On a method of estimating the genetic correlation between characters measured in different experimental units

Summary Yamada's method of estimating genetic co-variances between traits measured in different experimental units is discussed. It is shown that if the data are unbalanced, this method gives biased estimates of genetic covariances unless the traits have identical genetic and residual variances. An alternative unbiased procedure is suggested.     

水解工业废羊毛提取胱氨酸的工艺参数的改进

利用人发、猪毛水解提取胱氨酸的生产线,以工业废羊毛为原料水解提取胱氨酸,给出了改进后的工艺参数。试验证明：成品收率提高到４．９％,成品合格率１００％。     

白皮松天然群体遗传结构的地理变异分析

为探讨白皮松天然群体遗传结构在地理分布上的差异,利用7对SSR引物对5个白皮松分布区域的遗传结构进行了分析。结果表明：7对SSR引物在5个区域内476个单株中共检测到14个多态性位点。各区域间观测等位基因数（Na）、有效等位基因数（Ne）、Shannon’s 信息指数（I）、观测杂合度（Ho）、期望杂合度（He）、Nei’s期望杂合度（Nei’s）分别介于1.7143~2.1429、1.1942~1.571、0.1948~0.4954、0.1726~0.3116、0.1178~0.3325、0.1172~0.3307之间。白皮松遗传多样性水平总体较低,区域间差异较大;遗传多样性水平最高的区域为秦岭西侧群体,其次为大巴山区群体;太行山与吕梁山群体多样性水平相对较低。区域间的遗传分化系数Fst介于0.0138~0.2242之间,基因流Nm介于0.865~17.8646之间。遗传分化较大、基因流水平较低的区域均发生在秦岭西侧及其与其他区域之间。各区域间遗传相似系数在0.8416~0.9964之间,遗传相似度最高的群体为太行山与吕梁山区域,遗传距离最大的为太行山与秦岭西侧区域。白皮松多样性分布的中心主要存在于秦岭西侧和大巴山区域,因此应对该区域进行重点保护。     

Genetic polymorphisms of glutathione S-transferases M1 and T1 modulate hematological changes of individuals chronically exposed to natural sour gas

In order to find the effect of genetic polymorphisms of glutathione S-transferase M1 (GSTM1) and GSTT1 on hematological changes of individuals chronically exposed to natural sour gas, the present study was done. Study subjects (59 males, 55 females) were residents of contaminated areas of Masjid-i-Sulaiman (southwest of Iran). The GSTM1 and GSTT1 genotypes were determined using a polymerase chain reaction-based method. The multiple linear regression method was applied. There is significant association between GSTs genotypes and either hemoglobin (t=2.185, P=0.031) or hematocrit (t=2.454, P=0.016). Also there is weak association between GSTs genotypes and WBC counts (t=1.802, P=0.074). The hemoglobin and hematocrit levels and WBC counts increased in individuals who had null genotypes of GSTM1 and GSTT1 compared to subjects with one or two active genes. Also the levels of hemoglobin and hematocrit and WBC counts increased in persons with one active genotype compared to subjects who had two active genes. There is no significant association between neither platelet nor WBC differential parameters and GSTs genotypes.     

Genotypic proportions in hybrid zones

We study a hybrid zone between two populations of a diploid organism. The populations differ at one locus. Homozygotes have equal fitnesses and the heterozygote fitness is reduced by + ( is the birth rate deviation and is the death rate deviation). The populations extend along a one dimensional continuous habitat, and migration occurs by diffusion of individuals. The model is formulated as a set of simple continuous time demographic models without age structure for the three genotypes, and the system is transformed into three new variables, the total population size N, the gene frequency p, and the deviation from Hardy-Weinberg proportions F. The gene frequency in a steady state cline always follows a hyperbolic tangent closely. Analysis of the asymptotic behavior of the cline far from the hybrid zone suggests a qualitative prediction of the shape of N, p and F over the zone. For weak selection the shape is determined by a central steepness of , as observed by Bazykin in 1969, where D is the diffusion coefficient. For strong selection the cline is less steep than the Bazykin cline, and the form is dominated by the migration process. The steepness at the center of the cline is close to where b is the birth rate of homozygotes.Supported in part by grant 11-9639-1 from the Danish Natural Science Research Council and grant 5.18.2023 from the Danish Biotechnological Research and Development Programme     

The reduction of abnormal behaviors in individually housed rhesus monkeys (Macaca mulatta) with a foraging/grooming board

A new environmental enrichment device, termed a “foraging/grooming board,” was presented to 8 individually housed rhesus monkeys for the explicit purpose of reducing the level of aberrant behaviors manifested by these animals. The device, consisting of a piece of plexiglass covered with artificial fleece, had particles of food treats rubbed into it and was attached to the outside of each animal's home cage. All animals foraged from the board to the point that a significant reduction in the level of abnormal behavior was noted. Most animals also groomed the fleece covering the board, utilizing the same motor patterns that would be directed toward grooming another monkey. These boards are inexpensive to construct and easy to sanitize, and do not require placing animal facility personnel at risk to maintain them.     

