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161.
162.
Nga Nguyen Russell C. Van Horn Susan C. Alberts Jeanne Altmann 《Behavioral ecology and sociobiology》2009,63(9):1331-1344
Close associations between adult males and lactating females and their dependent infants are not commonly described in non-monogamous
mammals. However, such associations [sometimes called “friendships” (Smuts 1985)] are regularly observed in several primate species in which females mate with multiple males during the fertile period.
The absence of mating exclusivity among “friends” suggests that males should invest little in infant care, raising questions
about the adaptive significance of friendship bonds. Using data from genetic paternity analyses, patterns of behavior, and
long-term demographic and reproductive records, we evaluated the extent to which friendships in four multi-male, multi-female
yellow baboon (Papio cynocephalus) groups in Amboseli, Kenya represent joint parental care of offspring or male mating effort. We found evidence that mothers
and infants benefited directly from friendships; friendships provided mother–infant dyads protection from harassment from
other adult and immature females. In addition, nearly half of all male friends were the genetic fathers of offspring and had
been observed mating with mothers during the days of most likely conception for those offspring. In contrast, nearly all friends
who were not fathers were also not observed to consort with the mother during the days of most likely conception, suggesting
that friendships between mothers and non-fathers did not result from paternity confusion. Finally, we found no evidence that
prior friendship increased a male’s chances of mating with a female in future reproductive cycles. Our results suggest that,
for many male–female pairs at Amboseli, friendships represented a form of biparental care of offspring. Males in the remaining
friendship dyads may be trading protection of infants in exchange for some resources or services not yet identified. Our study
is the first to find evidence that female primates gain social benefits from their early associations with adult males.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
163.
全氟辛烷磺酸(PFOS)急性暴露对斑马鱼鳃显微结构的影响 总被引:1,自引:0,他引:1
采用光镜和电镜的方法,探讨了高浓度全氟辛烷磺酸(PFOS)急性暴露对斑马鱼(Danio rerio)鳃显微结构的影响.暴露组PFOS浓度分别为0.5、1、2mg·L-1,同时设对照组,连续暴露7d,取鳃制备石蜡切片,进行光镜和扫描电镜观察.结果表明,7d后PFOS暴露组斑马鱼鳃部均有不同程度的损伤,石蜡切片上可观察到暴露组鱼鳃上皮细胞坏死脱落,鳃小片断裂或融合,并伴有鳃丝充血,且病变程度随PFOS浓度的升高而加重;扫描电镜下可观察到暴露组鱼鳃鳃丝表面分泌物增多,鳃丝细胞脱落或水肿,鳃小片前端细胞破损.高浓度PFOS急性暴露可在短期内对斑马鱼鳃组织造成严重损伤,且损伤程度存在剂量依赖效应. 相似文献
164.
五氯酚和八氯代二苯并二噁英复合暴露对斑马鱼胚胎发育的毒性效应 总被引:5,自引:1,他引:4
为了评价环境中五氯酚(PCP)和八氯代二苯并二噁英(OCDD)对水环境以及鱼类的影响,以斑马鱼为模式生物,研究了PCP和OCDD对其胚胎发育的单一及复合毒性效应.结果表明,PCP单独暴露(浓度25μg·L-1~5mg·L-1)对斑马鱼胚胎发育具有较强的毒性效应,可导致胚胎孵化率显著下降,死亡率、畸形率显著上升,而OCDD单独暴露(200、500μg·L-1)对斑马鱼胚胎发育没有明显的毒性效应;OCDD与环境浓度的PCP复合暴露(OCDD+PCP1:250μg·L-1+25μg·L-1;OCDD+PCP2:250μg·L-1+50μg·L-1)对斑马鱼胚胎的存活与发育等没有显著影响,对斑马鱼胚胎内CYP1A基因表达以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的酶活力也没有显著影响,在实验浓度下二者共存没有明显的复合毒性效应。 相似文献
165.
为评价双酚AF(BPAF)的甲状腺毒性,以雄性斑马鱼成鱼为受试模式生物,采用半静态染毒的方式对雄性斑马鱼成鱼染毒14 d(0、5、50和500μg·L~(-1)),分别设置7 d、14 d 2个时间节点,通过酶联免疫法(ELISA)分别检测斑马鱼血浆中总三碘甲腺原氨酸(TT3)、总甲状腺素(TT4)、游离三碘甲腺原氨酸(FT3)、游离甲状腺素(FT4)的含量水平,并对14 d暴露后斑马鱼甲状腺进行组织学检测分析。结果显示随着暴露浓度的提高,出现甲状腺滤泡上皮细胞增生,滤泡组织变形明显,细胞胶质缺失等病理学变化。雄性斑马鱼在BPAF暴露情况下,血浆中TT3、TT4、FT3、FT4含量随着暴露浓度的提升和时间的延长出现显著上升,呈现出甲状腺功能亢奋的干扰效应。 相似文献
166.
