Comparison of Conventional Freezing and Vitrification with Dimethylformamide and Ethylene Glycol for Cryopreservation of Ovine Embryos

The aim of this work was to evaluate the efficiency of the cryoprotectants dimethylformamide and ethylene glycol for cryopreservation of ovine embryos using vitrification and conventional freezing. The recovered embryos were distributed randomly in three treatment groups: Gr. 1: conventional freezing (n = 44), Gr. 2: vitrification with ethylene glycol (n = 39) and Gr. 3: vitrification with dimethylformamide (n = 38). Quality of fresh embryos in control group as well as of frozen and vitrified embryos was examined by three methodologies: staining with propidium iodide and Hoechst 33258 and evaluation under fluorescent microscopy, evaluation of re‐expansion and hatching rates after culture, and determination of apoptotic index with TUNEL technique. It was established that re‐expansion rate in all treatment groups was similar. In the same time, hatching rates were higher in Gr. 1 (40.5%) and Gr. 2 (35.3%) in comparison with Gr. 3 (15.5%, p < 0.05). The number of dead cells in vitrified embryos of Gr. 2 and Gr. 3 was higher (42.6 ± 26.2 and 63.2 ± 34.65, respectively) in comparison with Gr. 1 (conventional freezing, 10.1 ± 8.5, p < 0.05). Embryos vitrified with dimethylformamide included the same quality of apoptotic cells that Gr. 1 (conventional freezing) and fresh embryos. In conclusion, the dimethylformamide and ethylene glycol used as cryoprotectant to vitrify ovine embryos, in the concentrations and exposition time tested in this work, were not as efficient as the conventional freezing for cryopreservation of ovine embryos Thus, the conventional freezing with ethylene glycol was the most efficient method to cryopreserve ovine embryos in comparison with vitrification.     

棉花半配合材料 VSg-1的选育及其育种应用研究

从美国引入的海岛棉(Gossypium barbadense L.)半配合材料 VSg~(**),经过八年的选育和加倍,培育出适合我国气候的新品系 VSg-1。单倍体遗传频率达到69.9%。棉花半配合材料 VSg-1,已初步成功地应用于单倍体育种。已获得陆地棉(Gossypiumhirsutum L.)四个杂交组合育种初代材料的单倍体和少量加倍单培体种子。     

Aquaporin 9 is expressed in the epididymis of immature and mature pigs

Aquaporins (AQPs) are channel proteins that facilitate the transepithelial and bidirectional movement of water. AQP9 is an aquaporin that is expressed in the mammalian epididymis. This water transport contributes to epididymal sperm concentration. This study aimed to examine the morphology of epididymal epithelium in piglets and boars, as well as the expression and immunolocalization of AQP9. The piglets presented an epididymal epithelium in differentiation with principal, basal and apical cells. The cellular population of the epididymal epithelium in boars consisted of principal, basal, apical, clear and narrow cells. The migratory cells known as halo cells were observed in the epididymis of both piglets and boars. AQP9 expression presented differences between piglets and boars. Moderate intensity of AQP9 immunoreaction was observed in the apical border of the epididymal epithelium of the caput and cauda regions in the piglet epididymis. A moderate‐to‐intense reaction for AQP9 was observed in the nuclei of epithelial cells of the three epididymal regions in the boar epididymis. The region of the cauda epididymis showed reactivity for AQP9 also in the apical border of the epithelium. It is believed that the AQP9 is already functional in piglets at only 1 week of age and is more active, playing a pivotal role in the caput and cauda regions of the epididymis. Moreover, the intense AQP9 expression in the apical border of epithelial cells in the cauda region of the boar epididymis suggests a higher performance of AQP9 in this region, where sperm complete their maturation process, stored and concentrated.     

番茄斑萎病毒YN-1株系GN/GC基因的克隆与分析

作者以TSWV YN-1株系为研究材料,克隆了其G N/G C基因,测序后与GenBank中TSWV其他株系GN/GC基因进行比对,结果显示：YN-1 G N/G C基因全长3 408 bp,编码1 135个氨基酸,构建的系统发育树可分为4个群,YN-1属于群Ⅱ,与源自西班牙的SPAIN-2株系的G N/G C基因核苷酸相似性最高,达98.88%,氨基酸相似性达98.85%。YN-1株系N基因和G N/G C基因的起源不同,我们推断YN-1可能是一个发生重排（reassortment）的新株系,是不同地理起源的株系在共同传播过程中发生了重排的结果,具体原因有待进一步研究。