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1.
交配后性选择是雌性混交动物中的一种普遍现象,其选择机制较为复杂,是性选择研究领域中的重点和难点问题。脉红螺是我国重要的大型经济贝类之一,繁殖形式为多雌多雄混交模式。为了研究该模式繁殖机制,本研究利用6个微卫星标记及行为学观察对脉红螺3个家系进行父权分析。结果表明,3个家系均存在多父性现象,证实脉红螺繁殖属于真正遗传意义上的雌性混交模式。3个家系中父权比例与父本的6个形态学参数及交配持续时间不存在关联性,但均表现出最先与母本交配的父本其后代比例最高,而最后交配的父本其后代比例最低,表明脉红螺交配后性选择存在最先雄性精子优先受精现象,这一现象符合"topping off"假说,即最先交配的雄性排放了大量精子占据了受精囊的主要空间,导致其子代的比例最高;而最后交配的雄性由于受精囊空间的限制,其精子占据空间最少。本研究为海洋无脊椎动物的交配后性选择机制研究提供重要参考资料。  相似文献   

2.
许氏平鲉(Sebastes schlegelii)具有特殊的卵胎生繁殖模式和长期储存精子的特性。虽然先前有关于许氏平鲉多重父权的研究报道, 但关于交配后雌鱼卵巢内子代的父权分布尚未有报道。本研究选取已纳精的雌性许氏平鲉为实验对象, 采用 6 个高度多态的微卫星位点对 9 尾雌鱼卵巢前部(靠近泄殖孔端)、中部、后部(远离泄殖孔端) 3 个分区的子代(共 291 个)进行父权分析。结果显示: (1) 9 尾雌鱼中有 8 尾(88.89%)检测到了多重父权现象, 平均父权数 3.56。其中 4 个母本子代群(50%, B>0)的各父本贡献率存在不同程度的偏倚; (2) 单因素方差分析结果显示, 父本在雌鱼卵巢 3 个分区的子代比例差异不显著; (3) 卡方均匀分布检验结果显示, 每个母本卵巢各分区的父权分布均无显著偏倚, 表明许氏平鲉卵巢内子代多重父权随机分布。分析认为, 交配时雌鱼卵巢尚未发育成熟, 来自不同雄性的精子在细小的卵巢内得以充分混合并储存于卵巢中, 雄性精子数量与精子活性的差异可能是导致父权贡献率发生偏倚的重要原因。研究结果进一步丰富了许氏平鲉繁殖生物学研究内容。  相似文献   

3.
为研究短蛸(Octopus ocellatus)的性选择行为,本研究利用14个多态性微卫星标记,对3个母本、176个子代及17个候选父本进行亲权鉴定,对3个家系中有子代和无子代雄蛸、子代比例高和子代比例低的雄蛸的各形态参数进行t检验,并对子代比例高和子代比例低的父本与母本的遗传相似性与遗传距离进行分析。结果显示,短蛸为多雌多雄的交配模式,为真正意义的雌性混交动物;雄蛸有无子代与其形态参数无相关性;子代比例与父本的形态大小参数无关,而与父母本的遗传相似性和遗传距离有关,父母本遗传相似性越高,遗传距离越小,后代比例越高。本研究为揭示短蛸交配前后的性选择机制提供了重要线索,也为海洋头足类动物的性选择机制研究提供了基础资料。  相似文献   

4.
为揭示金乌贼精子进入纳精囊及产卵过程中的精子利用方式,丰富金乌贼繁殖生物学研究内容,本研究利用实验生态学和组织切片技术,检测了交配后不同时间段雌性口膜表面精子囊和纳精囊中精子数量的变化,观察分析了雌性金乌贼纳精囊的组织结构。结果显示,金乌贼纳精囊位于繁殖期雌性个体口膜腹面的突起处,共1对。纳精囊开口于口膜内表面,通过一根中央管连通整个纳精囊。中央管内壁含有大量褶皱和纤毛。在中央管两端,有12~20个储精小囊与之相连。储精小囊四周具有发达的环肌,其中储存有大量精子,并且大部分精子头部均朝向腔室内壁。完成一次交配后,雌性金乌贼对精子囊和纳精囊中精子的利用可以分为三个阶段,主要利用精子囊中的精子(交配后1~2 d);由利用精子囊中的精子向纳精囊中的精子过渡(交配后2~3 d);主要利用纳精囊中的精子(交配后3 d以上)。研究表明,从精子囊释放出的精子进入雌性口膜表面的褶皱中,通过自身运动到达纳精囊。进入纳精囊的精子通过自身运动及中央管内壁纤毛的摆动进入储精小囊,其中大部分精子头部朝向储精小囊内壁有规律地分布。在产卵过程中,雌性优先利用精子囊中的精子,而在精子囊中精子不足时,纳精囊通过肌肉收缩以及纤毛摆动将其中的精子逐渐释放出来,卵子在雌性口膜附近完成体外受精。  相似文献   

