家蚕心形眼纹(ces)的遗传与基因定位研究

通过对家蚕基因资源库保存品系的性状调查,发现一种幼虫眼状纹变异——心形眼纹(cordiform eye-spot,ces),其特征是:幼虫眼纹呈倒心型,相当于正常型眼纹的中间部分,色浅。与正常型进行杂交试验,表明该突变为隐性遗传,外显率稍低;与各染色体标记基因进行连锁分析,确认突变基因ces属于第14染色体;育成青熟油蚕(oa)与ces的双隐性系统后,通过ces与oa和Nd-s(丝胶茧)的三点测验,初步将ces基因定位于家蚕连锁图谱第14连锁群的50.7 cM位点,表示为ces(14-50.7)。     

家蚕体形突变第2数珠蚕(mf-2)的遗传学研究

经X射线诱导发现的家蚕体形突变第2数珠蚕(mf-2)在形态上与数珠蚕(mf:12-39.8)相似。通过二者间的杂交实验表明,mf-2与mf为独立遗传;与各染色体的标记基因进行连锁分析,发现mf-2与第15染色体的眼纹全黑(bl:15-0.0)连锁,说明mf-2基因属于第15连锁群;初步测定mf-2与bl间的遗传距离为27.7 cM。     

对家蚕多星纹基因ms的SSR标记定位分析

对家蚕幼虫斑纹突变多星纹基因ms进行分子标记定位,有益于对多星纹性状的分子标记辅助选择和对该基因的定位克隆研究。利用家蚕雌性染色体在减数分裂过程中不发生交换的特点,采用幼虫斑纹为素斑(p)的家蚕品系C108,幼虫斑纹为多星纹(ms)的家蚕品系g02,组配正反交群体(g02×C108)F1♀×g02♂和g02♀×(g02×C108)F1♂,分别记作BC1F和BC1M,利用已经构建的家蚕SSR分子标记连锁图谱中第12连锁群上的18对SSR标记引物在亲本间进行多态性筛选。BC1F群体中的普通斑个体均表现出与(g02×C108)F1相同的杂合型带型;而所有多星纹个体的带型与亲本g02一致,为纯合型。结果筛选出S1206、S1208、S1210、C5553S3共4个与家蚕ms连锁的SSR标记。利用BC1M群体构建家蚕ms及其连锁的SSR标记遗传连锁图,连锁图的图距为34.5 cM,4个SSR标记及ms的排列次序为S1206—S1208—S1210—C5553S3—ms,ms位于34.5 cM处,与ms最近的标记为C5553S3,遗传距离为12.4 cM。依据该SSR标记遗传连锁图谱可对ms进一步精确定位。     

家蚕体形突变新缢蚕(co-n)的遗传分析与基因定位研究

从西南大学家蚕基因库中发现体形自然突变"新缢蚕"。幼虫表型特征为:环节中央部位呈缢缩状,色素聚集,腹部节间膜呈隆起状,5龄中后期最明显,与缢蚕(constricted,co)相似。至成虫期观察,腹背通常少有鳞毛。经遗传分析,新缢蚕为隐性基因支配,将其命名为new constricted,基因符号:co-n。连锁分析结果表明,co-n与黄血(Y)基因连锁,故判定该基因属于第2连锁群。这是家蚕第2连锁群30多个突变中发现的第一个体形突变。经过新缢蚕(co-n)与灰色卵(Gr)、黄血(Y)基因间的三点测验定位实验,结合伴野丰2005年最新公布的家蚕连锁遗传图的第2连锁群基因座数据,将co-n基因座确定为:2-5.7。     

家蚕裸蛹基因(Nd)的SSR定位

家蚕裸蛹是自然突变产生的,裸蛹基因(Nd)与丝素重链基因(Fib-H)同处于第25染色体上,二者紧密连锁。利用家蚕雌性不交换的特点,以家蚕正常茧品种P50和裸蛹品种Nd为亲本获得P50×(P50×Nd)和(P50×Nd)×P50回交群体(分别记为BC1M和BC1F),再用已经构建的家蚕SSR分子标记连锁图谱对Nd基因进行定位,共筛选出7个与Nd基因连锁的SSR标记。BC1F群体中的所有裸蛹个体均表现出与(P50×Nd)F1相同的杂合型带型;而所有正常茧个体带型与亲本P50一致,为纯合型。利用另一个群体BC1M构建了Nd基因的遗传连锁图,连锁图的遗传距离为96.8 cM,Nd基因位于60.8 cM。同时得到了2个与Nd紧密连锁的SSR标记S2511及S2513,与Nd基因的距离分别为0.1 cM和1.1 cM。     

