人工饲养长江江豚的同性性行为和自慰行为

雌雄性之间的性行为对鲸类的生存和繁衍有着极其重要的意义。然而不具有繁殖功能的同性性行为和自慰行为在多种鲸类中存在。因此对鲸类非繁殖性性行为研究,将有助于深入认识该物种性行为特点和规律,并解决室内饲养可能存在的问题以及促进可控性人工繁殖的成功。本研究以人工饲养的7头长江江豚为研究对象,定义并描述了14种性行为。其中,同性之间的性行为定义为同性性行为,雌雄个体单独的性行为定义为自慰行为。雄性同性性行为发现于所有定义的性行为中,但雌性同性性行为仅在7种性行为中观察到。同性性行为（3633次）占总性行为（5563次）的65.31%,自慰行为（254次）占4.57%。同性性行为中,雄性之间的同性性行为（3438次,94.63%）远多于雌性同性性行为（195次,5.37%）。两头有父子关系的江豚（阿福和淘淘）之间的雄性同性性行为最多（1921次,55.88%）,雄性江豚之间的同性性行为可能存在结盟竞争关系或教育练习作用。两头青少年雌豚（F7和F9）之间的同性性行为最活跃（117次,60.00%）,雌性江豚之间的同性性行为很可能具有结伴交流的功能。     

定量评估豢养长江江豚个体间的优势关系

2000年1—4月和2000年4月—2002年4月,分别连续3个月和2年观察了中国科学院水生生物研究所白鱀豚馆6头长江江豚（3雌3雄,8个不同组合群）个体间发生的3种交互关系,即接近—逃开、接近—接触和接近—尾鳍击打。在累计8,162min的观察时间内,共观察到这些交互关系1,685次。本研究将江豚个体间发生的这3种交互关系作为个体间优势关系的指示,并分别给交互双方赋予不同的分值,采用优势比分矩阵方法定量分析了江豚个体之间的优势关系。结果表明江豚群体内存在优势关系。同性别个体之间,优势关系与年龄和饲养时间有关,年龄大的个体比年龄小的个体具有优势,饲养时间短的个体比饲养时间长的个体具有优势。但是,异性成年个体之间,优势关系通常是可变的。     

微卫星分型法应用于豢养繁殖长江江豚的父权鉴定

目的:鉴定武汉白鱀豚馆及安徽铜陵淡水豚保护区两个豢养长江江豚繁殖群体中出生的6头幼豚的生物学父亲.方法:选择8对江豚物种特异性微卫星引物对两个待鉴定群体的14个DNA样品进行了荧光标记PCR扩增,将纯化后的扩增产物在ABI3130遗传分析仪上进行基因分型,并根据GeneScan Rox 500内标确定不同等位基因的大小,随后对待鉴定对象进行等位基因分析,并计算主要多态性参数.结果:所采用的8个微卫星座位在待鉴定的两个江豚群体中均表现出不同程度的多态性.在母本已知的条件下,利用其中6个微卫星座位的等位基因数据,通过排除法成功地鉴定出两个繁殖群体中出生的6头幼豚的生物学父亲.结论:本研究首次成功地将6个物种特异性微卫星标记应用于豢养长江江豚的父权鉴定,从而为该物种微卫星亲子鉴定技术体系的建立及迁地保护繁殖群体遗传谱系的构建奠定了技术基础.     

长江中下游江豚种群现状评价

作者根据近年在长江中下游对江豚进行考察的资料和收集到的标本,系统分析评价了长江中下游江豚的种群现状,主要结果如下:1.长江江豚上至宜昌(距河口1669公里),下至长江口,以及洞庭湖、鄱阳湖均有分布。分布型式是沿长江纵向呈集群性分布,横向呈趋岸性分布;2.长江中下游江豚种群数量估计为2700头。其数量冬季最高,夏季最低。夏季的SPUE值仅为冬季的48.7％—58.6％;3.长江中下游江豚群体以1—5头最为常见,占88％;4.理论推算长江中下游每年新产生个体为539头,年出生率为20％;5.通过分析比较长江中下游和中国沿海以及日本Inland Sea江豚种群数量变动趋势,推测长江中下游江豚很可能进行“江—海”、“海—江”长距离大规模的迁移,这种迁移与生殖有关。     