5.
黑龙江银鲫新品系—松浦鲫的培育   总被引:1,自引:0,他引:1  
以纯种方正鲫作母本、以方正鲫(♀)与鳞鲤(♂)交配获得的雌性后代经性反转的生理雄性个体作父本进行育种试验,在3个组配中,发现有一组F_1表现出新的形态特征。经过对F_1及其后代作定向培育和观测,证实F_1形态指标与方正鲫差异显著,且其后代遗传性状稳定,可作为鲫鱼属的一个新品系。  相似文献   

6.
利用半滑舌鳎(Cynoglossus semilaevis Günther)性别连锁微卫星标记scaffold1128343和性腺组织切片的方法,研究半滑舌鳎8个普通家系和养殖场雄性亲鱼遗传性别与性逆转情况。首先,8个普通家系(28、30、38、39、40、44、57、69)遗传性别检测结果显示,遗传雌性比例最低为39家系(37.93%),最高为38家系和40家系(55.00%)。对其中4个家系(28、39、44、57)的两次遗传性别比例检测结果对比发现,家系间遗传雌性比例存在差异。其次,对4个家系(28、39、44、57)和养殖场雄性亲鱼的遗传与表型性别鉴定结果表明,不同家系表型雌鱼比例为18.75%46.88%,低于各家系的遗传雌性比例,不同家系间自然性逆转率存在显著性差异(P<0.05)。研究还发现,繁育场所用的普通雄性亲鱼中平均有28.42%的伪雄鱼。本研究结果表明,自然性逆转现象在半滑舌鳎养殖群体中普遍存在,半滑舌鳎不同家系的表型雌鱼比例存在显著差异,这为培育半滑舌鳎高雌性苗种提供了理论依据。  相似文献   

7.
脉红螺摄食节律的研究   总被引:1,自引:1,他引:0  
王平川  张立斌  潘洋  张涛  李朝霞  班绍君 《水产学报》2013,37(12):1807-1814
应用实验生态学方法,以菲律宾蛤仔为饵料对脉红螺的摄食行为规律进行了研究。研究结果表明,当温度达到10.40℃时,脉红螺第一次出现摄食行为,日均摄食量为0.01g/个;非交配期内,摄食量随温度升高而增大,当温度达16.20℃时,摄食量达最大值,为0.54g/个,摄食周期为4天;进入交配期后,脉红螺摄食量随温度升高先增加后减少,同时与交配率呈负相关关系;当温度达到18.05℃,交配率达最小值0.03,脉红螺日均摄食量达到最大的5.32g/个,此时摄食周期为3.72天。非交配期摄食量(c)与温度(t)间回归关系为:c = 0.01t2 - 0.24t 1.18,r=0.97,交配期摄食量(c)分别与温度(t)、交配率(m)的回归关系为:c = -0.13t2 5.18t – 48.08,r=0.61;c = -2.92m 3.33,r=-0.48。,综上所述,脉红螺摄食有4天左右的周期变化,且温度和交配率作为两个重要的因素对其有显著影响。  相似文献   

8.
刺参耳状幼体体长遗传力的估计   总被引:7,自引:2,他引:7  
基于全同胞组内相关法估计刺参(Apostichopusjaponicus Selenka)耳状幼体初中期体长的遗传力.实验中的30个亲参来自人工养殖的成体刺参群体,亲本交配采用巢式不平衡设计,通过人工授精技术,构建了8个半同胞家系和22个全同胞家系.在耳状幼体初期和中期,每个全同胞家系分别测定40~70个后代个体体长.利用SAS软件的GLM过程,计算表型变量的原因方差组分,估算体长遗传力.分析结果显示,雌性遗传方差组分均显著大于雄性遗传方差组分(P<0.05),雌性遗传方差组分存在显著的母性效应(P<0.05).基于父系半同胞组内相关法计算的狭义遗传力是刺参耳状幼体初中期体长狭义遗传力的无偏估计值,估计值分别为0.74和0.75.结果表明,基于刺参耳状幼体体长的加性遗传方差较大,选择育种对于刺参幼体早期生长的改良具有较大的潜力.[中国水产科学,2006,13(3):378-383]  相似文献   

