scholarly journals Cryopreservation of Mammalian Oocyte for Conservation of Animal Genetics

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Jennifer R. Prentice ◽  
Muhammad Anzar
Keyword(s):  
Cell Damage ◽  
Osmotic Shock ◽  
Complex Structure ◽  
Conservation Strategies ◽  
Ice Crystal ◽  
Intracellular Ice ◽  
Shock Solution ◽  
Cryopreservation Method ◽  
Solid Glass

The preservation of the female portion of livestock genetics has become an international priority; however,in situconservation strategies are extremely expensive. Therefore, efforts are increasingly focusing on the development of a reliable cryopreservation method for oocytes, in order to establish ova banks. Slow freezing, a common method for cryopreservation of oocytes, causes osmotic shock (solution effect) and intracellular ice crystallization leading to cell damage. Vitrification is an alternative method for cryopreservation in which cells are exposed to a higher concentration of cryoprotectants and frozen with an ultra rapid freezing velocity, resulting in an ice crystal free, solid glass-like structure. Presently, vitrification is a popular method for cryopreservation of embryos. However, vitrification of oocytes is still challenging due to their complex structure and sensitivity to chilling.

scholarly journals Strategies for Highly Efficient Rabbit Sperm Cryopreservation

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1220
Author(s):  
Kazutoshi Nishijima ◽  
Shuji Kitajima ◽  
Fumikazu Matsuhisa ◽  
Manabu Niimi ◽  
Chen-chi Wang ◽  
...  
Keyword(s):  
Cell Damage ◽  
Crystal Formation ◽  
Ice Crystal ◽  
Sperm Cryopreservation ◽  
Biomedical Sciences ◽  
Freezing And Thawing ◽  
Single Male ◽  
The Past ◽  
Thawing Process ◽  
Intracellular Ice

The rabbit is a valuable animal for both the economy and biomedical sciences. Sperm cryopreservation is one of the most efficient ways to preserve rabbit strains because it is easy to collect ejaculate repeatedly from a single male and inseminate artificially into multiple females. During the cooling, freezing and thawing process of sperms, the plasma membrane, cytoplasm and genome structures could be damaged by osmotic stress, cold shock, intracellular ice crystal formation, and excessive production of reactive oxygen species. In this review, we will discuss the progress made during the past years regarding efforts to minimize the cell damage in rabbit sperms, including freezing extender, cryoprotectants, supplements, and procedures.

Distributions During Cryoprotective Agent Loading in a Microchannel

2013 ◽  
Author(s):  
Thomas F. Scherr ◽  
Shelby Pursley ◽  
W. Todd Monroe ◽  
Krishnaswamy Nandakumar
Keyword(s):  
Cell Damage ◽  
Osmotic Shock ◽  
Ice Formation ◽  
Cryoprotective Agent ◽  
Long Term Storage ◽  
Intracellular Ice Formation ◽  
Intracellular Ice ◽  
Term Storage ◽  
Osmotic Pressure Gradient

Cryopreservation of cells and tissues is critical to long term storage and off the shelf availability of biomaterials for a variety of disciplines[1]. Typical cryopreservation protocols aim to remove intracellular water by exposing the sample to a cryoprotective agent (CPA) to create an osmotic pressure gradient[2]. While CPAs are useful in preventing cell damage due to intracellular ice formation, the dehydration process can induce harmful osmotic shock[3].

scholarly journals Development of In Situ Gelling Meloxicam-Human Serum Albumin Nanoparticle Formulation for Nose-to-Brain Application

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 646
Author(s):  
Gábor Katona ◽  
Bence Sipos ◽  
Mária Budai-Szűcs ◽  
György Tibor Balogh ◽  
Szilvia Veszelka ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Nasal Mucosa ◽  
Drug Absorption ◽  
Cell Damage ◽  
Lipid Fraction ◽  
Poloxamer 407 ◽  
Nasal Drug Delivery

The aim of this study was to develop an intranasal in situ thermo-gelling meloxicam-human serum albumin (MEL-HSA) nanoparticulate formulation applying poloxamer 407 (P407), which can be administered in liquid state into the nostril, and to increase the resistance of the formulation against mucociliary clearance by sol-gel transition on the nasal mucosa, as well as to improve drug absorption. Nanoparticle characterization showed that formulations containing 12–15% w/w P407 met the requirements of intranasal administration. The Z-average (in the range of 180–304 nm), the narrow polydispersity index (PdI, from 0.193 to 0.328), the zeta potential (between −9.4 and −7.0 mV) and the hypotonic osmolality (200–278 mOsmol/L) of MEL-HSA nanoparticles predict enhanced drug absorption through the nasal mucosa. Based on the rheological, muco-adhesion, drug release and permeability studies, the 14% w/w P407 containing formulation (MEL-HSA-P14%) was considered as the optimized formulation, which allows enhanced permeability of MEL through blood–brain barrier-specific lipid fraction. Cell line studies showed no cell damage after 1-h treatment with MEL-HSA-P14% on RPMI 2650 human endothelial cells’ moreover, enhanced permeation (four-fold) of MEL from MEL-HSA-P14% was observed in comparison to pure MEL. Overall, MEL-HSA-P14% can be promising for overcoming the challenges of nasal drug delivery.

scholarly journals Microstructural Characteristics of Frazil Particles and the Physical Properties of Frazil Ice in the Yellow River, China