甲基异噻唑啉酮(methylisothiazolinone,MIT)作为防腐剂,广泛用于个人护理品、日用品和涂料中。MIT随着污水进入地表水循环,普遍存在于水体中,但目前关于MIT对水生生物毒性的研究还比较少。本文以模式生物斑马鱼的胚胎作为受试对象,评价MIT对斑马鱼胚胎的毒性。将受精后3 h的健康斑马鱼胚胎暴露于梯度浓度的MIT下,观察其对胚胎生长发育的影响,用吖啶橙(AO)染色检测细胞凋亡情况。结果发现,48 h暴露浓度大于1.0 mg·L-1的胚胎孵化被显著抑制,72 h浓度大于1.52 mg·L-1的幼鱼心率显著降低,统计96 h幼鱼死亡和畸形数,并重复验证和计算得到96 h半致死浓度(96 h 50%lethal concentration,96 h-LC50)为6.15 mg·L-1,96 h半致畸浓度(96 h 50%teratogenesis concentration,96 h-TC50)为3.89 mg·L-1,测量96 h胚胎体长,分析最小生长抑制浓度(minimum concentration to inhibit growth,MCIG)为2.31 mg·L-1,AO染色显示72 h胚胎的凋亡细胞主要集中在脑部和尾部。不同时期下镜检观察到,胚胎出现的畸形主要包括尾部发育不良,脊柱弯曲,卵黄囊水肿和心包水肿。此外,高浓度处理组24 h胚胎自主抽动次数增加,72 h和96 h活动能力减弱,触碰反应迟钝。因此,推断MIT对斑马鱼胚胎的发育有较大影响,同时有一定的神经毒性。根据《危险化学品鱼类急性毒性分级试验方法》,判定MIT对斑马鱼胚胎为高毒,该毒性实验结果可为MIT在工业生产和环境中的风险管理提供依据。 相似文献
167.
168.
为获知水环境中亚致死剂量的氯吡嘧磺隆对斑马鱼肝脏的影响,将斑马鱼暴露在亚致死剂量的氯吡嘧磺隆药液中8 d,采用超高效液相色谱与四级杆-轨道离子阱质谱串联对斑马鱼的肝脏代谢物进行分析,采用SIEVE软件将图谱信息转换为含有保留时间、质荷比和相对峰面积的二维数据阵.同时,结合mz Cloud、Human Metabolome Database(HMDB)数据库共鉴定出33种代谢物,包括氨基酸、糖、有机酸等物质.最后,采用SIMCA软件对正离子和负离子模式下的检测结果进行主成分、偏最小二乘法和正交校正的偏最小二乘法分析.主成分和偏最小二乘法结果表明,对照组与处理组在2种检测模式下均存在差异代谢物.为了寻找造成对照组与处理组之间差异的代谢物,对代谢物进行S-Plot分析,结果表明,肌酸酐、牛磺酸、多巴胺和5b-胆甾醇硫酸酯组间差异最大(p0.01).4种代谢产物可作为斑马鱼在氯吡嘧磺隆亚致死剂量胁迫下肝脏代谢异常的潜在标记物. 相似文献
169.
Summary. In the moth Utetheisa ornatrix the female is promiscuous and receives a nuptial gift of pyrrolizidine alkaloid (PA) by seminal infusion from each mate.
The alkaloidal gifts are transmitted by the female to the eggs, which are protected as a result. We here show that individual
eggs may receive PAs from more than one male source and that individual males have no assurance that the PA they themselves
contribute to the female will find its way exclusively to eggs of their siring.
Received 28 June 2002; accepted 28 August 2002. 相似文献
170.
Studies on six generations of white rats kept at the experimental station in Chernobyl showed that the dynamics of hormonal rearrangements and endocrine responses evoked by additional stress (hypokinesia) were generation- and sex-dependent. The male rats of the first five generations were characterized by hypercorticoidism, early involutional shifts, and decreased reactivity in response to hypokinesia. By the sixth and seventh generations, the hormonal profiles shifted toward an increase in the background level of sex hormones and their role in the response to hypokinesia. In female rats, the hormonal indices and reactivity changed less significantly. 相似文献