Embryo transfer in domestic South American camelids

Intraspecific and interspecific embryo transfer in domestic South American camelids is developing into a well-established technique. Reports reveal many benefits of using reproductive biotechnologies to allow rapid propagation of alpacas and llamas of high genetic merit (e.g., high fiber quality, preserve color variation). The objective of this review is to provide up-to-date information about embryo transfer in domestic South American camelids. Specific information is provided on criteria for male selection, donor and recipient synchronization, the practice of single- vs. super-ovulation protocols, embryo recovery and transfer techniques, advances in cryopreservation of embryos, results of intra- and inter-specific transfer, and the future of the embryo transfer in domestic South American camelids.     

上海城区河道底栖动物群落特征与沉积物重金属潜在生态风险

2007年10月—2008年10月对上海市城区4条河道(午潮港、横港、朝阳河、曹杨环浜)底栖动物群落进行了逐月采样调查,共获得底栖动物20种,其中,软体动物门14种,环节动物门3种。分析表明:4条河道底栖动物多样性指数均较低,Shannon指数最高达0.602,均为重污染河道。大型底栖动物多样性指数客观地反映了河道的水体环境质量状况;软体动物体内重金属Pb、As和Zn残留分别超出国家标准1.15、0.32和0.23倍;沉积物中Cd、Cu、Pb、Zn含量均超出国家标准,软体动物体内和沉积物中重金属含量没有相关性;单金属潜在生态风险系数(Eri)显示,沉积物中6种重金属的潜在生态风险顺序为CdPbCuAsZnCr,Cd污染为强生态危害;多金属潜在生态风险指数(RI)显示,4条河道沉积物重金属污染为中等。     

自然环境胁迫对旱冬瓜Frankia菌基因多样性的影响

利用rep-PCR方法,研究云南鸡足山及无量山不同生境下旱冬瓜根瘤内Frankia菌基因多样性及其变化,以了解不同自然环境胁迫对Frankia菌基因多样性的影响。结果表明,多样性随地域、海拔和坡向不同而变化,鸡足山Frankia菌基因类型比无量山丰富。鸡足山旱冬瓜根瘤内的Frankia菌在山底2300m处,Shannon指数平均为0．90;山顶海拔2650m以上,Shannon指数随之上升到1．33。南坡Frankia菌多样性高于北坡,表明多样性指数与环境胁迫大小成正相关,自然环境胁迫是产生和保持Frankia菌基因多样性的重要因子之一。     

锥栗自然居群遗传多样性的ISSR分析

采用20条ISSR分子标记对栗属中国特有种-锥栗(Castanea henryi)的16个自然居群进行了遗传多样性与遗传关系分析。在449份试材上共扩增得到379个位点,其中多态性位点378个,多态性位点百分率(PPL)达99.74%,平均期望杂合度(He)为0.2950,Shannon信息指数(I)为0.4522;居群水平遗传多样性为46.09%,且不同居群遗传多样性水平有较大差异,16个自然居群中以湘西居群的遗传多样性水平最高(PPL=53.30%,He=0.1861,I=0.2781),其次为靖州、庆元、昭通及都江堰居群,南平居群最低(PPL=36.94%,He=0.1202,I=0.1817)。Nei’s遗传多样性和AMOVA分析表明,居群间产生了较大的遗传分化(Gst=0.4466),锥栗自然居群内的遗传变异稍占优势(52.51%)。UPGMA聚类分析将16个锥栗居群分为2大类5亚类。湘西地区可能是锥栗的次生分布中心和现代遗传多样性分布中心,是锥栗研究的资源中心,也是最有价值的基因库,需要重点保护。     

羊驼种群内亲缘关系的研究

应用RAPD技术对羊驼群体进行亲缘关系检测。在所采用的40条随机引物中筛选出10条,优化了RAPD的反应条件,确立了适合于羊驼基因组RAPD分析的最佳反应体系和反应程序。计算出个体间之间的带纹相似系数及遗传距离指数,带纹相似系数位于0.3901~0.7851之间,平均为0.5374;彼此间的遗传距离最小为0.2149,最大为0.6099,平均为0.4626,并绘制出个体间亲缘关系树状聚类图。结果显示羊驼种群内遗传基础广泛,证明其个体间的血缘关系较远,这将有利于羊驼种群的正常生长、发育、繁殖和快速扩群。     

