舟山群岛黄毛鼠种群的遗传多样性及多重父权研究

岛屿常被生态学家和进化生物学家视为研究生物进化的天然实验室。本研究利用微卫星分子标记技术,分析了舟山群岛优势鼠种——黄毛鼠(Rattus losea)刺山岛种群、六横岛种群、桃花岛种群3个种群的遗传多样性,并探讨该物种是否存在多重父权现象。研究结果表明,(1)黄毛鼠种群的平均观测等位基因数(NA)和平均有效等位基因数(Ne)分别为8.792和5.494,平均期望杂合度(He)和平均观测杂合度(Ho)分别为0.821和0.956,多态信息含量(PIC)均大于0.5,说明3个种群均具有较高的遗传多样性;(2)3个种群的平均遗传分化系数(Fst)为0.040,其中桃花岛种群与刺山岛种群的分化最大,分化系数为0.052,呈中度分化水平,不同种群间所贡献的变异百分数为3.98%,说明遗传变异主要发生在种群内,而种群间仅存在很小的遗传变异;(3)14只孕鼠中,有6只孕鼠的胚胎存在多重父权现象,占43%,最小父本值为2,其余8个孕鼠的胚胎均只有唯一父本。本研究提出黄毛鼠存在多重父权现象,为该物种繁殖策略及鼠害控制的研究提供依据。     

油菜蜜腺的形态解剖学研究

油菜的花通常具两对蜜腺,一对呈类肾形,另一对呈乳头状,分别称为中腺及侧腺。腺体的表面都覆盖有角质层,从扫描电镜中观察腺体的表面,在顶部有1—4个暗斑,大小不等、圆形,此处可能是角质层与表皮细胞壁之间形成角质层下空隙,成为蜜汁排出体外之前的临时贮存库。蜜腺的表皮具气孔器,主要集中分布在暗斑区域,其数量与泌蜜量有关。油菜蜜腺中除分泌细胞之外,尚有输导组织分布,但只有筛管和伴胞,筛管呈一条或多条积聚在一起,分布于表皮下的泌蜜组织中,筛管具有供应分泌物的作用。类肾形腺体中的筛管明显多于乳头状,且呈技状分布。从泌蜜量统计,类肾形的分泌量远较乳头状为多。花托维管束的木质部导管没见进入腺体内,而终止于腺体的基部。     

四川短尾鼩包皮腺的挥发性化学成分分析

哺乳动物的包皮腺分泌物对个体间性引诱及繁殖行为的信息交流和种群调节有着重要的作用。本研究以四川短尾鼩（Anourosorex squamipes）为研究对象对劳亚食虫目动物包皮腺挥发性化学成分和化学通讯功能进行报道。采用顶空固相微萃取—气质联用（HS-SPME-GC/MS）的方法,分析四川短尾鼩雄体包皮腺中挥发性物质的化学组成。结果表明：（1）四川短尾鼩雄体包皮腺的挥发性化学成分主要含烷烃类、醇类、酮类、醛类、醚类、酯类、酸类、芳香烃类等45种化合物;（2）成年雄性四川短尾鼩的包皮腺中挥发性成分有39种,幼年雄性含有28种,说明四川短尾鼩成年雄体的包皮腺中挥发性化学成分多于幼年雄体;（3）成年雄体的包皮腺分泌物中含有4种特有的挥发性化学成分,幼年雄体中特有成分仅为1种,表明四川短尾鼩包皮腺中的挥发性化学成分存在年龄差异;（4）四川短尾鼩包皮腺分泌物中不同化学成分相对含量不同,同种化学成分在不同个体间的相对含量存在差异。四川短尾鼩雄性包皮腺挥发性化合物种类丰富,个体、年龄差异明显。推测挥发性化合物中丁酸（Butanoicacid）、乙酸乙酯（Ethyl acetate）、苯酚（Phenol）为四川短尾鼩的信息素。本研究为进一步验证该物种的信息素成分及其传递机制提供了基础数据。     