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 617
Author(s):  
Yaodan Zhang ◽  
Zhijun Li ◽  
Yuanren Xiu ◽  
Chunjiang Li ◽  
Baosen Zhang ◽  
...  
Keyword(s):  
Physical Properties ◽  
Yellow River ◽  
The Yellow River ◽  
Ice Crystal ◽  
Microstructural Characteristics ◽  
Air Bubble ◽  
Frazil Ice ◽  
Sediment Content ◽  
Crystal Diameter

Frazil particles, ice crystals or slushy granules that form in turbulent water, change the freezing properties of ice to create “frazil ice”. To understand the microstructural characteristics of these particles and the physical properties of frazil ice in greater depth, an in situ sampler was designed to collect frazil particles in the Yellow River. The ice crystal microstructural characteristics of the frazil particles (morphology, size, air bubble, and sediment) were observed under a microscope, and their nucleation mechanism was analyzed according to its microstructure. The physical properties of frazil ice (ice crystal microstructure, air bubble, ice density, and sediment content) were also observed. The results showed that these microstructures of frazil particles can be divided into four types: granular, dendritic, needle-like, and serrated. The size of the measured frazil particles ranged from 0.1 to 25 mm. Compared with columnar ice, the crystal microstructure of frazil ice is irregular, with a mean crystal diameter less than 5 mm extending in all directions. The crystal grain size and ice density of frazil ice are smaller than columnar ice, but the bubble and sediment content are larger.

Genetic diversity of the extremely rare Habenaria dentata and the rare Habenaria linearifolia (Orchidaceae) in South Korea: implications for population history and conservation

2018 ◽  
Vol 151 (1) ◽  
pp. 48-60
Author(s):  
Mi Yoon Chung ◽  
Hoa Thi Quynh Le ◽  
Sungwon Son ◽  
Huai Zhen Tian ◽  
Myong Gi Chung
Keyword(s):  
Genetic Diversity ◽  
Southern China ◽  
Geographic Location ◽  
Population History ◽  
Population Variation ◽  
Conservation Strategies ◽  
Ancestral Population ◽  
Allozyme Diversity ◽  
Glacial Origin

Background and aims – Since historical events often leave an indelible mark on levels of genetic diversity of plant populations, one may indirectly infer their evolutionary history with the help of current patterns of genetic diversity. The terrestrial orchid Habenaria dentata, an element of warm-temperate/subtropical vegetation, reaches its northernmost limits in the Korean Peninsula, and thus it is extremely rare there. As H. dentata was absent from the Peninsula during the Last Glacial Maximum (LGM), it is likely to be of post-glacial origin having arrived from either a single refugium or multiple refugia. However, its rare, temperate/boreal congener H. linearifolia might have persisted in situ in either macrorefugia or microrefugia on the Peninsula during the LGM.Methods – To test which hypothesis is most appropriate for each species, we investigated levels of allozyme-based (17 loci) genetic diversity and population genetic structure in the two only known populations of H. dentata and in 12 populations of H. linearifolia.Key results – No allozyme diversity was found in H. dentata (He = 0.000), whereas H. linearifolia exhibited low within-population variation (He = 0.060) and high among-population differentiation (FST = 0.237). We found little association between populations in relation to their geographic location; several populations presented individuals belonging to different clusters.Conclusions – Our results suggest that H. dentata likely originated from a single ancestral population (perhaps from southern Japan or southern China) through post-glacial dispersal, whereas H. linearifolia probably survived the LGM in situ in microrefugia situated at low to mid-elevated regions. We further suggest that separate conservation strategies for each species should be employed, given that the two taxa have different ecological and demographic traits and harbour different levels of genetic diversity.

Genetic gap analysis of wildHordeumtaxa

2012 ◽  
Vol 10 (3) ◽  
pp. 242-253 ◽  
Author(s):  
Holly Vincent ◽  
Roland von Bothmer ◽  
Helmut Knüpffer ◽  
Ahmed Amri ◽  
Jan Konopka ◽  
...  
Keyword(s):  
Gap Analysis ◽  
Plant Genetic Resources ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Gene Pools ◽  
Barley Plant ◽  
Genetic Reserve ◽  
Set Up ◽  
Global Inventory

To facilitate the updating ofin situandex situconservation strategies for wild taxa of the genusHordeumL., a combined ecogeographic survey and gap analysis was undertaken. The analysis was based on the Global Inventory of Barley Plant Genetic Resources held by ICARDA plus additional datasets, resulting in a database containing 17,131 wildHordeumaccessions. The analysis concluded that a genetic reserve should be established in the Mendoza Province of Argentina, as this is the most species-rich area globally forHordeum. A network of reserves should also be set up across the Fertile Crescent in Israel, Palestine, Syria, Jordan, Lebanon and Turkey to provide effective conservation within the centres of diversity for gene pools 1B (Hordeum vulgaresubsp.spontaneum(C. Koch) Thell.) and 2 (Hordeum bulbosumL.). The majority of the species were deemed under-collected, so further collecting missions are required worldwide where possible. Althoughex situandin situconservation strategies have been developed, there needs to be further investigation into the ecological environments thatHordeumspecies occupy to ensure that any adaptive traits expressed are fully conserved. Additionally, studies are required to characterize existing collections and test the viability of rare species accessions held in genebanks to determine whether furtherex situcollections are required alongside the proposedin situconservation.

Sign in / Sign up

Export Citation Format

Share Document