利用SSR标记对家蚕黄血基因的定位及连锁分析

位于家蚕第2染色体的黄血基因(yellow blood,Y)控制类胡萝卜素由中肠进入血淋巴,是形成黄色茧系的基础。利用家蚕雌不发生交换的特点,采用黄茧品系KY和白茧品系C108组配正反交BC_1群体(C108×KY)×C108和C108×(C108×KY),分别记作BC_1F和BC_1M,根据已经构建的家蚕SSR分子连锁图谱,对Y基因进行了定位及连锁分析。筛选出6个与Y基因连锁的SSR标记,这些标记在BC_1F群中的所有黄血个体均表现出与(C108×KY)F_1相同的杂合型带型;而所有白血个体带型与亲本C108一致,为纯合型。利用另一个群体BC_1M构建了关于Y基因的遗传连锁图,遗传距离为18．9cM,Y基因位于15．6cM。     

利用SSR标记对家蚕卵非胶着性基因(Ng)的定位分析

家蚕卵非胶着性基因(No-glue,Ng)位于第12染色体,Ng突变体的雌性成虫生殖器的粘液腺只分泌极少量的粘性物质,因此产下的卵不能粘着而成为天然散卵,是研究家蚕粘液蛋白分泌机制的重要材料。利用雌性家蚕的W染色体和Z染色体间不发生交换的特点,采用产胶着卵的家蚕品系KY和产非胶着卵的家蚕品系巴格达特(Ba)组配正反交群体(Ba×KY)F1♀×KY♂和KY♀×(Ba×KY)F1♂2种材料,分别记作BC1F和BC1M,根据已经构建的家蚕SSR分子标记连锁图谱对Ng基因进行连锁分析及定位。BC1F群体中的所有产非胶着卵的个体均表现出与(Ba×KY)F1相同的杂合型带型;而所有产胶着卵个体的带型与亲本KY一致,为纯合型。筛选出4个与Ng基因连锁的SSR标记,并利用BC1M群体构建Ng基因的SSR标记遗传连锁图,连锁图的遗传距离为51.9cM,与Ng基因最近的引物为S1213,图距为0cM。     

对家蚕第2隐性赤蚁基因(ch-2)的SSR标记定位及连锁分析

家蚕蚁蚕体色突变之一的第2隐性赤蚁(ch-2)有作为特殊遗传系统的实用价值。采用家蚕正常黑蚁品种P50和第2隐性赤蚁品种k04为亲本组配正反交群体,回交后获得回交群体(k04×P50)×k04和k04×(k04×P50),分别记作BC1F和BC1M,基于雌性家蚕的W与Z染色体不发生交换的特点,用已构建的家蚕SSR分子标记连锁图谱对ch-2基因进行定位和连锁分析。在第18连锁群上的20个多态性标记中共筛选出7个与ch-2基因连锁的SSR标记。根据第18连锁群上已有但不表现多态性的微卫星序列,寻找其所在Scaffold上的其他SSR位点并设计引物,结果找到2个新的多态性SSR标记。BC1F群体中的所有黑蚁个体均表现出与F1(k04×P50)相同的杂合型带型,而所有赤蚁个体带型与亲本k04一致,为纯合型,说明家蚕ch-2基因位于第18连锁群。利用另一个群体BC1M构建了ch-2基因的SSR分子标记遗传连锁图,连锁图的遗传距离为70.7cM,ch-2基因位于69.6 cM处。2个与ch-2最近的SSR标记为S1814和S1819,与ch-2的距离分别为7.9、1.1 cM。     

玉米胚乳突变基因ae连锁累赘的SSR分析

本研究通过与玉米胚乳突变基因ae连锁的SSR标记对轮回亲本不同的2个回交一代群体amylose extender(ae)基因两侧的连锁累赘进行了SSR分析.通过均匀分布在ae基因所在的Chr5连锁群上的SSR标记对这2个回交群体的染色体遗传背景回复率开展研究,结果表明,通过MAS可以将回交群体CHBC1F2染色体两侧的连锁累赘分别限定到13.2和17.2 cM,将另一回交群体DHBC1F2的染色体的单侧连锁累赘限定到13.9 cM.背景选择的结果表明,通过基因组的负选择可以使CHBC1F2群体中某些植株的5号染色体的遗传背景回复率达到85.7%,使DHBC1F2群体的染色体的遗传背景回复率达到87.5%.通过高密度的遗传连锁图谱(比如10～20 cM)就可以直接选择在目的基因附近发生重组的个体,减少不需要的染色体片段,降低目标基因附近的搭载效应.     