桃蛀螟性外激素腺体的部位及其超微形态结构

鳞翅目昆虫性外激素通常是几种化学物质以一定的比例构成的混和物。为了进一步进行桃蛀螟Dichocrocis punctiferalis Guen(?)e性外激素微量组份的分析,首先要确定性外激素分泌腺体的部位。 一般状态下,桃蛀螟雌蛾的尾部(7—8节间膜、8节、8—9节间膜、9—10节。)缩于第7腹节内;召唤雄蛾时腹背部弯曲,伸出尾尖(Konno等,1980)。Konno等(1982)通过对桃蛀螟雌蛾尾部的提取,鉴定出该虫性外激素主要组份为反-10-十六烯醛(E-10-16:Ald)。由此可见,其分泌腺体大致位于尾郎,但具体位置和形态结构未见报道。     

岛屿生境下黄毛鼠种群的遗传变异

岛屿具有独特的生态系统,常被生态学家和进化生物学家视为研究生物进化的天然实验室,岛屿生物地理学也受到了越来越多科学家的关注。对舟山群岛8个面积不等岛屿的黄毛鼠(Rattus losea)种群进行了调查,分析了8个种群的遗传变异特征,对探讨岛屿理论中的种群动态和种群分化具有重要意义。采用线粒体分子标记技术,利用PCR扩增得到D-loop区基因序列815 bp,在330个黄毛鼠样本中共识别出15个单倍型,平均核苷酸多样性(P_i)为0.001,平均单倍型多样性(H_d)为0.364,表明舟山群岛黄毛鼠种群的遗传多样性较低。Tajima′s D中性检验显示除了小盘峙种群,均为显著负值(P0.01),表明种群受到了自然选择的作用,历史上发生过种群扩张。AMOVE显示,群体间的遗传分化指数平均值为0.745,处于较高的分化水平,表明遗传变异主要来自种群间,占74.5%。基于线粒体D-loop区序列构建的系统发育树和中值网络都表明8个岛屿的黄毛鼠种群起源于两个母系。此外,Mental检验显示不同岛屿种群间的遗传距离与岛屿间地理距离之间存在显著正相关关系(r=0.6077,P=0.004),种群遗传多样性与岛屿面积并未发现显著相关性(r=0.6255,P=0.1840)。研究结果可为岛屿黄毛鼠种群的微观演化以及一些岛屿物种的进化理论提供参考。     

黄毛鼠种群数量季节变动及其影响因素的研究

黄毛鼠是农业、卫生保健事业的主要害鼠之一,其种群数量的季节变动明显地表现为初春的数量上升,夏秋季低数量和冬季持续高数量3个阶段。数量消长曲线呈马鞍形。 菜地是黄毛鼠良好的栖息地,鼠密度终年多保持在较高的水平;旱地的鼠密度稍高;水田的鼠密度较低。 黄毛鼠种群数量的季节变动主要是种群的繁殖力和年龄组成变化的反映,同时又受到气候条件和农业生产活动的制约。     

黄毛鼠种群时空动态和近年来鼠害上升的原因的研究

本文主要阐述黄毛鼠种群季节消长空间分布和繁殖规律以及近年来鼠害加重的原因,结果表明黄毛鼠种群季节消长曲线呈双峰型,种群的空间分布和繁殖随农田作物生育期的变化而呈有规律的变动。而农田作物布局的变化,为害鼠提供良好的食物条件,栖居场所和越冬条件,是近年来鼠害加重的主要原因。     

鼠尿外激素的薄层层析和生物测定

外激素对于异性具有引诱作用,在家畜方面,诸如猪、狗、羊等早有应用。但是,对于野生动物的这方面研究,仅在近20多年来才受到重视,并且发展较迅速。目前,有关哺乳动物外激素的来源、化学结构及功能作用等问题,已有若干报道,例如对鼠尿外激素的研究,认为鼠尿中的气味物质有十几种,其结构特点也很相似,倘若分离出用于实践,则更具有意义。     

