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Methods in Molecular Biology (Clifton,... 2023In axolotls (Ambystoma mexicanum), fertilization takes place internally. After courtship, the male axolotl deposits spermatophores, which the female takes up into her...
In axolotls (Ambystoma mexicanum), fertilization takes place internally. After courtship, the male axolotl deposits spermatophores, which the female takes up into her cloaca in order to fertilize eggs internally. The success of axolotl breedings is subject to several poorly understood factors including age, pairing, and genotype. In some cases, individuals are unable to breed naturally despite having significant scientific value. Assisted reproductive technologies represent one approach to maintaining stocks of such individuals, as well as supplementing natural breedings of laboratory stocks.Here, we describe a protocol for artificial insemination--an assisted reproductive technology in which sperm is extracted from a male and transferred into the female cloaca, thus mimicking natural fertilization in axolotls. We believe that this simple method can be applied to other salamander species that have internal fertilization and also help restore endangered wild populations.
Topics: Humans; Animals; Male; Female; Ambystoma mexicanum; Semen; Cloaca; Breeding; Insemination, Artificial
PubMed: 36272091
DOI: 10.1007/978-1-0716-2659-7_27 -
Annual Review of Animal Biosciences Feb 2022Procedures to maintain viability of mammalian gametes and embryos in vitro, including cryopreservation, have been exceedingly valuable for my research over the past 55... (Review)
Review
Procedures to maintain viability of mammalian gametes and embryos in vitro, including cryopreservation, have been exceedingly valuable for my research over the past 55 years. Keeping sperm viable in vitro enables artificial insemination, which, when combined with selective breeding, often is the most effective approach to making rapid genetic change in a population. Superovulation and embryo transfer constitute a parallel approach for amplifying reproduction of female mammals. More recent developments include sexing of semen, in vitro fertilization, cloning by nuclear transfer, and genetic modification of germline cells, tools that are enabled by artificial insemination and/or embryo transfer for implementation. I have been fortunate in being able to contribute to the development of many of the above techniques, and to use them for research and applications for improving animal agriculture. Others have built on this work to circumvent human infertility, assist reproduction of companion animals, and rescue endangered species. It also has been a privilege to teach, mentor, and be mentored in this area. Resulting worldwide friendships have enriched me personally and professionally.
Topics: Agriculture; Animals; Cloning, Organism; Cryopreservation; Embryo Transfer; Female; Fertilization in Vitro; Insemination, Artificial; Mammals
PubMed: 34794329
DOI: 10.1146/annurev-animal-062521-090427 -
Philosophical Transactions of the Royal... Sep 2020While only a single sperm may fertilize the egg, getting to the egg can be facilitated, and possibly enhanced, by sperm group dynamics. Examples range from the trains... (Review)
Review
While only a single sperm may fertilize the egg, getting to the egg can be facilitated, and possibly enhanced, by sperm group dynamics. Examples range from the trains formed by wood mouse sperm to the bundles exhibited by echidna sperm. In addition, observations of wave-like patterns exhibited by ram semen are used to score prospective sample fertility for artificial insemination in agriculture. In this review, we discuss these experimental observations of collective dynamics, as well as describe recent mechanistic models that link the motion of individual sperm cells and their flagella to observed collective dynamics. Establishing this link in models involves negotiating the disparate time- and length scales involved, typically separated by a factor of 1000, to capture the dynamics at the greatest length scales affected by mechanisms at the shortest time scales. Finally, we provide some outlook on the subject, in particular, the open questions regarding how collective dynamics impacts fertility. This article is part of the theme issue 'Multi-scale analysis and modelling of collective migration in biological systems'.
Topics: Animals; Fertility; Flagella; Insemination, Artificial; Male; Motion; Sheep, Domestic; Spermatozoa
PubMed: 32713305
DOI: 10.1098/rstb.2019.0384 -
International Journal of Molecular... Apr 2021Seminal plasma (SP), the non-cellular component of semen, is a heterogeneous composite fluid built by secretions of the testis, the epididymis and the accessory sexual... (Review)
Review
Seminal plasma (SP), the non-cellular component of semen, is a heterogeneous composite fluid built by secretions of the testis, the epididymis and the accessory sexual glands. Its composition, despite species-specific anatomical peculiarities, consistently contains inorganic ions, specific hormones, proteins and peptides, including cytokines and enzymes, cholesterol, DNA and RNA-the latter often protected within epididymis- or prostate-derived extracellular vesicles. It is beyond question that the SP participates in diverse aspects of sperm function pre-fertilization events. The SP also interacts with the various compartments of the tubular genital tract, triggering changes in gene function that prepares for an eventual successful pregnancy; thus, it ultimately modulates fertility. Despite these concepts, it is imperative to remember that SP-free spermatozoa (epididymal or washed ejaculated) are still fertile, so this review shall focus on the differences between the in vivo roles of the SP following semen deposition in the female and those regarding additions of SP on spermatozoa handled for artificial reproduction, including cryopreservation, from artificial insemination to in vitro fertilization. This review attempts, including our own results on model animal species, to critically summarize the current knowledge of the reproductive roles played by SP components, particularly in our own species, which is increasingly affected by infertility. The ultimate goal is to reconcile the delicate balance between the SP molecular concentration and their concerted effects after temporal exposure in vivo. We aim to appraise the functions of the SP components, their relevance as diagnostic biomarkers and their value as eventual additives to refine reproductive strategies, including biotechnologies, in livestock models and humans.