家蚕抗浓核病育种材料的研究

采用添食病毒的方法,对200个家蚕品种进行了抗浓核病调查,发现28个抗病品种,并从秋丰、白玉中选育出抗浓核病品系黑抗、白抗;进而把眼纹全黑基因（bl）导入抗病个体,第15染色体上同时具有抗浓核病基因（nsd－Z）和斑纹基因眼纹全黑（bl）,从而育成了带斑纹标志的家蚕抗浓核病育种材料D01、D02。创建了利用斑纹基因作遗传标记,不用添毒的抗浓核病品种选育方法。     

野蚕黑卵蜂的生物学调查

野蚕照卵蜂是野蚕(Bombyx mandarina Moore)的主要卵寄生蜂,自然寄生率较高。在杭州,主要以一龄幼虫于越冬野蚕卵内过冬,一般4月底5月初开始羽出;在田间养虫室内,一年发生10代。25℃下,一世代的平均历期为18.56天,其中卵期约30小时,一龄幼虫期约2天,二龄幼虫期约3天,预蛹期约1天,蛹期10—13天。25℃下喂20％蔗糖液,雌蜂平均寿命45.37天,雄蜂43.21天。供蔗糖液,以家蚕卵为寄主,25℃下雄蜂平均产卵期20.39天,寄生卵粒51.27粒,产子蜂62.47头,于蜂雌性比平均82.10％。在4℃、76％R.H.下,幼期各虫态具一定的耐冷藏能力,尤以卵期为强。根据其生物学特性,认为该蜂在野蚕生物防治上很有利用前途。     

Seasonal abundance and distribution of Parafilaria bovicola ovipositional blood spots on cattle in South Africa

More than 23 000 cattle of both sexes and different ages were examined for blood spots caused by egg-laying females of P. bovicola. Although these studies extended over four years and involved 5 farms in different parts of the Transvaal Bushveld, the overall results were the same. Ovipositional bleeding was strongly seasonal with blood spots first appearing in winter (June), reaching a peak in spring (September-November) and thereafter declining rapidly as summer progressed. In a single year at Zoutpan Research Station up to 92,1% of the 1st year heifers had already bled by November and this proportion increased only slightly to 95,1% by the end of the bleeding season (May). The number of blood spots per animal showed a similar seasonal abundance except for a second peak of abundance in June for 1st year heifers and oxen. The prevalence of blood spots in cattle of different ages and sex varied markedly. At Mara Research Station half as many oxen bled in their 2nd year as in their 1st year, while at Zoutpan 19,2% fewer heifers bled in their 2nd year than in their 1st. Bulls bled the most, then 1st year oxen, 1st and 2nd year heifers and 2nd year oxen, with breeding cows bleeding the least. A high female hormone level appears to be associated with the development of immunity. The shortest period from birth to 1st blood spot (the apparent prepatent period) was 191 days, while 81,8% of oxen bled for the 1st time within 279 days after birth.(ABSTRACT TRUNCATED AT 250 WORDS)     

Gross morphological features of the lung and air sac in the Japanese quail

This study was conducted to reveal the morphological characteristics of the lung and air sacs in Coturnix coturnix japonica (Japanese quails). Ten quails were allocated into two groups. Tracheas of 5 quails with neoprene latex and 5 quails with methylmetacrylate were injected to fill the trachea and air sacs. Latex embalmed animals were stored in 10% formaldehyde solution for two months. Animals given methylmetacrylate were maserated in 30% potassium hydroxide at 40 degrees C for two days. Lungs were located in the dorsal part of the thorax and very close to the thoracic vertebrae and ribs. Shorter than the dorsal border, the ventral border lied between the 3rd and 6th ribs. Cervical, clavicular, cranial thoracic, caudal thoracic and abdominal sacs were identified. These sacs had connection with the 3rd, 4th and 5th lateroventral and 4th mediolateral bronchi. Saccus cervicalis was located on the left and right portions of the vertebrae cervicales et thoraricae with a pronounced communication ventromedially. However, the cervical sac aeration of only all cervical vertebrae was present in this study. Humerus was a non-aerated bone. Pneumatic foramen was absent and did not aerate the sternum. Cranial thoracic sac connected to the 1st, 2nd and 4th medioventral bronchi and gave no diverticulum for aeration. Cranial thoracic sac received air through the 4th medioventral and the 1st and 2nd lateroventral bronchi. Left and right abdominal air sacs paramedially produced diverticulum femorale, but this diverticulum did not enter the femur.     