影响中华蜜蜂工蜂王浆腺活性的因素

王浆腺是一对位于工蜂头部的泡状腺体,是分泌王浆的主要腺体。青年工蜂的王浆腺在春夏肥大,分泌王浆,饲喂幼虫及蜂王。采集蜂的王浆腺呈可逆的萎缩状态(Free,1961)。越冬工蜂的王浆腺虽肥大,但无泌浆活性(Brouwers,1983)。本试验为了寻找诱发工蜂王浆腺活性的主要因素,为王浆生产提供理论依据,故研究了工蜂王浆腺活性与幼虫、蜂王、花粉、温度之间的关系。     

莱氏拟乌贼缠卵腺的显微与超微结构

为了解莱氏拟乌贼(Sepioteuthis lessoniana)缠卵腺的结构和功能,本研究采用组织切片技术和透射电镜技术对该腺体进行显微与超微结构观察.结果显示,缠卵腺由腺壁组织、分泌叶瓣和结缔组织组成.其中,腺壁组织由外膜层和肌肉层组成,位于腺体外部;分泌叶瓣是腺体的主要部分,由分泌细胞和支持细胞组成,分泌细胞具有...     

COPULATORY ACTIVITY AND SPERM PRODUCTION IN BULINUS (PHYSOPSIS) GLOBOSUS (GASTROPODA: PLANORBIDAE)

Young Bulinus (Physopsis) globosus performed male copulatoryactivity and cross-fertilized other snails before their femalereproductive tracts were mature. The two most immature snailsshowed preputial eversion when secretion was present only inthe muciparous gland and at the carrefour region of the oviduct.Sixteen snails showed preputial eversion and four snails cross-fertilizedother snails when their oothecal glands and/or major portionof the oviducts contained either no secretion or only scantyamounts. When paired with a partner snail for 12 or 20 consecutive days,adult snails copulated as males on approximately 60% of thedays paired and up to 8 consecutive days. Virgin snails raisedin isolation copulated as male at the same rate as non-virgin,community-raised snails. Ability to copulate as male was notdependent upon previous experience as male or female. Aftera single copulation as male after 7 days isolation, the hermaphroditicducts of maleacting snails contained 87 000 sperm. Sperm productionoccurred at approximately 50 000 sperm.d-¹, until at 10 dayspost-copulation, snails contained 639 000 sperm. (Received 25 May 1982;     

Characterization of the secretory proteins of rat preputial gland in relation to urinary proteins

The water-soluble proteins of the rat preputial gland secretion were characterized in native and SDS-treated form on polyacrylamide gel electrophoresis. Nine major proteins were present in the secretion. One protein was a glycoprotein of molecular weight greater than 200,000 with beta-glucuronidase activity, and the other eight proteins had a molecular weight of 17,000, but with different charges. Acid phosphatase and arylsulphatase activities were present in the secretion in minor amounts. The isoelectric points of the secretory proteins ranged from 8.5 to 5.3; none of the proteins were lipoproteins, and there were no sex differences. The male and female rat urinary proteins were also characterized electrophoretically. The male rats had two different protein patterns, probably genetically determined. The female rats showed basically one urinary protein pattern, but their urines were frequently mixed with the preputial gland secretory proteins, which most likely played a part in the chemical communication. The mixing could not be correlated to daytime or estrous cycle.     

两种兔尾鼠的化学信息及其在群体中的作用

黄兔尾鼠(Lagurus lutens)及草原兔尾鼠(Lagurus lagurus)是新疆某些地区主要害鼠之一,它们的繁殖能力很强,数量高峰时,对草场危害极大。此外,它们还能传染某些地方性流行病,所以对这两种害鼠的防治是十分必要的。 近年来,我们在研究动物化学通讯的过程中,了解到外激素(信息素)在动物间传递信     

Aggression and preputial gland of male mice affected by the presence of other males

The level of aggressiveness and the weight of preputial gland and testis in male mice (Mus musculus) were influenced by housing condition, especially by the presence of cohabitant males. In this study, the relation between aggressiveness and the preputial gland and testis weight was studied for various housing conditions. The mouse individually housed in a cage that was linked to another cage containing another male separated by wire net was more aggressive than isolated or paired mice. The preputial gland weight also showed the same tendency, suggesting that the odor from other males promotes pituitary-gonadal activity in males, and that long-term cohabitance inhibits it.     

