Chromosome aberrations in metaphase II-oocytes. Stage sensitivity in the mouse oogenesis to amethopterin and cyclophosphamide

The stage sensitivity in oogenesis of C₃H mice was investigated by transplacental treatment of embryonic oogonia and oocytes at meiotic prophase I. After birth the stages of early and late dictyotene as well as the preovulatory and ovulatory phases were treated. Chromosome analysis was performed in unfertilized metaphase II-oocytes after induced ovulation [pregnant mare's serum (PMS) and human chorionic gonadotrophin (HCG)]. As test compounds both the folic acid antagonist amethopterin (M) and the alkylating agent cyclophosphamide (C) were used.Embryonic oogonia as well as the preovulatory phase of oogenesis proved to be most sensitive for the induction of chromosomal aberrations. The investigation with graded doses during the preovulatory stage demonstrated the dose-dependent frequency of the induced types of chromosomal abnormalities.The high sensitivity of these stages where chromosome segregation takes place, e.g. oogonia, preovulatory stage, seems to be related to an additional induction of aneuploidies.     

宋朝中国人的姓氏分布与群体结构分化

姓氏是一种十分有用的文化遗传因子,它的传递方式类似于Ｙ染色体的表现。１０００年前宋朝（公元９６０￣１１７９年）中国人姓氏频率的分布,是一组十分吻合Ｋａｒｌｉｎ－ＭｃＧｒｅｇｏｒ的中性等位基因分布理论的随机数据。１６个省区的姓氏种类丰度的相对参数α和迁移率的相对参数ｖ的分析,反映了这一时期的中国人群的迁移和人群间混合的程度。姓氏遗传距离和现状聚类图的分析,表明在１０００年前的宋朝中国人群已经形成了南     

Symbiotic microbial studies in diverse populations of Aphis gossypii,existing on altered host plants in different localities during different times

Complex interactions between symbiotic bacteria and insects ultimately result in equilibrium in all aspects of life in natural insect populations. In this study, abundance of principal symbiotic bacteria was estimated using qPCR in 1553 individuals of aphids, Aphis gossypii. Aphids were sampled from primary and secondary host plants—hibiscus and cotton. Hibiscus aphids were collected from 24 different locations in April, September, and November, whereas cotton aphids were collected between 2015 and 2017 from areas with wide variations in climatic conditions. About 30%–45% aphids were recorded with the most dominant symbiont, Arsenophonus. The other symbionts were in low frequency, and about 7% of aphids were noted with Hamiltonella, Acinetobacter, and Microbacterium, and 3% of aphids were verified with Serratia and Pseudomonas. Aphids infected with Hamiltonella, Arsenophonus, and Serratia can influence Buchnera densities. Hamiltonella has positive interaction with densities of Arsenophonus and Serratia. Almost 100% coinfection of Hamiltonella and Arsenophonus was detected in Xinxiang aphids and 50% coinfection was reported in aphids from North China, while no coinfection was detected in Hainan aphids. These findings describe the prevalence pattern and richness of core community of symbiotic bacteria in naturally occurring populations of A. gossypii and provide new insights for the study of symbiotic bacteria.     

中国及荷兰人群vWF基因内含子40多态性分析

本文调查了中国汉族及荷兰高加索群体中人类ｖＷＦ基因内含子４０ｎｔ３１／２２１５～２３８０区域ＨＵＭＦＡ３１（Ｃ）遗传多态性的基因频率及基因型频率分布。并对两群体之间的分布以拟然比方法进行比较。对９个等位基因片段测序的结果表明,在ｎｔ３１／２２３４～２２６５区域也有变异存在。提示该座位当被测等位基因ＤＮＡ片段长度相同时,仍可能存在遗传差异。     

Confirming the factor structure of the dream intensity inventory.