Topics: Animals; Female; Fertility; Humans; Insemination, Artificial; Male; Pregnancy; Reproduction; Semen; Sperm Motility
PubMed: 33922047
DOI: 10.3390/ijms22094368 -
Seminars in Reproductive Medicine Jan 2020Unexplained infertility is a common diagnosis among couples with infertility. Pragmatic treatment options in these couples are directed at trying to improve chances to... (Review)
Review
Unexplained infertility is a common diagnosis among couples with infertility. Pragmatic treatment options in these couples are directed at trying to improve chances to conceive, and consequently intrauterine insemination (IUI) with ovarian stimulation and in vitro fertilization (IVF) are standard clinical practice, while expectant management remains an important alternative. While evidence on IVF or IUI with ovarian stimulation versus expectant management was inconclusive, these interventions seem more effective in couples with a poor prognosis of natural conception. Strategies such as strict cancellation criteria and single-embryo transfer aim to reduce multiple pregnancies without compromising cumulative live birth. We propose a prognosis-based approach to manage couples with unexplained infertility so as to expose less couples to unnecessary interventions and less mothers and children to the potential adverse effects of ovarian stimulation or laboratory procedures.
Topics: Female; Fertilization in Vitro; Humans; Infertility; Insemination, Artificial; Male; Ovulation Induction; Pregnancy; Pregnancy Outcome; Uncertainty; Watchful Waiting
PubMed: 33124018
DOI: 10.1055/s-0040-1719074 -
The Veterinary Clinics of North... Mar 2024The cause of subfertility or poor fertility in naturally mated bulls should be differentiated from impotentia coeundi, generandi, or erigendi prior to ancillary semen... (Review)
Review
The cause of subfertility or poor fertility in naturally mated bulls should be differentiated from impotentia coeundi, generandi, or erigendi prior to ancillary semen evaluation. Bulls used for artificial insemination may undergo ancillary semen evaluation following low fertility rates as judged by poor conception or low pregnancy rates. Morphologically abnormal sperm have long been associated with bull subfertility and infertility. Some morphological defects such as improper sperm chromatin condensation are not visible using traditional light microscopy and require specialized staining. Ancillary semen evaluation is useful in cases where the reason for low or absence of fertility needs to be identified. As compared to SEM, TEM can be extremely useful for identifying minuscule acrosome defects, issues with chromatin, and centrosome defects and is considered the gold standard method for the identification of midpiece and tail defects.
Topics: Pregnancy; Female; Male; Animals; Cattle; Semen; Spermatozoa; Fertility; Insemination, Artificial; Chromatin; Infertility; Cattle Diseases
PubMed: 37442678
DOI: 10.1016/j.cvfa.2023.06.002 -
Molecular Reproduction and Development Jul 2023Over the years, reproductive efficiency in the swine industry has focused on reducing the sperm cell number required per sow. Recent advances have included the... (Review)
Review
Over the years, reproductive efficiency in the swine industry has focused on reducing the sperm cell number required per sow. Recent advances have included the identification of subfertile boars, new studies in extended semen quality control, new catheters and cannulas for intrauterine artificial insemination (AI), and fixed-time AI under commercial use. Therefore, it is essential to link field demands with scientific studies. In this review, we intend to discuss the current status of porcine AI, pointing out challenges and opportunities to improve reproductive efficiency.
Topics: Swine; Animals; Male; Female; Semen; Semen Analysis; Fertility; Insemination, Artificial; Sperm Count; Semen Preservation; Spermatozoa
PubMed: 36063484
DOI: 10.1002/mrd.23643 -
Journal of Feline Medicine and Surgery Sep 2022Despite substantial advances in assisted reproductive techniques having been recently reported in cats, the use of these is limited and routine application is still far...
PRACTICAL RELEVANCE
Despite substantial advances in assisted reproductive techniques having been recently reported in cats, the use of these is limited and routine application is still far from being a reality in veterinary clinics. Nevertheless, there is an increasing demand from domestic cat breeders for artificial insemination (AI) techniques that are already commonly used in dogs. Where natural breeding is not possible in tom cats and queens of high breeding value, AI could offer a solution. Clinical challenges: AI in cats is more difficult than in other species - both in terms of semen collection/handling and oestrous cycle management given that ovulation must be induced.