9.
微卫星分离模式显示雄性三倍体鲫产生非整倍体精子   总被引:1,自引:1,他引:0  
三倍体鲫(Carassius auratus)行天然雌核发育,其自然种群中却有较高比例的雄性个体,这些雄性个体的性腺发育正常,能产生有活力的精子。而且其精子的DNA含量约为体细胞的一半,显示三倍体鲫精子发生过程中可能经历了均等的减数分裂。流式细胞术虽然能够较准确地测定细胞群的平均DNA含量,但是却很难检测到单个精子中的个别染色体增减,要明确回答雄性三倍体鲫产生的精子是否为整倍体需要定量地检测单个精子的遗传组成。本研究用微卫星标记检测以雌性鲤(Cyprinus carpio)与雄性三倍体鲫为亲本构建的杂种家系的基因型,结果发现母本鲤的多态位点在子代中呈孟德尔分离,父本三倍体鲫具有三套鲫基因组,其等位基因在子代中呈随机分离。上述研究结果提示:三倍体鲫起源于二倍体鲫的同源加倍,而非二倍体鲫和鲤的种间杂交;三倍体鲫通过染色体的随机分离产生非整倍体的精子,其精子发生过程中没有均等的减数分裂。三倍体鲫行雌核发育生殖,却可能并非起源于种间杂交且群体中的雄性个体可育,因而是单性生殖鱼类中的一个特例。  相似文献   

10.
为评判中华绒螯蟹育苗工作亲本投放性比(♀∶♂=2~3∶1)的合理性,通过室内连续交配实验,对雄性个体的生殖潜力进行了研究。结果显示,雄蟹具备完成3次连续交配活动的生殖潜力;个体丧失交配能力前,贡献了超过60%的精子(≥6×109个)等雄性产物;多次交配活动并没有对雌蟹的个体繁殖力产生影响;雌蟹抱卵后,纳精囊亦没有出现明显的偏差;实验条件和基地育苗池个体纳精囊内均还存有一定数量的精子,表明雄蟹提供的雄性产物可以满足雌蟹受精的需要,因此,该性比在实际育苗生产中具有一定合理性,而作为亲本雄蟹的大规格及自身的生殖策略则可能是中华绒螯蟹避免精子限制发生的重要原因,其潜在的精卵比达(1.59~10.86)×10~3∶1。此外,研究成果揭示这个被广泛采用的亲本性比存在进一步优化的可能,可以提升至4∶1。  相似文献   

11.
Abstract – In most species, males have a higher reproductive potential than females, leading to skewed reproductive success, particularly in mating systems where pre‐ or postcopulatory sexual selection reinforces inequality in male mating success. We investigated multiple paternity, reproductive skew and correlates of male reproductive success in a wild population of the Trinidadian guppy (Poecilia reticulata). We used nine microsatellite loci to assess the frequency of multiple paternity, number of sires per brood and reproductive skew. Across broods, the frequency of multiple paternity was high with 94% of broods having multiple sires (range: 1–5), resulting in a reproductive skew of 0.14. Variation in male reproductive success was high (range: 0–14 offspring per male), suggesting that there is considerable opportunity for sexual selection. Next, we examined correlations between male reproductive success and sexual coloration, sperm velocity and gonopodium length. Relative area of orange, black, iridescent and total coloration, and sperm velocity were not correlated with reproductive success. However, gonopodium length explained 14% of the variation in reproductive success, suggesting that gonopodium length is likely a sexually selected trait. We discuss these findings in the light of other studies that genetically dissect joint‐sex parentage and examine correlates of male reproductive success in wild populations.  相似文献   

