Sperm freeze-drying and micro-insemination for biobanking and maintenance of genetic diversity in mammals

2016 ◽  
Vol 28 (8) ◽  
pp. 1079 ◽  
Author(s):  
Takehito Kaneko

Breeding by natural mating is ideal for maintaining animal populations. However, the lack of breeding space resulting from an increased number of strains and the decline in fertility caused by inbreeding inhibits the reproduction of subsequent generations. Reproductive technologies, such as gamete preservation and artificial fertilisation, have been developed to overcome these problems. These approaches efficiently produce offspring of laboratory, domestic and wild animals, and can also be used to treat human infertility. Gamete preservation using sperm contributes to improvements in reproductive systems and enables the use of smaller breeding spaces. Although cryopreservation with liquid nitrogen has been used to preserve spermatozoa, freeze-drying without liquid nitrogen, a novel method, facilitates long-term storage of spermatozoa. This method has recently been applied to maintain animal strains. Micro-insemination techniques, such as intracytoplasmic sperm injection (ICSI), are exceptional for improving assisted reproduction. ICSI can be used to fertilise oocytes, even with immotile and immature spermatozoa that are unsuitable for AI and IVF. Reproductive technologies provide a substantial advantage for biobanking and maintaining the genetic diversity of laboratory, domestic and wild animals. This review covers the latest method of sperm freeze-drying and micro-insemination, and future possibilities for maintaining animal strains and populations.

1990 ◽  
Vol 36 (5) ◽  
pp. 783-788 ◽  
Author(s):  
M N Nanjee ◽  
N E Miller

Abstract The concentration of high-density lipoprotein cholesterol (HDL-C) in plasma is now established as an independent risk factor for coronary heart disease, but more data are needed on the relative risk-predictive powers of different HDL subclasses. For epidemiologic and clinical purposes, isolation of HDL from other lipoproteins and separation of its two major subclasses, HDL2 and HDL3, are performed most conveniently by precipitation. Although storage of plasma is commonly necessary, little information is available on the long-term stability of HDL subclasses at different temperatures. Therefore, we quantified HDL-C, HDL2-C, and HDL3-C by dual precipitation with heparin-MnCl2/15-kDa dextran sulfate (H-M/DS) in samples of EDTA-plasma from 93 healthy subjects, after storage for one to 433 days at -20 degrees C, at -70 degrees C, or in liquid nitrogen (-196 degrees C). Fourteen samples (15%) were stored for a year or longer. At -20 degrees C, HDL-C decreased by 4.8% per year and HDL3-C decreased by 6.9% per year (P = 0.002 for both variables) relative to results obtained with samples stored in liquid nitrogen; total cholesterol, HDL2-C, and triglyceride did not change significantly at this temperature. When stored at -70 degrees C, none of the lipids showed any change relative to results obtained with liquid nitrogen. Thus, long-term storage of EDTA-plasma at -20 degrees C is unsuitable for subsequent quantification of HDL-C and its subclasses by H-M/DS dual precipitation. Storage at -70 degrees C is preferable, and is as reliable as storage in liquid nitrogen.


2018 ◽  
Vol 32 (1-2) ◽  
pp. 1-13
Author(s):  
Christina I. Barrón-Ortiz ◽  
Matthew R. Sawchuk ◽  
Carmen Li ◽  
Christopher N. Jass

Abstract Water-saturated vertebrate remains (e.g., bone, antler, and ivory) are particularly challenging to stabilize for long-term storage, research, and analysis. These types of specimens are sensitive to damage caused by water loss, which frequently results in delamination, twisting, and cracking. The recovery of late Quaternary vertebrate remains from underwater areas of Cold Lake, western Canada, prompted us to conduct a series of analyses to better understand the preservation of the remains and their susceptibility to damage, and to test different conservation techniques to achieve successful drying. X-ray fluorescence analysis of a sample of specimens revealed that the remains have particularly high iron concentrations, a condition that might have contributed to weaken their structure, further compromising their integrity when drying. Additionally, we found that certain bone elements, such as long bones, are more susceptible to severe surface delamination than others, and as a result these specimens should be monitored more closely during their treatment. Of the four drying methods we tested, controlled air-drying produced the best results, followed by solvent-drying. In contrast, vacuum freeze-drying and vacuum freeze-drying with 20% v/v Acrysol WS-24 in water, an acrylic dispersion, while rapid, resulted in differing degrees of delamination and cracking.


2005 ◽  
Vol 83 (10) ◽  
pp. 1248-1256 ◽  
Author(s):  
J. López-Pujol ◽  
F.-M. Zhang ◽  
S. Ge

Allozyme electrophoresis was used to evaluate the levels of genetic diversity and population genetic structure of the critically endangered Clematis acerifolia Maximowicz (Ranunculaceae), a narrow endemic species in China. On the basis of variation at 19 putative loci in nine populations covering the entire distribution of this species, low values of genetic diversity were detected (P = 20.5%, A = 1.27, and He = 0.072). A significant deficiency of heterozygotes was found in all populations. Most loci showed deviations from the Hardy–Weinberg equilibrium, probably as a result of population genetic structuring. The high genetic divergence among populations (FST = 0.273) can be interpreted as an effect of the extinction of local populations and genetic drift within extant populations, and has probably been enhanced by habitat fragmentation in recent decades. Threats to this species are mainly anthropogenic (road works, construction of holiday resorts, and extraction activities), although stochastic risks cannot be ignored. Therefore, to preserve extant genetic variation of C. acerifolia, in situ strategies, such as the preservation of its habitat or at least the most diverse populations, and ex situ measures, such as the collection and long-term storage of seeds, should be adopted.


