of offspring. The need for more research in this area is acute, as there are hundreds of Brazilian species under threat, with physiological specificities, and that inhabit varied habitats, which demand species-specific adaptations and specific habitats.

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Studying reproduction in wild animals is complex as there are as many biological traits as there are species. What we currently know is minimal compared to the large number of species that remain unstudied. In addition to the impressive diversity of natural mechanisms, other complexities limit the progress of wildlife reproductive science - little interest in animal reproduction, difficult access to animals, lack of expertise, hard working conditions, and insufficient funding. Despite those challenges, some species are being saved from extinction with the help of a precise understanding of reproduction, development of assisted reproductive technologies, and creations of cryo-banks. Those advances originate from huge progresses in non-invasive measurements of steroid metabolites in urine or fecal samples to study and monitor reproductive functions and pregnancies. Progresses in cryobiology also have been impactful in animal conservation. Importantly, emerging technologies (transcriptomics, microfluidics) and additional research areas (reproductive aging, microbiomes) could lead to more successes and address current challenges in the reproduction of rare and endangered species. However, while some emerging approaches like stem cell technologies may sound promising, it is necessary to design holistic strategies considering all available tools to optimize investments, time, and efforts in conservation.

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This study examined the artificial breeding and embryonic development of a mountainous fish species Garra cambodgiensis (Tirant, 1883) found in Promlok waterfall in Khaoluang National park, Phromkhiri district, Nakhon Si Thammarat province. The fishes were collected from June 2017- January 2018 and kept in aquaria. Afterward, the brood males and females were selected and injected with buserelin (LHRHa) (10 µg/kg body weight) and domperidone (10 mg/kgbody weight). After the injections, both females and males were kept together in the water at a proportion of 3 females: 1male. The fertilization of eggs started after 4 hours and 30minutes. The fertilized eggs were greenish-grey and semi-buoyant. After fertilization, one blastodisc turned into 2 equalsized blastomeres, and then each cell divided into 4, 8, 16, 32,64 cells respectively. The morula stage went to the blastula stage in about 3hr and 28 min, to gastrula stage in about 5 hr and 11 min, and to the somite stage in about 7 hr and 7 min. The optical vesicles and auditory vesicles developed after approximately 8 hr and 27 min, and 10 hr and 30 min, respectively. After approximately 12 hours and 58 minutes of fertilization, hatching of eggs occurred. Nowadays, the numbers of G. Cambodgienesis are declining rapidly in southern Thailand due to several environmental and anthropogenic reasons. Therefore, it is very important to conserve the populations of G. Cambodgienesis. Artificial breeding could be an effective way to conserve and restore this fish in their natural habitat in southern Thailand.(AU)

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The objective of this study was to evaluate the sperm quality obtained of domestic cats by electroejaculation and recovery of the tail of the epididymis after cooling at -1°C and 4°C for 24 and 48 hours. Twenty-nine adult cats (2 to 6kg) were used. Sperm collection was performed by electroejaculation (EEJ), and after 48 hours, the cats were orchiectomized, and sperm sample was obtained from the vas deferens and epididymis tail (EPD). The samples were diluted in ACP-117® extender, and the sperm characteristics were evaluated at three different moments: when still fresh, 24 and 48 hours after cooling. The objective of this study was to evaluate the sperm quality obtained of domestic cats by electroejaculation and recovery of the tail of the epididymis after cooling at -1°C and 4°C for 24 and 48 hours. Twenty-nine adult cats (2 to 6kg) were used. Sperm collection was performed by electroejaculation (EEJ), and after 48 hours, the cats were orchiectomized, and sperm sample was obtained from the vas deferens and epididymis tail (EPD). The samples were diluted in ACP-117® extender, and the sperm characteristics were evaluated at three different moments: when still fresh, 24 and 48 hours after cooling. In order to compare the two refrigeration temperatures, the first stage was to analyze if there was a difference between the harvesting techniques. After this, two experiments were conducted: in the first, sperm sample from 14 cats were used and the cooling was performed at -1°C; and in the second, sample from 15 cats were used and the sperm were refrigerated at 4°C. Sperm kinetics were evaluated by computerized analysis (CASA) and concentration by Neubauer chamber, spermatic morphology was evaluated by modified Karras staining, and membrane integrity was evaluated by eosin nigrosine. The results obtained were analyzed in R software, version 3.2.5 using the Mann-Whitney test for variables with abnormal distributions, considering significance at the level of 5%...(AU)

O objetivo deste trabalho foi avaliar a qualidade espermática de gatos domésticos obtidos por eletroejaculação e recuperação da cauda do epidídimo após a refrigeração a -1°C e a 4°C por 24 e 48 horas. Vinte e nove gatos adultos (2 a 6kg) foram utilizados. A colheita de espermatozoides foi realizada por eletroejaculação (EEJ) e, após 48 horas, os gatos foram orquiectomizados, e as amostras espermáticas foram obtidas a partir do ducto deferente e da cauda do epidídimo (EPD). As amostras foram diluídas em ACP-117® e as características espermáticas foram avaliadas em três momentos distintos: fresco, 24 e 48 horas após a refrigeração. Para ser possível comparar as duas temperaturas de refrigeração, a primeira etapa foi analisar se havia diferença entre as técnicas de colheita. Após isto, dois experimentos foram conduzidos: no primeiro, espermatozoides de 14 gatos foram utilizados e a refrigeração foi realizada a -1°C; e no segundo, amostras de 15 gatos foram utilizados e os espermatozoides foram refrigerados a 4°C. A cinética espermática foi avaliada por análise computadorizada (CASA), a concentração por câmara de Neubauer, a morfologia espermática foi avaliada pela coloração de Karras modificada, e a integridade da membrana foi avaliada por eosina nigrosina. Os resultados obtidos foram analisados no software R, versão 3.2.5, utilizando o teste de Mann-Whitney para variáveis com distribuições anormais, considerando significância ao nível de 5%...(AU)

