为了更好地了解葡萄浆果开裂的遗传基础，我们对不同葡萄品种进行了全基因组关联研究（GWAS）。基于混合线性模型（MLM），我们在两年内分别检测到五个和两个与浆果开裂指数和浆果开裂类型相关的单核苷酸多态性（SNP）位点；这些位点主要分布在四条染色体上，即1、2、3和18号染色体。这些相关的SNP位点与10个独特的候选浆果开裂基因相关。基因表达模式表明，易裂果品种的候选基因表达比抗裂果品种丰富。葡萄浆果是一个由多个基因控制的复杂性状，主要涉及包括多聚半乳糖醛酸酶、铜转运蛋白和受体样蛋白相关基因，这些候选浆果开裂基因的高表达可能促进浆果开裂的发生。本研究有助于阐明浆果开裂的遗传机制。

甘蔗具有庞大、复杂的多倍体基因组，阻碍了其基因组学和分子标记辅助选择的研究进展。简便易用的微卫星分子标记（SSR）因其理想的遗传属性而备受关注，但由于此前缺乏高质量染色体水平的甘蔗基因组，这些标记尚未在甘蔗全基因组范围内进行开发。本研究从甘蔗高贵种和割手密种基因组中鉴定到744,305和361,638个候选SSRs。为验证这些预测SSR的可靠性，使用11份代表性甘蔗材料（包括高贵种、割手密种、大茎野生种和现代栽培种）对1,200对种间特异SSR引物的多态性进行检测。结果表明，共有660对SSR标记在这些材料中呈现为种间多态性。此外，随机选取了100对SSR标记，对39份具有代表性的甘蔗材料进行遗传多样性分析。利用100条多态性引物共获得320个等位位点，每对SSR标记的等位位点为2-7个。遗传多样性分析结果表明，这些种质资源主要分布在4个类群中，分别为I类(14份割手密种)、II类(2份高贵种)、III类(18份现代甘蔗杂交种)和IV类(5份大茎野生种)。实验结果证明了本研究中基于甘蔗基因组预测所获得的SSR分子标记的可靠性。基于实验验证的大量SSR分子标记的开发对甘蔗遗传连锁图谱构建、比较基因组分析、全基因组关联分析和分子标记辅助选择等遗传研究具有重要意义。

The purpose of this study was to investigate the effects of methionine deficiency on cellular immune function by determining morphological and ultrastructural changes of thymus, thymic cell cycle and apoptosis, peripheral blood T-cell subsets, Tcell proliferation function and the serum interleukin-2 (IL-2) contents. 120 1-d-old broilers were randomly divided into two groups (6 replicates in each group and 10 broilers in each replicate) and fed on a control diet or methionine deficient diet for 42 d. Lesions were observed in experiment. Histopathologically, lymphopenia and congestion were observed in the medulla of thymic lobule. Ultrastructurally, there were more apoptosis lymphocytes, and the mitochondria of lymphocytes were swelled in thymus of methionine deficiency. The G0/G1 phase of the cell cycle of the thymus was much higher (P<0.01), and the S, G2+M phases and proliferating index (PI) were lower (P<0.01) in methionine deficiency than in control group. And the percentage of apoptotic cells in the thymus was significantly increased in methionine deficiency (P<0.01). The percentage of CD4+ and CD8+ T-cells was decreased in methionine deficiency compared with control group. Meanwhile, the proliferation function of peripheral blood T-cell was decreased in methionine deficiency. Also, the serum IL-2 contents were decreased in methionine deficiency. It was concluded that methionine deficiency could cause pathological and ultrastructural changes of thymus, reduce the T-cell population, serum IL-2 contents and the proliferation function of Tcells, and induce increased percentage of apoptotic cells. The cellular immune function was finally impaired in broilers.