长江江豚基因组大小测定

本研究采用流式细胞术,以公鸡(Gallusdomesticus)红血细胞DNA含量为标准,测定了23头长江江豚(Neophocaenaphocaenoidesasiaeorientali)的基因组大小(或称C值)。实验过程中采用了保存在3中不同条件下的长江江豚的全血样品,用3种不同的方法提取白细胞。为了获得本实验所用的公鸡红血细胞DNA含量的准确值,首先以人(Homosapiens)的C值为标准,对其进行了校正。然后其C值(2C=2.35pg)用于长江江豚的基因组大小测定。结果发现:长江江豚的单倍体DNA含量为3.27pg/C,由此得出其基因组大小为3.17×109bp;雌性和雄性的C值分别为3.25pg和3.29pg,野外长江江豚和豢养长江江豚的C值分别为3.30pg和3.05pg。对雌雄个体之间以及不同生长条件下长江江豚的C值应用独立样本t检验分析,发现:1)不同性别的长江江豚基因组大小之间没有明显的差异;2)豢养条件下的长江江豚和野生长江江豚之间的基因组大小有明显差异,豢养条件下的长江江豚的基因组明显小于野生条件下的长江江豚。据此推测必要环境因子的变化可能会对长江江豚的基因组DNA含量造成影响。     

长江江豚野外健康状况的调查

对铜陵江段捕获的7头长江江豚（Neophocaena phocaenoides asiaeorientalis)进行了体征与血液学分析。结果表明,健康的个体有2头,2头个体有明显的病变,余者营养不良,患不同程度的贫血症。这可能与长江渔业资源日趋枯竭有关。     

野生与豢养长江江豚血清氨基酸含量比较

应用高效液相色谱(HPLC)技术,首次测定了湖北石首长江天鹅州白豚自然保护区野生长江江豚(Neophocaena phocaenoides asiaeorientalis)和中国科学院水生生物研究所白豚馆人工饲养的长江江豚血清中17种氨基酸的含量.结果表明,除了脯氨酸Pro、蛋氨酸Met和组氨酸His外,人工饲养江豚血清中其余14种氨基酸(天门冬氨酸Asp、谷氨酸Glu、丝氨酸Ser、精氨酸Arg、甘氨酸Gly、苏氨酸Thr、丙氨酸Ala、异亮氨酸Ile、亮氨酸Leu、苯丙氨酸Phe、缬氨酸Val、赖氨酸Lys、酪氨酸Tyr、胱氨酸Cys)的含量显著高于野生长江江豚血清中相应氨基酸的含量.野生江豚和人工饲养江豚的血清氨基酸含量均没有显著的性别差异.野生江豚性成熟个体与未成熟个体之间血清氨基酸含量也没有显著性的差异.在所检测的17种氨基酸中,豢养江豚Glu含量最高,其次为Asp和Lys.野生江豚同样是Glu最高,其次是Lys和Asp.豢养和野生江豚都是Met含量最低.野生和豢养江豚必需氨基酸(EAA)和非必需氨基酸(NEAA)之间的比率分别是0.83和0.92,具有极显著的差异(p <0.01).     

长江江豚和东亚江豚染色体水平基因组微卫星分布特征分析

研究采用生物信息学方法, 首次对长江江豚(Neophocaena asiaeorientalis asiaeorientalis)和东亚江豚(N. a. sunameri)的染色体水平基因组(大小分别为2.62和2.50 Gb)的微卫星分布特征进行了分析和比较。结果表明, 在长江江豚和东亚江豚基因组中分别发现888424和867792个完美型微卫星, 总长度分别为15340771和14724482 bp, 均占基因组序列总长度的0.59%。在长江江豚和东亚江豚基因组中, 六种重复类型微卫星的数量分布模式基本一致: 单碱基微卫星最为丰富, 其次是二碱基、六碱基、四碱基、三碱基和五碱基重复微卫星; 数目最多的6种微卫星重复单元分别是A、AC、AT、CCCTAA、AGGGTT和C。研究还着重分析了长江江豚和东亚江豚Y染色体微卫星分布特征, 分别在两个亚种Y染色体基因序列中发现6195和5024个完美型微卫星。在Y染色体6种重复类型微卫星中, 单碱基是最丰富的碱基重复类型, 然后依次是二碱基、四碱基、三碱基、五碱基和六碱基重复。在Y染色体不同类别的完美型微卫星中, 以A、AC、AAT等为重复单元的微卫星最为丰富。研究分析了长江江豚和东亚江豚染色体水平基因组微卫星分布特征和差异, 为后续微卫星遗传标记的开发与利用奠定了重要基础。     