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This study examined the artificial breeding and embryonic development of a mountainous fish species Garra cambodgiensis (Tirant, 1883) found in Promlok waterfall in Khaoluang National park, Phromkhiri district, Nakhon Si Thammarat province. The fishes were collected from June 2017- January 2018 and kept in aquaria. Afterward, the brood males and females were selected and injected with buserelin (LHRHa) (10 µg/kg body weight) and domperidone (10 mg/kgbody weight). After the injections, both females and males were kept together in the water at a proportion of 3 females: 1male. The fertilization of eggs started after 4 hours and 30minutes. The fertilized eggs were greenish-grey and semi-buoyant. After fertilization, one blastodisc turned into 2 equalsized blastomeres, and then each cell divided into 4, 8, 16, 32,64 cells respectively. The morula stage went to the blastula stage in about 3hr and 28 min, to gastrula stage in about 5 hr and 11 min, and to the somite stage in about 7 hr and 7 min. The optical vesicles and auditory vesicles developed after approximately 8 hr and 27 min, and 10 hr and 30 min, respectively. After approximately 12 hours and 58 minutes of fertilization, hatching of eggs occurred. Nowadays, the numbers of G. Cambodgienesis are declining rapidly in southern Thailand due to several environmental and anthropogenic reasons. Therefore, it is very important to conserve the populations of G. Cambodgienesis. Artificial breeding could be an effective way to conserve and restore this fish in their natural habitat in southern Thailand.

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O objetivo do estudo foi comparar o efeito das técnicas hormonais e de luz artificial nas éguas receptoras de embrião acíclicas avaliando as taxas de gestação aos 14 e 28 dias durante a fase de transição de primavera. Os 48 animais foram distribuídos aleatoriamente nos grupos: controle (CONT, n=16), éguas cíclicas na fase ovulatória; luz artificial (LUZ, n=16), éguas acíclicas submetidas ao tratamento de luz artificial; e hormônio (HORM, n= 16), éguas acíclicas submetidas ao protocolo hormonal na fase de transição. As éguas do grupo LUZ foram estimuladas por 60 dias com luz artificial durante cinco horas por dia. Nos grupos CONT e LUZ, quando observada a presença de folículo ≥ 35 mm de diâmetro e edema uterino ≥ grau II, foram administrados 1,5 mg de acetato de deslorelina e 1500 UI de hCG para induzir a ovulação. As éguas do grupo HORM foram tratadas com três doses de 1,5 mg de benzoato de estradiol e seguiram os mesmos protocolos dos Grupos CONT e LUZ. Foi avaliada a taxa de gestação por ultrassonografia aos 14 dias e confirmação aos 28 em todos os grupos experimentais. Foi realizada análise descritiva e teste Qui-quadrado (significância de 5%). Taxas de gestação aos 14 e 28 dias foram semelhantes (p>0,05) entre todos os grupos. Os tratamentos HORM e LUZ durante o período de transição inverno-primavera mostraram-se eficazes para atender ao programa de transferência de embrião. Por ser um método mais natural, o protocolo LUZ tem potencial como mais uma ferramenta biotecnológica na reprodução de equinos.

The aim of this study was to compare the effect of hormonal and artificial light techniques on acyclic embryo recipient mares by assessing pregnancy rates at 14 and 28 days during the spring transition period. The 48 animals were randomly assigned to the groups: control (CONT, n = 16), cyclic mares in the ovulatory phase; artificial light (LIGHT, n = 16), acyclic mares subjected to artificial light treatment; and hormone (HORM, n = 16), acyclic mares submitted to hormonal protocol in transition phase. In the LIGHT group, mares were stimulated with artificial light for five hours a day, for 60 days. In CONT and LIGHT groups, when a follicle ≥ 35 mm in diameter and uterine edema ≥ grade II were observed, 1.5 mg of deslorelin acetate and 1500 IU hCG were administered to induce ovulation. In the HORM group, mares were treated with three doses of 1.5 mg of estradiol benzoate and followed the same protocols as the CONT and LIGHT groups. Pregnancy rate was assessed by ultrasound at 14 days and confirmation at 28 days in all experimental groups. Descriptive analysis and chi-square test (5% significance) were performed. Pregnancy rates at 14 and 28 days were similar (p> 0.05) among all groups. The HORM and LIGHT treatments during the winter-spring transition period proved to be effective during the embryo transfer programs. As it is a more natural method, the LIGHT protocol has the potential to be one more biotechnological tool in equine reproduction.

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