AIM
For practitioners wishing to perform AI in queens, there are challenges to overcome, and a good understanding of the techniques and procedures involved is pivotal. This review aims to contribute to improved knowledge by providing an overview of AI protocols, encompassing choice of breeding animals, procedures for semen collection, oestrus and ovulation induction, AI techniques and equipment.
EQUIPMENT AND TECHNICAL SKILLS
Depending on the animals involved and the specific AI technique chosen, essential equipment may include an artificial vagina, electroejaculator, endoscope (sialendoscope, which can be fairly expensive) and special catheters for transcervical insemination. Other instrumentation and materials needed are typically readily available in a veterinary clinic. In general, no particular skills are needed to perform the procedures described in this review, with the exception of endoscopic transcervical catheterisation, where the ability to use an endoscope is required.
EVIDENCE BASE
The information and advice/recommendations provided are based on specific feline research and reviews published in scientific peer-reviewed journals, animal reproduction textbooks, and presentations at national and international congresses. The authors also drew on their own clinical experience with regard to the choice of protocols and procedures presented in this review.
Topics: Animals; Cats; Dogs; Female; Insemination, Artificial; Ovulation; Ovulation Induction; Review Literature as Topic; Vagina
PubMed: 36002144
DOI: 10.1177/1098612X221118756 -
Reproduction in Domestic Animals =... Mar 2021Timed artificial insemination (TAI) has boosted the use of conventional artificial insemination (CAI) by employing hormonal protocols to synchronize oestrus and...
Timed artificial insemination (TAI) has boosted the use of conventional artificial insemination (CAI) by employing hormonal protocols to synchronize oestrus and ovulation. This study aimed to evaluate the efficiency of a hormonal protocol for TAI in mares, based on a combination of progesterone releasing intravaginal device (PRID), prostaglandin (PGF ) and human chorionic gonadotropin (hCG); and compare financial costs between CAI and TAI. Twenty-one mares were divided into two groups: CAI group (CAIG; n = 6 mares; 17 oestrous cycles) and TAI group (TAIG; n = 15 mares; 15 oestrous cycles). The CAIG was subjected to CAI, involving follicular dynamics and uterine oedema monitoring with ultrasound examinations (US), and administration of hCG (1,600 IU) when the dominant follicle (DF) diameter's ≥35 mm + uterine oedema + cervix opening. The AI was performed with fresh semen (500 × 10 cells), and embryo was recovered on day 8 (D8) after ovulation. In TAI, mares received 1.9 g PRID on D0. On D10, PRID was removed and 6.71 mg dinoprost tromethamine was administered. Ovulation was induced on D14 (1,600 IU of hCG) regardless of the DF diameter's, and AI was performed with fresh semen (500 × 10 cells). On D30 after AI, pregnancy was confirmed by US. The pregnancy rate was 80.0% in TAIG and 82.3% in CAIG (p > .05). The TAI protocol resulted in 65% reduction in professional transport costs, and 40% reduction in material costs. The TAI was as efficient as CAI, provided reduction in costs and handlings, and is recommended in mares.
Topics: Administration, Intravaginal; Animals; Chorionic Gonadotropin; Dinoprost; Embryo Transfer; Estrus Synchronization; Female; Horses; Insemination, Artificial; Male; Pregnancy; Pregnancy Rate; Progesterone; Uterus
PubMed: 33368635
DOI: 10.1111/rda.13884 -
Poultry Science Nov 2020The increased consumption of protein derived from poultry demands greater poultry production, but increased poultry production (meat and eggs) is dependent on the... (Review)
Review
The increased consumption of protein derived from poultry demands greater poultry production, but increased poultry production (meat and eggs) is dependent on the fertility of the parent flocks. Clearly, the fertility of poultry flocks is associated with the fertility of both males and females, but the low numbers of males used for natural or artificial insemination mean that their role is more important. Thus, enhancing the semen volume, sperm concentration, viability, forward motility, and polyunsaturated fatty acids in sperm, as well as protecting against oxidative damage, could help to optimize the sperm membrane functionality, mitochondrial activity, and sperm-egg penetration, and thus fertility. Therefore, this review summarizes the nutritional factors that could improve the fertility of poultry males as well as their associated mechanisms to allow poultry producers to overcome low-fertility problems, especially in aging poultry males, thereby obtaining beneficial impacts on the poultry production industry.
Topics: Animal Husbandry; Animal Nutritional Physiological Phenomena; Animals; Fertility; Insemination, Artificial; Male; Poultry; Spermatozoa
PubMed: 33142481
DOI: 10.1016/j.psj.2020.06.083