2010 ◽  
Vol 58 (2) ◽  
pp. 89 ◽  
Author(s):  
Y. Li ◽  
Y. L. Zhang ◽  
C. D. Jiang ◽  
T. Wang ◽  
Q. Wang ◽  
...  

To effectively preserve the vulnerable species of Alsophila, we studied the effects of varying the temperature and duration of storage on spore viability, early gametophyte development and the microstructure of brown spores of three Alsophila species. Spores of A. spinulosa (Wall. ex Hook.) Tryon and A. gigantea Wall. ex Hook. lost viability quickly when stored at room temperature and suffered from great loss when stored at –18°C from 6 to 12 months. Within 1 month, spore viability of A. spinulosa and A. gigantea stored at 4°C was higher than that of those stored in liquid nitrogen. In contrast, long-term storage in liquid nitrogen resulted in a comparatively small loss of viability for these two species. The spores of A. podophylla Hook. died within 3 months after storage at room temperature, 4°C and –18°C, and they died within 12 months when stored in liquid nitrogen. The spores of A. spinulosa and A. gigantea stored at room temperature, 4°C and –18°C, were prone to develop into abnormal gametophytes. These results suggest that storage of A. spinulosa and A. gigantea spores in liquid nitrogen is an effective method of preserving these vulnerable species. The reasons for the failure to preserve ephemeral A. podophylla spores by storage in liquid nitrogen are discussed.


1987 ◽  
Vol 17 (9) ◽  
pp. 1130-1134 ◽  
Author(s):  
P. K. Gupta ◽  
D. J. Durzan ◽  
B.J. Finkle

We describe a method for the possible cryopreservation of embryogenic callus of Piceaabies and Pinustaeda at −196 °C and the regeneration of somatic embryos from thawed cells of subcultured embryonal–suspensor masses. Piceaabies and Pinustaeda were frozen without cryoprotective agent, in the presence of dimethyl sulfoxide (10%), or in a mixture of polyethylene glycol, glucose, and dimethylsulfoxide (10, 8, and 10% w/v, respectively). Cell masses placed in plastic vials or aluminum envelopes were frozen at 1 °C/min to −30 °C and then immersed for 10 min in liquid nitrogen. Cells were thawed rapidly and placed on modified MS subculture medium. Six to seven somatic embryos per gram of fresh weight were regenerated from each piece of frozen cell mass as compared with 12–13 embryos per gram from unfrozen cells. Post-thaw cell growth was inhibited initially by up to 5 weeks. Inhibition was reversed after the third 10-day subculture. Results suggest that the long-term storage of embryogenic cell lines in liquid nitrogen may be feasible for tree improvement programs in circumstances where testing of progeny may take several years.


Author(s):  
Felizitas Bajerski ◽  
Manuela Nagel ◽  
Joerg Overmann

Abstract Modern biobanks maintain valuable living materials for medical diagnostics, reproduction medicine, and conservation purposes. To guarantee high quality during long-term storage and to avoid metabolic activities, cryostorage is often conducted in the N2 vapour phase or in liquid nitrogen (LN) at temperatures below − 150 °C. One potential risk of cryostorage is microbial cross contamination in the LN storage tanks. The current review summarises data on the occurrence of microorganisms that may compromise the safety and quality of biological materials during long-term storage. We assess the potential for the microbial contamination of LN in storage tanks holding different biological materials based on the detection by culture-based and molecular approaches. The samples themselves, the LN, the human microbiome, and the surrounding environment are possible routes of contamination and can cause cross contaminations via the LN phase. In general, the results showed that LN is typically not the source of major contaminations and only a few studies provided evidence for a risk of microbial cross contamination. So far, culture-based and culture-independent techniques detected only low amounts of microbial cells, indicating that cross contamination may occur at a very low frequency. To further minimise the potential risk of microbial cross contaminations, we recommend reducing the formation of ice crystals in cryotanks that can entrap environmental microorganisms and using sealed or second sample packing. A short survey demonstrated the awareness for microbial contaminations of storage containers among different culture collections. Although most participants consider the risk of cross contaminations in LN storage tanks as low, they prevent potential contaminations by using sealed devices and − 150 °C freezers. It is concluded that the overall risk for cross contaminations in biobanks is relatively low when following standard operating procedures (SOPs). We evaluated the potential sources in detail and summarised our results in a risk assessment spreadsheet which can be used for the quality management of biobanks. Key points • Identification of potential contaminants and their sources in LN storage tanks. • Recommendations to reduce this risk of LN storage tank contamination. • Development of a risk assessment spreadsheet to support quality management.


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