This study’s primary purpose was to examine the overall quality of the factorial structure of the Dream Intensity Inventory (DII). It was hypothesized that dream intensity was a multifaceted construct that could be accounted for by 3 latent factors, namely Dream Quantity, Dream Vividness, and Altered Dream Episodes. The 1st-order oblique, 1st-order orthogonal, and 2nd-order models, which represented 3 possible versions of the structural relations among the 3 latent factors, were subjected to the confirmatory statistical procedures. The goodness-of-fit indices indicated that the 2nd-order model and the 1st-order model hypothesizing 3 oblique factors were superior to that hypothesizing 3 orthogonal factors. The factorial characteristics of the two well-fitting DII models were shown to be equivalent across 2 samples. These results suggest that the theoretical construct of dream intensity can be pertinently described by the 3-factor measurement model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

微卫星标记在不同壳色虾夷扇贝家系亲权鉴定的适用性

实验选取8 个多态性微卫星位点, 用于虾夷扇贝4 个不同壳色全同胞和半同胞家系160 个子代的亲权鉴定。在亲本未知和一亲本已知的情况下, 8 个微卫星位点累积排除概率分别为0.823 和0.961。鉴于亲权分析时子代的亲本在已知和未知情况下位点的累积排除概率不同, 实验采用了两种方法用于家系的亲权鉴定。方法1: 当子代的父母本情况未知时, 根据子代基因型数据, 通过CERVUS 2.0 软件计算子代所对应的候选亲本的LOD 值, 直接将候选亲本中具有最大的两个LOD 值的亲本确定为子代的父母本; 方法2: 在子代的亲本未知情况下, 视具有最大LOD 值的候选亲本为子代的第一候选亲本, 然后将该亲本视为已知, 通过CERVUS 2.0 软件重新计算每个侯选亲本的LOD 值, 再从中选择具有最大LOD 值的候选亲本作为该子代的第二候选亲本。结果表明, 采用方法2 得到的家系亲权鉴定成功率达到95%以上, 确定了微卫星标记在虾夷扇贝家系鉴定中的可行性。所检测的微卫星位点在子代中出现无效等位基因现象, 而无效等位基因存在会引起子代与亲本的错配。实验在家系鉴定时采用了无效等位基因存在(情况1)和缺失(情况2)两种子代基因型文件进行分析, 不同情况下同一方法家系鉴定成功率相差无几。这表明了基于多个微卫星位点计算候选亲本LOD 值大小寻找子代真实父母本可以降低由无效等位基因引起的错配的几率。研究表明了微卫星标记适合于不同壳色虾夷扇贝家系亲权鉴定工作。       

Inclusive fitness analysis on mathematical groups

Recent work on the evolution of behaviour is set in a structured population, providing a systematic way to describe gene flow and behavioural interactions. To obtain analytical results one needs a structure with considerable regularity. Our results apply to such "homogeneous" structures (e.g., lattices, cycles, and island models). This regularity has been formally described by a "node-transitivity" condition but in mathematics, such internal symmetry is powerfully described by the theory of mathematical groups. Here, this theory provides elegant direct arguments for a more general version of a number of existing results. Our main result is that in large "group-structured" populations, primary fitness effects on others play no role in the evolution of the behaviour. The competitive effects of such a trait cancel the primary effects, and the inclusive fitness effect is given by the direct effect of the actor on its own fitness. This result is conditional on a number of assumptions such as (1) whether generations overlap, (2) whether offspring dispersal is symmetric, (3) whether the trait affects fecundity or survival, and (4) whether the underlying group is abelian. We formulate a number of results of this type in finite and infinite populations for both Moran and Wright-Fisher demographies.     

Factors governing flower visitation patterns and quality of pollination services delivered by social and solitary bee species to coffee in central Uganda

In Uganda, information on visitation frequency of pollinator species visiting coffee flowers is absent, although such information is critical for the stability of coffee yield through the enhancement of pollination services. This study was conducted to understand the role played by local and environmental factors on the visitation intensity of coffee flowers by different bee species. Stepwise multiple regressions were used to investigate the effects of light intensity, distance to forest, foraging time of the day, coffee blooming season and abundance of coffee floral resources on the flower visitation frequency of different bee species. Results indicated contrasting responses of different bee species. The most important factors for social bees included forest distance, light intensity and the time of the day, whereas most determinant factors for solitary bee species were the length of the flowering season and the abundance of coffee floral resources. There is a need for developing habitat and landscape management strategies for the conservation of frequent native species in the vicinity of coffee fields to increase the delivery of pollination services to coffee. It is recommended to farmers to grow their coffee farms in the adjacent of forest habitats and related semi‐natural habitats to receive high bee visitations.     

