狨猴的常见疾病及死因的分析研究

本文对棉顶狨猴、普通狨猴和鞍背狨猴在实验室笼养条件下,进行了近８年狨猴的发病类型及致死原因的分析研究,结果表明引起狨猴死亡的常见疾病是：肺炎、痢疾、消耗性综合症、产后大出血等。并根据狨猴的疾病摸索了一套有效的防治方案,这对于狨猴的饲养与繁殖,保证科学实验用健康的狨猴群体具有重要的意义。     

引进的棉顶狨猴群简介

棉顶狨猴(Cotton-top tamarin;Saguinus oedipus oedipus:以下简称棉狨)产于南美哥伦比亚,是珍稀濒危(犭胥)狨猴的一种。狨猴体型小,易于实验室笼养,是肿瘤、心血管病、肝炎、计划生育等研究中较为理想的模型动物。近年来,建立实验室狨猴繁殖群已在国内外引起重视。1988年7月,本所从英国引进6只(3雌3雄)育龄棉狨,计划由此建立实验室繁殖群落。经半年余适应性饲养管理,目前个个健康活泼,3只雌猴均有妊娠迹象。现将基本情况报告于后。     

狨猴生殖工程与基因修饰研究进展

人类疾病相关基因修饰动物模型已成为研究人类疾病分子机理和治疗靶点的重要途径和材料.狨猴是最小型实验灵长类动物,其体型小、繁殖快、遗传进化及生理生化方面与人类接近,是人类疾病动物模型研究的理想实验动物之一.因此,利用高效的生殖工程技术和基因编辑技术创制基因修饰狨猴具有巨大的生物医药价值.本文就狨猴生殖工程技术和基因修饰进行综述,旨在开拓人类疾病动物模型,推动疾病机理和新药创制的突破性发展.     

介绍一种灵长目实验动物——狨猴

狨猴属灵长目(Primates),狨科(Callithriadac),约有30个种及许多具有生育力的杂交种。最早在西方国家作为玩赏兽饲养,至60年代初才开始小群繁殖,以估计其用于生物学、医学研究的可能性。60年代后期便被广泛用于科学研究。目前以普通狨猴(Callithrix jaccus)繁殖情况最佳,用量也最多(见图1)。 成年狨猴体重300—500克,性情温顺,容易饲养,繁殖力高,一年可生二胎,一胎可产仔2—3只,怀孕期平均142天,流产率和死产率各仅1％左右,14—16周断乳,生育力无季节性差     

人类甲型肝炎动物模型（狨猴）的研究

本文报道以不同剂量的不同HAV毒株,经静脉和胃肠道分别接种普通狨猴和白须狨猴后,其血清ALT、AsT和LDH活性均见升高。对酶活性比接种前增加,大于十3SD值的6只狨猴作肝活组织检查,见有与急性病毒肝炎相一致的组织病理变化。此外,用免疫电镜法检出狨猴粪便中HAV颗粒,狨猴接种HAV后36天,血清IgM类和总抗HAV抗体均阳转。上述结果提示,普通狨猴有可能作为研究甲型肝炎的理想动物模型。     

野生白须狨猴的体内寄生虫

本文介绍了对我所引进的野生白须狨猴体内寄生虫检查初步结果,在14只白须狨猴静脉血液涂片检查中,均发现有微丝蚴;经对死亡6只白须披猴的尸检,发现感染最严重的是线虫,其次是蛇舌形虫、棘头虫。同时对寄生虫直接导致狨猴死亡的可能性和防治方法作了初步探讨。     

普通棉耳狨猴仙台病毒感染的报道

仙台病毒在分类上属副粘病毒科、副粘病毒属、副流感病毒 1型。仙台病毒过去的名称包括新生儿肺炎病毒 ,日本血凝病毒和Ｄ型流感病毒等。在国内普通实验小鼠群中仙台病毒感染非常普遍 ,而未见仙台病毒感染普通狨猴的报道。 1999年夏季 ,天津某高校一个狨猴实验室中暴发仙台病毒感染 ,动物发病率达 80 % ,病死率约 10 %。流行大约持续了一个月。狨猴发病初始均表现为精神不振 ,嗜睡 ,惧冷 ,食欲下降。继续发展表现为鼻腔出现分泌物 ,呼吸加快 ,发热 ,气喘 ,呼吸困难 ,多数病狨从发病至死亡在 3- 15ｄ。解剖发现病死狨猴肺叶呈杨梅色 ,切开时…     