Arithmetic inside the universal genetic code

The first information system emerged on the earth as primordial version of the genetic code and genetic texts. The natural appearance of arithmetic power in such a linguistic milieu is theoretically possible and practical for producing information systems of extremely high efficiency. In this case, the arithmetic symbols should be incorporated into an alphabet, i.e. the genetic code. A number is the fundamental arithmetic symbol produced by the system of numeration. If the system of numeration were detected inside the genetic code, it would be natural to expect that its purpose is arithmetic calculation e.g., for the sake of control, safety, and precise alteration of the genetic texts. The nucleons of amino acids and the bases of nucleic acids seem most suitable for embodiments of digits. These assumptions were used for the analyzing the genetic code.

The compressed, life-size, and split representation of the Escherichia coli and Euplotes octocarinatus code versions were considered simultaneously. An exact equilibration of the nucleon sums of the amino acid standard blocks and/or side chains was found repeatedly within specified sets of the genetic code. Moreover, the digital notations of the balanced sums acquired, in decimal representation, the unique form 111, 222, …, 999. This form is a consequence of the criterion of divisibility by 037. The criterion could simplify some computing mechanism of a cell if any and facilitate its computational procedure. The cooperative symmetry of the genetic code demonstrates that possibly a zero was invented and used by this mechanism. Such organization of the genetic code could be explained by activities of some hypothetical molecular organelles working as natural biocomputers of digital genetic texts.

It is well known that if mutation replaces an amino acid, the change of hydrophobicity is generally weak, while that of size is strong. The antisymmetrical correlation between the amino acid size and the degeneracy number is known as well. It is shown that these and some other familiar properties may be a physicochemical effect of arithmetic inside the genetic code.

The “frozen accident” model, giving unlimited freedom to the mapping function, could optimally support the appearance of both arithmetic symbols and physicochemical protection inside the genetic code.     

Estimation of heritability by offspring-parent regression when observations do not have a common mean

Summary Offspring-parent regression is a simple method for estimating heritability. This method yields unbiased estimates even when parents are selected. The usual model in offspring-parent regression assumes that observations have the same mean. This assumption, however, is not met in many situations. A method for estimating heritability by offspring-parent regression when observations do not have a common mean is presented. The estimator is distributed as a multiple of a t random variable centered at its parametric value and is unbiased even when the parents are selected. When observations have a common mean, the method reduces to the usual regression estimator.     

浙江省境内七子花天然种群遗传多样性研究

利用RAPD技术对浙江省境内的七子花9个天然种群遗传多样性和遗传分化进行研究.结果表明,12种随机引物对180棵植物进行检测,共得到164个可重复的位点.多态位点百分率在14.60%～27.44%(平均为20.73%),以括苍山种群最高,其次是四明山种群,最低是观音坪种群.Shannon指数和Nei指数均反映出七子花各种群具有较低的遗传多样性,但遗传分化明显.Shannon指数显示种群内遗传多样性只占总遗传多样性的27.28%,而种群间遗传多样性却占72.72%;Nei指数表明种群内的遗传变异较小,种群间的遗传变异较大,种群间的遗传分化系数为0.7157.七子花种群间的基因流为0.1987,遗传相似度平均为0.7306,遗传距离平均为0.3150,各种群间的遗传分化明显.根据遗传距离聚类分析,大致可以将9个七子花种群分为东部和西部两大类群.     

Inheritance of white, black and brown coat colours in alpaca (Vicuna pacos L.)

An experimental trial of the segregation of white vs. pigmented and black vs. brown colours in alpacas was conducted at the Peruvian INIA Quimsachata Experimental Station. One hundred and forty five offspring were born from the following matings: 4 white sires × 36 white dams, 4 white sires × 39 pigmented dams, and 9 pigmented sires × 70 pigmented dams. Among these last matings were, 4 black sires × 25 black dams, 2 black sires × 20 brown dams, and 3 brown sires × 25 brown dams. Statistical tests validate that the inheritance of white is due to a single gene which is dominant over pigmentation, without any modifying effect and independent of segregation of black and brown patterns. However, the evidence does not support a simple dominant inheritance of the black vs. brown.     

