Reproduction, Fertility and Development
Volume 28 Number 8 2016
RESEARCH FRONT: Biomaterials Repositories: The Science and Business of Biobanking
Coral reefs are some of the oldest, most diverse and valuable ecosystems on Earth because they can support one-quarter of all marine life in our oceans. Despite their importance, the world’s coral reefs continue to be degraded at unprecedented rates by local and global threats that are warming and creating a more acidic ocean. This paper explores the reproductive challenges of coral for ex situ conservation, using IVF and cryopreservation, and our practical biobanking methods.
The reproductive success of two Hawaiian coral species was potentially affected by bleaching. Previously, gametes from these species had been successfully cryopreserved. However, after bleaching the reproductive process for the cryopreserved coral failed increasingly at every step of the reproductive process. Thus, bleaching adds enormous urgency to cryopreserve this material while genetic diversity on reefs is still high in most oceans.
RD15399Biobanking genetic resources: challenges and implementation at the USDA National Animal Germplasm Program
Collecting genetic resources for preserving breeds or species, or for genetic analyses, is challenging for all agricultural species but especially difficult for minor breeds because of low numbers of animals, a lack of breed associations, and minimal information that can be used for categorisation of the animals. Since 1999 the USDA National Animal Germplasm Program has worked to overcome these obstacles and create a germplasm repository for all agricultural species in the USA. This manuscript describes these activities and illustrates them via a case study that describes how our efforts collecting Navajo-Churro sheep have created a secure backup of germplasm and how we specifically overcome these issues as they relate to rare and minor breeds of agricultural species.
RD15386Sperm freeze-drying and micro-insemination for biobanking and maintenance of genetic diversity in mammals
Reproductive technologies are now indispensable tools for the efficient production of offspring in various mammals. This review covers the latest method of sperm freeze-drying and fertilization by intracytoplasmic sperm injection. Reproductive technologies provide a substantial advantage for biobanking and maintaining the genetic diversity of laboratory, domestic and wild animals.
RD16021Roles of intracellular ice formation, vitrification of cell water, and recrystallisation of intracellular ice on the survival of mouse embryos and oocytes
Mazur and collaborators have been studying the validity of initial views on vitrification in mouse oocytes and embryos. After decades of work they have established that survival is dependent on the dehydration prior to vitrification, as well as on warming rate. This new paradigm of vitrification may broaden the application of vitrification and ultra-fast warming to other cells. It remains to be seen how widely these findings will be applicable.
Cryopreservation of equine blastocysts is hindered by their large size and presence of an embryonic capsule. Collapse of the blastocoele via micromanipulation allows successful cryopreservation of embryos up to 600 microns diameter. Embryos may be shipped overnight to laboratories to perform the collapse and cryopreservation.
The critically endangered black-footed ferret teeters on the edge of extinction with only approximately 600 left globally. With this genetically closed population, assisted reproductive technology has ensured every ferret passes his/her genes onto the next generation, and the use of a biobank has slowed the loss of gene diversity. With 30 years of experience, this recovery program serves as a model for other threatened wildlife.
RD15388Cryopreservation in fish: current status and pathways to quality assurance and quality control in repository development
The lack of comprehensive quality assurance and quality control programs has impeded the use of cryopreservation in aquatic species, delaying the establishment of repositories and commercial-scale applications. In this review we focus on the opportunities for standardisation throughout the cryopreservation process and introduce key factors that would assist the transition to commercial-scale application. The establishment of germplasm repositories is essential for conservation efforts, stock enhancement for wild fisheries and genetic improvement for aquaculture.
RD15466Cryopreservation and other assisted reproductive technologies for the conservation of threatened amphibians and reptiles: bringing the ARTs up to speed
Cryopreservation and other assisted reproductive technologies offer tools to address the accelerating biodiversity crisis affecting amphibians and reptiles. Cryopreserved sperm have been used to generate live offspring in amphibians but this has not yet been achieved in reptiles. Increased research investment is needed to develop these technologies, focussing on circumventing blocks to oocyte and embryo cryopreservation in amphibians, and the production of live young from cryopreserved sperm in reptiles.