Strategies for imputation to whole genome sequence using a single or multi-breed reference population in cattle

Background

The advent of low cost next generation sequencing has made it possible to sequence a large number of dairy and beef bulls which can be used as a reference for imputation of whole genome sequence data. The aim of this study was to investigate the accuracy and speed of imputation from a high density SNP marker panel to whole genome sequence level. Data contained 132 Holstein, 42 Jersey, 52 Nordic Red and 16 Brown Swiss bulls with whole genome sequence data; 16 Holstein, 27 Jersey and 29 Nordic Reds had previously been typed with the bovine high density SNP panel and were used for validation. We investigated the effect of enlarging the reference population by combining data across breeds on the accuracy of imputation, and the accuracy and speed of both IMPUTE2 and BEAGLE using either genotype probability reference data or pre-phased reference data. All analyses were done on Bovine autosome 29 using 387,436 bi-allelic variants and 13,612 SNP markers from the bovine HD panel.

Results

A combined breed reference population led to higher imputation accuracies than did a single breed reference. The highest accuracy of imputation for all three test breeds was achieved when using BEAGLE with un-phased reference data (mean genotype correlations of 0.90, 0.89 and 0.87 for Holstein, Jersey and Nordic Red respectively) but IMPUTE2 with un-phased reference data gave similar accuracies for Holsteins and Nordic Red. Pre-phasing the reference data only lead to a minor decrease in the imputation accuracy, but gave a large improvement in computation time. Pre-phasing with BEAGLE was substantially faster than pre-phasing with SHAPEIT2 (2.5 hours vs. 52 hours for 242 individuals), and imputation with pre-phased data was faster in IMPUTE2 than in BEAGLE (5 minutes vs. 50 minutes per individual).

Conclusion

Combining reference populations across breeds is a good option to increase the size of the reference data and in turn the accuracy of imputation when only few animals are available. Pre-phasing the reference data only slightly decreases the accuracy but gives substantial improvements in speed. Using BEAGLE for pre-phasing and IMPUTE2 for imputation is a fast and accurate strategy.     

白细胞介素23 受体基因rs6682925 多态与冠心病发病的相关关系

目的:本研究探讨白细胞介素23受体(Interleukin 23 Receptor,IL23R)基因单核苷酸多态位点(rs1884444与rs6682925)与中国北方汉族人群冠心病发病的相关关系。方法:本研究采用病例-对照的设计方法,收集568名冠心病患者以及45岁以上、年龄及性别匹配的524名正常对照个体为研究对象,采用测序法检测IL23R rs1884444与rs6682925单核苷酸多态性基因型,分析IL23R基因rs1884444与rs6682925单核苷酸多态位点的基因型及等位基因的分布情况。结果:IL23R rs6682925与rs1884444单核苷酸多态位点的基因型频率符合Hardy-Weinberg定律。IL23R基因rs6682925单核苷酸多态位点的三种基因型分布频率(CC型,TC型和TT型)在冠心病组为22.9%,39.6%和37.5%,在对照组分别为41.7%,47.2%和11.1%,IL23R基因rs6682925单核苷酸多态位点C等位基因是冠心病发病的一个独立的危险因素(P0.05);IL23R基因rs1884444单核苷酸位点的基因型和等位基因的频率在对照组和冠心病组之间不存在统计学差异(P0.05)。Logistic回归校正性别、年龄、体重指数、吸烟、高血压、高脂血症、糖尿病等冠心病的易患因素后,IL23R基因rs6682925 C等位基因仍是冠心病发病一个独立危险因素。结论:在中国北方汉族人群中,IL23R基因rs6682925 C等位基因可能是冠心病发病的独立危险因素。