不同种源刨花润楠苗期生长及叶片性状变异的研究

以刨花润楠主要分布区的14个种源为研究对象,在广州增城开展种源试验,通过对14个种源的刨花润楠苗高、地径、叶面积、叶周长等性状进行观测,分析不同种源苗期性状的遗传变异规律。结果表明：3个生长性状种源间和种源内变异系数相当,其种源间和种源内生长性状变异均较丰富;8个叶片性状种源间的变异系数为17.52%～44.71%,不同种源间叶片性状亦变异明显;生长性状的种源遗传力均大于0.750,说明在一定程度上刨花润楠的苗高、地径等苗期生长性状受自身遗传控制,且不同种源间变异明显,种源选择潜力较大。刨花润楠苗期生长性状的地理及气候变异趋势不明显,表现出随机现象;苗木生长性状与叶片大小呈负相关,即叶片越大、叶柄越长,苗木生长有变慢的趋势;对种源苗期性状进行聚类,可将刨花润楠14个种源划分为5个类群;刨花润楠苗期生长及叶片性状有一定的地理趋势,但也有一定的随机性。以地径为标准对刨花润楠优良种源进行筛选,初步选出永春、兴安、昭平3个种源作为适宜广东地区造林的优势种源。     

Biological Variability and Measurement Error Variability in Ocular Biometry in Samoyed Dogs

A-scan ultrasonography was performed in 40 healthy Samoyeds aged 2–5 years. Mydriasis and cycloplegia were induced in all dogs and 25 of the dogs were also sedated prior to the ultrasound examination. Five consecutive A-scans were taken on each eye and the intrasubject variance (measurement error) and true intersubject variance (true biological variation) were computed. The true biological variation was found to be of the same magnitude in both sedated and unsedated dogs, whereas the measurement errors were considerably larger in the group of unsedated dogs compared to the sedated ones. Magnitudes of the measurement errors for the anterior chamber depth and length of the vitreous body in the unsedated group were unacceptable. The sizes of the measurement errors in the sedated dogs were all within an acceptable range.     

IGF2基因表达调控及其遗传变异在动物生长发育中的研究进展

胰岛素样生长因子2（insulin-like growth factor 2,IGF2）作为胰岛素类激素家族中重要成员之一,广泛参与机体众多生理代谢过程,在癌症发生、神经调节、糖代谢疾病、骨质疏松、肌肉发育和脂肪沉积等方面具有重要的作用,其功能行使主要通过与受体IGF1R和IGF2R结合或与胰岛素样生长因子结合蛋白IGFBPs和IGF2BPs竞争性结合发挥功能。鉴于IGF2基因在肌肉发育和脂肪沉积中的重要作用,发掘IGF2基因相关分子标记并解析其内在调控机理,在畜牧生产中具有重要的意义。研究发现,众多IGF2基因遗传变异与动物的生长发育之间存在显著相关关系,其可能通过影响IGF2基因印记、甲基化状态、转录因子结合或miRNA靶向结合型转录后调控等方式发挥作用。因此,文章综述了IGF2基因表达调控模式,包括IGF2与其受体的调控关系,基因印记与miRNA参与的表观遗传调控,转录因子对其的调节作用,遗传变异等方面的内容,以期为IGF2基因在动物生长发育调控相关研究中提供相应的借鉴,为分子育种提供有效线索。     

五龙鹅早期血浆总蛋白质消长规律与成分研究

本试验选用五龙鹅蛋用系与快长系各150只进行网床育肥试验,测定血浆总蛋白质含量,并进行PAGE电泳。结果显示:初生雏鹅血浆总蛋白质含量较高,随着日龄(1~90 d)增加呈先下降后升高趋势,以对数函数和抛物线函数分段拟合效果较佳,R2为0.9445、0.9568;血浆总蛋白质含量在性别间差异不显著,品系间差异显著。PAGE电泳结果表明:血浆中蛋白质种类在品系、性别间没有差异,随日龄的增加亦没有条带变化。清蛋白含量的变化是引起血浆总蛋白质含量变化的主要因素。     