精制甲型肝炎灭活疫苗的狨猴保护实验

目的　检测精制甲型肝炎 (甲肝 )灭活疫苗的保护效果。方法　甲型肝炎病毒 (YN5株 )经Vero细胞培养制成精制甲肝灭活疫苗 ,采用普通狨猴进行疫苗的免疫原性和保护性研究。结果　 7只狨猴均有特异性抗体产生 ,无血清酶活性升高和肝组织学病理改变 ,接种疫苗的狨猴能抵抗甲肝病毒强毒 (Han ZD)株的攻击。但是 ,对照组狨猴均出现血清酶异常升高和肝组织学病理改变。结论　甲肝灭活疫苗 (YN5株 )具有良好的免疫原性和保护效果。     

人工饲养恒河猴、食蟹猴的繁殖性能初报

目的探索北京地区人工饲养恒河猴与食蟹猴的繁殖性能,为温带地区猕猴的人工饲养和繁殖方式提供借鉴。方法对军事医学科学院实验动物中心饲养的317只恒河猴繁殖群（30只雄猴,287只雌猴）和78只食蟹猴繁殖群（8只雄猴,70只雌猴）近两年的繁殖性状进行观察和统计分析。结果恒河猴母猴妊娠率、繁殖率和成活率分别为60.73%、54.45%和96.89%。食蟹猴母猴妊娠率、繁殖率和成活率分别为79.86%、56.12%和75.00%。结论食蟹猴和恒河猴可以成功的在温带地区饲养和繁殖,但人工饲养食蟹猴的妊娠率与产仔率较恒河猴高,而仔猴成活率则低于恒河猴。     

一株引起普通棉耳狨猴死亡病毒的分离与鉴定

1999年6月,天津医科大学动物中心饲养的珍贵灵长类实验动物——普通棉耳狨猴群体中暴发急性呼吸道传染病,病死率高达33％。在排除细菌感染的基础上,通过死亡狨猴肺组织匀浆接种鸡胚和MDCK细胞的分离培养,分离出一株具有高血凝效价的病毒株。经双份血清试验及动物接种试验,确认该病毒是本次疾病流行的病原体。又进一步通过与常见呼吸道病毒标准毒株及血清进行交叉血凝抑制试验、电镜观察、RT—PCR技术并结合生物信息学方法对该毒株进行鉴定,确认本次疾病流行的病原体是副流感1型病毒中的仙台病毒。     

High rates of pregnancy loss by subordinates leads to high reproductive skew in wild golden lion tamarins (Leontopithecus rosalia)

Across taxa, cooperative breeding has been associated with high reproductive skew. Cooperatively breeding golden lion tamarins (Leontopithecus rosalia) were long thought to have a monogynous mating system in which reproduction was limited to a single dominant female. Subordinates with few reproductive opportunities delayed dispersal and remained in the natal group to provide alloparental care to siblings, thus allowing dominant reproductive females to meet the energetic needs associated with high rates of reproduction and successful infant rearing. The goal of this study was to re-assess monogyny in wild golden lion tamarin groups based upon pregnancy diagnoses that used non-invasive enzyme immunoassay for progesterone and cortisol, combined with weekly data on individual weight gain, bi-annual physical examinations noting pregnancy and lactation status and daily behavioral observations. We established quantitative and qualitative criteria to detect and determine the timing of pregnancies that did not result in the birth of infants. Pregnancy polygyny occurred in 83% of golden lion tamarin groups studied. The loss of 64% of subordinate pregnancies compared to only 15% by dominant females limited reproductive success mainly to dominant females, thus maintaining high reproductive skew in female golden lion tamarins. Pregnancy loss by subordinate adults did not appear to result from dominant interference in subordinate hormonal mechanisms, but more likely resulted from subordinate abandonment of newborn infants to mitigate dominant aggression.     

Observations on the birth and subsequent care of twin offspring by a lone pair of wild emperor tamarins (Saguinus imperator)

The birth of emperor tamarin (Saguinus imperator) twins was observed in the wild. The mother was a member of lone pair in a marked population of emperor tamarins in the Manu National Park, Peru. This report describes the birth and provides subsequent information on infant care and survival. Despite some difficulties, this lone pair of relatively young, primiparous emperor tamarins was able to successfully raise twin offspring to the age of at least 1 month.     