12.
Is cod lekking or a promiscuous group spawner?   总被引:2,自引:0,他引:2  
The mating system of cod ( Gadus morhua ) has been described as promiscuous with few options for exercising mate choice. We, on the other hand, argue that cod fulfil the prerequisites of a conventional lekking mating system. A review of papers on cod mating behaviour suggests that mature males aggregate and possibly defend small territories on the spawning grounds, where male–male interactions are common. Females visit males at the aggregations when ready to spawn and males show an extensive courtship display including dance, fin display, and acoustic calls. This may allow females to discriminate between males and both fin size and mass of drumming muscles, the cod's acoustic organ, are related to a male's fertilisation potential. This, together with the presence of sexual dimorphism in drumming muscles, suggests that sexual selection by females is at work. Different courtship display combined with different mate preferences may be important premating mechanisms reducing or preventing interbreeding between groups of cod.  相似文献   

13.
The goal of the present study was to examine individual male potency in rainbow trout, Oncorhynchus mykiss (Walbaum), expressed as the fertilization ability of fresh and cryopreserved sperm. One female and four males bearing genetic markers enabling determination of the progeny paternity were chosen as gamete donors. Samples of eggs were inseminated with sperm from separate individuals or with pooled sperm. Genetic examination of the progeny obtained after fertilization of eggs with pooled milt showed differences in male potency. The proportions of offspring sired by four individual males after fertilization of eggs with the fresh milt were similar to those obtained after fertilization with cryopreserved milt (correlation r = 0.95; n = 4; P < 0.05). These proportions did not correlate with the proportions of progeny resulting from fertilization of eggs when sperm was not pooled.  相似文献   

14.
An algorithm to perform mate selection in aquaculture breeding using a computational optimization procedure called “differential evolution” (DE) was applied under optimum contribution selection and mate selection scenarios, to assess its efficiency in maximizing the genetic merit while controlling inbreeding. Real aquaculture data sets with 8,782 Nile tilapias from five generations and 79,144 coho salmon from eight generations were used to optimize objective functions accounting for coancestry of parents and expected genetic merit and inbreeding of the future progeny. The mate selection results were compared with those from the realized scenario (real mates), truncation selection and optimum contribution selection method. Mate selection allowed reducing inbreeding up to 73% for Nile tilapia, compared with truncation selection, and up to 20% for coho salmon, compared with realized scenario. There was evidence that mate selection outperformed optimum contribution selection followed by minimum inbreeding mating in controlling inbreeding under the same expected genetic gain. The developed algorithm was computationally efficient in maximizing the objective functions and flexible for practical application in aquaculture breeding.  相似文献   

15.
环境条件对中国对虾交尾影响的试验观察↑(*)   总被引:1,自引:0,他引:1  
本文报告了在室内条件下中国对虾雄性生殖系统不同部位精子形态、激活反应及外界环境对对虾交尾影响等的试验观察。雄性生殖系统被分为3部分:精巢(T)、输精管和精荚(TA);输精管又分为前、中、后3段,其中的前(AVD)、中(MVD)、后(PVD)3部分以及精巢和精荚被分别匀浆取样镜检,观察精子形态。结果表明:中国对虾雄性精巢、输精管、精荚及雌虾纳精囊内精子的形态、对卵水的激活反应能力有所差异,是一逐渐成熟过程;雄虾具有多次交尾能力,不同环境条件对中国对虾的交尾影响明显;当雌虾比例较高时交尾率也高;不同对虾密度对交尾影响不明显  相似文献   

16.
Zygote quality is a major issue in production aquaculture, and has been considered, for example, in terms of lipid content, readiness of the female spawner, potency of the male spawner and other issues. In the mean time, evolutionary biologists have been considering issues of mate choice and genetic compatibility of the parents. This paper gives an overview of the main hypotheses of female mate choice, the reasons for multiple mating of females and their potential effects on offspring quality. I suggest how these ideas, if taken into account in commercial aquaculture, might increase the value added of several species in commercial aquaculture, which is impeded by poor offspring quality. Theoretical and empirical research shows that females in general choose partners actively among different males and that females often mate with multiple males. Both active mate choice and multiple mating improve the quality of the offspring, for example as enhanced survival and growth. Active female choice also occurs at the gamete level, and according to the ‘cryptic female choice hypothesis’, eggs are able to affect which sperm from which male will be fertilized. Several proximate mechanisms regarding how the eggs can affect the sperm have been demonstrated. Improved offspring quality of active female choice, cryptic female choice and multiple mating are all in accordance with the ‘genetic incompatibility hypothesis’. This hypothesis states that the quality of the offspring depends on the degree of intragenomic conflicts due to interactions between maternal and paternal haplotypes, for example as increased immunity against a wider range of pathogens when choosing a mate with different immune‐coding alleles than your own. According to the genetic incompatibility hypothesis, eggs from a particular female are expected to do well when fertilized by a particular male, whereas eggs from the same batch from the same female should do poorly when fertilized by other males. Such sire–dam interactions have been demonstrated empirically. I argue that if such a sire–dam interaction is a general phenomenon, this might have major implications for the commercial aquaculture industry, concerning choice of number of brooders, fertilization method, methods to preserve gametes, spawning protocols and breeding programmes.  相似文献   