新生儿期长江江豚和印太江豚肠道微生物群落结构特征及差异分析

鉴于肠道微生物对于宿主的营养吸收以及免疫抵御等生理机能至关重要,肠道微生物已经成为保护生物学的重要研究内容之一。然而,目前濒危鲸类肠道微生物的研究还非常有限。为了探究新生儿期长江江豚（Neophocaenaasiaeorientalisasiaeorientalis）和印太江豚（N.phocaenoides）的肠道菌群结构和多样性,本文采用IlluminaMiseq高通量测序技术,对新生儿期长江江豚和印太江豚不同肠段的肠道菌群16SrRNA基因V3⁃V4区进行了测序和微生物群落分析。结果表明,新生儿期长江江豚和印太江豚的肠道菌群多样性、组成和潜在功能均存在显著性差异。与新生儿期印太江豚相比,新生儿期长江江豚肠道菌群多样性相对较低。长江江豚肠道内的优势菌门和菌属分别为厚壁菌门（Firmicutes）（65.25%）和梭菌属类群1（Clostridiumsensustricto1）（40.67%）;而印太江豚的优势菌则分别为变形菌门（Proteobacteria）（57.78%）和弧菌属（Vibrio）（27.85%）。功能方面,新生儿期长江江豚肠道菌群中全局及概要图、碳水化合物代谢以及复制与修复等功能丰度显著高于印太江豚,而细胞群落⁃原核生物、膜运输以及能量代谢等功能丰度显著低于印太江豚。此外,在新生儿期长江江豚和印太江豚中,直肠菌群多样性以及信号转导等功能丰度均低于肠道其他部位（前肠、中肠和后肠）,而糖生物合成和代谢的功能丰度高于肠道其他部位。本研究拓展了我们对新生儿期江豚肠道微生物群落组成和多样性的认识,将为探究婴幼儿江豚肠道微生物的建立和发育奠定基础。     

Population Genetic Structure of the Yangtze Finless Porpoise (Neophocaena phocaenoides asiaeorientalis): Implications for Management and Conservation

Understanding the population genetic structure is a prerequisite for conservation of a species. The degree of genetic variability characteristic of the mitochondrial DNA control region has been widely exploited in studies of population genetic structure and can be useful in identifying meaningful population subdivisions. To estimate the genetic profile of the Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis), an endangered freshwater population endemic to China, the complete mtDNA control region was examined in 39 individuals belonging to seven different stocks inhabiting the middle and lower reaches of the Yangtze River. Very low genetic diversity was found (nucleotide diversity 0.0011± 0.0002 and haplotypic diversity 0.65± 0.05). The mtDNA genetic pattern of the Yangtze population appears to indicate a founder event in its evolutionary history and to support the marine origin for this population. Analyses by F_st and Φ_st yielded statistically significant population genetic structure (F_st = 0.44, P < 0.05; Φ_st = 0.36, P < 0.05). These results may have significant implications for the management and conservation of the Yangtze finless porpoise in the future.     

基于PAE编码系统构建的半自然条件下长江江豚行为谱

识别和编制动物行为谱是深入研究动物行为及其与环境复杂关系的基础和前提。本研究于2013年8月至2014年4月以栖息在铜陵淡水豚国家级自然保护区半自然水域的8头长江江豚为研究对象,采用焦点动物取样法和随机动物取样法观察记录了动物行为发生的过程、内容和环境,并以"姿势—动作—环境"(posture-act-environment,PAE)为轴心,以行为的功能为依据,构建了长江江豚的PAE行为谱。共分辨记录了半自然水域长江江豚的8种姿势、33种动作和46种行为,并定性描述了不同行为出现频率与年龄组、性别的关系。该行为谱综合了姿势和环境信息,有助于进一步研究长江江豚的生态与行为、促进长江江豚的保护。     

Respiratory pattern of captive Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis)

Cetacean respiration usually happen in bouts. The most widely applied quantitative method used to analyze the structure of these bouts is the log_e-survivorship analysis, based on the assumption that the respiratory intervals are distributed as negative exponentials. However, for the data collected from three captive Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis), we failed to obtain a convergent result with the application of log_e-survivorship analysis. However, the two-Gaussian model, which was recently proposed to analyze the feeding behavior of cows, was successfully fitted to the data. According to the fitting results, the overall respiratory pattern of the captive Yangtze finless porpoises can be described as a dive with a mean duration of around 30–40 s, followed by two or three ventilations with a mean interval of approximately 9 s. The average intra-bout intervals during both active and inactive periods are constant at 7.7–9.9 s for all individuals. However, when shifting from active to inactive states, the adult male and female decrease their mean numbers of respirations per bout and average length of inter-bout respiratory intervals, while the estimates of both parameters increase for the juvenile female. It was pointed out that the two-Gaussian model might be more adequate for cetacean respiratory-bout structure analyses than the log_e-survivorship technique.     

Development and characterization of polymorphic microsatellite loci in the endangered Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis)

The finless porpoise (Neophocaena phocaenoides) is one of the smallest cetacean species widely distributed in the shallow coastal waters of the Indo-Pacific Oceans. The population size of the Yangtze subspecies (N. p. asiaeorientalis) has sharply decreased in the last two decades and access to objective data on its population structure and genetic diversity would be of great assistance for their proper management. Here we report on the isolation of nine polymorphic microsatellite using the “Fast Isolation by AFLP of Sequences Containing repeats” (FIASCO) protocol. Polymorphism was assessed using 30 porpoise individuals randomly sampled in the Yangtze River. The number of alleles per locus varies from 2 to 9, with an average value of 5.56, whereas the ranges of observed and expected heterozygosities were 0.300–0.633 (mean 0.496) and 0.473–0.804 (mean 0.659), respectively.     