ACCURACY OF POSITIONING THE CERVICAL SPINE FOR RADIATION THERAPY AND THE RELATIONSHIP TO GTV, CTV AND PTV

The purpose of the study was to evaluate the accuracy and precision of a rigid positioning device for repositioning the cervical spine accurately and precisely during conformal radiation therapy of dogs. Fifteen purpose bred research dogs in a radiation therapy study were included. The dogs were positioned using a head holder and a deflatable pillow attached to the treatment table. Port films were reviewed retrospectively, and repositioning precision was recorded by measurements in three orthogonal planes of the head, 2nd cervical vertebra and 1st thoracic spinous process. Mean treatment position was compared to the planning position for a measurement of systematic set-up error. Mean interfraction position variation of the 2nd cervical vertebra was 0.2, 0.1 and 0.2 cm for the ventrodorsal, caudocranial and laterolateral directions respectively, and the average systematic set up error was 0.2, 0.1 and 0.2 cm for the ventrodorsal, caudocranial and laterolateral directions respectively. Knowledge of the magnitude of reposition errors should be included when determining the margins around the tumor.     

天蚕营养指标的研究

本文报告了以新鲜白栎为饲料,对于蚕各项营养指标的测定结果,全幼虫期的食叶面积,食叶重量分别为307705.67平方毫米和36897.95毫克,蚁蚕体重为2.86毫克,熟蚕5267.43毫克,为蚁蚕的1841.76倍.相对摄食速率和相对生长速率均随虫龄增长而逐渐下降,消化量则相反,近似消化率开始逐渐上升,以三龄为最高,尔后逐渐下降,以末龄为最低,全幼虫期合计,幼虫近似消化率为28.33%;各龄近似消化率平均为45.53%.     

Ophthalmomyiasis externa in a puppy due to Cuterebra infestation

An 8 wk old Scottish terrier was evaluated for a 2×2 cm mass located directly adjacent to the lateral canthus of the right eye. Examination revealed a well-developed Cuterebra larva at the lateral aspect of the orbital cavity, anchored at the lateral canthus. The larva was manually removed under general anesthesia, and the eyelid margin was repaired. Systemic and topical antibiotics along with systemic anti-inflammatory treatment were instituted. The lesion healed completely, revealing a normal functional right eye 10 days after removal of the Cuterebra larva. Careful manual removal of the larva is recommended along with correction of any resultant conformational defects. The remaining cavity can be left to heal; however, antibiotic therapy is recommended.     

The presence of endotoxin activity in cases of experimentally-induced heartwater in sheep

The presence of endotoxin was examined in 5 sheep with experimentally-induced heartwater. Two peaks in endotoxin levels were recorded in 4 out of the 5 sheep during the acute stage of the disease. The 1st peak coincided with or occurred shortly after the febrile reaction (over 40 degrees C). The 2nd peak occurred 3-5 days after the 1st, and in 2 sheep this 2nd elevation in endotoxin levels was associated with severe clinical signs (rapid and laboured breathing, cyanosis and recumbency), and 1 of the 2 sheep died on the day of the 2nd elevation. Both endotoxin peaks were of short duration and levels had decreased in the 24-h follow-up samples.     

母水牛发情周期卵泡发育动态初步研究

运用B-型超声波仪观察了自然发情的6头河流型母水牛和6头沼泽型母水牛的卵泡发育动态,发现河流型母水牛的发情周期由2个卵泡发育波组成;沼泽型母水牛以2个卵泡发育波为主(66.7%,4/6)。河流型水牛2个卵泡波分别在发情周期的第1.3、12.2天出现,其第1波征集、选择卵泡数分别为14.8和2.5个,第2波分别为14.2和3.2个;沼泽型水牛2个卵泡波分别在发情周期的第1.1、11.0天出现,其第1波征集、选择卵泡数分别为8.0和1.0个,第2波分别为7.8和1.5个。以上数据的各波征集卵泡数和选择卵泡数中,河流型水牛和沼泽型水牛之间差异显著(P0.05)。     

Factors associated with mortality in Norwegian broiler flocks

Our aim in this longitudinal study (covering years from 1996 to 1999) was to use data regularly recorded in a production database, to identify farm- and flock-level factors associated with cumulative mortality in broiler flocks during: (a) the 1st week after housing and (b) the rest of the growout (2nd to 5th week). A total of 1664 broiler flocks kept in 132 broiler farms were included. The average weekly cumulative mortality was 1.54% (95% CI: 1.46, 1.62%) during the 1st week and 0.48% (95% CI: 0.47, 0.49%) during the rest of the growout.The final least-squares regression model of cumulative mortality during the 1st week identified the following significant factors: study year, flock size, stocking density, use of paper underlay for feeding during the 1st week, and the interaction terms between type of ventilation, drinking system and floor insulation. The final model for the 2nd to 5th week demonstrated that the factors age of the broiler house, heating system and control system for the air intake were associated with cumulative mortality, but the effects of the two latter variables were significantly modified by age of the broiler house. A significant difference in mortality between flocks delivered from various hatcheries was found in both analyses.Our results suggest that changes in several housing factors and management routines might reduce the mortality losses, but the relationship depends on the stage of production.