Preservation of Mouse Sperm by Convective Drying and Storing in 3-O-Methyl-D-Glucose

With the fast advancement in the genetics and bio-medical fields, the vast number of valuable transgenic and rare genetic mouse models need to be preserved. Preservation of mouse sperm by convective drying and subsequent storing at above freezing temperatures could dramatically reduce the cost and facilitate shipping. Mouse sperm were convectively dried under nitrogen gas in the Na-EGTA solution containing 100 mmol/L 3-O-methyl-D-glucose and stored in LiCl sorption jars (Relative Humidity, RH, 12%) at 4°C and 22°C for up to one year. The functionality of these sperm samples after storage was tested by intracytoplasmic injection into mouse oocytes. The percentages of blastocysts produced from sperm stored at 4°C for 1, 2, 3, 6, and 12 months were 62.6%, 53.4%, 39.6%, 33.3%, and 30.4%, respectively, while those stored at 22°C for 1, 2, and 3 months were 28.8%, 26.6%, and 12.2%, respectively. Transfer of 38 two- to four-cell embryos from sperm stored at 4°C for 1 year produced two live pups while 59 two- to four-cell embryos from sperm stored at 22°C for 3 months also produced two live pups. Although all the pups looked healthy at 3 weeks of age, normality of offspring produced using convectively dried sperm needs further investigation. The percentages of blastocyst from sperm stored in the higher relative humidity conditions of NaBr and MgCl2 jars and driest condition of P2O5 jars at 4°C and 22°C were all lower. A simple method of mouse sperm preservation is demonstrated. Three-O-methyl-D-glucose, a metabolically inactive derivative of glucose, offers significant protection for dried mouse sperm at above freezing temperatures without the need for poration of cell membrane

Mouse primary spermatocytes can complete two meiotic divisions within the oocyte cytoplasm.

This study was undertaken to determine whether primary spermatocyte nuclei can complete meiosis after transfer into maturing or mature oocytes and can participate in normal embryogenesis. When injected into maturing mouse oocytes at prometaphase of the first meiotic division, spermatocyte chromosomes became arranged on a first meiotic metaphase (Met-I) spindle. Thus, oocytes contained two sets of Met-I chromosomes. When these oocytes were matured in vitro and artificially activated, pronuclei and polar bodies of both maternal and paternal origin were formed, and zygotes began development. When single spermatocyte nuclei were injected into fully mature oocytes at metaphase of the second meiosis (Met-II), the spermatocyte nuclei transformed into a Met-I configuration, resulting in the formation of oocytes with both maternal (Met-II) and paternal (Met-I) chromosome complements. After activation of these oocytes, half of each chromosome set was separated into polar bodies. Transfer of nuclei from polar bodies of paternal origin into other Met-II oocytes resulted in the formation of oocytes with two sets of Met-II chromosomes, one maternal and one paternal in origin. When activated, two pronuclei and two polar bodies were formed and zygotes began development. It is concluded that nuclei of primary spermatocytes are able to undergo two successive meiotic divisions within oocyte cytoplasm. Thus, factors that drive chromosome condensation, organization of metaphase, and chromosome separation at anaphase in oocytes can drive these same maturation processes in primary spermatocyte nuclei. When a total of 258 two-cell embryos were transferred to foster mothers, only two live pups were born to two mothers. One died shortly after birth and the other 3 wk after birth. The reasons for poor embryonic and neonatal development remain to be determined

Nonlinear-laser chi((3))- and chi((2))-effects in fine-grained highly transparent optical Ba(Mg,Zr,Ta)O(3) ceramics and their microhardness

STIMULATED RAMAN-SCATTERING; CRYSTALS; DISORDER; STOKES; SC2O3; ION

Lack of acrosome formation in mice lacking a Golgi protein, GOPC

The acrosome is a unique organelle that plays an important role at the site of sperm–zona pellucida binding during the fertilization process, and is lost in globozoospermia, an inherited infertility syndrome in humans. Although the acrosome is known to be derived from the Golgi apparatus, molecular mechanisms underlying acrosome formation are largely unknown. Here we show that Golgi-associated PDZ- and coiled-coil motif-containing protein (GOPC), a recently identified Golgi-associated protein, is predominantly localized at the trans-Golgi region in round spermatids, and male mice in which GOPC has been disrupted are infertile with globozoospermia. The primary defect was the fragmentation of acrosomes in early round spermatids, and abnormal vesicles that failed to fuse to developing acrosomes were apparent. In later stages, nuclear malformation and an abnormal arrangement of mitochondria, which are also characteristic features of human globozoospermia, were observed. Interestingly, intracytoplasmic sperm injection (ICSI) of such malformed sperm into oocytes resulted in cleavage into blastocysts only when injected oocytes were activated. Thus, GOPC provides important clues to understanding the mechanisms underlying spermatogenesis, and the GOPC-deficient mouse may be a unique and valuable model for human globozoospermia