Tg29诱导糯玉米单倍体的效率及DH系鉴定

【目的】检验新选诱导系Tg29诱导糯玉米单倍体的效率以及糯玉米DH系的稳定性,为单倍体技术在糯玉米育种上的应用提供参考。【方法】将玉米孤雌生殖诱导系Tg29与16份不同基因型的自交系和杂交种杂交,并根据籽粒Navajo斑纹和ABPI紫色植株显性双标记系统对所诱导的孤雌生殖单倍体进行筛选;分析从京糯6/Tyc115中诱导出的单倍体经秋水仙素加倍获得的16份DH系的田间和农艺性状表现,从而对糯玉米DH系进行鉴定。【结果】在16份糯玉米母本材料中,从JN18、JN18/BN2和Tyc115中诱导单倍体的频率较高,分别为10.41%,9.79%和9.25%;而从浚白34和京糯6中诱导单倍体的频率较低,分别为3.45%和3.13%;Tg29的平均单倍体诱导率为6.55%。在株高、穗位、株型性状上,糯玉米DH系内均呈高度的一致性,其中Tyc115、京糯6、JN18等DH系在生长势和果穗性状上符合育种要求。【结论】利用Navajo斑纹和ABPI紫色植株显性双标记系统来鉴别杂交诱导的糯玉米单倍体是可靠的;Tg29对不同糯玉米基因型材料均能诱导产生单倍体,但诱导率与母本基因型材料有很大关系;糯玉米单倍体加倍获得的DH系的群体遗传结构是同质的,是完全意义上的纯合。     

P（AN—co—VAc）的结构与性能研究

根据ＩＲ、ＮＭＲ计算出Ｐ（ＡＮ－ｃｏ－ＶＡｃ）共聚物单体含量，聚合温度升高，单体配比ＡＮ／ＶＡｃ减小，共聚物中ＶＡＣ量增加，Ｐ（ＡＮ－ｃｏ－ＶＡｃ）的Ｔｇ随ＶＡＣ含量增加而降低，含水Ｐ（ＡＮ－ｃｏ－ＶＡＣ）的Ｔｇ较无水共聚物稍低，水分子起增塑作用，共聚物在热水中易加工成型，成型品具有一定硬度和强工，可应用于工农业做多生材料。     

人工合成小麦穗部特异性状的遗传分析

用人工合成的六倍体小麦RSP×改良品系88-1643获得的F1、F2、F3群体对合成小麦的穗部特异性状进行遗传分析,发现其包壳受到2对基因的控制。说明除节节麦的Tg基因外,还有另一个基因对合成小麦颖壳硬度的表现具有作用。小穗密度的遗传分析表明其受多基因控制。相关分析表明,穗长主要取决于小穗密度,且与包壳性状存在极显著的相关。QTL检测的结果显示2DS上有影响穗密度和穗长的QTL,这可能来源于Tg基因的效应。     

Classical natural ovine scrapie prions detected in practical volumes of blood by lamb and transgenic mouse bioassays

Scrapie is diagnosed antemortem in sheep by detecting misfolded isoforms of prion protein (PrP^Sc) in lymphoid follicles of the rectal mucosa and nictitating membranes. Assay sensitivity is limited if (a) the biopsy is collected early during disease development, (b) an insufficient number of follicles is collected, or (c) peripheral accumulation of PrP^Sc is reduced or delayed. A blood test would be convenient for mass live animal scrapie testing. Currently approved techniques, however, have their own detection limits. Novel detection methods may soon offer a non-animal-based, rapid platform with detection sensitivities that rival the prion bioassay. In anticipation, we sought to determine if diseased animals could be routinely identified with a bioassay using B lymphocytes isolated from blood sample volumes commonly collected for diagnostic purposes in small ruminants. Scrapie transmission was detected in five of six recipient lambs intravenously transfused with B lymphocytes isolated from 5~10 mL of blood from a naturally scrapie-infected sheep. Additionally, scrapie transmission was observed in 18 ovinized transgenic Tg338 mice intracerebrally inoculated with B lymphocytes isolated from 5~10 mL of blood from two naturally scrapie-infected sheep. Based on our findings, we anticipate that these blood sample volumes should be of diagnostic value.     

Overexpression of miR-132 attenuates Alzheimer disease-like learning and memory impairment

AIM: To obtain miR-132 lentivirus and to detect the effect of miR-132 overexpression on the improvement of learning and memory impairment in Tg2576 mice. METHODS: The pri-miR-132 gene was purified from mouse brain and cloned into lentivirus vector pLenti7.3-miR-132. The miR-132 lentivirus was packaged by co-transfected pLenti7.3-miR-132 with ViraPower Packaging Mix into 293FT cells. The miR-132 lentivirus was purified 72 h later from the supernatant by ultracentrifugation and poly(ethylene glycol) method. The efficiency of miR-132 lentivirus was identified by transfection into N2A cells and mouse hippocampus region. Tg2576 mice were injected with miR-132 virus in the hippocampus region and the expression of learning- and memory-related proteins and functions were determined. RESULTS: miR-132 lentivirus expression vector was constructed successfully. The purified virus was obtained with transfection activity. Tg2576 mice with overexpression of miR-132 had a significant improvement in learning and memory abilities. CONCLUSION: miR-132 lentivirus with biological activity was obtained. Overexpression of miR-132 in the hippocampus region of Tg2576 mice attenuates the learning and memory impairment.