用微卫星指纹识别天鹅洲保护区长江江豚个体

DNA指纹个体识别技术是保护遗传学研究中的一种非常重要的手段。为了准确地识别天鹅洲保护区中的每一头长江江豚以开展保护遗传学及其它相关研究 ,并实施有效的种群管理 ,本研究应用 4个微卫星座位初步构建了该群体的DNA指纹图谱 ,并利用此图谱成功地对不同时期在保护区捕获的江豚进行了个体识别研究。结果显示微卫星指纹技术是一种适用于长江江豚个体识别研究的可靠手段     

High MHC DQB Variation and Asymmetric Allelic Distribution in the Endangered Yangtze Finless Porpoise, Neophocaena phocaenoides asiaeorientalis

The endangered Yangtze finless porpoise is found in the middle and lower reaches of the Yangtze River and its adjoining big lakes. To explore the major histocompatibility complex (MHC) genetic diversity and allelic distribution patterns across its range, we investigated variation at DQB exon 2. From 76 porpoises, we identified 18 DQB sequences. The freshwater Yangtze populations had much higher allelic diversity than marine populations. Among these freshwater populations, the middle-reach population had higher allelic diversity than the lower-reach population. The high DQB diversity level, relative to that of a neutral mtDNA locus, suggests that balancing selection is acting at the DQB gene and that rapid evolution and local positive selection play critical roles in generating and retaining high MHC diversity in the freshwater population. As the balancing selection might be driven by environmental pathogens, we suggest that maintaining MHC variation should be a high priority in the conservation and management of this endangered population, especially as an ex situ conservation strategy.     

Reproductive seasonality and maturity of male Neophocaena phocaenoides asiaeorientalis in captivity: A case study based on the hormone evidence

To provide hormone evidence on reproductive seasonality and maturity of the Yangtze finless porpoise, the authors monitored the monthly variations of serum reproductive hormones of a male Yangtze finless porpoise in captivity via radioimmunoassay from 1997 to 2003. It was demonstrated that the immature animal had a serum T level of 28-101 ng dL^-1 (65 ± 52 ng dL^-1), reached puberty with the serum T concentration ranging between 250 and 590 ng dL^-1 (390 ± 130 ng dL^-1), and attained reproductive maturity when the serum T level went beyond 1120 ± 180 ng dL^-1 in the breeding season. The body length growth of the animal showed a pattern similar to the serum T variations during its adolescent period from the age of 4 to 6 years. Moreover, the serum T concentration of the male porpoise exhibited significant seasonal variations, indicating that its breeding season may start as early as March and end as late as September.     

长江江豚和瓶鼻海豚的血清转铁蛋白

血清转铁蛋白(Serum transferrin,Tf)是广泛存在于血清中的β球蛋白,其主要功能是将铁离子以安全的形式(Fe3 )在机体的吸收、储存和利用部位之间进行传递,为细胞生长提供铁(Fe3 )(Welch,1990);同时具有保护细胞、促进细胞分化和生长、抑菌和杀菌的作用(Paezetal.,2002;Liuet al     

Physiological responses to capture and handling of free-ranging male Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis)

We captured free-ranging male Yangtze finless porpoises over three seasons and assayed leukocytes and serum biochemistry to investigate physiological responses to the capture and handlings. Serum thyroid hormones (THs) declined sharply in those porpoises compared with hormone variation in a captive male finless porpoise. Hypernatremia and hypokalemia were also significant in the free-ranging animals suggesting that conservation of serum sodium might be acutely vital for this freshwater subspecies. The animals captured in spring showed more significant neutrophilia and eosinopenia than those captured in autumn suggesting that they may be more affected by capture during the breeding season. Furthermore, physical examination of porpoises when out of the water was apparently stressful, particularly when they were kept out of the water for longer periods. However, an increase in circulating THs may be an adaptive response to accommodate these short-term stresses.     

Isolation and characterization of microsatellite loci in the finless porpoise (Neophocaena phocaenoides)

Eight dinucleotide microsatellite loci were isolated from the finless porpoise (Neophocaena phocaenoides). Analysis of 30 individuals showed the number of alleles ranged from four to 21 with observed heterozygosity ranging from 0.300 to 0.833, and expected heterozygosity ranging from 0.437 to 0.932. Cross‐species amplification was tested in four other cetacean species. These microsatellite markers would be valuable tools for population genetic studies of finless porpoises and other cetacean species.