Reproduction in captive common marmosets (Callithrix jacchus)

Though sexual maturation may begin at around one year of age, first successful reproduction of the common marmoset (Callithrix jacchus) is likely to be later, and it is generally recommended that animals not be mated before 1.5 years of age. The average gestation period is estimated to be 143 to 144 days. A crown-rump length measurement taken by use of ultrasonography during the linear, rapid, prenatal growth phase (between approx. days 60 and 95) can be compared against standard growth curves to estimate delivery date to within 3 to 4 days, on average. Marmosets produce more young per delivery than does any other anthropoid primate, and have more variation in litter size. Many long-established colonies report that triplets are the most common litter size, and there is documented association between higher maternal body weight and higher ovulation numbers. Higher litter sizes generally do not generate higher numbers of viable young. Marmosets are unusual among primates in having a postpartum ovulation that typically results in conception and successful delivery; reported median inter-birth intervals range from 154 to 162 days. However, pregnancy losses are quite common; one study of a large breeding colony indicated 50 percent loss between conception and term delivery. The average life span for breeding females is around six years; the range of reported average lifetime number of litters for a breeding pair is 3.45 to 4.0. Our purpose is to provide an overview of reproduction in the common marmoset, including basic reproductive life history, lactation and weaning, social housing requirements, and common problems encountered in the captive breeding of this species. A brief comparison between marmoset and tamarin reproduction also will be provided.     

Unusually limited nucleotide sequence variation of the expressed major histocompatibility complex class I genes of a New World primate species (Saguinus oedipus)

Although major histocompatibility complex (MHC) class I molecules are, as a rule, highly polymorphic in mammalian species, those of the New World primate Saguinus oedipus (cotton-top tamarin) exhibit limited polymorphism. We have cloned and sequenced twelve MHC class I cDNAs from this species. Since cloned cotton-top tamarin cell lines express three to six MHC class I molecules, this species must have at least three functional MHC class I loci. There was, however, no evidence of locus-specific substitutions in the tamarin cDNAs. Unlike all other species studied, tamarin MHC class I cDNAs displayed limited nucleotide sequence variation. The sequence similarity between the two most divergent tamarin cDNAs was 95%. To ensure that the polymerase chain reaction (PCR) primers employed in these studies had amplified all of the tamarins' expressed MHC class I genes, we used another set of primers to amplify only exons 2 and 3 from RNA and DNA. PCR of genomic DNA resulted in the amplification of six distinct clones, of which only three were well expressed. Two of these nonexpressed genes were pseudogenes and the other was a nonclassical gene. Southern blot analysis demonstrated that the tamarin has 8–11 MHC class I genes, suggesting we had indeed cloned the majority of these genes. Cotton-top tamarins are, therefore, unique among mammalian species studied to date in that they express MHC class I molecules with limited nucleotide sequence variation.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers M38403-15.     

Molecular cloning of cDNA that encode MHC class I molecules from a New World primate (Saguinus oedipus). Natural selection acts at positions that may affect peptide presentation to T cells

To investigate the evolutionary pressures that drive the generation of polymorphism in primate MHC class I molecules, three cDNA that encode MHC class I alleles from a New World monkey, the cotton-top tamarin (Saguinus oedipus), were cloned and sequenced. These tamarin MHC class I alleles contained amino acid substitutions not found in any of the previously sequenced human MHC class I alleles. Moreover, the majority of these unique amino acid substitutions was located in the Ag recognition site at positions that have been shown to be critical in the presentation of viral peptides to T cells in mice and humans. These data suggest that selective pressures on MHC class I molecules preferentially act on the Ag recognition site and that the peptide binding or presenting functions of these molecules may drive the generation of MHC class I polymorphism. The novel Ag recognition sites of the tamarin MHC class I molecules, in addition to their restricted polymorphism, might account for the unusual susceptibility of the cotton-top tamarin to human pathogens.     