高寒草原类草地退化原因及其分析

高寒草原类草地是青海省及其藏北高原地区畜牧业发展的核心区域。近年来,随着畜牧业的发展及自然环境的变化使得该区域草地退化严重,严重制约着该区域经济的可持续发展。在草地畜牧业发展过程中,随着人类的干预强度的不断加大,草地退化程度正在不断加剧。文章主要对青海高原地区高寒草原类草地退化原因进行了分析,并针对性地提出了恢复对策。     

偃麦草种质资源外部性状变异及其形态类型的初步研究

对41份偃麦草Elytrigia repens种质资源的16个外部性状变异及其分布规律进行研究,并在对16个指标性状进行相关分析及主成分分析的基础上,对34份材料进行聚类分析。结果表明,偃麦草种内形态指标变异较大,变异系数为4.88%～33.30%,其中叶层高度变异系数最大,达33.30%,其次为旗叶长(26.03%),而种子宽度、种子长度、种子厚度、颖长、叶长变异较小,均在10.0%以下;海拔高度与偃麦草生殖枝高呈显著正相关(P0.01),与颖长呈显著负相关(P0.01),而在纬度上的相关性却呈现相反趋势;经度仅与穗下第1节间长呈显著正相关(P0.01);在对外部性状相关分析及主成分分析的基础上,通过聚类分析,在欧氏距离5.0处,34份偃麦草材料可被划分为高大型、偏高大型、特殊型、低矮型4个类型,且特殊型和低矮型均具有开发为草坪草的潜能。     

Ontogenetic variation and craniometric sexual dimorphism in the social giant mole-rat,Fukomys mechowii (Rodentia: Bathyergidae), from Zambia

The degree of maxillary molar tooth-row eruption and wear were used to assign samples of the social giant mole-rat, Fukomys mechowii, from Zambia, into nine relative age classes in order to assess ontogenetic (age) variation and craniometric sexual dimorphism, with reference to body mass. Univariate and multivariate statistical analyses showed craniometric differences between age classes 1–3 and age classes 5–9, with age class 4 being intermediate between these two age class groupings. This suggests that age class 4 lies at a point on a hypothetical growth curve where growth begins to stabilize. The intermediate placement of age class 4 in multivariate space broadly coincided with body mass categorizations into juveniles (age classes 1–3; <100 g), subadults (age class 4; c. 100–150 g), and adults (age classes 5–9; >150 g). The analyses also revealed the absence of sexual dimorphism in the relatively younger age classes 1–4 but its presence in the relatively older age classes 5–9, and these results are supported by data on body mass. These results may have implications in our understanding of the population and social structures, and reproductive strategies in this little-studied giant mole-rat.     

蒙古马基因组拷贝数变异的研究

拷贝数变异(copy number variation,CNV)在人类和动物基因组中普遍存在,是重要的遗传变异资源.本试验利用比较基因组杂交(comparative genomic hybridization,CGH)芯片对2匹蒙古马和1匹纯血马进行全基因组CNV检测,共检测到210个CNVs,长度6 109 bp至571.87 kb,平均值为37.81 kb,中值为14.45 kb.合并重叠的CNVs,共检测到70个CNV区域(CNV region,CNVR),大小从6 151 bp至573.59 kb,平均值和中值分别为38.93和14.45 kb,总长度为6.19 Mb.经CNV基因注释和功能分析发现,大部分基因与嗅觉受体活性、嗅觉感官知觉、化学刺激的感官知觉、识别和嗅觉传导等功能相关.对5个CNVRs进行qPCR检验,83.33%的qPCR结果与CGH芯片结果一致.通过对蒙古马基因组拷贝数变异的研究,证明CNV在马基因组中普遍存在,为揭示马基因组CNV与重要生物性状的关联性及品种改良奠定了基础.