Wild ungulates globally are threatened or endangered with extinction. Sperm cryopreservation technologies can assist with preserving rare genotypes, as well as aid the genetic management of these species. Recent advances have led to the production of live offspring in several species and the establishment of sperm banks for these rare species.
RD15429Implications of the Nagoya Protocol for genome resource banks composed of biomaterials from rare and endangered species
The objective of the Nagoya Protocol is to prevent the unfair commercial exploitation of a country’s biodiversity. However, it has major effects on the ability of researchers from around the world to access non-commercial genetic materials as well. Herein we review the unforeseen implications of the Nagoya Protocol, as well as the possible solutions in relation to biobanking and animal conservation.
RD14368Nutrition affects Sertoli cell function but not Sertoli cell numbers in sexually mature male sheep
A comprehensive evaluation of Sertoli cells has been used to investigate a reversible, non-pathological change in testis mass induced by nutrition in mature sheep. Under-nutrition did not affect Sertoli cell number but did affect Sertoli cell function, including reversal of cellular differentiation and disruption of tight-junctions. These responses were associated with major decreases in the output of spermatozoa.
The oocyte-derived growth factor bone morphogenetic protein (BMP) 15 plays important roles in fertility, but its mechanism of action remains poorly understood. Sequences of single-stranded DNA specifically recognising BMP15 have been generated by a directed molecular evolutionary process. These special sequences (aptamers) can be used as a tool to detect BMP15 and decipher its biological actions.
Holstein and Jersey embryos display difference in term of lipid profile and molecular characteristics, suggesting a variance in lipid metabolism. Using L-carnitine, we noticed a reduction in embryonic lipid content for both breeds, but the response to treatment is weaker in the Jersey. L-carnitine supplementation reduces lipid content of blastomere and offers the potential to improve cryopreservation success.
RD14211Breed-specific factors influence embryonic lipid composition: comparison between Jersey and Holstein
Dairy cattle breeds differ considerably in their milk production performance but breed effects are seldom considered for reproductive performance. It is known that Jersey embryos display poor post-freezing survival rates compare to Holstein. We demonstrate that Jersey embryos contain more lipid droplets associated with a lower mitochondrial activity and also that the lipid composition between the two breeds is different. Even under same management conditions, breed can influence the embryos lipid content and metabolism.
RD14198Expression and function of transcription factor AP-2γ in early embryonic development of porcine parthenotes
This is the first study to report on the expression and functions of transcription factor activator protein (AP) 2γ in pig embryos. AP2γ was detected at all stages during preimplantation and depletion negatively affected early embryo development. These findings suggest that AP2γ may play a role in critical cellular events, including cell adhesion, proliferation and cell fate, during preimplantation development.
Previous results obtained in our laboratory showed that maternal exposure to fluoxetine (FLX) alters testicular morphometric parameters in adult male offspring. The present study investigated the effects of maternal FLX exposure on maternal behavior and on testes function offspring in the weanling and pubertal periods in rats. FLX treatment did not impair mother–pup interactions; however, it could impair testicular function in offspring.
Millions of babies come from artificial reproductive technology, which harvests eggs commonly by superovulation. Is this safe? We studied the superovulation effects on mice egg mitochondria, the important organelle reflecting egg potential and with genetic function. The results showed a decline in the average mitochondrial quality by superovulation. However, it is not superovulation that causes the damage, it is superovulation that recruits more eggs with poor mitochondrial quality instead.
RD14226The effects of glucuronic acid and N-acetyl-D-glucosamine on in vitro fertilisation of porcine oocytes
Reducing the incidence of polyspermic penetration may aid in improving embryonic development and further the understanding of fertilisation in pigs. This study reveals that by supplementing oocytes with perivitelline space components, the space thickness increases and polyspermic penetration is reduced. The findings highlight the need for adequate environments to improve the maturation of oocytes prior to fertilisation.
RD14432Food deprivation and social inequality may lead to oxidative damage: a study on the preventive role of melatonin in the male rat reproductive system
Spermatogenic cells are susceptible to oxidative stress. Food deprivation and the sense of inequality in food-deprived rats that see other rats have access to normal food (hereafter referred to as ‘instability’) are known stressors that can increase oxidative stress. In this study, food deprivation and instability increased markers of oxidative stress, whereas melatonin treatment and isolation of rats (which balanced instability) decreased these markers.