Cross-generic Food Sharing in Tamarins

Adult-infant food-sharing behavior is a major component of the infant care strategies of callitrichids (marmosets and tamarins). It is particularly well-developed in cotton-top tamarins (Saguinus Oedipus) and lion tamarins (Leontopithecus spp), which show frequent adult-initiated food offering, as well as sharing of food in response to begging by infants. This report documents a case of cross-generic food sharing, in which a male golden-headed lion tamarin (Leontopithecus chrysomelas) shared food with an infant cotton-top tamarin. The lion tamarin provided more food to the infant than its mother did. This emphasizes the importance of this behavior in the reproductive strategies of the communally-rearing Callitrichidae and raises questions about mechanisms that underly it.     

Social and seasonal influences on reproductive biology in male moustached tamarins (Saguinus mystax)

In several primate taxa there is evidence that the social and physical environment can exert a significant effect on reproductive behavior and biology. In this paper we examine social and physiological factors influencing group composition and reproduction in free-ranging moustached tamarin monkeys (Saguinus mystax mystax). This species is characterized by cooperative care of the young and a breeding system that includes both polyandrous and polygyandrous matings. Body measurements collected on adult males residing in multimale groups indicate marked within-group differences in testes volume. In 12 of 17 groups examined, testes volume of at least two resident adult males differed by 21–174%. Among these males, testes volume was not correlated with either body weight or adult age class. We also examine whether factors such as time of year had an effect on reproductive condition. An analysis of body measurements of 128 adult male and 127 adult female moustached tamarins, wild-trapped and released in northeastern Peru, indicates cyclic changes in genital size. For males, mean monthly testes volume in July (712 mm³) was twice that recorded in June (351 mm³). Females exhibited a similar pattern. Although endocrine information on intra- and intersexual social effects on fertility are unavailable for S. mystax, given the high degree of social cooperation and lack of overt aggression among adult male group members, we offer the possibility that resident male moustached tamarins compete for access to the groups' lone breeding female through socially induced reproductive suppression and sperm competition. © 1996 Wiley-Liss, Inc.     

Do maternal food deprivation and offspring predator cues interactively affect maternal effort in fish?

The state of the environment parents are exposed to during reproduction can either facilitate or impair their ability to take care of their young. Thus, the environmental conditions experienced by parents can have a transgenerational impact on offspring phenotype and survival. Parental energetic needs and the variance in offspring predation risk have both been recognized as important factors influencing the quality and amount of parental care, but surprisingly, they are rarely manipulated simultaneously to investigate how parents adjust care to these potentially conflicting demands. In the maternally mouthbrooding cichlid Simochromis pleurospilus, we manipulated female body condition before spawning and exposure to offspring predator cues during brood care in a two‐by‐two factorial experiment. Subsequently, we measured the duration of brood care and the number and size of the released young. Furthermore, we stimulated females to take up their young by staged predator attacks and recorded the time before the young were released again. We found that food‐deprived females produced smaller young and engaged less in brood care behaviour than well‐nourished females. Final brood size and, related to this, female protective behaviour were interactively determined by nutritional state and predator exposure: well‐nourished females without a predator encounter had smaller broods than all other females and at the same time were least likely to take up their young after a simulated predator attack. We discuss several mechanisms by which predator exposure and maternal nutrition might have influenced brood and offspring size. Our results highlight the importance to investigate the selective forces on parents and offspring in combination, if we aim to understand reproductive strategies.     

Parental care, cost of reproduction and reproductive skew: a general costly young model

Understanding the mechanisms by which animals resolve conflicts of interest is the key to understanding the basis of cooperation in social species. Conflict over reproductive portioning is the critical type of conflict among cooperative breeders. The costly young model represents an important, but underappreciated, idea about how an individual's intrinsic condition and cost of reproduction should affect the resolution of conflict over the distribution of reproduction within a cooperatively breeding group. However, dominant control in various forms and fixed parental care (offspring fitness dependent solely on total brood size) are assumed in previous versions of costly young models. Here, we develop a general costly young model by relaxing the restrictive assumptions of existing models. Our results show that (1) when the complete-control assumption is relaxed, the costly young model behaves very differently from the original model, and (2) when the fixed parental care assumption is relaxed, the costly young-costly care model displays similar predictions to the tug-of-war model, although the underlying mechanisms causing these similar patterns are different. These results, we believe, help simplify the seemingly divergent predictions of different reproductive skew models and highlight the importance of studying the group members' intrinsic conditions, costs of producing young, and costs of parental care for understanding breeding conflict resolution in cooperatively breeding animals.