17.
Abstract –  The idea that sexual selection can lead to rapid evolution of premating isolation among independent populations (speciation) has been controversial, but is rapidly gaining acceptance among many evolutionary biologists as empirical examples accumulate. A survey of male signals and female preferences (mate recognition systems, MRSs) across the contact zone between divergent populations of threespine stickleback ( Gasterosteus aculeatus ) in Conner Creek, WA, revealed a spatial pattern of MRSs that is consistent with speciation via sexual selection. Females from locations that possessed melanic males preferred melanic males whereas females from populations possessing typical mosaic males (red chin, blue iris, and blue-green dorsum) preferred mosaic males. I argue that sensory drive sexual selection, acting through geographically varying spectral properties, is responsible for the observed population differences and premating isolation between the adjacent populations.  相似文献   

18.
中国沿海脉红螺群体遗传多样性及其遗传结构   总被引:2,自引:0,他引:2  
杨智鹏  于红  于瑞海  孔令锋  李琪 《水产学报》2015,39(10):1443-1449
我国脉红螺自然资源日趋衰减,为制定相应保护措施需要对脉红螺遗传多样性及遗传结构进行分析研究。利用9个微卫星标记分析了我国沿海9个脉红螺群体的遗传多样性和遗传分化水平。遗传多样性分析结果显示,群体平均等位基因丰度(AR)为8.6~9.5,期望杂合度(HE)为0.705~0.777,观测杂合度(HO)为0.498~0.626。遗传分化分析结果显示,群体间遗传分化指数(FST)范围为0.012 2~0.093 6,各群体间没有显著的遗传分化,遗传距离(DC)为0.212~0.349。本研究结果表明,我国沿海脉红螺群体具有较高的遗传多样性,各群体间没有显著分化。  相似文献   

19.
Some shrimp hatcheries use artificial insemination (AI) to improve the male to female ratio in their breeding populations. We describe a sperm extender solution, which allows the short‐term storage of diluted sperm in Litopenaeus vannamei, and its use in an artificial insemination process. We also evaluate its fertilization capacity. An AI experiment was designed using two, one, or half spermatophore segments. We tested four treatments involving three different male:female ratios: Natural mating (1:1), Regular and Regular diluted (1:2) and Half diluted (1:4). Data analysis revealed that the number of nauplii produced per mating was affected by treatment, with Regular (158 420) performing better than Half diluted (112 864) (P < 0.05), but with no differences between the latter and Regular diluted (130 340) (P > 0.05). A binomial variable named female success (FS) was defined as successful when the number of nauplii obtained per mate was ≥25 000. Analysis showed differences for FS across treatments (P < 0.001), but not between Regular (79.2%), the hatchery conventional AI technique and Half diluted (60.4%), maybe due to sample size. Since the number of nauplii per mate is crucial to consider AI successful, it is necessary to improve this AI technique before it can be used in the shrimp industry.  相似文献   

20.
Transmission electron microscopy was applied to sperm removed from males and females belonging to Litopenaeus vannamei, L. stylirostris and L. occidentalis. It was discovered that a region named filamentous meshwork (FM), located between the nucleus and the hemispherical cap, develops differently in these three closely related species. In L. vannamei, the FM is synthesized in the male reproductive system, but seems to complete its formation after mating. In L. stylirostris, the FM region was not present in spermatophores collected from males or in sperm from the thelycum. In L. occidentalis, the FM region is fully developed in male sperm. It is suggested that completion of the FM is required for acrosome maturation, and the process continues after mating in some species of Litopenaeus. In vitro induction of the acrosome reaction in sperm from males and females of L. occidentalis demonstrated for the first time that reactivity is significantly superior in sperm cells that have been attached to the open thelycum for some hours, as compared to sperm in males (prior to transfer). This finding suggests that matured sperm cells of L. occidentalis become capacitated to react against egg water after mating.  相似文献   

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