酪氨酸酶与羊驼毛色相关性的研究

为揭示羊驼毛色形成机理以及毛用性状改良奠定基础,选用羊驼作为试验动物群体,以酪氨酸酶作为影响羊驼毛色性状的候选基因,采用荧光定量PCR技术、免疫组织化学、免疫印迹等生物学方法从基因与蛋白方面分析了羊驼酪氨酸酶(tyrosinase,TYR)在不同毛色个体的表达量.荧光定量PCR结果显示TYR基因在棕色个体中的mRNA表...     

Genetic parameters for oocyte number and embryo production within a bovine ovum pick-up-in vitro production embryo-production program

Genetic factors influencing the outcome of bovine ovum pick-up-in vitro production (OPU-IVP) and its relation to female fertility were investigated. For the first time, genetic parameters were estimated for the number of cumulus-oocyte complexes (Ncoc), quality of cumulus-oocyte complexes (Qcoc), number and proportion of cleaved embryos at Day 4 (Ncleav_D4, Pcleav_D4), and number and proportion of total and transferable embryos at Day 7 of culture (Nemb_D7, Pemb_D7 and NTemb_D7, PTemb_D7, respectively). Data were recorded by CRV (formally Holland Genetics) from the OPU-IVP program from January 1995 to March 2006. Data were collected from 1508 Holstein female donors, both cows and pregnant virgin heifers, with a total of 18,702 OPU sessions. Data were analyzed with repeated-measure sire models with permanent environment effect using ASREML (Holstein Friesian). Estimates of heritability were 0.25 for Ncoc, 0.09 for Qcoc, 0.19 for Ncleav_D4, 0.21 for Nemb_D7, 0.16 for NTemb_D7, 0.07 for Pcleav_D4, 0.12 for Pemb_D7, and 0.10 for PTemb_D7. Genetic correlation between Ncoc and Qcoc was close to zero, whereas genetic correlations between Ncoc and the number of embryos were positive and moderate to high for Nemb_D7 (0.47), NTemb_D7 (0.52), and Ncleav_D4 (0.85). Genetic correlations between Ncoc and percentages of embryos (Pcleav_D4, Pemb_D7, and PTemb_D7) were all close to zero. Phenotypic correlations were in line with genetic correlations. Genetic and phenotypic correlations between Qcoc and all other traits were not significant except for the phenotypic correlations between Qcoc and number of embryos, which were negative and low to moderate for Nemb_D7 (-0.20), NTemb_D7 (-0.24), and Ncleav_D4 (-0.43). Results suggest that cumulus-oocyte complex (COC) quality, based on cumulus investment, is independent from the total number of COCs collected via OPU and that in general, a higher number of COCs will lead to a higher number of embryos produced. The correlation between the estimated breeding values for Ncoc and PTemb_D7 of sires in this study and the sires breeding index for female-fertility based on the Dutch cattle population was close to zero. This study revealed OPU-IVP traits (Nemb_D7, NTemb_D7, and Ncoc) that could be of potential value for selection. Introduction of such traits in breeding programs would enhance the number of offspring from superior donors as well as improve the cost efficiency of OPU-IVP programs.     

Plot size for progeny selection in maize (Zea mays L.)

Summary Six progeny trials that included 147 half-sib progenies of maize (Zea mays L.) population ESALQ PB-5 were conducted for the purpose of studying plot size and its consequences in recurrent selection programs. The progenies were evaluated in three 7x7 duplicate simple lattice experiments using one-row plots of 5 m². At harvest each plot was partitioned into five sub-plots (sampling units), and data was collected from each sampling unit. At the same time and place the same progenies were evaluated in three 7x7 duplicate simple lattice experiments using 1-m² (linear row with 5 plants) plots. Data were collected for plant and ear height, ear diameter, total ear weight, and total grain yield. The data were combined by using adjacent sampling units, and the analyses were performed by considered five plot sizes in addition to those of the independent trials with 1-m² plots. The experiments with 1-m² plots were less efficient in discriminating for yield traits among progenies than those with 5-m² plots. The combination of plot size and number of progenies evaluated indicated that an optimum plot size for yield was between 3 and 4 m², or 15–20 plants per plot. With such sizes the expected gain was maximized for the four replications used in this study. If the total area covered by each progeny is constant, the maximum gain from selection, however, is attained by decreasing plot size and increasing the number of replications. The minimum size of plots is, however, limited by practical or theoretical criteria. Plot size affected the estimates of additive genetic variance, coefficient of heritability, and genetic coefficient of variation for all of the traits. No practical limitation was observed for conducting experiments with 1-m² plot.