Long-term exposure of male and female mice to 50 Hz magnetic field: effects on fertility

The effect of an extremely low frequency (ELF) magnetic field on the fertility of adult male and female Swiss mice was investigated. Adult male and female mice were exposed to a 50 Hz sinusoidal magnetic field at approximately 25 microT (rms) for 90 days before they were mated with unexposed counterparts. There were no exposure related effects on the fertility of male or female mice. The number of implantation sites, viable fetuses, and the total number of resorptions were not significantly affected in females impregnated by males exposed to the 50 Hz magnetic field as compared with the control group. The number of implantation sites, viable fetuses and the total number of resorptions in exposed females were also not statistically different from the control group. There were no significant effects on the weights of the testes, seminal vesicles, preputial gland or body weights of males exposed to 50 Hz magnetic field. Furthermore, body and uterine weights were not affected in females exposed to 50 Hz field; however, ovarian weight was significantly increased in females exposed to the same field. These results suggest that exposure of male and female mice to low frequency magnetic field had no adverse effects on fertility and reproduction in mice.     

Genetic and endocrine studies of the pregnancy-blocking pheromone of mice.

Secretion of the pregnancy-blocking pheromone was stimulated by injection of depo-testosterone cypionate into females and males of inbred strains of mice which do not normally secrete the pheromone. Testosterone treatment of SJL males altered pheromone secretion so that pregnancies were blocked when the stud male was of the same inbred strain; an event that does not normally occur. Injection of epiandrosterone, androstenedione, androsterone or testosterone significantly increased pheromone secretion in SJL females, but progesterone and dehydroepiandrosterone were ineffective. Kidney weights were significantly increased by administration of androgen metabolites and the possibility of the kidney being the site of pheromone synthesis is discussed. The preputial gland can be excluded as the site of pheromone synthesis since males which are hemizygous for the Tabby-J gene and have no preputial glands blocked pregnancies as effectively as their normal littermates. Preliminary results are also presented concerning the isolation of the pregnancy-blocking pheromone from urine. Urine was analysed by gas chromatography and a peak was observed whose concentration could be correlated with secretion of the pheromone, although the compound(s) has not been identified or tested for biological activity.     

Leucine aminopeptidase (LAP) activity and sexual dimorphism in rat exorbital lacrimal gland

Leucine amonopeptidase (LAP) activity was histochemically studied in the rat exorbital lacrimal gland. The enzyme is present in the secreting cells of both male and female prepuberal rats, in vivo and in monolayer cultures, while in the adult rat it is demonstrable only in the female. Furthermore, LAP is influenced by the sex hormones, disappearing in the female gland after testosterone treatment and appearing in the adult male gland after administration of estradiol or cyproterone acetate. These results show that the behaviour of LAP can be considered as another character of sexual dimorphism of the rat exorbital gland. Furthermore, our findings, showing an inverse relationship between LAP activity and the PAS positivity of the secretion products, suggest the hypothesis that the presence of this exopeptidase could induce qualitative modifications of one or more secreted glycoprotein.     

Testosterone and dihydrotestosterone levels in epididymis, vas deferens, seminal vesicle and preputial gland of mice after hCG injection

Temporal changes of testosterone (T) and dihydrotestosterone (DHT) levels were measured by RIA in epididymis, vas deferens, seminal vesicle and preputial gland of adult male mice after a single injection of hCG. The response of circulating T to hCG stimulation was rapid and persisted over a period of 48 h. The temporal changes of androgen content of target organs paralleled the modifications of circulating T. In all organs the high androgen levels attained at 1 or 4 h plateaued until 24 h, decreased thereafter and returned to basal values at 72 h. The concentration of T by sex accessory organs was more accelerated by hCG injection than its conversion into DHT.